Does it make any sense that there is a speed limit in the universe?

Question

Is it a mathematical logical explanation why the speed limit in the universe is the speed of light or it could have been twice as fast and no one say it's wrong?

Answer 1

Absolutely.



The speed of light is the universe's physical analogue for infinite speed, since actual infinities do not exist in the real world.



The "reason" these physical analogues exist (think of them as an inevitable logical necessity deriving from the universe's natural geometry, rather than an intentional construction for the purpose of having the math come out right) is so the universe has a valid way to produce real and meaningful values when multiplying by zero. For example, matter, which possesses positive, finite mass, must travel at a positive, finite speed in order for it to possess a valid value for momentum. Energy, on the other hand, possesses zero mass, and so in order for particles of energy to possess a momentum that makes any mathematical sense in the real world, energy *must* travel at "infinite" speed, which, in reality, means the universe's physical analogue for infinite speed, the speed of light. The universe has an analogue for "infinite" temperature as well, called the Planck Temperature (about 10^32°F), and for essentially the same reason.





"Is it a mathematical logical explanation why the speed limit in the universe is the speed of light or it could have been twice as fast and no one say it's wrong?"



We can be sure there's a logical explanation for why the speed of light possesses the value it does, but the actual reason is as of yet unknown.



If I were a betting girl, and I am, I would wager that the constants we find in nature are all interdependent. For example, a universe where the speed of light were double what it is in our universe might require that universe to possess only half the total mass our universe contains. Or, if the speed of light were only half what it is, it might require the masses of the fundamental fermions to be twice as heavy.



I wouldn't be surprised if a change in *any* fundamental constant required a compensating difference in *every other* constant. They might all have interdependently self-necessitating values.



We don't know this to be the case, but that'd atleast be *my* guess. Indeed, all possible permutations might even physically manifest in essentially (if not identically) the same way, atleast to our external perspective. Whether or not reality forces the universe to behave in this fashion is still an unknown. I have little doubt that we will *eventually* discover if this happens to be true or not, but for now, it's just supposition.

Answer 2

The universe has no such speed limit. The idea that it does comes from the mistaken belief that mass is velocity-dependent. It isn't. It is only charged particles in a particle accelerator that become more difficult to accelerate with increasing velocity, i.e. as they approach the propagation speed of the accelerating field (c with respect to the static accelerator). Nothing to do with increasing mass. This page gives the common sense explanation:

http://www.alternativephysics.org/book/RelativisticMass.htm

(specifically the "Wind Tunnel" section)



It is the lorenz force on a charged particle that is dependent on velocity (with respect to the source of the accelerating electromagnetic field). Unfortunately mainstream science has got into the bad habit of using the gamma term in the wrong place and therefore jumps to completely the wrong conclusions. The deification of Einstein has got a lot to do with this.

Answer 3

What seems like a speed limit to us is actually a direction called time. If I point toward a distant peak, no one questions if it makes any sense that there is a direction limit on that peak from here. This only becomes apparent though when we start approaching the speed limit and realize that those directions start to become just as weird as time to comprehend.

Answer 4

Yes, it's that speed limit because that's the rate at which the time dimension slips past the space dimensions. Since everything we do is dependent on time moving, even if time were to travel at twice the speed or half the speed, we wouldn't notice because we would be moving faster or slower depending time's rate.

Answer 5

This is a really good question because no one knows the answer --- why is the speed of light the value that it is (yes, yes, it's the result of the permeability and permetivity of free space, but why are they what they are?). The speed of light is the relation between space and time and is fundamental to everything. It's on the first page of every text about field theory, with no explanation, just a brute fact.

Answer 6

Yes, it does actually.



"and no one say it's wrong?" Uh, this has been tested countless time for years and years and years and years. It's not just a mathematical guess dude. Even back at least as far as 1887 the speed of light was confirmed to be a constant in the famous Michelson-Morley experiment. Long before Einstein and his theories of Relativity came along.

Answer 7

It is not so much a "logical explanation" as it is a hypothesis.



It was already known (with experiments with radio signals which are themselves photons of longer wavelength than visible light) that photons appeared to always travel at the same speed, regardless of the motion of the transmitter and the motion of the receiver. And this apparent speed was the same for all wavelengths used in the experiments.

This speed was called "the speed of light" and calculations showed that this speed should also apply to visible light, since it was the same kind of electromagnetic radiation.



When Einstein wrote his Theory of Relativity, he asked himself:

--what if the speed of light really were a speed limit in our universe, and

--what if that speed looked the same to all observers, regardless of their relative motion?



He then used mathematics to answer his own questions of "what if".

So far, his theory only described "what kind of universe would we have if the hypotheses turned out to be true".



Since then, scientists have been comparing the theoretical description with how things behave in the real universe... and they match (at least, as precisely as we can measure, up to now).

Many scientists are still looking for any sign that the theory is wrong... and have not found any yet.



The "speed of light in a vacuum" is the speed limit. We call this speed "c"

Light itself sometimes goes slower (for example, in water, light travels only at 3/4 of c).



Some particles come out of radioactive material at 0.99 c (99% the speed of light). Because these particles have some mass, it takes them some time to slow down if they meet with resistance.



Radioactive material put underwater will emit particle which (for a brief fraction of a second) will travel faster than the speed of light

0.99 c is faster than 0.75 c



look at:

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



Light itself (in the form of radio waves) have been observed to travel faster than c (in old radar guide tubes, for example), but the information being carried does not travel faster than c. And that is OK under the theory. This was discovered during the Second World War. Einstein was still alive when the information was finally made public, and he had no problems with it. As long as the "information" carried by the photons did not go faster than c, the theory was OK.



In fact, the theory of Relativity does not specify "which way" the speed limit works. The theory does allow particles going faster than c (they would be called "tachyons"). The "speed limit" states that such particles could not slow down to below the speed of light. Therefore, the speed of light would remain a "speed limit" and tachyons would be unable to slow down past this limit.



But tachyons have never been observed.



So, the mathematics are not an explanation. There are only a way to apply the concept of a speed limit, to how things should behave if that speed limit really existed in our universe.



Because the universe seems to behave in the same way as described in the mathematics, we conclude that the idea of a speed limit could be true.

Answer 8

It is what it is. Nobody decided what it was going to be. The speed of light was a discovered thing, not a decreed thing.

Answer 9

The constant c is tied into lots of things. If it changed the Universe would change.

Answer 10

Yeppers.