Can we travel faster than the speed of light?

[Holocene]

Why is the speed of light the speed that it is?

What laws of physics govern its speed?

 

[rbj]

Why is the speed of light the speed that it is?

What laws of physics govern its speed?

i am presuming that you mean the speed of light in vacuo, not the ostensible speed of light in some transparent material, no? we've been to this question before ("why is c?") and the best answer i can give you is that it is not the salient meaningful question. similar questions can be asked about other dimensionful physical contants and those question are likewise not the salient meaningful questions.

the gravitational constant, G; the speed of propagation (EM, gravitation, information, whatever is your "instantaneous" action), c; Planck's constant, \hbar; permittivity of free space, \epsilon_0; these are all numbers that are purely human constructs resulting on how humans chose to define units of time, length, mass, and charge. note the 4 constraints and the 4 unknowns (that are eventually measured in terms of these anthropometric units). i know that the meter is now defined to be the distance traversed by light in 1/299792458 second, but that wasn't the original definition, for the sake of illustration, let's revert the definition of the meter back before 1960.

now, if instead, you measure everything in terms of Planck units, the values for all these constants become 1, 1, 1, and 1/(4 \pi). the only numbers given to us by Nature are dimensionless numbers. so, to ask "why is the speed of light equal to 299792458 meters per second?" causes us to ask the more basic questions that are "why are there about 6.1821 x 10³⁴ Planck lengths in a meter?" and "why are there about 1.8549 x 10⁴³ Planck times in a second?" those are the meaningful questions.

you see, if we measure and describe everything in Planck units, there simply is no c, or G, or \hbar, or 4 \pi \epsilon_0. those numbers just go away from all of our algebraic equations of physical law.

we know that the meter and second are determined to be related to our experience of reality. a meter is approximately how big we are. and a second is, well, not the absolute shortest period of time in our bioological perception, but close to it. somewhere i read that, at our prime, we can do about 20 basic logical operations or computations (crude compare operations) per second in our conscious mind, don't know if that is true or not. when we get older, our CPU slows down but we got a better database.

so then we might start asking, why are there about 10²⁵ Planck lengths in the Bohr radius (about the size of atoms)? and why are there about 10⁵ atoms in the length of a biological cell? and why are there about the same number of cells in the length of a sentient organism like us?

you could construct similar questions about physiological processes regarding why it takes about 10⁴⁰ Planck times for us to do anything with our bodies (without tools). there is a relationship of the speed of our consciousness and the time around a second. if we were tiny insects, a second might seem like a long period of time. but then we wouldn't be thinking about why the speed of light is what it is. suppose we lived for 1000 years and it took us what we now consider a minute to think every new thought. we wouldn't be manuvering cars at 100 km/hr and i don't think a second would be our unit time and the speed of light would seem even faster to us.

you answer those questions, then you'll get close to why the meter and the second are as big as they are (relative to some Natural units), and, from that, you'll have an idea why the speed of light (which as far as Planck units are concerned is just 1, not some dumb and arbitrary number like 299793458) is what it is, from our perspective.

the speed of light (and of all things instantaneous) is just the natural speed of things in the universe of which to reference all other speeds against.

now the Elementary Charge, that's something else, since the natural unit of charge is already defined. it's interesting (to me at least) that the electron charge, relative to the Planck charge, is just \sqrt{\alpha}. one can say that e is what it is because of the value of the fine-structure constant (this important dimensionless number that the universe does give us), or (what i prefer) the fine-structure constant is what it is because of the amount of charge that Nature has bestowed upon electrons and other charged particles. because i think that they should have normalized \epsilon_0 and 4 \pi G instead of 4 \pi \epsilon_0 and G, i think the most natural units would come out slightly different than the Planck units (but be the same order of magnitude) and then, measured in these natural units, the electron charge would be \sqrt{4 \pi \alpha} which is about 0.30282212 . VERY close (as far as orders of magnitude go) to unity. i think 0.30282212 is the number theoretical physicists should put on their walls instead of 137.035999679 . i think the latter flows from the former.

those are the sort of numerical "why?" questions i might be wondering about.

 

[Krelian]

Well there is a theorem that was proofed somehow, but not generally accepted. Bell's theorem, where it implies that any entangled particle can transfer information instantly. Well the idea is that this is a "non local" effect, while general relativity is "local".

The problem here is that you can verify the Bell's inequity experimentally, but the interpretation it was given, to think that the reality is non-local, and everything is entangled, could give you into some problems and ideas that will tell you that you could travel faster than light, or quantum transportation (you could "think" you are instantly transporting information).

The actual idea came from Einstein, Polanski, and Rosenberg, 1934 paper, the possible ways to solve this paradox included "hidden variables", "many worlds", "non locality" and others.

The "non local" idea came also from the regularization in quantum field theory to deal with infinite would eventually give you a "non local" action.