The Red Shift without Expansion

@layman,

Layman wrote:

I don't understand special relativity, so it must be wrong. (paraphrased)

When a scientist comes across something that doesn't seem right, he or she checks the math, reads the papers and if no experiments have already been done sets up an experiement.

The principle Layman is complaining about is "Lorentz Contraction". It is basic physics, any second year student in a Physics program will understand it. It was actually understood before Einstein developed Special Relativity. And it has been confirmed with numerous experiments. If Layman would have the patience to take a couple Physics courses in a local college, he not only would understand what Special Relativity actual says... he would also know the experiments that confirm it.

This illustrates the difference between philosophy and science. In science, differing ideas are judged by experiment and observation. If there are competing theories, then you work out the math and then devise an experiment. The theory that matches the prediction based on the mathematical model is accepted.

The idea that you should reject any idea that doesn't make sense to you is not a way to advance knowledge. There are many places that Physics is counter-intuitive. This has been true since Galileo (or before)... and from the time of Galileo this has gotten Physicists into conflict with philosophers. However, without the counter-intuitive parts of physics airplanes, computers, radios... etc. etc. would not be possible.

In Philosophy you can reject ideas that don't make sense to you. In science, you can't do this. If the experiments confirm that the predictions made by a theory are correct, then you accept the theory whether or not it matches your philosophy or not.

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@layman,

georgeob1 wrote:

It is interesting to note that Hubble, the discoveror of the red shift, died believeing the universe was static and that his earlier deduction of an expansion was in error.

Actually, from what I'm reading it never was his deduction. He just happened to compile the data upon which the deduction was based:

Quote:

...he found a roughly linear relation between the distances of the galaxies and their redshifts, a discovery that later became known as Hubble's law.

Yet the reason for the redshift remained unclear. It was Georges Lemaître, a Belgian Catholic priest and physicist, who found that Hubble's observations supported the Friedmann model of an expanding universe....Hubble himself remained doubtful about Lemaître's interpretation.

https://en.wikipedia.org/wiki/Edwin_Hubble

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@maxdancona,

Heh, Max, you've given your soapbox sermon a million times now. It's presumptive and inaccurate, but the worst part is that it's just so damn boring and repetitive.

Just answer the damn question, eh?

1 Reply

@layman,

Sure, Layman. I will answer your question. Of course, this is a mathematical answer to a mathematical question.

http://hyperphysics.phy-astr.gsu.edu/hbase/Relativ/imgrel/lencon.gif

This is the math for length contraction. Since "c" is a constant, you will notice that the independent variable is "v" (which is the velocity between the football field and the observers frame of reference).

You will also not that if "v" is very low compared to the speed of light, that the difference between L0 and L will be immeasurably small.

Of course if the person with the yardstick is standing on the football field, than V will be 0, in which case your example has nothing to do with Lorentz contraction since L will be equal to L0.

1 Reply

@maxdancona,

maxdancona wrote:

Sure, Layman. I will answer your question. Of course, this is a mathematical answer to a mathematical question.

Wrong, on so many counts, but the main one is that you didn't even begin to understand, let alone answer, a very simple question.

You're right, my question doesn't have a damn thing to do with any lorentz transformation. The illustrative example I gave is all premised upon both A and B being in the same inertial frame of reference.

Just answer the damn question, eh?

It's actually a VERY simple question, which I think you can understand if you really try.

1 Reply

@layman,

The theory you are discounting (on account of the fact you don't understand it) is a mathematical theory that involves the equation I gave you based on the relative velocity of two frames of reference.

If your story has nothing to do with "Lorentz Contraction" than what is the point? A fictional story that has nothing to do with two frames of reference has nothing to do with the theory. By the way, Lorentz Contraction (as it is called) is a feature of both Special Relativity and what you are calling Lorentzian Relativity.

Your question makes no sense.

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@maxdancona,

maxdancona wrote:

Your question makes no sense.

Max, I think we could communicate better if you paid even the least bit of attention to what I actually say, and less attention to trying to tell everyone else what you (inaccurately) say I am saying.

Here's the simple question again:

Quote:

Tell me Max, is there, or can there be, any difference between what a quality is "measured to be" and what it actually is?

Perhaps you really ARE incapable of comprehending such a simple question and so say it "makes no sense."

But I think any normal person can make sense of it.

It's not complicated. Your answer can either be "yes," or "no."

1 Reply

@maxdancona,

I think the point that your story is trying to make is the philosophical idea of "truth".

Science isn't philsophy. In philosophy you can make musings about what feels like "truth to you". Things that you sense are "real" are considered truth. Then you work backwards and state that anything that contradicts your intuition as false. That is why your analogy about football fields makes sense to you.

Science doesn't work that way. In Science we build a mathematical model which we use to make predictions. We then confirm these predictions through observation or experiment. Intuition is important for think about new ideas to try, but in the end... what matters is the theories that can be confirmed by experiment.

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@layman,

You are asking a philosophical question, not a scientific one. That is your error.

Science is not philosophy.

There are many questions that can't be answered by science.

But science is the best way to answer scientific questions that are answerable by testable models.

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@maxdancona,

There was, later, a second follow-up question, but let's just take them one at a time. The follow up was this:

Quote:

LR would say that the goalposts never moved at all and that the distance between them remained constant.

What would you say, Max?

I would like to hear your answer to that too, but you can do that later.

1 Reply

@layman,

Relativity uses the mathematical equation that I already posted. That is the only answer that science can give you. But it is the "correct" answer in the sense that it is the equation that can predict the way that Nature actually works.

I leave philosophical questions to philosophers. These philosophical musings aren't that important to scientists in their advancement of human knowledge and discovery.

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@maxdancona,

OK, Max, once again you've proved that only a fool would undertake to engage you in any kind of rational discourse.

And once again, I've proved that I'm a damn fool.

My apologies.

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@maxdancona,

maxdancona wrote:

That is outside of the scope of my education Foofie (I did just google it).

I am also not sure if that is a scientific question. Science only deals in things that are testable... but it is likey that a more knowledgable physicist may have more to say on the subject.

It is just that time doesn't seem to matter in relativity equations, if I understood what I read. This Block Theory of time seems to claim that if one was outside the universe (a God?) there would be no time, since time is diffferent based on the gravity one is being effected by. The only thing I can be sure of is that the older I get, the less time I have, to plan anything in the future. Now that's a revolting devlopment.

1 Reply

@Foofie,

Quote:

It is just that time doesn't seem to matter in relativity equations, if I understood what I read.

I don't exactly know what you mean by "time doesn't matter". And I don't know which "relativity equations" you mean.

Physics is expressed in mathematics, and your question demonstrates why that is. English is a very inexact language, whereas mathematics is very specific and each term can be defined exactly.

So let's make this a little more of a mathematical question. I am interpreting the question "does time matter" as "does a change in the variable called 'time' significantly change the result of calculations we might do". The answer is clearly yes.

In many relativity equations you will find a variable called "t" which stands for "time"). There is also a variable "v" that means velocity which is a shorthand for "dP/dt" (where again the "t" stands for time). If you change the value of time in these equations, the result will change significantly.

In relativity, time is relative. And, usually the time we are interested in is elapsed time (in each frame of reference). But in almost any experiment that is done by Physicists, time is an important part of the calculation.

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@maxdancona,

maybe the guyw hung up on the concept of "apparent velocity"

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@maxdancona,

maybe your guy is hung up on the concept of "apparent velocity"

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@maxdancona,

maxdancona wrote:

Relativity uses the mathematical equation that I already posted. That is the only answer that science can give you. But it is the "correct" answer in the sense that it is the equation that can predict the way that Nature actually works.

This post isn't really directed to you Max, even though I am citing your claim.

Let's look at that transform equation, which you say gives "correct answers," for a minute, eh? In effect that equation says that, relative to a "stationary" one, a moving clock will slow down (and its length will contract). But does it tell you how it should be applied? Does it tell you who is "moving?"

Take two guys, one sitting next to a railroad track, drinking some wine, and one sitting in a passenger seat on a then-passing train.

Which one's watch slows down?

1. What does the "equation" tell you about that? Exactly nothing, right? It doesn't give you ANY answer whatsoever, let alone a "correct" one.
2. What does SR tell you about that?
3. What does LR tell you about that?

Anyone?

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@layman,

It's relative to who the observer is.

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@McGentrix,

McGentrix wrote:

It's relative to who the observer is.

How do you mean, Gent?

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@McGentrix,

I should have asked this first: Do you agree that "the equation" doesn't, and can't, answer that question, Gent?

1 Reply

The Red Shift without Expansion

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