“Reading a great book on the General Theory of Relativity. One of the most mind-bending concepts all is that everything is already moving through 4-dimensional timespace at the speed of light. Because our trajectory through 3-dimensional space is relatively small, most of our velocity is applied against our time vector – meaning, we are traveling through time very rapidly (as compared with something moving past us at high speed, for which time appears (to us) to move more slowly. ) Welcome to light speed, people.
The next mind-bending idea: its possible that all four dimensions (of timespace) are identical, however, based on our trajectory, the dimension we are moving most quickly through is foreshortened (a known relativistic effect) to the depth of a flat surface. Meaning, we can’t see the 4th dimension because we are moving through it at the speed of light.
The final piece I am struggling with: a photon coming to us from a distant star, say 3 billion light years away, appears to us to have taken 3 billion years to reach us because its time (from our reference point) has slowed to a near-stop. But from the reference point of the photon, its entire life journey is instantaneous. It dies as soon as it is born. Furthermore, an onboard camera on the said photon would only perceive a single point of light directly ahead of the direction of movement. There is no way for light to reach a photon laterally.
And lastly, when ships approach the speed of light in TV shows and see stars streaming by, this is an impossible occurrence. As you approach the speed of light, the apparent direction of all light moves to the front of your craft. A bundle of stars in front of your ship is all you would see at near-light speed.”
-My brother Jon
The book is: Relativity Visualized, by Lewis Carroll Epstein.