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Does the Special Theory of Relativity "form" the foundation of Modern Physics?

My question is in reference to Geoff Brumfiel's Scientific American article "Particles Found to Travel Faster than Speed of Light", about which I have two questions.

I have become engaged in discussions about this news that include some confusion about Mr. Brumfiel's wording. Mr. Brumfiel's sub-heading & a portion of the article state:

  • "Neutrino results challenge a cornerstone of Albert Einstein's special theory of relativity, which itself forms the foundation of modern physics."
  • "The idea that nothing can travel faster than light in a vacuum is the cornerstone of Albert Einstein's special theory of relativity, which itself forms the foundation of modern physics."

Please help me with answers to the following:

  1. Is it appropriate to say that Special Theory of Relativity "forms" [serves as the framework to] the foundation of Modern Physics?
  2. Is it appropriate to say the idea that "nothing can travel faster than light in a vacuum" is the cornerstone of the Special Theory of Relativity?

I have added highlights to my question help specify where in Mr. Brumfiel's wording the confusion rests.

(the confusion question 1 asks about is the phrase "[Special Theory of Relativity] forms the foundation", not is the foundation... If I reword the question, I may ask, "Is it appropriate to say Special Theory of Relativity serves as the framework to the foundation of Modern Physics?")

DanielSank
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AaronB11
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4 Answers4

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  1. Special relativity (SR) is only one of the foundations of the modern physics. Other foundations are general relativity (GR) and quantum field theory (QFT), but those two are currently incompatible because we still lack consistent theory of quantum gravity (QG). SR lies at the intersection of GR and QFT, i.e. it is what you get when you remove the minimal amount of features from both so they become the same.

  2. Perhaps it would be better to formulate it as "there is a finite invariant velocity". This is because tachyons are consistent with SR, in fact they are only defined in the context of SR and they are only able to travel faster than light. They are hypothetical, but that's beside the point.

    However, if one would like to keep the message that "nothing can travel faster than light" (FTL), one should highlight that it follows from SR + causality, not SR alone.

Community
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Danijel
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Yes the limit of the velocity of light in vacuum can be described as the corner stone of special relativity. If it goes, special relativity goes, but it is important to keep in mind about context, and what "goes" means.

In general physics theories are able to absorb small corrections to up to then absolute norms, and also in general, any new theories which emerge will include the thousand of successes of describing data by the use of special relativity.( If this measurement is not due to a systematic error). After all special relativity is irrelevant to the physics of driving one's car. The mechanics within the accuracies of speeds attained are Newtonian and special relativity in the low speed limits becomes Newtonian smoothly. This new measurement has a special context ( neutrino behaviour) and a very small effect, so we wait for validation and see what theorists will devise to describe the situation.

As for 1). Special relativity is one of the foundation stones of modern physics, not the only. Another is quantum mechanics, then we go to field theories, general relativity, etc. 1) is not accurate.

Special relativity is a necessary but not sufficient condition for part of the modern theoretical framework. An equally important necessary condition for the physics theories we use to describe data is quantum mechanics.(not sufficient) Since it is only in this one subset of thousands of reactions that a possible break down of the speed of light limit might be seen to be broken, certainly the damage is not as great as taking away a corner stone from a building.

anna v
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Another way of looking at this is looking at symmetries and invariances of nature. Lorentz invariance (the main result of special relativity) is a key property in all of modern physics. Quantum field theories are essentially applying Lorentz invariance/covariance to the basic quantum mechanical systems. Similarly, General Relativity apply's Lorentz invariance/covariance to the concept of curved space-time.

So to some extent these fields are still "there" without Lorentz invariance, but without that constraint things get very complicated and very confused, very quickly, or they just collapse down to a older pre-relativistic theory (e.i. qft mostly just becomes a form of qm without Lorentz invariance).

Benjamin Horowitz
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All theories are actually models we use trying to describe what we can see and measure. These models are not the Universe itself, we are just trying to find the model that fits best. As physics evolves, we create better models. These usually expand/modify the 'previous one'. In this meaning SR is the foundation of GR, but Newtonian physics is also foundation to both of them. To sum it up:

  • If you take this evolution and consider an earlier theory the foundation of the next one, then yes, SR is the foundation of GR.
  • If you mean that SR is a foundation in the meaning that you take SR and just build more things on it, then no, it is not the foundation of GR.
Bgs
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