The physical world is composed of energy, which began as an undifferentiated quantity of energy, but later varied to produce specific configurations. Along came the faculty of awareness, possessed of sensory organs to discriminate patterns in these configurations. We refer to them as color, brightness, sound, solidity… Enough to build a complete picture of the “world” we live in.
This picture rests on a foundation of space and time. Without space and time (spacetime), electrons could not whirl, producing the electromagnetic fields to keep atoms apart; nor would quarks combine to create nucleons, etc. Matter would not be. There would still be energy, but no configuration. Thus, configuration depends on spacetime, like the circle created while spinning a ball on a string. Spacetime makes the circle possible – which is as real to our senses as “real” can be.
But what is time? Does the whirling of electrons “happen” within a stable framework of space and time? To examine that question, let’s journey on a light beam.
As we move faster and faster, the value of spacetime changes: The nearer we get to the speed of light, the shorter and slower we appear to those who aren’t moving. If I started in a long spaceship, with a clock spinning on the wall, near lightspeed I would seem very flat, and my clock hardly to move. But from my point of view on the ship, it would be the universe that flattens, not me! The distance between myself and my goal would shorten, and the speed of clocks outside would slow.
As I approached lightspeed, my destination would appear closer and closer. It might be billions of miles away, but exactly at the speed of light, it would seem to occupy the same space as my ship; the beginning and end would become one. In fact, everything along my direction of travel would suddenly be the same place. The universe would look like a giant donut, with in its point-sized hole. There would be no “here” or “there” in the direction of travel. “Space” and “time” would cease to be. Physics says I cannot reach this speed, for it has no meaning for something to be of null length, or zero time.
I wonder about photons, though, which do travel at lightspeed. For them, there is no universe. When bits of light leave their parent star, there is no big world out there; there is no space between them and their end-point – which in a hyperspherical universe is the other side of the same star! They see all of this as null, a single point: all the energy of the universe compacted, without configuration, into a timeless, spaceless ball.
So time and space are most real if one is traveling slowly in relation to something else. As one’s velocity approaches the speed of light, the length of a meter and the duration of a second are seen to approach 0. The universe outside the traveler starts contracting and slowing, until it nears the impossible. If it did reach that speed, there would be no “distance” or “duration” anymore. But what about things already traveling at lightspeed? To us, they would have no space or time. There is no “length” to a photon. It’s a point energy, whose only measurement is the quantity of energy it contains. If the universe had no spacetime, that’s all we could say about it, too. Which is how we describe things before the Big Bang “occurred”.
It puzzles me that it requires spacetime to travel, yet travel nullifies spacetime. Because the reality of spacetime is directly linked to how slowly two things move in relation to each other. If two objects are said to be “separate”, we imply they exist in different frames of reference, where the variables of motion differ. It is not that spacetime has a certain value in either frame, but that they have offset values with respect to one another. If the speed between them differs greatly, the value of spacetime differs greatly; if it becomes a difference of lightspeed, spacetime is no longer perceived by one reference frame within the other. Conversely, as the two approach a relative rest velocity, the value of spacetime equalizes.
The greater the difference in velocity between two frames of reference, the less value spacetime has. A meter in one is perceived as less than a meter in the other; a second, less than a second. Near lightspeed, they become simply energy to each other. That is, if a ten square meter box starting moving at light speed from me, it would become a box with no length – or no a box at all. I could reckon it then only in terms of its energy.
So the perception of spacetime depends on a rest state between two frames of reference. Things nearby us are more real than what is far away, since distant objects move very quickly relative to us. The Andromeda galaxy, for example, moves at a relative speed of 300,000 miles per hour. A meter in that galaxy is slightly shorter to us than a meter in our own galaxy. If a galaxy is far, far away, the difference is much greater; until at a certain distance – in an expanding universe – things cease to have meaning at all in terms of spacetime.
We do not view our world as pure energy, however, since we perceive configurations within that energy, owing to spacetime. Perception depends on spacetime, which is real only insofar as we remain at rest relative to some object. Being truly at rest is impossible: there is no standard object to be “at rest” in relation to. There are simply faster and slower relative reference, some seeming to vanish toward null spacetime, and others that have a similar spacetime to ourselves.
However, motion requires spacetime in order to happen! Without spacetime, there would be no concept of “rest”, and no resting reference frames to give rise to spacetime. How does spacetime create the possibility of spacetime? If relative rest is necessary for the perception of relative rest, how does it begin? From the point energy that begin our universe, a huge number of reference frames seem to have appeared, giving rise to the very spacetime which made possible those separate reference frames. Somewhere, out of nowhere, a chicken laid an egg.
Now, it is possible for energy to appear at rest relative to multiple frames of reference, while continuing to move at lightspeed: when it moves in a circle. This circle would not appear as a circle to the point energy itself; rather, to external frames of references it would seem to convert some of its energy into angular momentum, causing it to appear as a stable “bit” of energy to other stable bits. But even this “spinning” would require an initial spacetime matrix.
How did relative rest first appear, without a framework of spacetime to describe “rest”?
It has been a while since I studied physics, so if anyone can direct me toward better lines of thought, please e-mail me.