I read that Albert came up with the Theory of Special Relativity, at least partially, by using a thought experiment. At the age of 16 he imagined chasing a beam of light:
His space travel was all in his head but it served him to come up with one of the, if not the most important discovery in the history of mankind. Years later he would come up with his greatest second when he incorporated gravity in a second theory of relativity. I find them both equally interesting. But I'll focus on the second one: General Relativity.
One aspect of this theory is that gravity warps space. If you were to travel on a photon of light, you would actually divert from what would appear as a straight line as you approached a large object like earth. The often used example is it is like placing a large bowling ball on a trampoline. The trampoline is space and the bowling ball earth. It warps the trampoline by depressing it. If you then rolled a marble on it, it would follow the depressed area of the trampoline (space).
I was thinking of this after DS, a brighter engineer than I, commented on last week's post. He got me thinking about light traveling through space with his comment about the dual nature of light (wave and particle), and what exactly is a photon (what exactly is a package of energy?).
Light is an electromagnetic wave, one of several electromagnetic waves that permeate space. The other wave being gravitational waves that influence and shape space as I just discussed. But, are these waves space (and time) itself? Some suggest that these gravitational waves are waves of the fabric of space-time itself:
But, something occurred to me after contemplating the comments of DS regarding light traveling in vacuum. I'm sure its occurred to many others, but I don't recall ever reading about it.
I was thinking about new space-time as I discussed here;
Since the distance between distant galaxies is expanding faster than the speed of light, that means new space (and time) must be created to cause this. That's because nothing can travel faster than light through space. So, if the distance (or space) between galaxies is increasing faster than the speed of light, new space must be formed (from dark matter/ energy as reader NJM suggests?),
Well, if new space is causing this distance to increase faster than light, then light, electromagnetic waves, and gravitational waves cannot possibly travel through this new space-time being created. Since it is being created faster than the speed of light, and, assuming the new space-time is absent of mass and energy (perhaps a wrong assumption), then these waves can't keep up with this newly created space-time. It would then be absent of gravitational waves (and light).
It also appears the rate of this increase in new space-time is accelerating. Then, unless this begins to decelerate, parts of this new space-time will always be void of gravity and light (and possibly entropy as R3 suggests).
So, what does that mean? Well, the theory that gravity are waves of space-time cannot be true as some physicists propose. Unless, as I mentioned, this newly created space-time is created with mass already present (if that's true then new galaxies are forming all the time). But, if so, doesn't that violate the law that mass can't be created or destroyed? Unless it comes from this nebulous dark crap that's thrown out there without definition, then some means must be found to account for gravity in new space-time. Or, maybe it just doesn't exist.
Joining Einstein on his thought experiment and riding a beam of light through the outer galaxies, what would new space look like? If I'm riding a photon (impossible, I know, as a photon is massless and I am not), and new space is being created in front of me without gravity, what would I see? Well, I suppose I wouldn't notice a thing since the existing gravitational waves would be traveling with me. I would still follow the contours of warped space-time from existing gravity, since I can't "outrun it".
Additionally, we can never know what's really in new space-time (assuming it is without gravity or electromagnetic waves), because it would be impossible for information to travel fast enough to escape new space-time. We can only "see" new space-time after it is permeated and therefore "contaminated" with waves! So we can never know the mystery of newly created space-time. Only the old stuff waves have passed through.
That's my thinking right now. But, I'm 95% sure I'm wrong on this. With so many variables, so many unknowns, and with my own ignorance on the matter, I'm probably quite generous giving myself a 5% probability of being right!