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Author Topic: That length contraction does not apply to large objects (or distances)  (Read 16183 times)

Offline simplified

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Someone on the bus should send his photons  at 150 degrees relatively of own motion direction.

Yes - that's what I meant by 60 degrees behind, but you've expressed it better.
And if I am motionless observer then the light(of instant flash) travels by way of one arch of wave(if to not calculate energy waves) relatively of me.Therefore I can see the light under the same mirror angle.
I have forgotten that only any perpendicular motionless observer can see this light.Therefore the light, radiated at 150 degrees, extends perpendicularly,but has angle of attack 60 degrees relatively of extending.
« Last Edit: 01/10/2012 11:02:25 by simplified »
 

Offline JP

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I apologise if anything I've said has been taken as a personal attack. When I describe a question as stupid, it doesn't mean the person who asked it is stupid. We are all capable of asking stupid questions, and I recently asked one here about things being in more than one place at a time (where my way of testing the properties of such a thing would actually have destroyed its ability to be in more than one place at a time). I don't take any of Old Guy's comments as a personal attacks on me either - he is merely expressing frustration with this situation as things don't appear to be getting anywhere, but it is that that makes this particularly interesting as we continue to try to identify a key point where something might be forced to give.

David,

While I appreciate that you don't mean offense or take offense from the comments in this thread, my request to refrain from personal attacks also has to do with keeping the tone of the forum mild enough that other users can't take offense at it.  If it were acceptable here to label questions stupid or to call other users arrogant, then we'd end up dissuading a lot of users from posting here, even if no offense was meant.

So regardless of what your intent is, please keep this in mind in future posts.

Thanks!
 

Offline David Cooper

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David,

While I appreciate that you don't mean offense or take offense from the comments in this thread, my request to refrain from personal attacks also has to do with keeping the tone of the forum mild enough that other users can't take offense at it.  If it were acceptable here to label questions stupid or to call other users arrogant, then we'd end up dissuading a lot of users from posting here, even if no offense was meant.

So regardless of what your intent is, please keep this in mind in future posts.

Thanks!

Yes - it needs to be toned down a fair bit. There are different cultures in different places and it's hard to know which approach will work best where and with whom, so it's really a matter of experimenting in each place until you find the right approach for it, finding the point where the maximum rate of progress can be made. In some places the confrontational approach works really well because no one takes offence and the progress is rapid, but it doesn't fit everywhere - in most places you have to tread so carefully that it's very hard to get anywhere at all as no one dares to say anything that conflicts with what the majority believe, so existing beliefs simply get enforced rather than being tested. That makes it all a very difficult balancing act.
 

Offline old guy

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JP,
I hope you agree that it would be unfair to lock this thread because of D.C.'s continuing insults and insinuations that I am too stupid to understand his "explanations" of his favorite two versions of length contraction, which he is here to promote.

I will try one more time to explain the intent of my "probe" example as proof that length contraction is not "real" but only apparent, as an effect of observational differences at relativistic speeds.

The idea was that the probe can not "really" be two different lengths, just as the Earth can not have a thousand different diameters "as measured from" a thousand different frames. Planets have the shape they were 'given' by gravity (a "law of physics) when they were formed, and different ways of measuring them does not create new laws of physics which make them change shape. They are, after all, "solid objects." Likewise, a space vehicle has and keeps the length it was built with, which does not change with observation of it approaching at high speed.

So... if Earth sees a probe approaching at .866 c, it will appear to be 10 meters long. But it is not actually/really 10 meters long. The proof of that is that it will not fit into a 10 meter cargo bay sent out to capture it... which obviously requires entering its own frame of reference by matching its velocity.
There were so many distortions of this very basic example, changing the simple parameters I set, that there were collisions and an open-bay-door pass through, all arguing that length contraction is "real" and all manner of denial of my point,... that the probe was really 20 meters long, not the 10 meters it appeared to be *as contracted.*
 

Offline old guy

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Here is another example of me talking to a brick wall.
 Me:
Quote
** You beat on that drum assuming that space, time, and "the fabric of spacetime" exist as entities. Three dimensional volume (space) contains entities, including objects and forces. Space itself is the volume in which entities exist, not itself an entity. Planets are such objects and the gravity which holds them in orbit around the Sun is a force.**
D.C.:
Quote
It doesn't work without a fabric. Your volume is a fabric, regardless of your inability to recognise a fabric of more than two dimensions. If your volume was literally nothing, it would not be able to dictate separations between things - two things with literally nothing between them must be touching....
...What you need to do then is up your game so that you can speak out of knowledge instead of ignorance,

If calling this attitude "arrogance" is wrong, then honesty is not allowed here.

I replied in post 69. (Check it out.) Then the exchange continued, and he still didn’t get what I said.
Me:
Quote
I said, answering your direct question, that I "imagine" space to be the 3-D volume in which objects move around, guided by the force of gravity. I also said that distance is the linear component of that 3-D volume. (Do you even know what that means?) So, as solar systems form around stars, planets are formed as nearly spherical (not flattened) and the distances between them are due to where/how the raw materials of each body were distributed as the planets were formed and distributed in space.
D.C.
Quote
And that isn't a fabric of space? What's the difference between the two ideas then? Your 3D volume isn't just nothing - it enforces three space dimensions on its contents rather than four or five of them. You have distances enforced by your 3D volume too, so how is there no fabric of space in this? When light travels through your 3D volume, how is it restricted to the speed of light? What is it interacting with that enables it to maintain exactly the right speed while it travels through your 3D volume for billions of years?

This as if he didn’t even read my**...** above. This is not a conversation.
I also said earlier that constant 'c' does not require a "fabric" to enforce the speed limit... because 'c' is just how fast light travels through 'empty space' (3-D volume), a vacuum.
Three dimensions, called volume, is what I call “space.” What it contains is another story. It contains objects and forces. There is no “fabric.” A whole international society of physicists and philosopher/ontologists agree that there is no “fabric”,...that spacetime is just a coordinate system for designating the position of “things IN space” as they move, which requires time.
D.C. continues to reify "the fabric of spacetime" without, apparently knowing what reification even means, let alone that he is doing it.
I do sincerely hope that this conversation with him is over.
« Last Edit: 01/10/2012 23:29:00 by old guy »
 

Offline David Cooper

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JP,
I hope you agree that it would be unfair to lock this thread because of D.C.'s continuing insults and insinuations that I am too stupid to understand his "explanations" of his favorite two versions of length contraction, which he is here to promote.

I think you're more than capable of getting your own threads locked without any help from anyone. You still don't recognise help when it's being offered to you.

Quote
I will try one more time to explain the intent of my "probe" example as proof that length contraction is not "real" but only apparent, as an effect of observational differences at relativistic speeds....

...all arguing that length contraction is "real" and all manner of denial of my point,... that the probe was really 20 meters long, not the 10 meters it appeared to be *as contracted.*

You have provided no such proof. You were shown that in a Lorentzian universe, the contracted probe really could fit for a moment in a 10m long space, and that could well be how reality actually works - Lorentz's theory is fully compatible with the known facts, so your "proof" has failed the test unless you can also find a way to prove his theory wrong. In SR, you have also provided insufficient proof: in some frames of reference the probe appears to fit, but because it fails to fit when viewed from other frames it makes it impossible to provide an absolute answer, and that again would cause a problem for your "proof".

Here is another example of me talking to a brick wall.
 Me:
Quote
** You beat on that drum assuming that space, time, and "the fabric of spacetime" exist as entities. Three dimensional volume (space) contains entities, including objects and forces. Space itself is the volume in which entities exist, not itself an entity. Planets are such objects and the gravity which holds them in orbit around the Sun is a force.**
D.C.:
Quote
It doesn't work without a fabric. Your volume is a fabric, regardless of your inability to recognise a fabric of more than two dimensions. If your volume was literally nothing, it would not be able to dictate separations between things - two things with literally nothing between them must be touching....
...What you need to do then is up your game so that you can speak out of knowledge instead of ignorance,

If calling this attitude "arrogance" is wrong, then honesty is not allowed here.

Are you not being arrogant when you lay claim to the authority of "realism"? You describe something which does all the work of a fabric of space, but you give it a different name and assert that it isn't a fabric of space, and that isn't being arrogant? You're right about this being a conversation with a brick wall, but how can you be sure which one of us is the brick wall?

How does a volume impose itself on its contents if it is nothing? How does it apply rules to those contents to give them separation? How does it impose geometrical relationships on them?

Quote
I replied in post 69. (Check it out.) Then the exchange continued, and he still didn’t get what I said.
Me:
Quote
I said, answering your direct question, that I "imagine" space to be the 3-D volume in which objects move around, guided by the force of gravity. I also said that distance is the linear component of that 3-D volume. (Do you even know what that means?) So, as solar systems form around stars, planets are formed as nearly spherical (not flattened) and the distances between them are due to where/how the raw materials of each body were distributed as the planets were formed and distributed in space.
D.C.
Quote
And that isn't a fabric of space? What's the difference between the two ideas then? Your 3D volume isn't just nothing - it enforces three space dimensions on its contents rather than four or five of them. You have distances enforced by your 3D volume too, so how is there no fabric of space in this? When light travels through your 3D volume, how is it restricted to the speed of light? What is it interacting with that enables it to maintain exactly the right speed while it travels through your 3D volume for billions of years?

This as if he didn’t even read my**...** above. This is not a conversation.

I've read it all very carefully. This isn't a conversation because you're not prepared to answer questions like those. You're describing something that sounds like a fabric of space and behaves like a fabric of space, and yet you insist that it isn't a fabric of space. I'd like to know how you're differentiating the two ideas.

Quote
I also said earlier that constant 'c' does not require a "fabric" to enforce the speed limit... because 'c' is just how fast light travels through 'empty space' (3-D volume), a vacuum.

Here it is again - you have "empty space" performing exactly the same role as a fabric of space: I could say that c is just how fast light travels through the fabric of space. In both cases though, there is a speed limit involved which light cannot break, even though in your case you're thinking of it travelling through nothing. As I said before though, if there was nothing to it more than nothing, there would be nothing to set any distances, so light would be able to appear to break its speed limit due to the lack of enforcements of distance. Something has to hold those distances, and pure nothing isn't up to that task.

Quote
Three dimensions, called volume, is what I call “space.” What it contains is another story. It contains objects and forces. There is no “fabric.” A whole international society of physicists and philosopher/ontologists agree that there is no “fabric”,...that spacetime is just a coordinate system for designating the position of “things IN space” as they move, which requires time.

I think you'll find you're very much on your own. Einstein talked of the need for some kind of aether in the sense of a fabric of space, and his Spacetime is a fabric of space - it's just a 4D fabric instead of a 3D one with a Newtonian time. In GR his fabric is distorted to account for gravity. What you're calling volume is what I call a fabric. Your volume has distinct properties which are identical to those of my fabric.

Quote
D.C. continues to reify "the fabric of spacetime" without, apparently knowing what reification even means, let alone that he is doing it.

I'm just giving you a few lessons in real realism.

Quote
I do sincerely hope that this conversation with him is over.

You hope nothing of the kind - that's a clear invitation for more interaction. You obviously came here looking for a robust discussion where your beliefs would be tested and you'd be put under pressure to back them up with explanations where you can prove that they're right, and that's exactly the chance you're being given. Maybe if you answered the questions I've asked you could push me into a corner and show that my realism isn't as good as yours.

How is your volume not a fabric of space? My fabric of space has three dimensions just like your volume. Light travels through my fabric of space at the speed of light, just as it travels through your volume. Your volume imposes a 3D geometrical structure on the arrangement on its contents just as my fabric of space does. What insight am I missing which you have uncovered?

It's possible that you've got an image of a 3D tartan rug spread through space and can't detatch yourself from that picture to imagine the kind of fabric that I have in mind, so if that's the case, you need to chuck the rug and envisage instead something much remarkably like your volume and with the same properties as your volume. Your volume is not nothing: it imposed 3D geometry on its contents rather than 1D, 2D, 4D, 5D or any other D that isn't 3. Could it do that if it was literally nothing? I don't think so. There's something there that isn't nothing, and that something is what I'm calling a fabric.
 

Offline old guy

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This must be brief for now.
"What insight am I missing which you have uncovered?"

I didn't uncover it, but Occam's razor covers it. What does a "fabric" add to either space or time or both that 3-D volume (the 'vacuum of space') and the passage of time as things move through space does not already have 'covered?'

Have you checked out the literature yet from the conferences held by the International Society for the Advanced Study of Spacetime? That is of course a rhetorical question, as you show no sign of either interest in or understanding of the ontology of space, time, or "spacetime.'
 

Offline David Cooper

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This must be brief for now.
"What insight am I missing which you have uncovered?"

I didn't uncover it, but Occam's razor covers it. What does a "fabric" add to either space or time or both that 3-D volume (the 'vacuum of space') and the passage of time as things move through space does not already have 'covered?'

It appears to be adding nothing at all as your 3D volume clearly serves the same role. I could ask you the same question: what does your 3D volume add to it when I've already got it covered with a 3D fabric of space? If you can't actually pin down a difference between the two things, I would suggest that we are just using different names for the same thing. Your description simply pays less attention to the structure that your 3D volume provides. Perhaps if you read through everything I've written and translated "fabric of space" into "3D volume" it might make more sense to you that way.

Quote
Have you checked out the literature yet from the conferences held by the International Society for the Advanced Study of Spacetime? That is of course a rhetorical question, as you show no sign of either interest in or understanding of the ontology of space, time, or "spacetime.'

Would it be worth the time when the problem is actually with your refusal to understand the idea of a fabric of space (which is a description of your "volume" that directly addresses its structural qualities)? No amount of reading on my part (or anyone else's) is going to fix your problem.
 

Offline old guy

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Me:
Quote
    I didn't uncover it, but Occam's razor covers it. What does a "fabric" add to either space or time or both that 3-D volume (the 'vacuum of space') and the passage of time as things move through space does not already have 'covered?'
You:
Quote
It appears to be adding nothing at all as your 3D volume clearly serves the same role. I could ask you the same question: what does your 3D volume add to it when I've already got it covered with a 3D fabric of space? If you can't actually pin down a difference between the two things, I would suggest that we are just using different names for the same thing. Your description simply pays less attention to the structure that your 3D volume provides. Perhaps if you read through everything I've written and translated "fabric of space" into "3D volume" it might make more sense to you that way.

So you don't understand Occam's razor either, as you say:
" I could ask you the same question: what does your 3D volume add to it when I've already got it covered with a 3D fabric of space?"

The fabric adds nothing to a simple 3-D volume as what space is. Occam's razor "cuts out" stuff that adds nothing to a theory or the concept of space. The simplest definition of space is the empty volume in which objects/particles exist... no "fabric." The fact that the contents of space move around introduces the time factor. But that does not make time an entity either, and still no "fabric" is required to explain how masses attract other masses and make them move in, for instance, elliptical orbits around the sun. The orbits of planets do not require the "fabric" as a metaphorical coordinate system to guide them. The latter is simply a model for the math, which helps to predict those movements.
You:
Quote
Would it be worth the time when the problem is actually with your refusal to understand the idea of a fabric of space (which is a description of your "volume" that directly addresses its structural qualities)? No amount of reading on my part (or anyone else's) is going to fix your problem.

I have no problem.

Space needs no "structural qualities" (fabric) to allow gravity to function as mass attracts mass as things move through space.

Ps regarding this exchange:
Me: "I do sincerely hope that this conversation with him is over."
You:
"You hope nothing of the kind - that's a clear invitation for more interaction."

You are way out of line and looking very foolish to "correct me" yet again by telling me that I do not hope what I directly said that I hope. Are you now claiming to be the authority on what I do and do not hope? That is taking arrogance and condescention way beyond what I even expected of you.

As you continue to misrepresent what I have attempted to clearly communicate, I must either correct you or "roll over and play dead," and let your continual confusion (about what I said) stand uncontested. That will not happen, but I continue to sincerely hope that you will 'go away' (quit hijacking my threads) and start your own thread to promote your arguments.

« Last Edit: 04/10/2012 00:38:58 by old guy »
 

Offline David Cooper

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Me:
Quote
    I didn't uncover it, but Occam's razor covers it. What does a "fabric" add to either space or time or both that 3-D volume (the 'vacuum of space') and the passage of time as things move through space does not already have 'covered?'
You:
Quote
It appears to be adding nothing at all as your 3D volume clearly serves the same role. I could ask you the same question: what does your 3D volume add to it when I've already got it covered with a 3D fabric of space? If you can't actually pin down a difference between the two things, I would suggest that we are just using different names for the same thing. Your description simply pays less attention to the structure that your 3D volume provides. Perhaps if you read through everything I've written and translated "fabric of space" into "3D volume" it might make more sense to you that way.

So you don't understand Occam's razor either, as you say:
" I could ask you the same question: what does your 3D volume add to it when I've already got it covered with a 3D fabric of space?"

Every time you fail to understand something, you immediately accuse the other person of not understanding. Can you not just get the point I was making that it appears that your 3D volume = my fabric of space and that neither involves any addition to the other?

Quote
The fabric adds nothing to a simple 3-D volume as what space is. Occam's razor "cuts out" stuff that adds nothing to a theory or the concept of space. The simplest definition of space is the empty volume in which objects/particles exist... no "fabric." The fact that the contents of space move around introduces the time factor. But that does not make time an entity either, and still no "fabric" is required to explain how masses attract other masses and make them move in, for instance, elliptical orbits around the sun. The orbits of planets do not require the "fabric" as a metaphorical coordinate system to guide them. The latter is simply a model for the math, which helps to predict those movements.

Your "empty volume" is not nothing - it is something structured which may contain nothing, but it is not nothing. If it was literally nothing, it wouldn't be specifically 3D and it wouldn't allow separation between things with measurable sizes. Your 3D volume is no simpler than my fabric of space. You appear to be sticking your head in the sand and refusing to see the complexity that must be tied up in your 3D volume. But you don't even need to pull your head out of the sand to make progress here because it doesn't matter to the main discussion. I've told you that your 3D volume will do fine, so just replace every mention of a fabric of space with a 3D volume and you should be able to cope.

Quote
You:
Quote
Would it be worth the time when the problem is actually with your refusal to understand the idea of a fabric of space (which is a description of your "volume" that directly addresses its structural qualities)? No amount of reading on my part (or anyone else's) is going to fix your problem.

I have no problem.

Space needs no "structural qualities" (fabric) to allow gravity to function as mass attracts mass as things move through space.

It actually does, but you can believe what you like on this whole irrelevant issue.

Quote
Ps regarding this exchange:
Me: "I do sincerely hope that this conversation with him is over."
You:
"You hope nothing of the kind - that's a clear invitation for more interaction."

You are way out of line and looking very foolish to "correct me" yet again by telling me that I do not hope what I directly said that I hope. Are you now claiming to be the authority on what I do and do not hope? That is taking arrogance and condescention way beyond what I even expected of you.

What is it you want then? You push away everyone who tries to help you with this and are unspeakably rude to them. I've been extremely generous with my time in trying to help you with this, but you can't see that - you just assume that I have some other motive to promote my own agenda, but that is not the case.

Quote
As you continue to misrepresent what I have attempted to clearly communicate, I must either correct you or "roll over and play dead," and let your continual confusion (about what I said) stand uncontested. That will not happen, but I continue to sincerely hope that you will 'go away' (quit hijacking my threads) and start your own thread to promote your arguments.

I'm not interested in promoting anything other than the search for truth. I don't like seeing false knowledge being pushed as facts when it's just theory, and that's why I had to put the case for Lorentz's theory to show that far from being dead, it ought to be considered to be one of two major players. With that point out of the way (a long time ago now), I have been free since then to focus on trying to help you recognise the points where you are wrong. Unfortunately, you don't appear to be interested in exploring any points where you might be wrong, and that's why you're stuck in the 1800s.
 

Offline JP

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Locked because this thread's been getting too personal.
 

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