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Physics, Astronomy & Cosmology / Re: How Can We Know The Cosmos Age If We can Only See The Observable ?

« on: Today at 15:12:44 »

A quick question, Halc: taking your example of a time dilation factor of 4, suppose our galaxy was receding slightly faster, say 1.03c, what becomes of the Lorentz factor? It will now be a complex number. Does this feed through to a complex age?

The recession rate of 0.97c was relative to the 'inertialish' frame of the distant place. Under such a frame, recession rates cannot exceed c.  The recession rates you see published are rates of increase of proper distance over time, not speeds. They're relative to an expanding frame, and in such frames, recession rates are rapidities, not speeds. (see bottom of post for example)  Rapidity adds the regular way and has no upper bound.  If, relative to this expanding frame, galaxy X is receding from us at .8c and Y (at twice the distance) is receding from X at 0.8c, then Y would be receding from us at 1.6c. The speeds don't add the relativistic way that they do in inertial frames.

Few of the typical rules of physics apply in such a non-inertial frame. Neither energy nor momentum is conserved. Moving objects tend to come to rest. The wavelength of a light pulse grows over time, the energy going down with it. Light does not travel at c except locally.

Relativity of simultaneity still applies, hence if one is considering the 'current age' of the entire universe of points in space well outside our visible universe, given the right choice of frame, one can make, at that distant location, any point in time be simultaneous with us at Earth, hence the distant parts of the universe having no defined age. So they define a preferred frame, which is the frame in which all events on comoving worldlines at similar gravitational potential as us, are simultaneous with each other. This is known as the frame of constant cosmological time (or just cosmological frame), and it is not an inertial one.

Apologies if that got a little complex. I did several edits trying to make it simpler/more clear.

An example of rapidity.  There is a highway to the next galaxy with little signs every light year like mile posts.  In my fast ship, I can measure my rapidity by the rate at which they go by. One sign per year is a rapidity of c. If I accelerate more, I can see one go by every day, and hence I can cross to the next galaxy before I die with a fast enough ship. The ship is moving at a speed of under c, but a rapidity of 365c in this case (not yet fast enough to get to the next galaxy in a lifetime)

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Physics, Astronomy & Cosmology / Re: How Can We Know The Cosmos Age If We can Only See The Observable ?

« on: Today at 00:53:18 »

General Relativity (GR) seems to be a fairly good model, it has withstood several tests.   Provided that model is right, we do not need to be able to see the whole universe.

Well, if we're going to go strictly by what relativity says, it posits the entirety of 4D spacetime as 'the universe', and therefore it has no meaningful age at all. What we have is the temporal distance between the spacetime event of the existence of humanity and the spacetime event of the big bang, as expressed by Earth's frame. That's not the age of the universe, it's just the time coordinate of humanity in that frame.  For the universe to have an actual age, it would need to be contained by time (presentism), and that's quite a different theory than what relativity says.

As for the 'Earth's frame' bit, one can make the 'current' time as large as you want by picking a different frame. That lets relativity of simultaneity work for you. So say you want to compute the current age of the universe relative to the (inertialish) frame of some galaxy relative to which our galaxy is moving away at say .97c. In that frame, our clocks are dilated by a factor of 4, so the event on that far galaxy simultaneous with humanity here is somewhere around 55 billion years since the big bang.

There are also ways to make 'the age' lower by choosing yet different frames.

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New Theories / Re: If there was one Big Bang event, why not multiple big bangs?

« on: Yesterday at 04:07:01 »

My view is that the infinities of space, time, and energy have always been the case, forever. Since I posit that there was no beginning, time has always been passing, everywhere across that infinite expanse.

Sounds like the steady-state hypothesis

As part of that picture, I often discuss the "sameness doctrine" which says, on a grand scale, the universe is essentially the same no matter where you are in it

Better known as the cosmological principle

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New Theories / Re: What is non-returning twin paradox?

« on: 29/09/2023 20:25:50 »

You're making up facts. There's no conflict when different physicists explain it in different ways since none of the explanations are wrong. But the way I showed seems the most simple, and requires but the one equation.

Not just a different way, but different interpretation of the cause.

But one interpretation of 'the cause' doesn't invalidate any of the others. Personally I don't think there is a cause. Asking for one is like asking what causes a table to be longer than it is wide. It is perhaps caused by which dimension one decides to designate as the length.

Lorentz' relativity interpretes time dilation is caused by relative motion against stationary aether. Thus no paradox is generated.

But that's pretty much the answer I gave in post 1, except without the aether, which has no method of detection. Instead there is just a preferred frame. You choose one, and exactly like the Lorentz case, no paradox is generated.

Einstein's 1905 Relativity dismissed aether  ...
Since there is no more universal reference, it's no longer clear which clock ticks faster.

Nobody ever claimed that a clock ticked faster. Your problem for suggesting otherwise, but don't blame relativity theory when making such a blunder.

Einstein's 1921 relativity reintroduced aether, with some modifications. It no longer carries some physical characteristics. It was then renamed to space-time continuum.

'Spacetime' was coined by Minkowski in 1908. Einstein never wrote the term "space-time continuum:, which seems to be a pop term introduced as early as 1930 in a fiction story. I am unaware of a physics paper that uses the term ever, but if you have a quote from Einstein, that would really help illustrate that you're not just making up your own facts. And no, he never reintroduced aether either, but GR does introduce a preferred (non-inertial) frame relative to which cosmological time (adjusted for potential) is constant at simultaneous events, something that can be measured since cosmological time is an empirical measurement. None of that has anything to do with a proposal of a medium through which light travels.

If you dismiss frame changes

Nowhere do I dismiss them. I just said that computations are more complex if you choose to do them. Please try to actually read what I say and not make up your own crank story about what you hoped I said. The computation in posts 1 and 9 did no frame changes, and they both arrived at the same answer of 8 and 9 1/6 and they did it with only the one equation instead of several that would have been required to do the same thing with frame changes.

I just want to know how to do it right

This is very apparently a lie. If you wanted to know how to do it, there are many correct ways to do so, but I illustrated probably the easiest way. I invited you to work out yourself how to do it in the frame of the B's 2nd leg. That's how you learn, by doing, or at least attempting. You declined. You show no indication of wanting to learn how to do it, so the above statement is false.
It is this obvious lack of desire to learn that makes myself and other ignore the majority of any of your posts.
Prove me wrong and attempt the calculation using the 3rd frame and the numbers already provided in posts 1 & 9.

STR requires that all inertial frames are equally valid frame of reference.

That it does, but it doesn't say you are required to use them all. You can if you want, but it's a lot more work since transformations are required every time you change frames.

Minutephysics' video also depicts both twins see each other age more slowly during constant velocity motion. Only when the travelling twin turns around, he sees the staying twin ages much faster.

If it doesn't say that each of them sees the other twin age faster when approaching, then the video is wrong.
An explanation based on what people see is not wrong, but again, more complicated than this simple situation needs to be. You again need more than one formula to get the correct answers.

He mentions acceleration as the cause, instead of gravity. But GR says they are equivalent.

This is wrong, and the video is wrong if it says this. GR says the two are equivalent only locally, not over any significant distance. The two are very distinguishable over distance.
The problem with using videos for education is so many of the videos have no peer review.

The format of the information source should not prevent the content to be delivered correctly.

No, it shouldn't, but only peer review helps ensure the content is correct, and almost no video undergoes such review. I've pointed out blatant errors in videos by very respected, famous and popular authors.

If you think there are good videos, you can just put the link here

I've never had the time to search for good ones, and I've never chosen any to do the actual learning.
Watch out for any video that claims to be the one correct way to explain the situation.

Without frame switching, both twins are equally valid observers

First of all, it is you that needs to do frame switching or not, not the twins, who require no more intelligence than the ability to read the clock that's strapped to their wrist.
Secondly, all people and devices for that matter are valid observers. Frame switching doesn't somehow cancel the ability of a thing to make a measurement, but in the twins scenario, the only measurement is the local consultation of one's watch. There are other scenarios where actual observation beyond clock watching is necessary, but the twins scenario doesn't require observers at all. It can be (and has been) done by just zooming clocks around without people serving any purpose other than that of a courier.

confusion is caused by many supporters of STR have their own versions of the theory which are incompatible with one another, but claim that they are the standard STR.

There is one STR, and it is mathematically perfect, meaning it cannot be falsified from an armchair, only by empirical means. If somebody actaully alters the theory, that person is wrong, but most just convey the concepts in different ways. I've seen no wrong replies to you for instance. You're the only one making blatantly incorrect assertions.

I asked Google Bard about Twins Paradox.

Should be entertaining since it, like chatGPT, uses all the disinformation online as part of its training material. I would never trust an answer from a chatbot.

What is the twin paradox?

Bad start. You didn't ask about your scenario specifically (asking it for the ages at the end of your experiment in the OP, nor did you ask it about 'the cause' of the differential aging. So you're now asking a far more generic question. But you're in luck since it does directly attribute the potential differential aging to asymmetry, and the asymmetry to non-symmetric acceleration. So the answer is actually quite good this time. It says that asymmetry 'allows for' differential aging, but correctly doesn't go so far as to say it causes it, since there are plenty of asymmetric situations where there is no differential aging.

Another way to think about it is that the traveling twin's worldline is not a straight line in spacetime, but rather a curved line. The stay-at-home twin's worldline, on the other hand, is a straight line. This difference in worldlines is what accounts for the difference in aging.

This is quite close to the explanation I gave in the 'what is the cause' topic that has so many of your posts.
This answer is less intuitive and more complicated, but also more generic (can be applied to any situation), something not true of the first explanation.

The twin paradox has been experimentally verified using atomic clocks. In one experiment, two atomic clocks were synchronized and then one was flown around the Earth on a jet aircraft. When the clock was returned, it was found to have lost a tiny fraction of a second. This was due to the time dilation effect predicted by special relativity.

This part is a little off, since GR was needed to predict the results. The entire experiment took place at various altitudes in a gravity well. SR was not up to making any prediction better than the fact that the westbound clock would accrue more time than the eastbound one.

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Physics, Astronomy & Cosmology / Re: How Can We Know The Cosmos Age If We can Only See The Observable ?

« on: 29/09/2023 15:12:06 »

From what I understand the Observable Universe is 93 billion light years.

93 G light years in diameter. That's a distance, not an age.
Half that (the radius) is the current distance to the furthest piece of matter/energy that could possibly ever have had a causal influence on us. If ewe were to emit a light pulse at our location in space, I think right as the inflation epoch ended (implausible since the universe wasn't transparent back then, so a light pulse would get anywhere), 46 Gly is how far away that light pulse would be now.

It is often said that we have no idea how big the unobservable is because we shall never see it due to the expansion speed being faster than C.

And that would be something often misstated.
The expansion is faster than C at the Hubble radius, only about 14 BLY away. We see all kinds of stuff that is currently further away than that. The CMB is probably the furthest at about perhaps 45 BLY distant in all directions. Anything further away than that needs to use something other than light to measure, like say gravitational waves or something, and they've yet to invent a GW telescope.

So, my instinct then is to ask is how can we tell how old the universe is if all we have is the observable universe to deduce from ?

Again, simple answer: by noting Hubble's constant, which is the inverse of that age.
Before Hubble's time when it was discovered that galaxies are receding, and at a rate proportional to their distance from us, there was no concept of the universe having a finite age. After the discovery, the age was pretty much known, but there was still no estimate for the size of the observable universe, which isn't a function of its age, but rather of the rate at which expansion is changing, something which wasn't measured until far more recently.

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Physics, Astronomy & Cosmology / MOVED: What is non-returning twin paradox?

« on: 29/09/2023 04:15:38 »

This topic has been moved to New Theories.
https://www.thenakedscientists.com/forum/index.php?topic=86510.0
The topic is heading into denialist territory and has no business in the main physics forum

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New Theories / Re: What is non-returning twin paradox?

« on: 28/09/2023 13:41:25 »

This is also incorrect since the conclusion is abstract (mental, not physical) unless they are in each other's presence, in which case it is called 'differential aging', which is the unequal comparison of clocks physically in each other's presence.

Do you mean that A's clock will be equal to B's clock at the destination point?

No. 8y is not equal to 9y 2m.  Why would you suggest otherwise?

So, you are not confused if the problem can be simplified to 0 or 1 inertial frame change, but you start to get confused with 2 or more inertial frame changes. Cmiiw.

As I said before, doing it via frame changes just adds complications, requiring multiple formulas, some of those being more complicated.

Using what I showed, no frame change is made ever. You pick just one and stick with it.

The confusion comes from asymmetrical results produced by symmetrical situations.

The situation was never symmentrical, and if it is (like the one in one of your recent threads), then the result is very much symmetrical. But adding more characters just adds more complications which is inadvisable if you cannot in any way understand even the simplest case.

How much difference is caused by the changing reference frames?

None actually, since a change of reference frame is a mental abstraction, not physical. A mental change doesn't in any way alter what actually happens.

The other half is asymmetrical results between the twins, which means that one of them will observe time contraction of the other twin, instead of time dilation.

There is no such thing as 'time contraction'. There is time dilation, but you speak of this time contraction as if it is something different.

t's the cause of this supposed asymmetry which created disagreement among physicists.

You're making up facts. There's no conflict when different physicists explain it in different ways since none of the explanations are wrong. But the way I showed seems the most simple, and requires but the one equation.

Halc's answers. Reply #1 only addressed half of the question, which is reasonably hasn't touched the paradoxical part.
Perhaps the misunderstanding can be avoided if we use the term "switch of inertial frame" instead of "change of inertial frame"

I didn't touch on a paradoxical part because there isn't one.
The misunderstanding can be best avoided if we avoid switching inertial frames altogether, as I suggested in post 1.It only leads to confusion if you don't understand how to do it right, and doing it right that way is considerably more complicated than sticking to one frame as I suggested.

Lorentz factor is usually represented by gamma symbol γ instead of lambda λ.

I stand corrected on that one

Reply#15 is supposed to answer time dilation experienced by twin A as observed/calculated by twin B. But he refused to give numeric result, on the account that twin B switched his frame of reference.

I instead encouraged you to work it out yourself. Even an attempt with mistakes would have been a learning experience, and we could have helped. But you declined since apparently learning anything isn't your goal. Hence my not bothering to reply much anymore.

The answer is easy. If 'the frame of B' is used, 8 years are logged by twin A, and 9y2m by twin B.

The video below tries to solve twin paradox using acceleration.
But this video below doesn't touch the paradox yet. It only describe time dilation observed by earth twin, without being bothered by travelling twin's perspective.

The first is a terrible video. It has many errors, such as asserting that they see each other age more slowly, which is only true when they watch each other recede. The twins scenario is not in any way about what anybody sees. Then they try to explain things via gravity which is utterly wrong. This is a special relativity scenario in which gravity is never taken into consideration.

The second video isn't much better. It say 'time slows down as you approach the speed of light'. That's just wrong. 'I move at nearly light speed relative to a muon created in the upper atmosphere. It doesn't make time slow down to me. He then attempts to reference an invalid frame of a light-like worldline, which is obfuscation at best, and wrong at worst. He never actually gets back to the twins after that.

There are good videos out there, but hunting down bad ones seems a favored pasttime to those that don't want to learn. Take the advice of other posters and find a good physics text if you actually want to learn this, which I suspect you don't. Stay away from you-tube, pop sites, and especially social media.

Let's describe the same case from twin A's perspective. He stays in his own reference frame, while Alpha Centauri moves closer at 0.4c.

This statement is incorrect.  Twin A does not stay in his own constant inertial frame.  He starts in earths frame, accelerates to the cruising frame then decelerates to Alpha Centauri's frame.

His statement is pretty much my words from post 9. The statement doesn't suggest that any planet undergoes any acceleration. I was talking about the frame in which A is stationary for the entire duration of the exercise. Everybody 'stays in' this frame since it is impossible to exit an inertial frame. To 'be in' a frame is simply to have valid and unique coordinates to your event in that frame. So acceleration doesn't necessarily cause a change of frame, since a frame is simply an abstract choice, and the simplest choice is to never switch frames. So the other players (planets, twin B) are still in this frame, they're just not stationary relative to it.

Relative to that frame, which we've called 'A's frame', Alpha Centauri moves closer to twin A at 0.4c. There's no suggestion that it needed to accelerate to do so since it was always moving at that speed relative to that frame, as was Earth. Yes, twin A needed to accelerate to a halt in that frame, but that fact is irrelevant since he spent zero duration at that alternate speed. Acceleration computations do not figure into the simplified method I suggested in at the top.

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New Theories / Re: Chaos theory, Butterfly and Lorenz Attractor, Butterfly effect, Mystery

« on: 27/09/2023 02:25:33 »

Well, I guess that answers my question as to whether or not this was the same Lorentz that Lorentz contraction was named after...

Often mistakenly attributed to Lorentz, but it was actually Braxton-Hicks
Not to be confused with butterflies in your stomach.

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New Theories / Re: If there was one Big Bang event, why not multiple big bangs?

« on: 25/09/2023 01:32:52 »

Given all of the possible points from which to make such an observation

In an infinite universe, there are of course infinite locations from which an observable universe can be defined. But they come in clumps, which in our case is our local group of galaxies.  Any light that can reach any point in our local group of galaxies can also reach any other part of the group, hence it acts as a sort of single center of one observable universe.  This is not true of any observer not in the group. Light might reach that observer and nothing in our group, or reach our group and not that observer, not even after infinite time.
So again, yes, there are infinite points of observation when talking about an observable universe, but the different 'points' of observation are pretty far apart.

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New Theories / Re: What is non-returning twin paradox?

« on: 17/09/2023 16:14:56 »

This is a slightly modified twin paradox to distinguish the effects of relative speeds and acceleration.

In a different inertial reference frame (one in which both stars are moving at -0.4c), this is pretty much exactly the twin paradox, with twin A being stationary the entire time, and twin B going out and back, albeit at 0.4c only outbound, and faster on the return.

OK, so this is trivially computed in the Earth frame. The resolution for any exercise in special relativity is to simply choose a frame (we'll pick Earth since Earth time was specified), all you need to do is compute the dilation factor due to the speed relative to that frame. This is computed (in natural units) with

λ = 1/√(1-v²)

Twin A started a journey to Alpha Centauri 4 light years away in a space ship moving at 0.4c  is expected to arrive 10 years later, according to earth observer.

OK, so in Earth frame, λ=1.091 so 10 / 1.091 = 9 years 2 months elapsed time for twin A.

Twin B stayed home to improve the space ship, so he can go to Alpha Centauri 5 years later at 0.8 c.

0.8c yields a λ of 1.667 so 5 years at home and 3 during the trip, so 8 total.  Not so hard, right? You can do this yourself without asking each and every time.

Classical physics calculation predicts that they'll arrive at Alpha Centauri simultaneously.

Classical in what sense?  Classical physics refers to non-quantum physics. I think you mean Newtonian physics, not classical.  Yes, every theory (including Newtonian) says they get there simultaneously. This is an objective fact, true in any reference frame.

How old are they when they meet up at Alpha Centauri?

As computed above, 9y2m and 8y respectively.

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General Science / Re: Just how does a metal detector work?

« on: 08/09/2023 12:50:19 »

surely there must be something to do with magnetism that helped it find metal

It has to do with electrical permeability which is related to magnetism. Magnetism would only find ferrous materials, so not say copper, but a metal detector is quite good at finding copper objects.

The idea is that it puts out an EM field which energizes (sets up eddy currents in) anything that allows the internal formation of magnetic lines of force (stainless steel being very bad at this). Then it shuts off and detects ('listens') for the currents created in the objects below. So the object needs to be able to pass electrical current, and it's mostly only metals that do this.

That surely any pirates would be very frustrated by the people who have made metal detectors and by us for finding their treasures so easily!

A decent pirate would bury his treasure a little further than the range of most detectors, and they put it where people tend not to look for it. Metal detectors are great for coins and jewelry dropped in public places like parks and beaches where the grass and sand quickly hide small dropped objects.

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Just Chat! / Re: Is the universe real?

« on: 06/09/2023 15:59:38 »

Recently I learned, through a conversation with Halc, that quantum theory says that one of the following statements must be false: (A) there can be no retrocausality and (B) counterfactual definiteness exists.

More specifically, the principle of locality and principle of counterfactual definiteness (CFD) cannot both be true *.

which is why we need science.

I don't see the two statements as mutually exclusive.

Funny, since it was science (not mere philosophy) that demonstrated the mutual exclusivity of the two principles.

The idea that either of these is false seems incomprehensible to me, on an INTUITIVE level.

I was raised as a Christian and educated in a parochial school which taught me that the teachings of science and mathematics do not contradict the teachings of the Church. But then (around my 20's) the Church decided this was no longer true and one was not allowed to pay attention to the man behind the curtain (Oz reference if you don't get that). I was forced to choose, and that turned out to be pretty simple. I removed one premise that I held (the divine origin of the scripture) and so many pieces fell into place with startling ease.
Clearly it was a good thing to question one's beliefs, and so I learned to identify as many as I could (those intuitions you talk about) and question each of them, learned how to not rationalize, but rather to be rational. That part is not easy.
So began my journey into philosophy, but it turned out that all the pre-20th century philosophers were working on assumptions that science has since cast extreme doubt.  To find the answers I was seeking, I needed to learn the relevant science, not enough to pass a grad-level course, but enough to know the implications. I came to TNS fairly ignorant of relativity and QM, but I learned, and I changed my views as I learned more.

I don't buy into these "simulation" ideas which in my opinion are just science fiction gone crazy.

Most people don't ever think it through, as evidence by the fact that there are two very different versions of it that are nevertheless treated the same. I agree and don't buy into the various versions either.

Buddhism states that reality is an illusion- is it that too far off the mark?

That's a philosophical stance. I don't know exactly what they mean by that statement, so I'm not much qualified to comment further. For instance, how do they define 'reality' and 'illusion'?



* There's a loophole in superdeterminism under which both principles hold, but which is way off the weird end of the scale, and is not listed as a valid interpretation since it suggests that no science can be performed at all.

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New Theories / Re: If there was one Big Bang event, why not multiple big bangs?

« on: 05/09/2023 21:48:27 »

I'm not suggesting that time is an illusion

I actually never understood those arguing that time is an illusion. I mean, a physical clock measures it, and a physical device cannot measure something that doesn't exist. So to suggest that time isn't real has to also include the clock not being real, and then you not being real. That's a less popular stance, valid, probably just a refusal to apply the term 'real' to anything.

instead, time has always been passing, and everything that has happened, or is happening, or will happen, takes place somewhere in the infinite and eternal time continuum. That continuum has just one direction, and that is forward in time.

That's an intuitive philosophical stance known as presentism. Most people are presentists, especially those unfamiliar with the term, but it does contradict Einstein's theories, contradicting the most basic premises.  If you deny that all local inertial frames are equally valid, and you deny the constant speed of light, you end up with a totally different theory that came along about a century after Einstein's papers. In this theory, the universe is 3D, not 4D. It is contained by eternal passing time just like you say. There is no big bang, only a (single) big bounce. There are no black holes,. Those things are artifacts only of Einstein's theory.
Look up I. Schmelzer if you're interested, but the theory is more complicated than general relativity, so it isn't an easy read. But it supports the presentism that so many people seem to want.

But also, the time continuum is characterized by a concept called "places".

I think that would be the space continuum, not the time continuum.

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New Theories / Re: Dark Motion. Is it the answer to the Dark Matter and Dark energy problem

« on: 04/09/2023 22:42:21 »

Nasty remarks like that only serve to demean he who delivers them.

Momentus has earned a 10 day vacation for that remark, before which this topic will be closed, so no more posts here from him.
There will be a more careful watch on posts in other topics.

He is not open to anything that challenges his great discovery, as he sees it.

Totally agree that logic, mathematics, and reason fall on deaf ears with this guy. He is here for the conflict, not to learn anything.
I suspect the ban will be permanent before too long.

Thanks to both of you for your efforts, which are noticed by the non-participating reader if not the OP.

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Just Chat! / Re: I'm due to be crowned!

« on: 04/09/2023 01:03:46 »

I'm due to be crowned!

Coming from my father, those words were a threat. "One of these days I'm going to crown you!".

Also, despite the coronation, you'll also always be a hero to me.  You have my thanks that you made the milestone the way one should, not spewing a thousand posts of crap, a feat far more easily achieved as evidenced by some that manage not to get banned on the way there.

You are all invited to the subsequent bash, as soon as the formalities are completed.

I might decline as my wife seems to disapprove of events involving overt debauchery.

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New Theories / Re: Dark Motion. Is it the answer to the Dark Matter and Dark energy problem

« on: 01/09/2023 16:36:38 »

That's quite a handgun!  I'd expect that speed only from a rifle.  Irrelevant. We'll work with those numbers.

The bullet in the breech is obviously travelling at 100km/h and I now pull the trigger and the bullet flies off at 700m/s. The bullet continues it's travel in the direction of the train at 100km/h but now has a speed of 2520km/h.

Exactly, so the force on the bullet cannot always have been perpendicular to its motion.

The force is applied over say 100 usec (a 10th of a msec) which would yield ~700 m/sec over the length of a handgun barrel. We'll assume for simplicity that the force is constant for those 100 usec and zero before and after.

At time 0 the force becomes nonzero, and applied perpendicular to the bullet's initial 28 m/sec motion. After 0.1 usec (a thousanth of the total acceleration time), the bullet has accelerated 0.7 m/sec to the side. Total speed is 28.009 m/sec, which is pretty much the same speed as before because the force is mostly being applied perpendicular to the motion.

But now the bullet is already moving at 0.7 m/sec to the side and any continued force in that direction is now partially behind it, not perpendicular. The speed relative to the tracks begins to climb significantly.

After 10 usec (10th of the time under acceleration, 1/100th of the distance down the barrel, the bullet is now moving at 70 m/sec left and 28 m/sec forward which is 75.4 m/sec total, and now the trajectory is already mostly to the side, so about 0.9 of the force (sin(70 deg))being applied to the bullet contributes to increasing its speed. So the vast majority of the acceleration is pretty much directly in line with the motion of the bullet, not perpendicular with it. Only at first (a nanosecond or so) is the force perpendicular.

Since the direction of the bullet motion changes and the force direction doesn't, the force does not remain perpendicular.
With orbits, as the trajectory changes direction, the force does in lockstep, so it is perpendicular at all times.

It's all the same with the balls, with about 100 usec of acceleration time, perpendicular only at first and not the rest of the time.

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New Theories / Re: If there was one Big Bang event, why not multiple big bangs?

« on: 31/08/2023 19:56:31 »

it is during entropy that everything happens

What does the phrase 'during entropy' even mean?
That's like saying 'during momentum', like they describe a period of time.

The entropy of Earth has more or less been constant over the last billion years, and an awful lot of interesting stuff has happened during that period, so I'm not so sure if the interesting stuff happens when entropy is changing, but you also didn't say 'when entropy was changing'.

1)  the entropy I am referring to is taking place in a finite space that is surrounded by the infinite greater universe

Earth say ...
Again, entropy isn't a process that takes place. It's a value that can be measured, that can change.
 

In line with a premise that all space has always existed, any space that happens to be associated with, i.e. within the vacinity of the aftermath of a big bang event, has a higher energy density than the average density of the greater universe

High enough localized mass density (very little mass is required) that the matter would all exist within its own Schwarzschild radius, meaning it is a big collapse with no outward 'explosion' so to speak. It would result in an instant black hole with a event horizon radius far greater than the radius of our observable universe.

Just saying. That's what necessarily happens if you bang new matter into a small region of existing space. One can be in denial of gravity of course, but then why does it hurt when I fall down?

18

Physics, Astronomy & Cosmology / Re: Quantum Entanglement and Interstellar Communication.

« on: 29/08/2023 16:01:26 »

Don't think so, Alan, but I am not good enough( not good at all!

No, you very much are good enough, and you are correct here.

Now force your particle into an up state:  you therefore know mine is down, and I can measure it.

This is very much wrong. Entanglement does not mean that 'what is done to one particle affects the other'. Yes, a message could be sent if that were true, but it isn't. Spooky action at a distance (as it is called) has never been demonstrated. If it was, all the local interpretations that forbid it would have been falsified.

Spin entanglement says (in short) that if you measure both things in the same way, the results will be correlated.  If you force one of the particle spins, that is the same as declining to take one of the two measurements, leaving nothing to compare.

19

New Theories / Re: If there was one Big Bang event, why not multiple big bangs?

« on: 21/08/2023 00:22:53 »

We know time passes, but the beginning of time is not easily established. Was there a beginning, or has time been passing eternally?

...
Obviously, All the above imagined images would have Different Time slots.
(egg-t1, crack-t2, served-t3)

Yes, true even if time isn't something that passes. Those three states still have different time slots.

If the Egg is a Fundamentally essential object, without which, no still images can be imagined.

Have no idea what you might be suggesting with this one. An egg hardly seems fundamental, and an image is not an egg, and we have plenty of images of things (unicorn is traditional) that seem not to exist.

Can We then conclude, Without the Egg, Time does not Exist.

That's like saying without the unicorn, time doesn't exist. Time can exist just fine without an egg.
Time can exist without motion, but it's harder. The paint fades over time. That's evidence of time without utilizing the motion of anything.

How do We really measure Time?

Typically by counting regular events. That works, flow or no flow. There is no way to detect flow, so one cannot measure time by any empirical detection of flow.

How do We measure Entropy without the Existence of molecules, atoms, electrons, protons, quarks etc etc?

There would be no 'we' to measure it without that stuff. Entropy isn't especially a particularly meaningful thing without matter or radiation to measure.

Hope some of this helps.

20

New Theories / Re: If there was one Big Bang event, why not multiple big bangs?

« on: 13/08/2023 01:14:08 »

From Zero's link: Alan Guth.

Just to clarify, the quote does not appear anywhere on the Negative energy wiki page liked by Zero, but it does appear on the blurb for Alan Guth's book, which is one of the references on that wiki page.

Theory of known American theoretical physicist Alan Harvey Guth of the inflationary universe modifies the scientific Big Bang theory, describing the origin of all space, time, matter, and energy, 13.7 billion years ago, from the violent expansion of a singular point of extremely high density and temperature.

Don't know who wrote this blurb, but it is wrong, and I don't think Guth would have worded it that way. The universe was never a singular point since you can linearly (older model) or exponentially (inflation theory) expand one all you want and it will remain a point.

Yes, Guth was one of the major contributors to inflation theory, a significant change and improvement to the big bang model.
This universe is not in conflict with say the Cyclic model of Penrose, which stacks one conformal universe atop the next in infinite series. So in that sense, it does not refer to any one 'the beginning' since there are always more before and after.

If I interpret this correctly, it means that this diagram

can be stacked one atop another, but I might be wrong about that.