I’m sure that this has been asked before. Maybe I’ve even asked it before, and the answer simply hasn’t stuck. But…
So let’s say that we could view me as standing still, or as moving very quickly in a cosmic corkscrew as the Solar System hurtles through space. It’s all relative. If I’m launched very quickly away from Earth, we could still say that I’m sitting still and Earth is being launched away from me.
Effectively, we can never say that I’m going “fast” nor “slow”, we can only say that I’m going “fast” compared to, for example, the average motion of the various space bodies in existence. And I could see how this relation could cause pancaking and so on, since it’s my observation of that relative difference which is being affected.
But how do I hit C? I have heard of things (very small things) being sped up to C (I believe), which would imply that there is some universal concept of an actual, as opposed to relative, speed. But if I’m always staying still, from my own perspective, how do I actually hit that point?
I have a question that might reflect my lack of background in physics. Can the components of mass be sped up to C independently? There might not be any such ting as components of mass, if not ignore my question.
Nothing gets accelerated to c. They get asymptotically close to c with more and more energy, but they never reach c. Not unless they are massless, in which case they are already travelling at exactly c, and don’t travel at any other speed.
If you are being launched away from the Earth you will feel an acceleration, which the Earth does not. This is the key point in a lot of questions - if you are changing speed you are, by definition, being accelerated, and your frame of reference is not of the same ilk as objects that are not. You could, in principle, measure your acceleration, and over time integrate it to workout your change in speed since you started out. That will give you a measure of your velocity relative to the Earth.
Where things get odd, is that even if you were to accelerate to a large fraction (say 0.75) of c relative to your starting location, if you encountered an object coming in the opposite direction, one that had started out from a location that was moving at the same velocity as the Earth, and also perceived its own speed as 0.75 c, neither of you would see the other as travelling toward you at a speed greater than c. Both of you think you have accelerated to 0.75 c. And in opposite directions. Your closing speed is however not 1.5 c but 0.96 c.
Albert Einstein actually disliked the name “Relativity” for his theory, because it leads to the confusion as expressed in the OP. He would have preferred it were called “The Theory of Absolutes” or something like that, because in his theory, c is an absolute speed. Everyone, no matter how they’re moving, sees a particle traveling at c as traveling at c relative to them.
The idea that speeds are relative is an old one, dating back to Galileo. Einstein’s innovation was to show that it’s incorrect. Speeds do not just add linearly as in Galilean relativity. If I’m moving at a speed x relative to you, and an object is moving at speed y relative to me, the object does NOT move at speed s = x+y relative to you, as Galilean relativity predicts. Instead it moves at s = (x+y)/(1+xy/c[sup]2[/sup]). If you work out the math, you’ll see that when y = c, s is also c, regardless of what x is. In other words, everyone measures c as the same speed. You’ll also see that when x and y are small compared to c, the denominator is very close to 1, which explains why Galilean relativity seems reasonably accurate in everyday life.
Regarding a slightly different aspect of this: relativity says that physics works the same in all inertial reference frames, but it does not exclude the possibility of inertial reference frames that are “special” for other reasons - and the universe seems to have one, specified by the CMBR.
Also, rotation involves acceleration, so the idea that all reference frames are equivalent does not apply in the same way.
I seem to recall some deal about “relative to the ‘fixed stars’”, which I guess is an average of things very far away; nowadays that would be the sum total of distant galaxies.
How about the Cosmic Microwave Background? Does that give a preferred frame? When I looked this up in the past, I found the answer confusing, kinda like “yes and no”.
Alas, no. At present, physicists hold that there are only two kinds of things: those that have mass, and those that (kinda) don’t. Those that don’t can go the speed of light (they might not even have a choice.) Those that do can be pushed remarkably fast, as in particle accelerators, but their mass is part of their nature.
(Now, a Star Trek style transporter… Never mind, I’ll shut up now.)
Special relativity says that says that light (or more generally massless energetic particles) travel at c in all inertial frames of reference. As light must travel at c in all inertial reference frames it cannot have an inertial rest frame, which is not a problem as there’s no need to consider the frame of reference of light.
Special relativity also states that the laws of physics are not altered at all when transferring between inertial reference frames. This means that if you perform identical experiments in different inertial frames you will get identical results there is no way to determine an absolute speed, so speeds (except for objects travelling at c) can only be defined relative to some frame or object.
From these two principles you can derive time dilation, Lorentz-Fitzgerald contraction, etc, etc.
General relativity is a much more complex theory and special relativity can be seen as the special case of general relativity in flat pseudo-Euclidean spacetime. Locally general relativity always reduces to special relativity, which means hand-wavingly means that for every event in spacetime there will be a neighbourhood (a surrounding region) for which special relativity approximately applies.
Big bang cosmology comes from the general relativity and a key principle in big bang theory is that there exists a global reference frame in which the Universe appears (on a large scale) to be the same everywhere and have no directional dependences. There can only be one reference frame where this is true as moving relative to this frame will automatically introduce directional dependences and the frame which it is true often called the CMB frame as the easiest way to find it is to check the directional dependences in the CMB.
So in special relativity there is no preferred frame of reference, but in big bang cosmology there is a frame that it would not be entirely inaccurate to describe as preferred. However though the idea of an inertial frame in special relativity and the CMB frame in big bang theory are not completely unrelated they are also quite distinct ideas occurring in distinct contexts.
I recommend going through the whole channel (not at once of course…just as you can). It is quite enlightening (such as what E=MC[sup]2[/sup] really means, the true nature of mass and a bunch of other things…for instance did you know atoms weigh less than the sum of their parts?..was new to me till they explained why). When done you will not be an expert but you’ll have about as good a grasp of the nature of the universe as one can without getting deep into the math of it all.
That question is as meaningful as asking how many kilograms tall you are. Voltage and speed are two different things. What you might be asking is how quickly changes in EMF can propagate, and the answer to that is in fact c, because the relevant particles there are not electrons, but photons.
And the OP’s misunderstanding might be due to some very bad public outreach produced by CERN a few years ago, which said that particles were accelerated up to the speed of light, and then, because they couldn’t get any faster, they started gaining mass instead. Which is just plain all kinds of wrong, and I don’t know how it ever got past anyone working at CERN, all of whom should have been able to recognize how wrong it was.
In an electrical current, the propagation of electrons through the wire is on the order if less than a millimeter per second. Yet “electricity” moves at speeds on the order of speed of light.
Imagine a tube full of balls of a little smaller diameter than the tube. You push on the ball at one end, and eventually the ball at the other end is pushed out a bit. The balls themselves moved very little, but the effect moved much faster.