# The Naked Scientists Forum

### Author Topic: That length contraction does not apply to large objects (or distances)  (Read 16142 times)

#### mirormimic

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##### Re: That length contraction does not apply to large objects (or distances)
« Reply #25 on: 16/09/2012 20:45:03 »
May I illustrate some things in order to demonstrate how all of you may be correct in essence though seemingly contradicting one another.

First of all one of the posters stated that earth is not “malleable. “ We tend to refer mass objects as either malleable or not. Yet if we really ascribe to science and Einstein (as well other discoveries and theories) we will remember that everything is really better described as energy. If mass is more a product of invisible space energy then I would ask: Is energy malleable? If we are correct in our evaluations of the equivalence of energy and mass then we should conclude that energy is able to be molded and take on other or alternate forms within “a” designated mass space. If we really accept this equivalence, and as well as take into considerations the seeming relevance of relativity, then perhaps the following illustration will reconcile the differences of view reflected in the room.

Illustration: Imagine that the earth is not really a solid “sphere” at all, rather an energy (light) sphere. We could think of the earth as a light sphere with accompanying energy. We could consider this light -sphere -planet as being a reflected image of a light source far away from where the planet seems to reside.; occupying its own space. Here I am saying that a light source (photon or particle(s)) is communicating both its light quality and energy quality to a reflective plane. We have now introduced into the scenario. Something that creates the relativity of the light photon to its reflected image. We could refer to this medium either as a plane or an aether, relative to the light photon , thus receiving the light and energy and representing it on the surface of the plane or aether. If this plane is comprised of a surface and a thickness, as well, an opposing reflective membrane opposite the surface, then we could imagine a light sphere forming.

On the surface there will appear a light ring or a series of light rings (Representing a wave phenomenon?) These light rings are then refracted into the thickness, followed by being reflected back to the surface. The light rings on the surface, after traveling through the reflective thickness (refraction) and colliding with the reflective opposing side, will produce a light sphere. A sphere earth. We could imagine any particular portion of the sphere earth as actually originating on the surface or horizon( the plane surface of reflection). Whatever part of the earth represents the closest part to the surface( closest representation of the light ring) would represent the singularity relative to  the entire space of the light sphere. Perhaps this “point” would represent one of the poles. If one pole represents the surface ring then the opposing pole would represent the farthest point away from the surface of reflection, and represents the whole sphere after being refracted through the thickness.

If the earth sphere is representative of the reflection and refraction of light then the light being reflected exists outside of the plane of reflection, yet its light ray is being communicated to the plane. The incidence angle could correspond to the angle of the sphere relative to the angle of the light ray. This could account for the tilt of the earth. (Or not). However, if the plane of reflection is not exactly parallel to the light ray then this deviation from true parallelism to the reflector photon would represent the sphere as stretched; verses purely spherical. Conversely (inversely?) if the earth is parallel then the sphere would be a true sphere.

Now we add into the equation a relative observer. Let’s first say that the plane of reflection is exactly parallel to the light ray. This would mean that the “real absolute  relativity” of the plane reflected image to the light ray is: Parallel.( No deviation from true parallelism). If a relative observer were looking out from the center of the light ray source he would see the reflected light sphere as a true sphere. Yet if another relative observer were looking at this scenario from any other vantage point besides where the light source is, or looking out from the center of the ring toward the surface. (THat is to say; looking at the whole experiment outside of a parallel vantage point) then he would see the sphere as slightly stretched. The farther away from true parallelism any relative observer is determines how stretched the sphere will appear. In this scenario we could see how all light sources or all reflections of light source (rings or spheres) could indeed be exact spheres! Yet  they appear a variety of ways (more stretched) contingent upon the direction each relative observer is looking at this.

This can be illustrated by shining a flashlight or laser toward the face of a mirror. If the flashlight is exactly parallel to the face of the mirror (or vise versa) then the light ring represented on the face of the mirror will be spherical. However if one turns the flashlight away from parallelism, then  the formally spherical representation will begin to change toward an oblate spheroid. The more extreme the angle of the light (path of light ray) relative to the plane of reflection, the more stretched the image will appear to be. Or: The more extreme the view of the relative observer..away from true parallelism.. the more stretched the sphere will appear to be.

This seems to suggest that any experiment to measure a true sphere  must take into consideration the principles of incidence angle, and  deviation from true parallelism. This would necessitate that any experiment conducted must be able to view the whole scenario in an exactly parallel way. Perhaps the 2-slit experiment produced the result it did because either they failed to take these things into consideration, or true parallelism is hard to attain. True relativity is hard to come by. ( Yes I said TRUE relativity).

Thus from one vantage point the earth may look like a true sphere. However,: Viewing the earth from other relative vantage points may cause one to arrive at another conclusion (stretched). What we must decide is: What is more relevant to study? A true sphere or round objects stretched? As well we must decide what is the real relationship between light and light reflected. Is the reality  true spheres, or stretched horizons?

Perhaps when we view the Milky Way galaxy we see a stretched disk like shape. Yet! What if the Milky Way is a true sphere but  relative view makes it appear  to us as a stretched disk. If this were true we would have to take pictures of the Milky Way from another angle..more parallel to the  perceived “center”. ( Is a true center more superior than a perceived center?) Or: We may need to discover the light source that is reflecting to the Milky Way. In either case I believe that we would discover that ALL disk like nebulas, galaxies, planets or “mass objects” are  really  and truly best described through perfect circles/spheres.

This would say that relative observation is technically a force in itself. How so? One of the posters stated that “laws of physics dictate that for a solid object to change shape, a force must be applied to it ‘
First of all, for purposes of analogy, let’s relegate the idea of something being a solid or not. Let’s just consider something being a shape. In the particular a round shape. If what I am presenting were the reality then any and all true circles or spheres (shapes) can conform to deviating spheres simply based upon relative observations. In this case the “force” that alters the true shape is the force of observation.( Entropic choice changes relative perception? Entropic decisions influences the outcome of any experiment?) .. that is opposed to true parallel observation(s). As well, if my postulate were correct (that all spheres we see are reflected from other points outside the reflective plane) then the true force that could stretch a sphere would be the force of “movement” of the reflector ..AWAY.. from true parallelism to the reflected sphere. OR: The “motion” of the plane receiving the light ray..AWAY…from true parallelism to the light ray it is reflecting.
This would say that, in the strictest sense, if we were looking at a true sphere from an extreme angle away from true relative parallelism  then the earth could appear to be so flat. So flat as to have the potentiality of disappearing or vanishing.

Are black holes representative of former reflected circles turning completely away from relativity to its reflected light source. Or: Could a black hole be an area of space ( another plane of reflection relative to ours) that is turned completely toward the light source but completely away from our relative view.
.’
What could be an “intrinsic property” of the universe besides the properties of light and energy? This would be represented as a neutral plane of reflection that merely is a receiver of light and energy and is neither light or energy (or very limited comprised of energy) or “mass”. This plane of reflection could be the a description of the Higgs field comprised of Higgs particles. Or the field is the reflective plane and the bosons represent the relationship or relativity of the particles with the anti-particles. In either scenario the Higgs would represent a phenomenon that creates relativity verses is part of either side of the relationship. Indeed! A mediator between true light energy and it’s light energy forms or reflected images. A reflective medium? A relationship defined as one side light the other side reflected light.

The pull of gravity would be the entropic exchange of energy experienced on both sides of the “string.” The pull of gravity would be nothing more than the relationship (bond, force, attachment) of a reflector to its reflected image! If this relationship were defined as such then the strong or weak force between the two would seem to suggest entropic exchange of energy. ( It also implicates a change in distance between the two sides). The nuclear force would represent the singularity of the reflector to the reflectee (the plane surface). Electro - magneticism would be nothing more than the resistance (polarized: Entropic breakdown) or attraction (magnetic…entropic allowance) between the force on one side relative to the force on the other side. The one side is energy (electricity carries magnetism) the other side is energy (magnetism carries electricity) . As “they’ co-exist, the relationship at all points is represented as a pulling together or repelling of the..distance.. between the two vectors. That is to say: Thw one e side is energized and relative to the other side that is also energized. Their energy is connected. They are “magnetized” to one another due to the principle s of reflection playing out. How strong the attraction is may be contingent upon the entropic choices of both sides. How weak the force between them is based upon entropy on both sides as well. Gravity would represent the origin of the energy. Gravity in its purest form and innate “Extrinsic properties” exists solely on the left side and is simply and elegantly communicated to the plane. Once the plane existential receives this energy portion of the whole of gravity , “they” use it relative to both the reflective phenomenon and the entropic phenomeona. Either the choice is to entropic ally allow a force to act upon “it” or to  deviate from the reception of the energy. ( choose not to accelerate or be accelerated…?)

The ‘(NO) LAW OF PHYSICS‘ that would “..make planets (etc) change shapes as they are observed “could be called the law of: Reflecto-Parralell verses Reflecto-Deviate. ( As so coined)

In this mirror analogy the earth could be observed as a pancake or an oblate spheroid or a perfect sphere. All relative observers would be correct in their observations. This is logically deduced based on the illustrations I have provided.

As for the shrinkage or expansion of spheres OR as  well; the contracting or expanding of space and distance (or so-called “mass”)  OR as well; mass- volume-space  to singularity-horizon-conversion.: All can be described through the principles of reflection.

Move the light close to the mirror surface (plane of reflection= horizon) and the represented light circle contracts. Move the mirror far from the light (expansion of “mass” body) and the represented light circle as communicated to the mirror..expands.

Actually these experiments with “mirror matter” relative to un-reflected light and space allow a sort of unification in numerous ways.

I will be describing and explaining these observations relative to my thread.

I appreciate the opportunity to contribute to this insightful and challenging discussion.

#### old guy

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##### Re: That length contraction does not apply to large objects (or distances)
« Reply #26 on: 17/09/2012 20:24:05 »
Me:

Quote
Our cargo bay, as stated, is 10 meters. The "contracted length" of the probe, as seen from Earth's frame appears to be 10 meters. The point of the whole exercise was that 10 meters is not the probes *real length*, so sending out the above shuttle would be very stupid, because the probe is *really* longer than 10 meters. So there is your functional definition of "What is real?"
Imatfaal (my bold):
Quote
But it is a definition - that a) is not needed because the concept of reality as you define it is not important for the mathematical model and b) when the probe is moving very quickly I could get it in the open-ended shuttle bay at rest (with arbitrarily quick closing doors) .  b) does not in my mind, challenge the "reality" of the probe being longer than 10m in it's rest frame - but it shows that differentiation between real and apparent are unimportant, dangerous, and misleading.

Re a): The point of my example was that the *math model* of length contraction will not make a 20 meter probe (using its speed relative to earth as 86.6 % of 'c' for specificity and round numbers for length) fit into a 10 meter bay. Period. Its *apparent length* was contracted to 10 meters as seen from earth. From at rest with the probe (the only way to capture it!) it was 20 meters. It would not fit, illustrating the difference between its *apparent length* and its *actual or real length.* Can you not see that yet?

Re b): "The differentiation between real and apparent" is essential to the success of the retrieval mission. If you send out our shuttle with a 10 meter bay to capture a 20 meter probe, you are wasting everyone's time and money... and maybe risking the continued existence of Planet Earth (depending on the alien probes mission.)
More later.

#### old guy

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##### Re: That length contraction does not apply to large objects (or distances)
« Reply #27 on: 17/09/2012 21:18:33 »
JP:
Quote
Old Guy, I'm not sure what you want me to reply to.

At this point I would settle for one straight answer from you.
Do you believe that Earth changes shape? Does it acquire a very contracted diameter *as observed*( in the direction of travel) by a relativistic fly- by frame?
Would it change into 1000 different shapes as 1000 different "frames" flew by in 1000 different directions at 1000 different velocities?
Thanks.

#### old guy

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• Posts: 165
##### Re: That length contraction does not apply to large objects (or distances)
« Reply #28 on: 17/09/2012 21:24:55 »

Me:
Quote
Essentially this argues that, because of “time dilation” (their rate of decay slows down at higher velocity), these mouns “live longer” than expected of lower velocity muons, and since length contraction is the math reciprocal of time dilation, for those muons “the atmosphere is contracted."
From “the frame” of the whole picture however (earth and incoming muons) , there is no contracting of the atmosphere around each muon. “For a muon” does not change  the atmospheric science of its thickness/depth.

Imfataal:
Quote
You cannot have a rest frame which encompasses two objects with relative velocities.

Just because relativity does not recognize the concept of a global perspective, including the whole earth and its atmosphere, does not forbid me from observing both "frames" as one reality... earth and incoming muons. My last sentence in the quote above still holds true.
Me:
Quote
My argument here simply questions how "real" length contraction is. Does a fast moving ship make stars move closer together? No, but its clock will "tick" more slowly the faster it flies, and its occupants will probably age more slowly.
You:
Quote
Clocks only tick slower when viewed from another frame!  And the fact that the earth bound observers see the space clocks as ticking slowly does not explain how the spacemen (who measure no dilation on their own clocks) reach alpha centauri in less than 4.37 years again according to the spacemen

Earth orbits the sun 4.37 times (that's 4.37 years, as years are defined) during the time that light travels from Alpha Centauri to here. You are confused if you think that a spaceship can make the journey in less time. The ship's clock slows down relative to a given earth-based clock. So "ship's time" will go a lot slower for the ship than earth's time, but a year is standardized based on one earth orbit.
Me... again:
Quote
Quote
Do objects have shapes and lengths independent of how they are measured? Yes, there is a "real cosmos with real objects" in it, but they may well appear contracted from very fast fly-by frames.

Can you really " fit the probe (very briefly) entirely within the shuttle's cargo bay?"
No.
Let's make the velocity of the probe relative to earth specific at 86.6 % of 'c.' If the "contracted length" as measured from earth is 10 meters, as established, it will then be 20 meters in its own frame and as measured from the shuttle once it enters that frame, at rest with the probe. A 20 meter probe will not fit into a 10 meter cargo bay, period, no matter how "briefly." Sorry.
You:
Quote
The whole point of the corollary thought experiment is that the shuttle bay allows the probe in without matching velocity ie it is not in the rest frame of the probe - there is a high relative velocity; and then the probe will fit in!

No, the whole point of my thought experiment was a practical (future)  application of length contraction theory illustrating the difference between the probe's appearance as measured from earth and its real, actual length  as measured from at rest with it, which is a requirement for retrieval of any object in space.
imatfaal:
Quote
Can you just confirm to me whether you agree that (with arbitrarily fast doors) a shuttle bay with doors at front and back could hold the probe moving with relativistic velocity compared to and observed by the shuttle at rest?

No. Retrieval requires being at rest with the probe. The shuttle cargo bay is 10 meters long. The probe is 20 meters long. It will not fit.

#### JP

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##### Re: That length contraction does not apply to large objects (or distances)
« Reply #29 on: 17/09/2012 22:14:10 »
JP:
Quote
Old Guy, I'm not sure what you want me to reply to.

At this point I would settle for one straight answer from you.
Do you believe that Earth changes shape?
It doesn't matter what I believe about it changing shape.  This is a science forum, not a belief forum, so I can only tell you about measurement results, so let's discuss those...

Quote
Does it acquire a very contracted diameter *as observed*( in the direction of travel) by a relativistic fly- by frame?
Yes.

Quote
Would it change into 1000 different shapes as 1000 different "frames" flew by in 1000 different directions at 1000 different velocities?
1000 different observations from 1000 different reference frames would yield measurements of 1000 different shapes.

Now, can you prove the earth doesn't change shape by sticking solely to measurements?

#### imatfaal

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##### Re: That length contraction does not apply to large objects (or distances)
« Reply #30 on: 17/09/2012 22:36:42 »
Old Guy -

1. your use of SR in the Alpha Centauri example is simply wrong.  Time is not dilated in the rest frame.   Read the blog - it is the standard SR description.  That it clashes with your preconceptions is a problem.

2. no one is arguing about the probe in the shared rest frame (if you ask in faux exasperation if I understand that it cannot fit again I think I will knock this on the head) .  But there is only one shared rest frame - all the other combinations of frames give different answers.  That is what SR is able to do - make testable predictions about all frames; and such predictions we have tested have been on the money.  And the difference between actual and real and apparent and all the other terms you wish to throw at the problem is not science - because measured is really the only one that matters.

3.  muons - oh yes, you can make any frames you like, including ones that include - all at the same time - numerous particles with mutually relativistic velocities, an exceedingly complex atmosphere, and a rotating massive object - BUT you cannot do it in Special relativity.  And you cannot get a meaningful measurement of objects such as muons without taking into account the relativistic effects of SR.  So what you are doing is no longer science because your measurements will be make believe.

#### old guy

• Sr. Member
• Posts: 165
##### Re: That length contraction does not apply to large objects (or distances)
« Reply #31 on: 18/09/2012 19:04:54 »
JP,
Was “one straight answer" too much to ask? ("Do you believe that Earth changes shape?") You insist that Earth does in fact change shape but you don't want to admit that you "believe" that it does. So I’ll rephrase the question and keep hoping for a direct answer:

Does Earth change shape?

Me:
"Does it acquire a very contracted diameter *as observed*( in the direction of travel) by a relativistic fly- by frame?"
You:
"Yes."
Rephrased:
Does the actual solid physical Planet Earth (assuming it exists independent of observation) acquire a very contracted diameter at any time?" (period.) If so, what force is applied, according to the laws of physics, to make a large solid physical object drastically change shape?
Me:
"Would it change into 1000 different shapes as 1000 different "frames" flew by in 1000 different directions at 1000 different velocities?"
You:
"1000 different observations from 1000 different reference frames would yield measurements of 1000 different shapes."

I agree that different frames will yield different observations and measurements. The question remains, "Does Earth change shape?"
You:
"Now, can you prove the earth doesn't change shape by sticking solely to measurements?"

I can prove that changes in such measurements do not reflect changes in the object measured. In fact I already did above. The laws of physics dictate that in order for an object like Earth to drastically change shape an extremely powerful force would be required. But "length contraction" does not posit such a force causing contraction. No force applied; no change in Earth's scientifically well established shape.
The comparison of idealism vs realism is very relevant to this discussion. Observation does not re-create reality. An elephant is not shaped like a rope or a tree trunk or a fire hose, regardless of what the 'three blind men' "observe." It has a shape of its own... the 'whole elephant.' So does Earth, as everyone besides idealists (including length contraction advocates) well know.

imatfaal:
"And the difference between actual and real and apparent and all the other terms you wish to throw at the problem is not science - because measured is really the only one that matters." (my bold)

The point was that the probe was measured to be 10 meters from Earth but it is 20 meters long, as the example was amended to be specific. The scientists on retrieval team must certainly know the difference before they attempt to capture it.

Btw, backtracking a bit, you said: “Differentiation between real and apparent are unimportant, dangerous, and misleading.”

“Dangerous?” How so?
“Misleading?” Isn’t it obvious that the retrieval team must distinguish between the probe’s “apparent” (contracted) length and its  “real” length (as it was built... in its own frame) before sending out a shuttle with a 10 meter bay?

imatfaal:
"And you cannot get a meaningful measurement of objects such as muons without taking into account the relativistic effects of SR.  So what you are doing is no longer science because your measurements will be make believe."

I know that  as particles travel faster their internal processes (muon decay here) slow down, so they “live longer.” So these muons travel further than expected. This does not mean that Earth’s  atmosphere becomes thinner (contracted) to accommodate each incoming muon... “realistically speaking” that is... granting that Earth’s atmosphere stays about the same thickness/depth regardless of incoming muons.
The measurements  of earth's atmosphere compiled over the years by atmospheric science and experienced by many space age trips through it are not "make believe."
I simply advocate that "at rest" with an object being measured will reasonably yield a more accurate result than measuring from relativistic frames of reference and claiming fluctuations in the properties of the object measured. I do not question that the Lorentz formula is an accurate tool of "transformation" between such frames, but that does not mean that a "flattened Earth" is "equally valid."

Ps re your: "1. your use of SR in the Alpha Centauri example is simply wrong.  Time is not dilated in the rest frame.   Read the blog - it is the standard SR description.  That it clashes with your preconceptions is a problem."

I did read the blog, claiming that a fast ship can get to AC in ten minutes. That is "simply wrong."
What is wrong with my last comment on it?:
"Earth orbits the sun 4.37 times (that's 4.37 years, as years are defined) during the time that light travels from Alpha Centauri to here. You are confused if you think that a spaceship can make the journey in less time. (Edit: Nothing with mass can travel as fast as light.) The ship's clock slows down relative to a given earth-based clock. So "ship's time" will go a lot slower for the ship than earth's time, but a year is standardized* based on one earth orbit. (*By very accurate clocks with less variation than successive orbits.)
"For the ship" does not make the distance to AC less than 4.37 light years in the real universe as known to precise astronomy... nor does the ship's slower clock (time "for the passengers) make the journey possible "in ten minutes." This is science fiction dressed up as science... in "the emperor's new clothes."
« Last Edit: 18/09/2012 19:51:27 by old guy »

#### imatfaal

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##### Re: That length contraction does not apply to large objects (or distances)
« Reply #32 on: 18/09/2012 20:30:09 »
Ok sorry Old Guy - the Muon example and the Alpha Centauri example are both good physics.  My knowledge of SR is good but not great, and not developed enough to teach it to someone who seems to be prevented from grasping the correct but seemingly paradoxical nature due to pre-existing philosophical axiomata.

I think I will bow out now; on the probe in the shuttle bay, I understand what you are saying but I feel it is irrelevant to science and physics.  The underlined and bolded 'is' - this is not modern science, it is privileging the rest frame as an absolute frame.  The scientists do know the length in the rest frame (because of SR) - they measured the length and used lorentz transformations, but the length if it is allowed to rush past is (and it is just as much 'is') 10m.  This is not an convenient fiction, nor an observational illusion.

dangerous and misleading - well it has thoroughly confused your understanding of SR!  Allowing what 'must be true', what is 'just common sense', what 'follows from basic logic' to dictate ones understanding, modelling, and explanations of physical laws is an incorrect approach - observations, measurement and experimentation must take the lead.  Over-extending a physical theory to encompass metaphysical questions is just as bad.  Physics does not answer questions of meta-physics, and meta-physics cannot trammel physics.

On the muon / alpha centauri - your insistence on your position has lead to the fiction that time is dilated in the rest frame which is simply not the case.  As I mentioned above I do not have the background to explain this in the depth I think you require.

#### JP

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##### Re: That length contraction does not apply to large objects (or distances)
« Reply #33 on: 18/09/2012 21:06:48 »
Old Guy,

Well, since science deals with predicting measurements, and you want me to commit to predicting something beyond the realm of measurements I'm going to have to bow out and leave this one to metaphysics.

#### old guy

• Sr. Member
• Posts: 165
##### Re: That length contraction does not apply to large objects (or distances)
« Reply #34 on: 18/09/2012 23:06:46 »
Old Guy,

Well, since science deals with predicting measurements, and you want me to commit to predicting something beyond the realm of measurements I'm going to have to bow out and leave this one to metaphysics.

All I wanted you to do was answer one simple direct question, " Does Earth change shape?" You refuse, and the reason you refuse is obvious to everyone but those brainwashed by the "length contraction" part of SR:
Earth does not change shape. Observations from extreme frames will, no doubt, see it differently, but seeing it differently does not mean that it is different each time it is seen differently.

And no spacecraft (all having mass*) can go faster than light. I think that it is time that length contraction/time dilation advocates got over it. No spacecraft* can go to Alpha Centauri in ten minutes.

I rest my case for both a naturally occurring nearly spherical Earth and a cosmos created by well known laws of physics in which stars do not move closer together because of "length contraction" as a theoretical concept of SR.

If anyone has anything intelligent to say about that, I will 're-open the case.'

#### old guy

• Sr. Member
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##### Re: That length contraction does not apply to large objects (or distances)
« Reply #35 on: 19/09/2012 03:33:46 »
A quick 'fly-by.'
Imatfaal said;
"...your insistence on your position has lead to the fiction that time is dilated in the rest frame which is simply not the case."

You may have "bowed out" but you left a "fiction" which you attributed to me, which I must correct... that I claim that  "time is dilated in the rest frame" of the ship traveling to AC.

First, I have always said that "time dilation" is a misnomer. Empirically we observe that clocks run slower when they are accelerated to faster velocities. "Time" is not an entity which 'expands' or "dilates."

I said that clocks on high speed spacecraft will "tick" more slowly than their 'home base' (say, Earth) counterparts. So "for the ship" much less time will pass, according to their micro-cosmic 'time'... which, for physics, is "that which clocks measure"... than "for Earthlings," whose clocks will be synchronized with standard Greenwich Mean Time.
"For Earthlings" much more than 4+ years will have passed during the "ten minute" journey to AC "experienced" by the crew. And Earth will have orbited the Sun more than 4.37 times during the ship's trip.

Shall we make the "ship's time" for 'a year' "equally valid" for what 'a year' means, or shall we continue to say, as scientists, that a year is the (standardized) elapsed time for one Earth orbit of the Sun?

Science Q&A: Can a spacecraft really go to AC in ten minutes?... thousands of times faster than light?
A: No. Seriously.

#### old guy

• Sr. Member
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##### Re: That length contraction does not apply to large objects (or distances)
« Reply #36 on: 19/09/2012 19:20:38 »
For the benefit of any newcomers to this thread or anyone wondering how/why it died...

I have “rested my case” unless there are forthcoming intelligent answers to the following questions and challenges:
(Edit; now numbered for easy reference)

1: Does Earth change shape?...

2: If so, what force is applied, according to the laws of physics, to make a large solid physical object drastically change shape?

3: Will an “alien probe” approaching Earth at 86.6 % of ‘c’ and measured from Earth to be 10 meters long fit into an Earth-based shuttle cargo bay 10 meters long?
(Point #4 bolded):
Note: Its velocity relative to Earth will make it appear to be contracted to 10 meters, while it actually IS, as built, in its own frame, 20 meters long, according to the math. This illustrates the difference between how long it APPEARS, from Earth, and how long it IS, a point of difference which length contraction advocates refuse to acknowledge.

5: Regarding the “muon argument” for length contraction, I said:
I know that  as particles travel faster their internal processes (muon decay here) slow down, so they “live longer.” So these muons travel further than expected. This does not mean that Earth’s  atmosphere becomes thinner (contracted) to accommodate each incoming muon... “realistically speaking” that is... granting that Earth’s atmosphere stays about the same thickness/depth regardless of incoming muons.

Regarding the claims of time dilation for a spacecraft going to Alpha Centauri at near ‘c’  and length contraction of the distance from here to there, I said;

6: "Earth orbits the sun 4.37 times (that's 4.37 years, as years are defined) during the time that light travels from Alpha Centauri to here. You are confused if you think that a spaceship can make the journey in less time. (Edit: Nothing with mass can travel as fast as light.) The ship's clock slows down relative to a given earth-based clock. So "ship's time" will go a lot slower for the ship than earth's time, but a year is standardized* based on one earth orbit. (*By very accurate clocks with less variation than successive orbits.)
"For the ship" does not make the distance to AC less than 4.37 light years in the real universe as known to precise astronomy... nor does the ship's slower clock (time "for the passengers) make the journey possible "in ten minutes." This is science fiction dressed up as science... in "the emperor's new clothes."

So, there you have it... a summary of the issues debated in this thread and originally in my length contraction thread in the Physics section before it was banished as not scientific, not appropriate physics discussion.

If there are any further comments, please let them address the above points/questions/challenges. Please don't automatically assume that I don’t understand SR and repeat that “all frames of reference yield equally valid measurements” as if that were an established fact. Thank you.
(I bolded the above as a reminder to you, David Cooper)
« Last Edit: 20/09/2012 18:11:21 by old guy »

#### David Cooper

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##### Re: That length contraction does not apply to large objects (or distances)
« Reply #37 on: 19/09/2012 20:33:11 »
For the benefit of any newcomers to this thread or anyone wondering how/why it died...

It hasn't died, but you really need to stop slapping people across the face for attempting to answer your questions. I'm going to have another go because I'm curious to see how you'll react, and as before I'm going to do my genuine best to try to provide good answers, but I will still have to give you two different answers each time as there are two rival theories on the go which both have to be taken seriously. I'll label these with LU for Lorentzian Universe and SR for Einstein's Special Relativity. It's up to you to make up your own mind about which (if either) is true and which are consequently the true facts.

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Does Earth change shape?...

SR: The Earth does not change shape. Observers rushing past it will measure it as being a different shape and it will be that observed shape within their frame because it is angled differently in Spacetime and part of its length is expressed in the time dimension of the frame in which it appears contracted. [This may be contested by some people who think that observed objects are physically changed as a result of being observed from different angles, but any attempted description of this could still be misunderstood, so it isn't entirely clear. Whatever the case though, SR does not require you to believe such a thing.]

LU: The Earth is contracted in its direction of travel through the fabric of space, but we can't tell how fast or whether it's moving.

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If so, what force is applied, according to the laws of physics, to make a large solid physical object drastically change shape?

SR: No force is applied.

LU: The balance of forces between atoms automatically makes them sit closer together in their direction of travel through the fabric of space - it is not a compression caused by acceleration.

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Will an “alien probe” approaching Earth at 86.6 % of ‘c’ and measured from Earth to be 10 meters long fit into an Earth-based shuttle cargo bay 10 meters long?

SR: I answered this one incorrectly before in saying that it will fit for a moment in a 10m long space, but when you analyse it from other frames it becomes clear that there's a simultaneity issue with that in SR, so it isn't valid. Damocles came up with an experiment which also goes wrong for the same reason when you examine it carefully, so I think you've got a good point - it's impossible to answer. If you slow the alien probe or speed up the suttle so that they're going at the same speed as each other, clearly the probe won't fit. The maximised size of things (found by observing them from their own frame) appears to me to be the truest measure of their real size, and I that's backed up by the idea that when they're contracted the missing part of their length is expressed in the time dimension instead, but is fully visible to you once your own speed matches that of the thing you're observing. I don't know if that idea is a standard interpretation of SR though as it may just be one interpretation of it.

LU: The probe really can fit for an instant inside a shuttle of 10m long if you can provide an opening for it at one end, but only in a case where the shuttle is not moving through the fabric of space. If you slow the probe or speed up the shuttle to the same speed, it will not fit, but the length of one or other (or both) will actually change.

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Regarding the “muon argument” for length contraction, I said:
I know that  as particles travel faster their internal processes (muon decay here) slow down, so they “live longer.” So these muons travel further than expected. This does not mean that Earth’s  atmosphere becomes thinner (contracted) to accommodate each incoming muon... “realistically speaking” that is... granting that Earth’s atmosphere stays about the same thickness/depth regardless of incoming muons.

SR: The muon finds a shorter physical path through the atmosphere which is not available to slower moving things. These shorter paths are always there, but only open to things that move fast. As the speed of an object approaches the speed of light, the path available to it becomes closer to zero distance, and for light itself the path must be zero distance (if we ignore the slowing caused to it by passing through the atmosphere). While the distance through space is reduced, these faster moving things either cover a greater distance along the time dimension or find shorter paths into the future (I'm not clear on which of these is the case as different people say different things). [This is not strictly speaking how it works - you still have to strip all notions of Newtonian time out of it to get a true understanding of SR, at which point all the movement and passage of time is replaced with lengths, so it's very hard for people to get their head round it and even harder to express what's going on clearly.]

LU: The internal mechanisms of the muon are slowed down, so it lasts longer and travels further.

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Regarding the claims of time dilation for a spacecraft going to Alpha Centauri at near ‘c’  and length contraction of the distance from here to there, I said:
"Earth orbits the sun 4.37 times (that's 4.37 years, as years are defined) during the time that light travels from Alpha Centauri to here. You are confused if you think that a spaceship can make the journey in less time. (Edit: Nothing with mass can travel as fast as light.) The ship's clock slows down relative to a given earth-based clock. So "ship's time" will go a lot slower for the ship than earth's time, but a year is standardized* based on one earth orbit. (*By very accurate clocks with less variation than successive orbits.)
"For the ship" does not make the distance to AC less than 4.37 light years in the real universe as known to precise astronomy... nor does the ship's slower clock (time "for the passengers) make the journey possible "in ten minutes." This is science fiction dressed up as science... in "the emperor's new clothes."

SR: As in the case of the muon, a shorter path (length) is available, as is a shortcut into the future.

LU: The clocks on the ship actually do run slow due to the longer pathways required for all the parts of the mechanisms of any kind of clock that can be devised.

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So, there you have it... a summary of the issues debated in this thread and originally in my length contraction thread in the Physics section before it was banished as not scientific, not appropriate physics discussion.

I personally think it is fully appropriate for a physics discussion - physics has to be rooted in reality and not just stop at the point where things can be described by mathematical formulae. You want to know if things are really contracted or if they have an inherent, real shape and size. In SR, the nearest thing you're going to get to that is the shape and size things have in their own frame. As all frames are equally valid, every object will have a range of shapes which are revealed by observing them from different frames, but in the middle of this infinite range of shapes will be one where the sizes are maximised, and that has to count for something. In LU, the inherent or real shape of things is arguably the one they have when they aren't moving through the fabric of space, but the actual shape is the one they have from moment to moment as they move through that fabric. In both theories though, there could be further aspects influencing the real shape of things depending on how the fabric of space is distorted in extra dimensions, so you'd need to know a lot more than is available to us to determine the real shape of anything - as it stands, we can only speculate.
« Last Edit: 19/09/2012 20:38:42 by David Cooper »

#### old guy

• Sr. Member
• Posts: 165
##### Re: That length contraction does not apply to large objects (or distances)
« Reply #38 on: 19/09/2012 22:34:31 »
Another quickie, until I find more "time."

David Cooper:
"As all frames are equally valid, every object will have a range of shapes..."

...Will appear to have different shapes or will be different shapes? Do you understand the difference? That is the core of the argument.

Me:
"Please don't automatically assume that I don’t understand SR and repeat that “all frames of reference yield equally valid measurementsas if that were an established fact.
"
Did you even read that request? If so, did you understand its significance?

More later about your assumptions about the nature of time as an entity and the "fabric of space"... or "spacetime" as the two non-entities are usually called as they coalesce into unity... in Minkowski's mind,  and then endorsed by Einstein.

#### old guy

• Sr. Member
• Posts: 165
##### Re: That length contraction does not apply to large objects (or distances)
« Reply #39 on: 20/09/2012 19:24:48 »
David:
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It hasn't died, but you really need to stop slapping people across the face for attempting to answer your questions.

I am radically honest. Look it up if you aren't familiar with the ‘radical’ part. No one yet has even attempted to answer the most fundamental key challenge illustrating how bogus length contraction is as applied to large objects. See #1 above and especially the final bolded note to you now edited in.
You:
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I'll label these with LU for Lorentzian Universe and SR for Einstein's Special Relativity.

So rather than addressing the issues I again presented above, you are again using this thread, as you did the one in Physics, to promote your own pet project.
You:
"SR: The Earth does not change shape."

Agreed, but JP, a moderator with expertise in SR, though he will not admit it directly, argues that measurements are all we have for “reality,” so if we could measure earth from a near ‘c’ fly by frame it would BE very contracted in diameter, i.e., it would change shape.
You:
"...part of its length is expressed in the time dimension of the frame in which it appears contracted."

Nonsense. Time is only the concept required for all movement, not an entity. Solid objects do not shrink when observed from fast moving frames in which clocks slow down.
You:
"SR: No force is applied."

Of course not. And a “squished earth” would require a force of extreme magnitude for any change of shape, and even then it would be destroyed, not crushed into a severely oblate spheroid.
Regarding the probe capture challenge, you said:
"...it's impossible to answer. If you slow the alien probe or speed up the shuttle so that they're going at the same speed as each other, clearly the probe won't fit."

It is not impossible to answer. The answer is, “The probe won’t fit.” See again my point #4 bolded above for the significance of the answer.
It was obvious from the beginning that the shuttle must match the velocity of the probe to capture it, but I also made that explicit after all the collision speculation and proposed open doors for the probe to fly through the bay... nonsense.
You:
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SR: The muon finds a shorter physical path through the atmosphere which is not available to slower moving things. These shorter paths are always there, but only open to things that move fast....
SR: As in the case of the muon, a shorter path (length) is available, as is a shortcut into the future.

Nonsense! Like the overall shape of earth does not change, neither does the thickness/depth of its atmosphere. The fact that faster moving muons “live longer” (degrade more slowly) than expected of slower ones means that they travel further than expected in the ‘lifespan' of a lab muon. That allows them to reach earth’s surface. The atmosphere does not contract to accommodate them. The simpler explanation, here again, is the correct one. And there is no magically contracting atmosphere involved.

You: "... or find shorter paths into the future ..."

Science fiction. There is no time travel. The present is the ongoing “now” always. The future is not yet present (here, now), and the past is not still present (here now.)
You:
"As all frames are equally valid, every object will have a range of shapes..."

Answered yesterday. You are simply parroting SR dogma.
A “flattened earth” and a nearly spherical earth are not “equally valid.” Get over it.
You:
"...on how the fabric of space is distorted in extra dimensions,..."

What extra dimensions? Like the seven extra ones in the metaphysics (not physics) of M-theory?

Space is 3-D volume, not a malleable entity/medium. Likewise time... that which elapses as things move. Put them together and what do you have? The volume (space) in which all things exist and move ( requiring time.) Not “The fabric of spacetime.”  (Another version of “The Emperor’s New Clothes.”)...
Minkowski’s “glorious nonentity.” (Ref: title of a paper by Brown and Pooley, compiled in a volume by Deiks of papers presented at one of the conferences of the International Society for the Advanced Study of Spacetime.)

Does anyone here really believe that Earth changes shapes? Is that really "science?"
« Last Edit: 20/09/2012 19:35:58 by old guy »

#### David Cooper

• Neilep Level Member
• Posts: 1505
##### Re: That length contraction does not apply to large objects (or distances)
« Reply #40 on: 20/09/2012 21:12:20 »
David Cooper:
"As all frames are equally valid, every object will have a range of shapes..."

...Will appear to have different shapes or will be different shapes? Do you understand the difference? That is the core of the argument.

You can interpret SR in more than one way on that point - it's up to you to make up your own mind and stop worrying about what other people think. My interpretation of SR is that objects appear to have different shapes when viewed from different frames but that their actual shapes are fixed as the ones you see when in their frame. Other people see objects as having an infinite range of different shapes all at the same time, and which one you see at any point in time depends on which frame you're looking from. Other people may imagine that things physically change their shape to fit in with how they're being viewed at the time, even if there are multiple observers looking at them from different frames at the same time - how they deal with the contradictions in that is up to them, and there's no obligation on you to agree with them. SR accomodates a wide range of beliefs.

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Me:
"Please don't automatically assume that I don’t understand SR and repeat that “all frames of reference yield equally valid measurementsas if that were an established fact.
"
Did you even read that request? If so, did you understand its significance?

When an answer is labelled with SR, it necessarily has to conform to the assumptions of that theory. If you want an answer that doesn't comply with the rules of SR, you need to find another theory. You don't like the Lorentzian universe either, so that means you need to present us with a New Theory. If you do that, I can then answer your questions in relation to that theory as well. What I cannot do is answer any of your questions in such a way as to conform with absolute truth because I don't know what that is - all I can do is work with theories.

David:
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It hasn't died, but you really need to stop slapping people across the face for attempting to answer your questions.

I am radically honest. Look it up if you aren't familiar with the ‘radical’ part. No one yet has even attempted to answer the most fundamental key challenge illustrating how bogus length contraction is as applied to large objects. See #1 above and especially the final bolded note to you now edited in.

Why are you attaching the word "bogus" to length contraction? Have you found some way to account for the Michelson Morley experiment which doesn't involve length contraction?

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You:
Quote
I'll label these with LU for Lorentzian Universe and SR for Einstein's Special Relativity.

So rather than addressing the issues I again presented above, you are again using this thread, as you did the one in Physics, to promote your own pet project.

I'm not promoting anything - I'm trying to give you the answers you're asking for, and I only know of two theories which have ways to handle the length contraction which MM demonstrates. If there is another theory that can handle it, point me to it and I'll look into it and answer your questions from that perspective too. You don't appear to like SR because you think you've found a flaw in it, so what is it you want from people here? Do you want them to answer purely in terms of SR and keep telling you the thing you've banned them from telling you? What else is anyone supposed to do? You aren't going to get them to say, "Well, okay - you must be right: length contraction is bogus and the MM experiment must have a fault in it which no one can find."

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You:
"SR: The Earth does not change shape."

Agreed, but JP, a moderator with expertise in SR, though he will not admit it directly, argues that measurements are all we have for “reality,” so if we could measure earth from a near ‘c’ fly by frame it would BE very contracted in diameter, i.e., it would change shape.

The measurements certainly change. I'm not sure what he thinks actually happens to the Earth, but this is unimportant - there is a wide range of beliefs compatible with SR on this point and it doesn't matter what anyone thinks. You can simply make up your own mind about this and stop worrying about conforming with other people.

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You:
"...part of its length is expressed in the time dimension of the frame in which it appears contracted."

Nonsense. Time is only the concept required for all movement, not an entity. Solid objects do not shrink when observed from fast moving frames in which clocks slow down.

It may well be nonsense - I'm just repeating something I've picked up from other people's writing about SR and how Minkowski deals with it.

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You:
"SR: No force is applied."

Of course not. And a “squished earth” would require a force of extreme magnitude for any change of shape, and even then it would be destroyed, not crushed into a severely oblate spheroid.

A flattened Earth could happen without being destroyed as the distances between the atoms in the direction of travel would seem to be normal within its frame of reference, so it would hold together perfectly well through the normal application of forces between atoms. [If you could get it up to the speed of light, that would damage it beyond repair though, and the same would apply if it became flattened to the point where the granularity of the universe (if there is such a thing) makes it impossible to maintain suitable separations.] There would be no crushing forces involved in such contraction.

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Regarding the probe capture challenge, you said:
"...it's impossible to answer. If you slow the alien probe or speed up the shuttle so that they're going at the same speed as each other, clearly the probe won't fit."

It is not impossible to answer. The answer is, “The probe won’t fit.” See again my point #4 bolded above for the significance of the answer.

Within the rules of SR, it's impossible to answer. If you are determined to get a definite answer to your question, you have no option other than to look to other theories. You reject the only alternative that I know of too, so I don't know what you think you're left with.

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It was obvious from the beginning that the shuttle must match the velocity of the probe to capture it, but I also made that explicit after all the collision speculation and proposed open doors for the probe to fly through the bay... nonsense.

Quote
You:
Quote
SR: The muon finds a shorter physical path through the atmosphere which is not available to slower moving things. These shorter paths are always there, but only open to things that move fast....
SR: As in the case of the muon, a shorter path (length) is available, as is a shortcut into the future.

Nonsense! Like the overall shape of earth does not change, neither does the thickness/depth of its atmosphere. The fact that faster moving muons “live longer” (degrade more slowly) than expected of slower ones means that they travel further than expected in the ‘lifespan' of a lab muon. That allows them to reach earth’s surface. The atmosphere does not contract to accommodate them. The simpler explanation, here again, is the correct one. And there is no magically contracting atmosphere involved.

My answer was rooted in SR, as labelled up front. If you don't like SR on this point, you need to propose another theory. The simpler explanation you have provided and which you insist is the correct one is taking you into another theory, such as the one you call my pet theory, but you don't like the Lorentzian universe either, so you're going to need to come up with a third theory.

Quote
You: "... or find shorter paths into the future ..."

Science fiction. There is no time travel. The present is the ongoing “now” always. The future is not yet present (here, now), and the past is not still present (here now.)

Again my answer was an SR reply. What you're describing is Lorentzian.

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You:
"As all frames are equally valid, every object will have a range of shapes..."

Answered yesterday. You are simply parroting SR dogma.
A “flattened earth” and a nearly spherical earth are not “equally valid.” Get over it.

Yes - it's SR dogma. If you want an answer from within SR, it has to conform to the rules of SR. I don't have access to the dogma of absolute truth, so I can't give you an answer conforming to its rules. All we can do is look at theories or come up with new ones and then push them to their logical limits to see how well they hold together. We can then put our own ratings on them as to how likely they are to be correct. You appear to reject SR on many points, preferring LU instead, but overall you appear to rate SR as better than LU. At the same time, you appear to have your own ideas about another theory (called reality) which is superior to both the other theories. I would like to see you develop that theory to find out how you explain the MM experiment.

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You:
"...on how the fabric of space is distorted in extra dimensions,..."

What extra dimensions? Like the seven extra ones in the metaphysics (not physics) of M-theory?

Space is 3-D volume, not a malleable entity/medium. Likewise time... that which elapses as things move. Put them together and what do you have? The volume (space) in which all things exist and move ( requiring time.) Not “The fabric of spacetime.”  (Another version of “The Emperor’s New Clothes.”)...
Minkowski’s “glorious nonentity.” (Ref: title of a paper by Brown and Pooley, compiled in a volume by Deiks of papers presented at one of the conferences of the International Society for the Advanced Study of Spacetime.)

In a two dimensional universe, there's someone like you arguing that this universe is the shape it appears to be to him. He has no idea that it's actually wrapped up into a tube, but he thinks he's right because he can't see outside of his own world.

#### old guy

• Sr. Member
• Posts: 165
##### Re: That length contraction does not apply to large objects (or distances)
« Reply #41 on: 20/09/2012 21:47:16 »
Very briefly...

David:
“You reject the only alternative that I know of too, so I don't know what you think you're left with. “

I am left with an Earth which is a natural object formed by gravity to BE a near sphere. It does not change shape ( unless/until it is crushed by some force) to accommodate any version of length contraction.
You:
"By forcing the shuttle to match the speed of the probe, you destroyed the very question you were asking. Perhaps you worded the question badly?"

Perhaps you continue to miss the point of the whole exercise. The point was that the probe IS NOT REALLY  10 meters long as measured from earth as it approaches. Length contraction advocates claim that IT IS  10 meters long, as measured (measurement = reality), not that it APPEARS TO BE 10 meters long. So the REALITY of how long it IS shows up when we arrive next to it and see that it IS REALLY 20 meters long. Is that clear enough?

Not even finished reading yet but must go.

#### old guy

• Sr. Member
• Posts: 165
##### Re: That length contraction does not apply to large objects (or distances)
« Reply #42 on: 21/09/2012 19:06:47 »
Continued reply to David’s post 40:

“...it's up to you to make up your own mind and stop worrying about what other people think.”

If I were “worrying about what other people think” would I continue to criticize length contraction and deny that all reality depends on observation... and that objects change shapes/lengths as they are viewed differently?!

“My interpretation of SR is that objects appear to have different shapes when viewed from different frames but that their actual shapes are fixed as the ones you see when in their frame.”

I agree, with emphasis on “appear to have.”

“SR accommodates a wide range of beliefs.”

The  fact that earth does not change shape with how it is viewed is not a belief.

“If you want an answer that doesn't comply with the rules of SR, you need to find another theory.”

No, I don’t. The fact that Earth is nearly spherical is not a theory. The theory (any version) that it changes shape with how it is observed is, as I said, ‘bogus.’

“Have you found some way to account for the Michelson Morley experiment which doesn't involve length contraction?”

Yes. The speed of light is constant even when seen from or projected from a moving frame of reference. I don’t know ‘why’ , but I have no argument against the evidence. Light is *very mysterious* that way. This well documented evidence, however, does not require that physical objects either shrink or move closer together in space. Observation does not re-create reality (The belief that it does is classical idealism). The cosmos is as it is, independent of how it is observed... unless one is an idealist who believes that nothing exists but what is observed, or that  things do not  have  properties of their own, independent of how they are observed.

“I'm just repeating...”

That covers it pretty well, in a nutshell.  To what do you think “the time dimension” refers, ontologically? What is it that is “curved” when GR insists that “mass curves spacetime?” That is what all introductions to relativity keep “repeating.” (GR is, of course, a different animal than SR and length contraction... so lets not go there in this thread.)

“A flattened Earth could happen without being destroyed as the distances between the atoms in the direction of travel would seem to be normal within its frame of reference, so it would hold together perfectly well through the normal application of forces between atoms.”

You agreed that no force is applied in length contraction. Do you have an answer to what could make “a flattened Earth happen” without applying any force?

“You reject the only alternative that I know of too, so I don't know what you think you're left with."

My answer to this yesterday referred to earth as an immutable (in this context) nearly spherical natural object which no theory can make flattened. But your comments referred to the probe example. Again, the probe won’t fit into a 10 meter bay because it is not 10 meters long, as measured from Earth, but rather actually, in reality, 20 meters (if it is approaching Earth at 86.6 % of ‘c’.) This was a “reality check” on its actual length vs its apparent (contracted) length. Do you get my point?

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You actually asked a question which invited the answer yes for two reasons: firstly you failed to lock it down to a capture where the two craft were travelling at the same speed, and secondly you were inviting answers relating to whether length contraction could make the probe fit in the cargo bay, which is something that's only going to work while the probe is moving at high speed relative to the shuttle.

The original project  was to retrieve the probe. As we all know, in order to retrieve an object traveling at high speed through space (say in orbit around earth) the retrieval craft must match the velocity of the object to be retrieved. Your objection seems to ignore this very basic fact. And I did  specify that after "collisions" and an "open bay fly through" were proposed... not the exercise which I presented.

“That made for an interesting question, but it seems that it isn't the one you intended to ask.”

I’ll be the spokesman for what I not only intended to ask but did in fact ask... “Will it fit?”
No. The bay was 10 meters. The probe’s *apparent length* was 10 meters ( as seen from earth) while its *actual length* was 20 meters (as seen "alongside" as I did specify.)

On your “finding shorter paths into the future”...
“Again my answer was an SR reply. What you're describing is Lorentzian.”

No. My answer is based on my interest in and study of the ontology of time over many years, not “Lorentzian.” The concept of time as an entity through which one can travel is pure science fiction with absolutely no scientific evidence to support it. “It” is always “now”... no escaping it, no matter how fast or to where you go.

A “block universe” with all the past and all the future somehow “present” is another concept to which “bogus” applies. Where are the dinosaurs today? How about that human colony on Mars. Do they exist? (That's present tense.) No.

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In a two dimensional universe, there's someone like you arguing that this universe is the shape it appears to be to him. He has no idea that it's actually wrapped up into a tube, but he thinks he's right because he can't see outside of his own world.

... In your imagination, which doesn’t seem to require referents in (or have any use for the term) “the real world.”
Space is three dimensional. Count them: Length, width, and height. For “the universe” they have no limits... The universe has  no “walls.”
A line is one dimensional. Two dimensions describe a plane. Anything or anyone *on that plane* will be a three dimensional being. Did you ever study basic geometry?

#### David Cooper

• Neilep Level Member
• Posts: 1505
##### Re: That length contraction does not apply to large objects (or distances)
« Reply #43 on: 21/09/2012 23:19:56 »
Progress at last! Now I'm beginning to understand your position.

Quote
“If you want an answer that doesn't comply with the rules of SR, you need to find another theory.”

No, I don’t. The fact that Earth is nearly spherical is not a theory. The theory (any version) that it changes shape with how it is observed is, as I said, ‘bogus.’

That is a theory, and a very old one, but it was put into severe difficulty by the Michelson Morley experiment - that is what led to Lorentz and Einstein coming up with their theories. If you don't have length contraction, you've got a massive problem to tackle.

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“Have you found some way to account for the Michelson Morley experiment which doesn't involve length contraction?”

Yes. The speed of light is constant even when seen from or projected from a moving frame of reference. I don’t know ‘why’ , but I have no argument against the evidence. Light is *very mysterious* that way. This well documented evidence, however, does not require that physical objects either shrink or move closer together in space. Observation does not re-create reality (The belief that it does is classical idealism). The cosmos is as it is, independent of how it is observed... unless one is an idealist who believes that nothing exists but what is observed, or that  things do not  have  properties of their own, independent of how they are observed.

I agree with second half of that, starting at the word "Observation" [though I wouldn't rule out its possible role in triggering the collapse of wavefunctions in quantum mechanics - that's another topic]. The first half is where all the problems lie - you cannot get all the pieces of the puzzle to fit together without length contraction being part of the picture.

Imagine a train racing along a track next to a long platform. A light signal can be sent along the platform from a source to a detector, and it can carry a message. A light signal can also be sent down the middle of the moving train, covering the same distance, but that light cannot travel any faster than the light does over the stationary platform - if it could, we could send a signal faster than the one along the platform by diverting it into the train, along through the train at higher speed (this could be a new light signal generated in the train, triggered by the one coming in from the side), and back out onto the platform. Try it with the train moving at 0.866c and you'll find that you have to halve its length to avoid being able to send signals twice as fast through the train as they go along the platform, though that's also assuming that clocks on the train will run at half the normal rate. If you insist on the train not being length-contracted while also making sure that light can't go faster through the train than it does over the platform, you're going to have to adjust something else to compensate, and that means the clock on the train will need double time dilation, meaning that it will run four times slower than a clock on the platform. If clocks run that much more slowly, then muons will travel a lot further before decaying than they are actually known to do.

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“A flattened Earth could happen without being destroyed as the distances between the atoms in the direction of travel would seem to be normal within its frame of reference, so it would hold together perfectly well through the normal application of forces between atoms.”

You agreed that no force is applied in length contraction. Do you have an answer to what could make “a flattened Earth happen” without applying any force?

In SR there is no need for real contraction - objects can simply rotate and hide some of their length in the time dimension, but that may be just one interpretation of SR and may not be accepted by everyone in the SR camp. In a Lorentzian universe, however, objects really would contract, but they do so by their atoms sitting closer together in the direction of travel simply through the normal forces which hold them apart. The best way to visualise this is to imagine a rocket with a room in it and a lamp in the middle of the room. When the rocket is moving fast, the light spreads out more before it hits the front wall because it has to go further than normal to catch up with the wall, whereas the back wall is rushing towards the lamp and will hit the light before its had a chance to spread out as much as it would if the rocket wasn't moving. The front wall should therefore be dimmer and the back wall brighter, but this doesn't happen because the movement of the lamp makes it behave differently, concentrating more of its light forwards such that even illumination of the walls is maintained at any speed, just so long as the room is length-contracted in the standard way. The same will happen to all the forces holding atoms together, concentrating them forwards more at higher speeds, and this will automatically result in atoms sitting at points where the forces of attraction and repulsion balance out, so the distances are length contracted in the direction of travel in the same way as happens with illuminating the walls - if a wall's dimmer than normal, it's too far away from the light source, while if an atom's too far away from another atom and the repulsion is weaker than the attraction, it will move towards the other atom - the point where these forces are balanced is now closer to the other atom, and this is happening throughout the rocket with the result that it contracts its length and brings the front and back walls closer to the lamp. [The business of how the forces of attraction and repulsion are only matched at one point with repulsion being stronger than attraction at closer distances and attraction stronger than repulsion at greater distances is another discussion, and one which I'm not qualified to go into (though a simple way to think of it is that the repulsion force must decay more rapidly with distance than the attraction force, perhaps by leaking out into other dimensions), but the point where they are matched will certainly move closer to the atom in the direction of travel.]

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“You reject the only alternative that I know of too, so I don't know what you think you're left with."

My answer to this yesterday referred to earth as an immutable (in this context) nearly spherical natural object which no theory can make flattened. But your comments referred to the probe example. Again, the probe won’t fit into a 10 meter bay because it is not 10 meters long, as measured from Earth, but rather actually, in reality, 20 meters (if it is approaching Earth at 86.6 % of ‘c’.) This was a “reality check” on its actual length vs its apparent (contracted) length. Do you get my point?

Everyone here got that point from the start, but you aren't then comparing a contracted object with an uncontracted one, so it doesn't tell you whether length contraction is real or not.

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I’ll be the spokesman for what I not only intended to ask but did in fact ask... “Will it fit?”
No. The bay was 10 meters. The probe’s *apparent length* was 10 meters ( as seen from earth) while its *actual length* was 20 meters (as seen "alongside" as I did specify.)

Well, if Lorentz was right, it will genuinely fit for an instant while it's moving at very high speed because the length contraction is absolutely real for that theory, though you can't actually know if that's actually happening or not because you can't pin down whether anything is moving or not. With SR, it can appear to fit in the same way when analysed from one frame, but not to fit when analysed from another - this is almost the same as in a Lorentzian universe, but there is no hidden absolute answer and it's therefore impossible to say it fits because it also doesn't fit at the same time.

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On your “finding shorter paths into the future”...
“Again my answer was an SR reply. What you're describing is Lorentzian.”

No. My answer is based on my interest in and study of the ontology of time over many years, not “Lorentzian.” The concept of time as an entity through which one can travel is pure science fiction with absolutely no scientific evidence to support it. “It” is always “now”... no escaping it, no matter how fast or to where you go.

That's Newtonian time, and it's the kind of time used in a Lorentzian universe. Your position is almost the same as that of Lorentz, only you don't do length contraction and I don't know if you're doing strange things to clocks to compensate, but whatever you're doing isn't going to fit the facts demonstrated by actual experiments. That is why length-contraction is the only game in town, though SR does provide a means by which it isn't real, even if lots of SR people insist that it is. It does, however, require you to accept the block universe at the same time.

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A “block universe” with all the past and all the future somehow “present” is another concept to which “bogus” applies. Where are the dinosaurs today? How about that human colony on Mars. Do they exist? (That's present tense.) No.

A Lorentzian universe could still build a block universe, so it can't be ruled out completely - the dinosaurs would still be back there in time, but you aren't going to be able to travel back there as your journey back there would already have to be written in the past of the block and that would result in circular causality.

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Space is three dimensional. Count them: Length, width, and height. For “the universe” they have no limits... The universe has  no “walls.”
A line is one dimensional. Two dimensions describe a plane. Anything or anyone *on that plane* will be a three dimensional being. Did you ever study basic geometry?

A two-dimensional being would not be three-dimensional. Of course a two-dimensional being might not be viable for a number of obvious reasons, but I was illustrating the point that the shape we see things doesn't tell us what their true shape is - our universe could be rolled up in a fourth dimension just as easily.

#### old guy

• Sr. Member
• Posts: 165
##### Re: That length contraction does not apply to large objects (or distances)
« Reply #44 on: 22/09/2012 01:26:47 »
My take on preview (limited time again):
David:
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A two-dimensional being would not be three-dimensional.

By definition. And only points and lines and designated 'areas' can 'live' on a plane, also by definition. So that stretches the meaning of "being" quite a bit, not very "viable" as you said, but fine for just imaginary, virtual beings.

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Of course a two-dimensional being might not be viable for a number of obvious reasons, but I was illustrating the point that the shape we see things doesn't tell us what their true shape is - our universe could be rolled up in a fourth dimension just as easily.

So a flattened earth is not its "true shape?"...  Even if it were possible to "see it" as flattened. That sounds like realism, and I agree.

So how should science best examine and measure Earth for best accuracy? Flying by at relativistic speeds or at rest with Earth, in Earth's frame of reference?

The correct answer to this question will solve the whole debated dilemma.

right

#### old guy

• Sr. Member
• Posts: 165
##### Re: That length contraction does not apply to large objects (or distances)
« Reply #45 on: 22/09/2012 18:46:32 »
Me:

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Again, the probe won’t fit into a 10 meter bay because it is not 10 meters long, as measured from Earth, but rather actually, in reality, 20 meters (if it is approaching Earth at 86.6 % of ‘c’.) This was a “reality check” on its actual length vs its apparent (contracted) length. Do you get my point?
You (my bold):

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Everyone here got that point from the start, but *you aren't then comparing a contracted object with an uncontracted one*, so it doesn't tell you whether length contraction is real or not.

You still didn’t get it. The whole point of the exercise was to compare the contracted version of the probe as seen from earth (10 meters) with the non-contracted actual, real probe as seen from its own frame (20 meters.) Maybe that is just too simple for you to wrap your complicated concepts about length contraction around. The “contracted  probe” was not its actual length. That was the point.
Like the warning on convex mirrors (..."Objects may appear larger/ closer than they are"), new version:
"Objects approaching at high speeds may appear much shorter than they are!" So don't sent out a shuttle with a 10 meter bay to retrieve a 20 meter probe!

You:
“...only you don't do length contraction and I don't know if you're doing strange things to clocks to compensate,”...

So you haven’t comprehended anything I’ve said in this thread or the other about clocks at higher velocity ‘ticking” slower* or muons at higher velocities degrading slower and therefore traveling further than expected... rather than Earth’s atmosphere contracting "for each muon.”
In the first case (*) ‘ship’s time, as recorded by its clock, shows less than 4.37 years elapsed on the way to Alpha Centauri, but meanwhile earth will have orbited the sun more than 4.37 times (as a reference to what ‘a year’ means.) Meanwhile, its slower clock does not make earth and AC move closer together, because the real universe  including the distance between stars, is not a result of how it might look from relativistic speeds.

You:
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A Lorentzian universe could still build a block universe, so it can't be ruled out completely - the dinosaurs would still be back there in time, but you aren't going to be able to travel back there as your journey back there would already have to be written in the past of the block and that would result in circular causality.

Again, ou confuse science and sci-fi. The dinosaurs are all dead, not “back there in time” still grazing and killing each other. You can’t “travel back there” because “there” is not a place in a “timescape” to which you can travel. Same for a possible future colony on Mars. you can’t “visit” a “time in the future” which has not yet happened.

Yours is a colossal confusion, not only about time but the real world of nearly spherical planets and stars and the distances between them as they were distributed by gravity when they were formed as near spheres.

I will not address yet again your long-winded essays on length contraction. Yes, light  speed is constant, regardless of frame of reference from which it is either seen or projected. I said that already. I also said that there is no empirical, scientific evidence whatsoever to show that  constant ‘c’ requires that or causes solid objects and the distances between them to contract.

As I said the nearly spherical earth is a fact, not a theory, and SR theory can not make it, or any other planet or star “flattened.”
I am done belaboring this debate with you as one who believes in time travel and  in malleable planets and stars which can be squished flat via “length contraction.”

#### David Cooper

• Neilep Level Member
• Posts: 1505
##### Re: That length contraction does not apply to large objects (or distances)
« Reply #46 on: 22/09/2012 20:38:26 »
So how should science best examine and measure Earth for best accuracy? Flying by at relativistic speeds or at rest with Earth, in Earth's frame of reference?

We don't know the best way to measure it - it depends on which theory is correct, and we don't necessarily even have the right one in our list of available theories. If SR is correct, my take on it would be to say that measuring the Earth while stationary/moving with it will give you its real shape - from other frames you are not seeing it properly. Many people in the SR camp will disagree with that, and you are free to do likewise. In a Lorentzian universe, you can't tell which is the preferred frame as you can't detect the fabric of space (that may change some day if its granular and the grain can be detected, but for now it's beyond reach) so you can't tell what shape the Earth may have been distorted into, and yet it doesn't really matter as the whole fabric may be distorted in other dimensions anyway - for most practical purposes, the shape of the Earth is the one it appears to be when you're moving with it, and that's also the shape it would take up if it was stationary in the preferred frame.

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The correct answer to this question will solve the whole debated dilemma

It would, but you'd need to know things that we don't and probably never can know.

Me:

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Again, the probe won’t fit into a 10 meter bay because it is not 10 meters long, as measured from Earth, but rather actually, in reality, 20 meters (if it is approaching Earth at 86.6 % of ‘c’.) This was a “reality check” on its actual length vs its apparent (contracted) length. Do you get my point?
You (my bold):

Quote
Everyone here got that point from the start, but *you aren't then comparing a contracted object with an uncontracted one*, so it doesn't tell you whether length contraction is real or not.

You still didn’t get it. The whole point of the exercise was to compare the contracted version of the probe as seen from earth (10 meters) with the non-contracted actual, real probe as seen from its own frame (20 meters.) Maybe that is just too simple for you to wrap your complicated concepts about length contraction around. The “contracted  probe” was not its actual length. That was the point.

If it was genuinely contracted, then its contracted length was its actual length at that time. It is completely incorrect to remove the contraction, measure it and then declare that it can't really have been contracted because it's now 20m long.

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Like the warning on convex mirrors (..."Objects may appear larger/ closer than they are"), new version:
"Objects approaching at high speeds may appear much shorter than they are!" So don't sent out a shuttle with a 10 meter bay to retrieve a 20 meter probe!

That's largely correct, but if you don't mind crushing it you can actually collect it in a 10m container in a Lorentzian universe with all the crushing happening after it's been captured because it really can fit for an instant while it's still moving fast.

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You:
“...only you don't do length contraction and I don't know if you're doing strange things to clocks to compensate,”...

So you haven’t comprehended anything I’ve said in this thread or the other about clocks at higher velocity ‘ticking” slower* or muons at higher velocities degrading slower and therefore traveling further than expected... rather than Earth’s atmosphere contracting "for each muon.”

What makes you think that? In SR and LU you have exactly what you describe (though with an different explanation in SR when Newtonian time is fully removed from it involving shortcuts into the future instead). The key point is how much the clocks are slowed and how much the lengths are modified. At 0.866c you get a slowing of clocks to half their normal rate and a contraction of length to half the normal length. You are trying to rule out the length contraction part of that, but that's going to cause you problems in explaining the results of the MM experiment, resulting on clocks being slowed by anywhere from twice to four times as slow, depending on their alignment to the direction of travel.

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In the first case (*) ‘ship’s time, as recorded by its clock, shows less than 4.37 years elapsed on the way to Alpha Centauri, but meanwhile earth will have orbited the sun more than 4.37 times (as a reference to what ‘a year’ means.) Meanwhile, its slower clock does not make earth and AC move closer together, because the real universe  including the distance between stars, is not a result of how it might look from relativistic speeds.

The problem there is that you can't tell if it's the stars that are stationary and the ship moving or if the stars are all moving and the ship is stationary - the universe might have been created in such a way that most of the original content was moving at close to the speed of light through the fabric of space, so a ship making a journey at speeds thought to be close to the speed of light may actually be stationary while all the stars are racing past, in which case it is actually the ship which is the only thing recording true time.

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You:
Quote
A Lorentzian universe could still build a block universe, so it can't be ruled out completely - the dinosaurs would still be back there in time, but you aren't going to be able to travel back there as your journey back there would already have to be written in the past of the block and that would result in circular causality.

Again, ou confuse science and sci-fi. The dinosaurs are all dead, not “back there in time” still grazing and killing each other. You can’t “travel back there” because “there” is not a place in a “timescape” to which you can travel. Same for a possible future colony on Mars. you can’t “visit” a “time in the future” which has not yet happened.

I was discussing the theoretical idea of a block universe, in this particular case as a preservation of the past in a form which is effectively frozen, but through which you might imagine that consciousness could still flow along in either direction through time, thereby still giving the inhabitants of that block the feeling that they are alive and happening now. The future of the block would only exist if the primary Newtonian now is beyond it, but we're certainly going into territory which probably has little to do with reality.

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Yours is a colossal confusion, not only about time but the real world of nearly spherical planets and stars and the distances between them as they were distributed by gravity when they were formed as near spheres.

The confusion is entirely yours. I'm exploring various ideas in an attempt to cover the ground of what might be. If you only want me to take up a single position, I'll go for the one which seems at the moment to be the one most likely to be correct, at which point I'll rule out the block universe as superfluous.

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I will not address yet again your long-winded essays on length contraction. Yes, light  speed is constant, regardless of frame of reference from which it is either seen or projected. I said that already. I also said that there is no empirical, scientific evidence whatsoever to show that  constant ‘c’ requires that or causes solid objects and the distances between them to contract.

Then you still don't understand the implications of MM. The "long-winded essay" about the train is the key thing that's missing from your understanding of how things actually work - if you aren't prepared to take it on board, you will merely turn yourself into an ignorant troll and spend the rest of your life wasting everyone's time with objections which don't hold water. You aren't doing that yet - you have good reason to be where you are, but that's going to change if you continue to ignore the path to real understanding which has been set out in front of you. The train thought experiment is crucial - don't ignore it.

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As I said the nearly spherical earth is a fact, not a theory, and SR theory can not make it, or any other planet or star “flattened.”
I am done belaboring this debate with you as one who believes in time travel and  in malleable planets and stars which can be squished flat via “length contraction.”

I don't believe in time travel, other than the normal kind where we continually move into the future. You seem to be incapable of considering the idea that other people can think their way into different theories and explain things in different ways from each without actually believing in them and without being confused by the points where they contradict each other. Maybe that's because you lack the skill to do it yourself, so you assume the same of everyone else and decide that they must be confused instead of recognising your own limitations. When I put across an idea with my SR hat on, what did you do? You attacked me for putting across SR dogma as if I believed in it! I'm not in the SR camp - I was giving you the SR vantage point on things as honestly as I, an outsider, can.

On the length contraction thing, I have no difficulty with the idea of a planet or star being increasingly flattened at higher speeds, but you certainly aren't going to cause any flattening to them by accelerating yourself to any speed.

You don't want to discuss this with me any more, and that's fine by me - I can use the time to do other things, but it isn't the best thing for you because my sole aim has been to help you find your way through this stuff. You seriously need to think your way through the train thought experiment as it will show you that your model of reality has a massive fault in it.

Imagine a clock based on sending pulses of light from a laser to a mirror and back, a new pulse being sent out every time the previous one returns. This can keep time simply by counting up the pulses, a certain number of them equating to one second. If you line up such a clock across the width of the train (which is moving along at 0.866c), the movement will result in it running at half the normal rate as the light will have twice as far to go to make the round trip (the path the light has to take now being at 60 degrees to the alignment of the clock). If you then angle the clock along the length of the train, it will take four times as long to make the round trip instead of twice. That is exactly what people thought must be the case before they did the MM experiment. The MM experiment is effectively a pair of these light clocks, one of them aligned across the train and one along its length, and a single pulse of light is split by a semi-silvered mirror to send it along the two paths. The light pulses both return at exactly the same time, but they can only do so if either the length of the arm pointing along the length of the train has been length-contracted to half it's normal length, or if the speed of light in the direction of the train is doubled, but we can rule out the latter straight away as it would allow faster than light communication. That is why length contraction is the only game in town, and you have to take it on board if you're seriously searching for truth. Not to do so would be like watching a wooden ball and a lead ball being dropped simultaneously from the top of a tower and hitting the ground together and then declaring that the lead ball must have hit the ground long before the wooden one because it's just obvious that nature works that way, and never mind what actual experiments show.

#### old guy

• Sr. Member
• Posts: 165
##### Re: That length contraction does not apply to large objects (or distances)
« Reply #47 on: 23/09/2012 19:27:55 »
David Cooper:
Quote
Of course a two-dimensional being might not be viable for a number of obvious reasons, but I was illustrating the point that the shape we see things doesn't tell us what their true shape is - our universe could be rolled up in a fourth dimension just as easily.

Speculative cosmology has its place in science as “ brainstorming.” But ultimately science requires empirical verification, and logic/ reason can not be totally dismissed in either cosmology or SR (or GR for that matter, with its "spacetime" remaining a convenient non-entity that "is curved by mass" with no mention of *what is actually curved.*)

For instance, regarding a universe “rolled up into a fourth dimension”: The word “dimension” must first be defined before it can be used intelligently. M-theory has created seven extra, imaginary “dimensions” beyond 3-D space and time (a stretch as a dimension already.) This metaphysical treatment of cosmology can never be empirically verified (or falsified), which makes it merely imaginary. If you think about a “rolled up universe” intelligently and reasonably, you must ask what is beyond the “walls” of the “roll.”... An imaginary non-universe? Hmm... What?

Me;
Quote
So how should science best examine and measure Earth for best accuracy? Flying by at relativistic speeds or at rest with Earth, in Earth's frame of reference?

The correct answer to this question will solve the whole debated dilemma.
You:
Quote
It would, but you'd need to know things that we don't and probably never can know.
...

We don't know the best way to measure it - it depends on which theory is correct, and we don't necessarily even have the right one in our list of available theories. If SR is correct, my take on it would be to say that measuring the Earth while stationary/moving with it will give you its real shape - from other frames you are not seeing it properly.

To the bolded phrase: Of course. And since relativistic speeds on large scale (see title) are still not possible, (for empirical evidence) all the shrunken bodies and distances will remain theory in denial of what physics already knows about planet and star formation and distribution in space.

SR theory did not debunk everything science knows about Earth, other planets, stars and cosmic distances. We do know the best way to measure things, and science knows precisely the shapes, sizes and distances I have been talking about in these length contraction threads.

The fact that light speed remains constant does not change all laws of physics which formed these bodies (as nearly spherical) and placed them in space as actually measured precisely by very competent astronomers.
(A near 'c' fly-by of Earth-and-Sun would not change the AU from its average 93 million miles, for instance.)

Back yet again to my probe illustration, which you simply refuse to accept as I presented it:
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You still didn’t get it. The whole point of the exercise was to compare the contracted version of the probe as seen from earth (10 meters) with the non-contracted, actual, real probe as seen from its own frame (20 meters.) (edit) ...The “contracted  probe” was not its actual length. That was the point.
You:
Quote
If it was genuinely contracted, then its contracted length was its actual length at that time. It is completely incorrect to remove the contraction, measure it and then declare that it can't really have been contracted because it's now 20m long.
(my bold)

Assuming that the probe (like the example using earth as a solid object) is a rigid metallic object, what force do you propose as applied to it to make it “genuinely contracted,” (to 10 meters) given that, as it was built, and as it is measured in its own frame, it is actually 20 meters long?
Again, differences in how things are observed, yielding different  measurements for the same thing do not make the things themselves change shape. Very basic. Real forces are required to make real  solid/rigid objects  change shape. Observation does not change that which is observed. Until you understand that, this conversation is useless.

You even turn around and contradict your “genuinely contracted” assertion as follows:
Me:
Quote
"Objects approaching at high speeds may appear much shorter than they are!" So don't sent out a shuttle with a 10 meter bay to retrieve a 20 meter probe!
You:
Quote
That's largely correct, but if you don't mind crushing it you can actually collect it in a 10m container in a Lorentzian universe with all the crushing happening after it's been captured because it really can fit for an instant while it's still moving fast.

...And I *do mind crushing it!* I set up the example. It’s my baby. The mission was to retrieve it, not to destroy it, as if changing frames of reference could apply such a crushing force. You are very confused, having already  agreed that length contraction does not entail any such force. You continually contradict yourself.
You:
“The key point is how much the clocks are slowed and how much the lengths are modified.”

My key point is that the slowing down of clocks at high velocity does not make lengths change. Actual force is required to change the length/shape of physical things. Apparent change is not the same as actual physical change. This point is lost on you and all proponents of length contraction.
It is hardly worth continuing such a discussion until my above points are finally addressed.
There is no point in repeating my comments on the great mystery of constant ‘c’ and the MM experiment. The paradoxical property of constant ‘c’ does not re-create all physical objects and the distances between them into malleable effects of variable observation/ measurement.
You:
“On the length contraction thing, I have no difficulty with the idea of a planet or star being increasingly flattened at higher speeds, ...” (my bold)

This is completely out of touch with the physics of “solid objects” and the forces required to actually “flatten”, say, planets and stars. Length contraction confuses appearances with the things and distances so appearing.

It all started with Einstein saying that there is no reality but what appears to the observer. Ever since then one must be labeled as ignorant/ confused or bite the bullet, bow to his Great and Infallible Genius and blindly accept that SR has totally redefined physics... that objects actually change as they are observed to change.

That makes idealism the ruling philosophy of science, and realists must suffer the resulting ridicule and confine their babble to the backwaters of science forums, like this.

#### David Cooper

• Neilep Level Member
• Posts: 1505
##### Re: That length contraction does not apply to large objects (or distances)
« Reply #48 on: 23/09/2012 20:58:12 »
And since relativistic speeds on large scale (see title) are still not possible, (for empirical evidence) all the shrunken bodies and distances will remain theory in denial of what physics already knows about planet and star formation and distribution in space.

Even the Earth is moving fast enough for length contraction to be relevant - the MM experiment would not produce a null result otherwise if there wasn't length contraction. The horse isn't going to drink though, so I don't think this is going to get any further.

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Assuming that the probe (like the example using earth as a solid object) is a rigid metallic object, what force do you propose as applied to it to make it “genuinely contracted,” (to 10 meters) given that, as it was built, and as it is measured in its own frame, it is actually 20 meters long?
Again, differences in how things are observed, yielding different  measurements for the same thing do not make the things themselves change shape. Very basic. Real forces are required to make real  solid/rigid objects  change shape. Observation does not change that which is observed. Until you understand that, this conversation is useless.

Length contraction happens in the arms of the MM apparatus, and it works in SR by rotating some of the length into the time dimension or in LU by the atoms sitting closer together in the direction of travel due to the shift in the positions where the forces are balanced. There is no need to add any crushing force.

Quote
You even turn around and contradict your “genuinely contracted” assertion as follows:
Me:
Quote
"Objects approaching at high speeds may appear much shorter than they are!" So don't sent out a shuttle with a 10 meter bay to retrieve a 20 meter probe!
You:
Quote
That's largely correct, but if you don't mind crushing it you can actually collect it in a 10m container in a Lorentzian universe with all the crushing happening after it's been captured because it really can fit for an instant while it's still moving fast.

...And I *do mind crushing it!* I set up the example. It’s my baby. The mission was to retrieve it, not to destroy it, as if changing frames of reference could apply such a crushing force. You are very confused, having already  agreed that length contraction does not entail any such force. You continually contradict yourself.

Your failure to understand something does not equate to me contradicting myself. You miss the point every time that the length contraction can be absolutely real and the the probe can genuinely fit in a 10m long space for a moment - what subsequently results in it being crushed is (if you can decelerate it evenly and instantly so that it isn't crushed by any impact) the change in the positions where the forces are balanced, leading to the atoms pushing each other further apart in what was their direction of travel a moment before.

Quote
You:
“The key point is how much the clocks are slowed and how much the lengths are modified.”

My key point is that the slowing down of clocks at high velocity does not make lengths change. Actual force is required to change the length/shape of physical things. Apparent change is not the same as actual physical change. This point is lost on you and all proponents of length contraction.
It is hardly worth continuing such a discussion until my above points are finally addressed.

This has been explained to you repeatedly and you still haven't got it. It may be that you're incapable of getting it (I don't know), and it could be a mistake to go on trying to explain it to you for that reason. I don't know if you're bothering to read anything carefully enough to take things in or not, but it's pretty unrewarding trying to tell you anything. In a Lorentzian universe, which is actually closest to your position, time is not slowed by movement, but clocks run slow because it takes longer for their components to produce each tick due to the direct increase in distance they have to travel to complete each cycle, and that applies to mechanical clocks exactly as it does to light clocks because everything that happens in them is governed by the speed of light. Length contraction comes directly out of that too, which you would be able to see if you took on board the idea of the room in the rocket with a lamp in the middle of it. The MM experiment also demonstrates actual length contraction.

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There is no point in repeating my comments on the great mystery of constant ‘c’ and the MM experiment. The paradoxical property of constant ‘c’ does not re-create all physical objects and the distances between them into malleable effects of variable observation/ measurement.

Quote
You:
“On the length contraction thing, I have no difficulty with the idea of a planet or star being increasingly flattened at higher speeds, ...” (my bold)

This is completely out of touch with the physics of “solid objects” and the forces required to actually “flatten”, say, planets and stars. Length contraction confuses appearances with the things and distances so appearing.

The MM experiment says otherwise.

Quote
It all started with Einstein saying that there is no reality but what appears to the observer. Ever since then one must be labeled as ignorant/ confused or bite the bullet, bow to his Great and Infallible Genius and blindly accept that SR has totally redefined physics... that objects actually change as they are observed to change.

It all started with the MM experiment. Those who took it on board dumped the old theory which you still cling to. SR does not require observation to change anything - you're being misled by an extreme interpretation of SR.

Quote
That makes idealism the ruling philosophy of science, and realists must suffer the resulting ridicule and confine their babble to the backwaters of science forums, like this.

Realists look at the MM experiment and conclude that length contraction is real. At that point, they either shift into the SR or Lorentzian camp. Your answer to MM appears to be to ignore it and pretend it isn't there, but it most certainly is there and it shows you to be wrong. That's why your babble belongs in the backwaters of science forums.

#### old guy

• Sr. Member
• Posts: 165
##### Re: That length contraction does not apply to large objects (or distances)
« Reply #49 on: 23/09/2012 22:10:24 »
Lets take this to the most basic level which no one can deny (well... almost no one.)
I said:
"The paradoxical property of constant ‘c’ does not re-create all physical objects and the distances between them into malleable effects of variable observation/ measurement.'
You said;

Do you agree that physical objects like Earth and spacecraft exist and have properties like shape and size independent of observation?
Same question in  reverse: Do you think that Earth changes shape as a result of how it is observed?

If not, do you think that the craft can BE both 20 meters and 10 meters long or that the Earth can have both a nearly 8000 mile diameter and a 1000 mile diameter... in the direction of an observing high speed frame, of course?
If so, do you experience cognitive dissonance as you claim both to be true?
Do you deny that there is a real world independent of observation?

Skipping the middle of your post for the moment, your last statement was:

Quote
"Realists look at the MM experiment and conclude that length contraction is real. At that point, they either shift into the SR or Lorentzian camp. Your answer to MM appears to be to ignore it and pretend it isn't there, but it most certainly is there and it shows you to be wrong. That's why your babble belongs in the backwaters of science forums.

A realist will answer my first two questions above in agreement with the first and denying the second. A realist will not agree that differences in observation require differences in that which is observed. They must ask by what means is a planet is squished flat and a spacecraft built 20 meters long is contracted to 10 meters, for whatever brief time in a theorist's mind. For a realist things do not change with how they are observed. Do you get at least that much of the argument from realism? If not, this is a totally futile exercise in communication.
« Last Edit: 23/09/2012 22:14:13 by old guy »

#### The Naked Scientists Forum

##### Re: That length contraction does not apply to large objects (or distances)
« Reply #49 on: 23/09/2012 22:10:24 »