This is another question I have pondered. If the universe is indeed infinite, then it's infinite in every direction. Wouldn't there be as much infinite space within my body as the rest of the universe?
As we are part of the Universe or at least our component parts are, what ever the Universe does we will be going along for the ride, if the universe is infinite then we are part of something that is infinite and could be recycled an infinite number of times. Even if it is finite your component parts will be recycled for a very long time as they have already been. Perhaps there is a fundamental law that prevents the Universe becoming infinite as there is for the speed of light and for absolute zero temperature. Maybe thinking about infinities is simply infinitely futile. This road not only leads to insanity but also an infinite number of gods and religions.
right now i am traveling 1.34 million miles an hour with our local cluster and I can't feel it. That drives me more insane than thinking about infinities. There are many things that we can ponder that should just give us pleasure and not fear of insanity and surely not the fear of infinite gods and religions. The more we understand about ultimate reality the more god is pushed out and and infinity could be just one part.
Of course you can't feel it. That's a STEADY-STATE condition, for all intents and purposes, a constant. If it alters, it does so slowly that you would never be able to sense it, and indeed, it would take the most sensitive accelerometers in the world to do so.
It used to be that the geocentrists of 500 years ago argued against the earth rotating, saying that at the speed it rotated at, the atmosphere would be whipping about everyone at hundreds of miles an hour. The fact that friction causes the atmosphere to (mostly) move with us never occurred to them.
Thinking about infinities is as pointless as thinking about gods, infinities are to maths as gods are to science. If the universe goes on for what might be called forever it will reach a state where there is only a quantum vacuum and some time long after that time and size may well be meaningless but you are still no closer to infinity than when you started. For want of a better expression you might as well say I don't know! Infinities are good for one thing and that is that your sums are infinitely wrong.