Eventual disappearance of rest mass

[lark]

If the universe were expanding very, very rapidly, would rest mass disappear?
I've been reading "Cycles of Time" by Roger Penrose, which is about his "conformal cyclic cosmology" theory. The gist of it is that in the VERY VERY distant future, like a googol of years from now, when all the black holes have decayed by Hawking radiation, the universe will have only massless particles like photons, it will lose any sense of scale, since particle masses are what provides a scale. So it collapses to a new Big Bang! Neatly connecting the new observation that the universe is open and has a nonzero cosmological constant, with a cyclic universe! A universe that was closed wouldn't work for conformal cyclic cosmology.
A hitch in this idea is that not all of the mass would be in black holes. So he needs to have rest mass decay somehow, for this to work.
The universe is open, it seems, and it's going to look more and more like de Sitter spacetime. De Sitter spacetime expands at an (exponentially I think) increasing rate. After a googol of years - or enough time, anyway, any kind of particle interaction is going to be impossible. Even something a Planck distance away would be as hard to interact with as a galaxy that's not in the observable universe is now. A signal from a Planck distance away would never get there.
So couldn't this rapid expansion of spacetime tear the Higgs mechanism to pieces, since it's based on interactions?
Penrose sort of touches on this idea. He says that in time each particle would be isolated inside its own event horizon. But he seems to think that a particle isolated this way would still have mass and charge. I'm wondering if it wouldn't.
This question probably goes way beyond known physics. But I'm hoping that people who know about particle physics and the Higgs mechanism could shed some light.
This "Cycles of Time" book is very worth reading -
Laura

 

[AndyW]

,

Thank you for bringing up this interesting topic. I can say that the idea of the universe rapidly expanding and eventually losing all rest mass is not supported by current scientific understanding.

First, let's clarify what is meant by "rest mass." Rest mass is the mass of an object when it is at rest, meaning it is not moving. This is different from the total mass of an object, which includes its kinetic energy (energy due to motion). In physics, mass is a fundamental property of matter and cannot be created or destroyed.

The Higgs mechanism, which is responsible for giving particles their mass, is a crucial part of the Standard Model of particle physics. It is based on the idea of a Higgs field, which permeates all of space and interacts with particles to give them mass. This mechanism has been extensively tested and is a fundamental aspect of our understanding of particle physics.

In a universe that is rapidly expanding, the Higgs field would still exist and interact with particles, giving them mass. While the expansion of spacetime may make it more difficult for particles to interact, it would not tear apart the Higgs mechanism. In fact, the Higgs field is thought to be responsible for the expansion of the universe, as it contributes to the cosmological constant.

Furthermore, the idea of all particles eventually being isolated within their own event horizons is not supported by current understanding of the universe. While black holes are a natural consequence of general relativity, there is no evidence to suggest that all particles will eventually become black holes.

Overall, while it is always important to explore new ideas and theories, it is crucial to base them on current scientific understanding and evidence. The idea of the universe rapidly expanding and losing all rest mass is not supported by our current understanding of the universe and particle physics.