That blew my mind! So now it turns out Einstein was wrong??
We can't get particle to seriously travel faster than light and there is entire galaxy going faster??
We can't get particle to seriously travel faster than light and there is entire galaxy going faster??
In fact, space is being created everywhere, including yourself and the computer screen. However the amount is so small that you don't notice and local forces nullify the change anyway. With large distances, this amount accumulates, and overwhelms the force of gravity and starts to create the apparent acceleration of distant galaxies away from us. Further explanation from paulddraper: https://news.ycombinator.com/item?id=11068125
It seems like creating space to fill the "voids" between particles moving at-what-would-be-faster than the speed of light is like a tesseract for whatever matter is in that rapidly created/expanding space. Unless that space is only accessible to the particles creating it by their relative motion (which still gives us problems with our ideas of dimensions)?
What you said isn't even pop science, it is blatantly wrong.
https://en.wikipedia.org/wiki/Metric_expansion_of_space
https://en.wikipedia.org/wiki/Dark_energy
And the money quote:
It is called "dark" because it is not interacting with normal matter, but only with the space time structure.
What I said was an attempt to explain how the basic model cosmologists use works in layman's terms. It wasn't intended to be "pop science" or even "real science"; that would be building the model, not trying to explain how it works.
The references you give are not "real science" either. Try looking in a cosmology textbook or a peer-reviewed paper. Or, even better, work out the science for yourself instead of arguing from authority.
That's an intriguing way of phrasing, never thought of it this way. I'm aware that space is expanding, so space must indeed being created in-between.
I'm guessing this space has to contain no energy at all, so it must be made of absolutely nothing, right?
No, because the light speed limit only applies to things moving through space, not to space itself, which can and does expand faster than light speed.
> We can't get particle to seriously travel faster than light and there is entire galaxy going faster??
The galaxy isn't traveling through space at faster than light speed, it's being conveyed along with the space that surrounds it at a speed that exceeds light-speed from the perspective of some distant location in space.
If it's photons emitting from flashlights pointed in opposite directions relative to each other, then are they compressing space as they travel so as not to exceed the speed of light? Or even massive particles accelerated to over half the speed of light at different times around an ellipse so there is a moment when their opposite directions make one traveling at greater than the speed of light relative to the other? (Or even particle accelerators on two different planets already expanding away from each other - does this just mean that space is really twisting and turning all the time to make sure no particle ever exceeds the speed of light relative to any other particle?)
It has been my understanding - and appreciation at Einstein's unbelievable insight and brilliance - that relativity is truly relative because there really isn't any such thing as an arbitrary particle or space that all other motions are measured from. But if this is true, does that really mean that space is really so constantly twisting and turning that SOL can't be exceeded?
I'm sure there are great answers to this, but I've always wanted a definitive one. Anyone have any comments on this?
It's a theory postulating that a particle can't travel faster than the speed of light in relationship to a particle that isn't moving. In practice all particles are moving in relation to some other particle thus it's not something you can visibly measure or see. At least that is the way I always viewed it.
IANAP, but I've never read that space twists to prevent the SOL from being exceeded. I think you're thinking of time and mass. It would require an infinite amount of time or infinite acceleration to for something to accelerate to the speed of light relative to something else.
Space is twisted by the presence of matter, and we call that gravity.
If it's photons emitting from flashlights pointed in opposite directions relative to each other, then are they compressing space as they travel so as not to exceed the speed of light
No. My understanding is that from the point of view of a photon time is completely stopped. Nothing moves relative to it because of this. Since nothing moves relative to it, nothing is exceeding the speed of light relative to it.
It's based on the observation of two points of references moving a different speeds shining light and the light from each traveling at the same speed. So the speed of light is measured relative to other light. The speed of light is constant, and it is so regardless of point of reference. Flashlights pointed in opposite directions has nothing to do with the speed of light. The light is traveling at the same speed in opposite directions.
Relative to a local inertial frame, i.e., relative to an inertial observer (i.e., an observer in free fall, feeling no force) who is at the same spatial location as the particle whose speed is being measured. That is the only context in which the concept of "relative velocity", as it appears in the "can't travel faster than light" condition, has any physical meaning.
All of your suggested examples attempt to compare "relative velocity" between objects that are not at the same spatial location. That has no physical meaning in GR.
> does that really mean that space is really so constantly twisting and turning that SOL can't be exceeded?
The speed of light stays the same and both time and space twist and turn around it. It's weird, but having a preferred reference frame would be just as weird. c is a dimensionless constant, and light happens to travel at that speed because it has no rest mass.
So it's not that you can't travel at c meters per second; it's that if you do, you'll zero out your velocity in the "seconds" component.
To cite an example from one of Neal DeGrasse Tyson's lectures, that's one of the funky things about photons from the most distant stars: they don't experience the passage of time at all from their own point of view. They arrive at our eyes/telescopes/radios as soon as they're emitted. Meanwhile, their velocity is limited to c from our point of view. The same thing would presumably happen to you if you could travel at c... but there would be other inconvenient effects in that case, such as an infinite increase in mass.