One of the various theories proposed to explain the negative result of the famous Michelson-Morley experiment with light waves (conceived to measure the absolute space), was based on the ballistic hypothesis, i.e. On postulating that the speed of light predicted by Maxwell's equations was not given as relative to the medium but as relative to the transmitter (firearm). Had that been the case, the experiment negative results would have not caused such perplexity and frustration (as we shall see in forthcoming sections).
It is worth noting that a wrong folkoric definition of an Inertial Frame in the Popular Science literature (even in text books) reads that 'it is a frame in uniform motion'. We know very well by now that the idea of motion requires a frame of reference, so that such a definition of an Inertial Frame has no meaning whatsoever, confusing the reader because it tacitly reaffirms the idea of absolute motion -- when the goal of every didactic exposition of Relativity Theory should be precisely the opposite.
The Heart of Gold fled on silently through the night of space, now on conventional photon drive. Its crew of four were ill as ease knowing that they had been brought together not of their own volition or by simple coincidence, but by some curious perversion of physics- as if relationships between people were susceptible to the same laws that governed the relationships between atoms and molecules
Relationships are physics. Time transforms things- it has to, because the change from me to we means clearing away the fortifications you'r put up around your old personality. Living with Susannah made me feel as if I started riding Einstein's famous theoretical bus. Here's my understanding of that difficult idea, nutshelled: if you're riding a magic Greyhound, equipped for light-speed travel, you'll actually live though less time than will any pedestrians whom the bus passes by. So, for a neighbor on the street with a stopwatch, the superfast bus will take two hours to travel from Point A to Point B. But where you're on that Greyhound, and looking at the wipe of the world out those rhomboidial coach windows, the same trip will take just under twenty-four minutes. Your neighbor, stopwatch under thumb, will have aged eighty-six percent more than you have. It's hard to fathom. But I think it's exactly what adult relationships do to us: on the outside, years pass, lives change. But inside, it's just a day that repeats. You and your partner age at the same clip; it seems not time has gone by. Only when you look up from your relationship- when you step off the bus, feel the ground under your shoes- do you sense the sly, soft absurdity of romance physics.
There is a philosophy that says that if something is unobservable -- unobservable in principle -- it is not part of science. If there is no way to falsify or confirm a hypothesis, it belongs to the realm of metaphysical speculation, together with astrology and spiritualism. By that standard, most of the universe has no scientific reality -- it's just a figment of our imaginations.