Eventual decay of all matter - question from an amateur

[Jota]

I suppose I should start out by confessing that I'm hopelessly ingorant on the subject of physics, so please, be gentle. :)

My question is about the eventual decay of matter into...well, random subatomic particles, or iron...I can't recall what the theorie/s state precisely. But apparently, at some point in the far distant future, all of the matter in the universe will, in laymen's terms, 'fall apart'. Right?

If, hypothetically, there were a group of people in a spaceship traveling at relativistic speeds while the rest of the universe was 'ending', would they be able to postpone their own 'decay' (though obviously they could not competely prevent it) via time dilation?

Also, how long does the universe have until matter-decay renders any biological life assunder?

 

[Chalnoth]

I suppose I should start out by confessing that I'm hopelessly ingorant on the subject of physics, so please, be gentle. :)

My question is about the eventual decay of matter into...well, random subatomic particles, or iron...I can't recall what the theorie/s state precisely. But apparently, at some point in the far distant future, all of the matter in the universe will, in laymen's terms, 'fall apart'. Right?

Yes, basically. This Wikipedia article does a good job of explaining it:
http://en.wikipedia.org/wiki/Future_of_an_expanding_universe

If, hypothetically, there were a group of people in a spaceship traveling at relativistic speeds while the rest of the universe was 'ending', would they be able to postpone their own 'decay' (though obviously they could not competely prevent it) via time dilation?

Well, since the time span for the decay of protons is more than 10^{34} years, the people on the ship would die long before it decayed, no matter how fast they go.

However, ostensibly, yes, this would be one way to survive nucleon decay. As a thought experiment this is accurate, but practically I'm pretty sure it's impossible (basically, it would require constant acceleration, which wouldn't be possible if there's no matter out there to act as fuel). Not very useful, though, as you still have the exact same amount of time remaining before your protons all decay from your perspective, as your time frame is the same as the time frame of the protons that make up your body.

I suspect that the only way around this would be to use the energy of black holes to create matter (use a collider to generate protons/anti-protons, and fire the anti-protons into the black hole).

Also, how long does the universe have until matter-decay renders any biological life assunder?

Well, except possibly with the aid of much more advanced technology than our own, biological life will have died long before then.

 

[Jota]

Thanks! I appreciate your reply; I just have two more amateur-ish questions:

I suspect that the only way around this would be to use the energy of black holes to create matter (use a collider to generate protons/anti-protons, and fire the anti-protons into the black hole).

Well, although I'm quite the grown-up, with the excessive joint-popping arthritis to prove it... could you give a basic rundown of how that would work, and explain it as if you were talking to an 8th grader. :)

Also, approximately how much time does the universe have until all of what we we'd think of as "normal" matter [such as rocks, gold, diamonds and mcdonald's french fries] would, even if preserved in some otherwise safely located time capsule, be destroyed, or at least unrecognizable due to matter decay?

 

[Chalnoth]

Well, although I'm quite the grown-up, with the excessive joint-popping arthritis to prove it... could you give a basic rundown of how that would work, and explain it as if you were talking to an 8th grader. :)

Well, you can extract energy from a spinning black hole. Basically, if it's rotating, stuff that you throw into it gets expelled as a particle stream out of the poles of the black hole, at an energy nearly equal to the mass-energy of the matter that falls in. This energy comes from the rotation of the black hole, so it doesn't last forever. But if you can harness the energy being shot out of the poles of the black hole, you might be able to build a civilization around one.

Now that I think of it, though, I don't think this would help you with proton decay. Less matter comes out of the poles than goes in, so you'd have to have a ready supply of matter on hand.

Also, approximately how much time does the universe have until all of what we we'd think of as "normal" matter [such as rocks, gold, diamonds and mcdonald's french fries] would, even if preserved in some otherwise safely located time capsule, be destroyed, or at least unrecognizable due to matter decay?

Well, we don't know exactly. More than 10^34 years. How much more, we're not sure.

 

[Kevin_Axion]

In approximately 10^{10}^{26} - 10^{10}^{76} years from now, quantum tunneling effects will cause iron stars to collapse into neutron stars or black holes. The black holes then decay through Hawking Radiation.

 

[Jota]

In approximately 10^{10}^{26} - 10^{10}^{76} years from now, quantum tunneling effects will cause iron stars to collapse into neutron stars or black holes. The black holes then decay through Hawking Radiation.

But, does that amount of time apply only to the stars, OR, is that the amount of time it would take any given matter to decay. For instance, if hypothetically a rock were placed in some unimaginably safe place, prevented from the process of erosion, prevented from being consumed by supernovas, or black holes, etc. and just sat in said place indefinately...is 10^{10}^{26} - 10^{10}^{76} how long it would take to decay?

 

[Chalnoth]

In approximately 10^{10}^{26} - 10^{10}^{76} years from now, quantum tunneling effects will cause iron stars to collapse into neutron stars or black holes. The black holes then decay through Hawking Radiation.

That would seem to be longer than the lifetimes of the nucleons (by quite a stretch), and thus unlikely to happen in practice.