The Vanishing

Imagine an object speeding up, its speed repeatedly doubling, with each doubling of its speed taking half the time of the previous doubling. If this object does not collide with anything, it will quickly approach the speed of light. But what if there was no light speed limit, and no chance of collisions because there were no other objects?

We naturally think of space extending endlessly in all directions, so the simplest space for us to imagine is an infinite space (the word infinite comes from the ancient Greek for unending). For any finite distance (such as any counting number of miles), such a space contains places separated by that distance (that number of miles). But note that space being infinite in that sense does not mean that there are parts of it that are separated by infinite distances (distances greater than any finite distance). It does not mean that there are parts of it that are actually at spatial infinity.

Imagine an object—let us call it X—in an infinite space with no parts at spatial infinity, and suppose that X is subject to forces—let us call them F—that cause it to accelerate in a straight line by repeatedly doubling its speed, with each doubling taking half the time of the previous doubling. With only one object in the whole of space, motion relative to another object is impossible, so X just sits there, not moving at all. So, imagine another object, Y, sitting next to X.

X and Y start out together, and then X moves one mile from Y in one hour (at an average speed of one mile per hour), and then another mile in half an hour (at 2 mph), and then another in a quarter of an hour (at 4 mph), and another in an eighth of an hour (at 8 mph) and so on, until after one hour plus half an hour plus a quarter of an hour plus an eighth of an hour and so on—two hours in total—X will have travelled further from Y than any counting number number of miles. From the point of view of Y, X seems to be going to spatial infinity, and then vanishing at spatial infinity because there is nowhere it could be (without teleporting), there being no place at spatial infinity in this space.

It is easy to imagine that such endlessly increasing forces being applied to X might cause it to explode or disintegrate, at some point. So, it is conceivable that if X did survive each of those endlessly increasing forces, it would have to vanish (or teleport) at spatial infinity because of all of those forces. Of course, from the point of view of X, Y seems to be going to spatial infinity, and it is inconceivable that Y would vanish (or teleport) because of the forces applied to X at such increasingly huge distances from Y. But I don't suppose that Y would have to vanish (or teleport) if X vanished (or teleported). What if Y was also subject to forces F, though?

If X and Y were subject to exactly the same forces, then they would remain together, neither of them moving relative to the other. They would just sit there, not moving at all. Neither of them would seem to the other to be going to spatial infinity, so neither of them would have to vanish (or teleport) at spatial infinity for that reason.

Would they both vanish (or teleport) because they were both subject to such forces? Maybe. And maybe the single object in the otherwise empty space of the original scenario would similarly vanish (or teleport), even though it did seem like it would just sit there. But have we discovered that any possible object in such a simple space would, were such forces possible, have to be such that it would vanish (or teleport) if it was subject to such forces and was able to survive each of them individually? Or is it more plausible that for any such space with no parts at spatial infinity, there would be something like the light speed limit that actual space seems to have? Perhaps we have discovered the reason for there being a light speed limit.

Although there are other alternatives. Perhaps objects in simple infinite spaces do not vanish at spatial infinity because they get to spatial infinity. There would be parts of simple infinite spaces at spatial infinity if unit volumes of such spaces contained 1/0 points (as outlined in my 2005 paper) and the counting numbers were indefinitely extensible (see my 2010 post and my 2024 booklet).

In view of the light speed limit that actual space seems to have, it may well be more plausible that a speed limit is a metaphysical necessity, even for such simple spaces. If philosophers interested in physics knew more about the nature of that necessity, would that help them to understand the actual light speed limit? Maybe, but knowing more about such a necessity would presumably involve finding out more about the alternatives, such as the one described in my 2005, in which there has been little interest.