Are the transformations just observed ones or real ones?

In summary, the transformations of time dilation, length contraction, and relativistic mass have all been observed and measured, making them considered as real by most physicists. However, the effect of length contraction has not been directly observed, and is instead a fundamental result of the theory of relativity. Additionally, the concept of relativity of simultaneity suggests that these transformations are not absolute, but rather dependent on the observer's frame of reference.
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DrGreg said:
This is, of course, an argument over words and not an argument over physics. The argument can be avoided by just doing the maths and not attempting to describe it with words.

I would say that the primary meaning of length-contraction is the between-frames version. I would say that the over-time version is a consequence of, or corollary to, length-contraction, as it applies only in special cases where objects behave as if they are "rigid", whereas the between-frames version always applies.

I think this matters because people learning the subject can get confused. They think that "acceleration causes contraction", and then get confused in cases such as Bell's spaceship paradox, or electrons moving in an uncharged wire, where things accelerate but don't move closer together.
I don't think this is only an argument over words, precisely being intent on addressing the physics of it instead of just the abstract mathematical aspect is what makes both length contractions the same physically and have them separated only in a very abstract sense where even the concept "length contraction" which is a very physical one loses its content.
I mean that if we are talking about a change in length we either implicitly assume there is an "equilibrium length", or rigidity consistent enough to measure a length at all or there is no sense at all physically in talking about "length contraction" consistently. Yes we always have the mathematical definition of the lorentz transformation but that is just an abstract operation wrt to lenghts if we don't give it some physical meaning to the concept length or to its putative contraction as something empirical.

DaleSpam said:
What I am getting at is that (a) and (b) are additional assumptions which are not always valid. What is known as length contraction in modern terms does not include those additional assumptions and is therefore more general.
See above. But in this case I'd say you are more interested in the semantic aspect so it is alright to make the distinction.
stevendaryl said:
I agree that equilibrium length is not always an appropriate concept, but then, neither is the concept of the "rest frame of an object". If the object is not rigid, then the pieces can have nonzero velocity relative to each other, and it doesn't make sense to talk about a single rest frame for the object.

That's it, and as I wrote above it doesn't make sense to talk about "length contraction" either in any physical way. Only in an abstract mathematical sense that will not have a physical consequence unless we add the corresponding obvious assumption about ideal rods and consistent lengths in equilibrium (body rigidity at low speeds wrt c).
DaleSpam said:
Yes, in the case where you additionally assume a constant equilibrium length then the between-frames length contraction together with those additional assumptions imply the over-time length contraction. While that is the normal case when talking about rockets etc. it is not the case when talking about currents...
I would say then that if we agree (wich is maybe debatable) that in the case when talking about currents we cannot make that assumption, one should abstain from using physical length contraction as an explanation for magnetic fields as they do in the video, it causes more confusion than understanding and ultimately it is not physically correct, don't you think?
 
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<h2>1. What is the difference between observed transformations and real transformations?</h2><p>Observed transformations refer to changes that are visually perceived or measured, while real transformations involve actual physical changes in an object or system.</p><h2>2. Can observed transformations be considered as real transformations?</h2><p>No, observed transformations are not always equivalent to real transformations. Sometimes, what is observed may not accurately reflect what is actually happening.</p><h2>3. How do scientists determine if a transformation is real or just observed?</h2><p>Scientists use various methods such as experiments, mathematical models, and data analysis to determine if a transformation is real or just observed. These methods help to validate and confirm the existence of a transformation.</p><h2>4. Why is it important to differentiate between observed and real transformations?</h2><p>It is important to differentiate between observed and real transformations to ensure the accuracy and validity of scientific findings. Understanding the difference helps to avoid making incorrect conclusions and allows for a better understanding of the natural world.</p><h2>5. Can a transformation be both observed and real?</h2><p>Yes, a transformation can be both observed and real. In some cases, what is observed may accurately reflect the real changes happening in an object or system. However, it is important to verify and confirm the existence of a transformation through scientific methods.</p>

1. What is the difference between observed transformations and real transformations?

Observed transformations refer to changes that are visually perceived or measured, while real transformations involve actual physical changes in an object or system.

2. Can observed transformations be considered as real transformations?

No, observed transformations are not always equivalent to real transformations. Sometimes, what is observed may not accurately reflect what is actually happening.

3. How do scientists determine if a transformation is real or just observed?

Scientists use various methods such as experiments, mathematical models, and data analysis to determine if a transformation is real or just observed. These methods help to validate and confirm the existence of a transformation.

4. Why is it important to differentiate between observed and real transformations?

It is important to differentiate between observed and real transformations to ensure the accuracy and validity of scientific findings. Understanding the difference helps to avoid making incorrect conclusions and allows for a better understanding of the natural world.

5. Can a transformation be both observed and real?

Yes, a transformation can be both observed and real. In some cases, what is observed may accurately reflect the real changes happening in an object or system. However, it is important to verify and confirm the existence of a transformation through scientific methods.

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