What is Vacuum Decay like?

[Sociotard]

One of my mildly stressful classes is "Physical Chemistry". I was studying for the exam yesterday, and I hit this passage.

Some physicists have speculated that the univers might currently exist in a metastable high-energy false-vacuum state that is seperated by an energy barrier from a lower energy true vacuum state. if this is so, there is a slight probability for the universe to spontaneously undergo a phase transition to the true vacuum state. The Transition start at a particular location and would propogate through the universe at nearly the speed of light. In the true vacuum state, the laws of physics would differ from those in the false-vacuum state. "Vacuum decay is the ultimate ecological catastrophe . . . after vacuum decay . . . life as we know it is impossible"

It has even been speculated that just as a tiny crystal of ice dropped into supercooled water nucleatest the formation of ice a high concentration of energy produced in a collision experiment by physicists might nucleate a phase transition to the true vacuum state, thereby destroying the universe as we know it.

Now, I didn't understand a whole lot of that? If these patches of true vacuum travel at the speed of light, couldn't they already exist, and just not have reached us yet? What is a true vacuum? what is an energy barrier? why would I die in a true vacuum? (I don't think it's the same as dying because there isn't any air or air pressure)

[Captain Obvious]

Re: What is Vacuum Decay like?

 

I don't really understand it either, but it kinda makes me want to grab a pitchfork and a torch and form a mob outside the nearest particle accelerator.

[Sociotard]

Re: What is Vacuum Decay like?

 

I've actually seen a couple of different way's an accelerator could destroy us all. For example, there is a chance, however slight, that the collision could create a black hole the size of an electron. If it hit more matter before evaporating, it would grow and consume the earth.

[Metaphysician]

Re: What is Vacuum Decay like?

 

Ah, that would be Quantum Vacuum Collapse, in which 0 Energy becomes a lower value. Don't worry, you'd need a particle accelerate roughly the diameter of the solar system to even attempt to trigger it.

 

As for quantum black holes, don't look now: there are quite a few of them passing through your body right now. Since they are smaller than electrons, though, they can't actually eat much.

[Dr. Anomaly]

Re: What is Vacuum Decay like?

 

Ah, that would be Quantum Vacuum Collapse, in which 0 Energy becomes a lower value. Don't worry, you'd need a particle accelerate roughly the diameter of the solar system to even attempt to trigger it.

 

As for quantum black holes, don't look now: there are quite a few of them passing through your body right now. Since they are smaller than electrons, though, they can't actually eat much.

Quantum black holes passing through your body right now? Uh...nope. Sorry. The smaller a black hole is, the faster it evaporates, and the higher temp at which it does so. A quantum-sized black hole would violently radiate at a temp of several trillion degrees, then explode as it gave up the last of its stored mass. And it does this in a few millionths of a second.

 

A quantum black hole wouldn't last long enough to be able to pass through your body, because it would be radiating its mass away as energy far faster than it could suck things in.

 

If you want the math, I can give you the equations and show you the exact life span for a quantum black hole of any given arbitrary mass...

 

[Metaphysician]

Re: What is Vacuum Decay like?

 

Hmm, I might be confusing quantum and primordial black holes. . .

[Dr. Anomaly]

Re: What is Vacuum Decay like?

 

Either way, there wouldn't be large number of them passing through your body. "Primordial" black holes, in the sense the term is usually used, is just a descriptive term for how a particular size of black hole (the very small kind) may have formed. It doesn't matter the origin of the black hole, though, for this purpose...all that matters is its mass. If its mass is small enough to pass harmlessly through your body (well, small enough for its gravitational gradient to be harmless to you) then it would be radiating in the terawatt range (cooking you and your surroundings into vapor) and then exploding, all in a fraction of a second.

 

You're just not going to have black holes that small last long enough to pass through your body.

[Chris Goodwin]

Re: What is Vacuum Decay like?

 

Ah, that would be Quantum Vacuum Collapse, in which 0 Energy becomes a lower value. Don't worry, you'd need a particle accelerate roughly the diameter of the solar system to even attempt to trigger it.

 

Hope this doesn't make you lie awake at night, but.... what are the chances of one of those coming about naturally?

 

This is a serious question. In Gabon they found a naturally occurring nuclear reactor in the Oklo River (here).

[Outsider]

Re: What is Vacuum Decay like?

 

Sounds like a possible "doomsday" device for an adventure or story arc.

[Hisho]

Re: What is Vacuum Decay like?

 

I don't know if you know about this site

 

http://www.xs4all.nl/~mke/exitmundi.htm

 

it has a lot end-of-world scenarios, written in a (as I think) funny style (warning! black humour) but based on scientific facts (except the ones based on religion)

 

I think for this Vacuum Decay thingy you have to look under Science->Q-Collapse

[Dr. Anomaly]

Re: What is Vacuum Decay like?

 

Hope this doesn't make you lie awake at night, but.... what are the chances of one of those coming about naturally?

 

This is a serious question. In Gabon they found a naturally occurring nuclear reactor in the Oklo River (here).

None.

 

Really.

 

Not via a particle-particle collision/interaction, anyway. Avoiding the math, the rational is something like this:

 

Subatomic particles coming in from space collide on a daily basis with our upper atmosphere. The interaction energies of these collisions are many orders of magnitude higher than we can do with the best particle collider we've built (or could concievably build in the forseeable future). There are many other places in the galaxy, let alone the universe, where particle-particle collisions happen at levels of energy many orders of magnitude above those (such as near the event horizon of a black hole, in the core of a star exploding as a supernova, and so on). If such a particle-particle interaction could occur in nature, it would have by now, and we wouldn't be sitting here debating the topic.

[Sociotard]

Re: What is Vacuum Decay like?

 

Ah, but what if it's already happened in nature? It say's the region of decay grows at "nearly" the speed of light. depending on how fast "nearly" is, we could have a few spheres of decay out there, implacably growing straight for us. It's a big universe, and so it could just be taking a while for these regions to swallow us up. (okay, I don't really know what I'm talking about, but that should be obvious by now.

[Dr. Anomaly]

Re: What is Vacuum Decay like?

 

Ah' date=' but what if it's already happened in nature? It say's the region of decay grows at "nearly" the speed of light. depending on how fast "nearly" is, we could have a few spheres of decay out there, implacably growing straight for us. It's a big universe, and so it could just be taking a while for these regions to swallow us up. (okay, I don't really know what I'm talking about, but that should be obvious by now.[/quote']

The most extreme interactions possible are at the event horizons of black holes. For these purposes, the size of the black hole ("standard" stellar-sized ones or multi-million-solar-mass monstrosities) doesn't matter.

 

If it could happen in nature, the best candidate would be near the event horizon of a black hole.

 

We have black holes in this galaxy.

 

Our galaxy is only 100,000 light-years across but more than 10 billion years old in its present form.

 

On the law of averages, if it was going to happen, it should have done so long before now. Given the length of time the galaxy has been around, versus the size of the galaxy, means there would have been plenty of time for the lightspeed wave front to obliterate the entire galaxy.

 

We're still here, so unless the odds are unbelievably loaded in our favor, it's never happened within our galaxy. If it hasn't happened here in more than 10 billion years, the odds of it happening somewhere very distant but not happening here are vanishingly small.

 

There's no way to tell absolutely for sure unless there's some (impossible) means of scanning every part of the physical universe as it is now, in realtime, but the odds of it ever happening through a natural process triggered by a particle-particle collision are not zero, but they're so close you'd have a hard time finding enough places to the right of the decimal point to actually get a non-zero chance.

[Nyrath]

Re: What is Vacuum Decay like?

 

Ah' date=' but what if it's already happened in nature? It say's the region of decay grows at "nearly" the speed of light. depending on how fast "nearly" is, we could have a few spheres of decay out there, implacably growing straight for us. It's a big universe, and so it could just be taking a while for these regions to swallow us up.[/quote']

Yes, if a decay region was growing at almost the speed of light, we would never know until a short time before it ate the solar system (if it was travelling at the speed of light we would never see what hit us, the decay would gobble you up before the nerve impulses from your eyes could reach your brain).

 

The length of 'a short time' depends upon how nearly to the speed of light the decay travels at.

 

In the same way, the Sun is eight light-minutes away from Earth. This means that if the Sun went nova (though stars like the Sun do not) we on Earth wouldn't know until eight minutes later. At least not without a superpower that included an "FTL" advantage.

[Doc Democracy]

Re: What is Vacuum Decay like?

 

You're just not going to have black holes that small last long enough to pass through your body.

 

Wouldn't it depend on how fast it was travelling?

[Blue Jogger]

Re: What is Vacuum Decay like?

 

One of my mildly stressful classes is "Physical Chemistry". I was studying for the exam yesterday' date=' and I hit this passage. Now, I didn't understand a whole lot of that? If these patches of true vacuum travel at the speed of light, couldn't they already exist, and just not have reached us yet? What is a true vacuum? what is an energy barrier? why would I die in a true vacuum? (I don't think it's the same as dying because there isn't any air or air pressure)[/quote']

 

Think of it this way, when the big bang occurred, the universe went from a high energy state to a lower energy state, crossing some not-fully-understood one-way energy barrier. In theory, (no one knows for sure), another simular event could occur and generate another lesser energy universe right in the middle of ours.

 

It's hard to imagine what a true vacuum would be like. It's like our entire universe being under water and finding a patch that has no longer has water in it. You would probably die is a strange and bizarre way as what we know as the laws of physics would not apply. See, in a lower energy state, all the things that we think of as matter is really strings of energy and those strings vibrate to express its matter state. So if you fell into a lower energy state, suddenly your matter starts to vibrate slower and that would mean you are now something completely different. I mean matter is less energetic energy, so you would turn into whatever is even less energetic than matter.

[Bucky]

Re: What is Vacuum Decay like?

 

I don't really understand it either' date=' but it kinda makes me want to grab a pitchfork and a torch and form a mob outside the nearest particle accelerator.[/quote']

As someone who works at a particle accelerator in real life, I would advise against it. Not that it would be dangerous to you or anything. It would just be annoying to us, and might stop my paycheck.

[Bucky]

Re: What is Vacuum Decay like?

 

I've actually seen a couple of different way's an accelerator could destroy us all. For example' date=' there is a chance, however slight, that the collision could create a black hole the size of an electron. If it hit more matter before evaporating, it would grow and consume the earth.[/quote']

um... Does this really make sense? I know this has been widely stated, back when Brookhaven (?) was starting up their large hadron accelerator, but I think this was just sensational BS.

 

Remember, a black hole that small has a very small mass. Mass determines gravity and gravity is the weakest of the 4 forces.

 

Plus, there is the whole issue of Hawking radiation. If Hawking is right (and right now that seems to be the case) then such tiny black holes would evaporate too quickly to ever suck in enough matter to grow.

 

BTW. I am not a physicist, nor do I play one in TV. (Not even in our Champion's game) I am just a tech at an atom smasher.

 

And they won't let me take any anti matter home. *pout*

[Bucky]

Re: What is Vacuum Decay like?

 

One of my mildly stressful classes is "Physical Chemistry". I was studying for the exam yesterday' date=' and I hit this passage. Now, I didn't understand a whole lot of that? If these patches of true vacuum travel at the speed of light, couldn't they already exist, and just not have reached us yet? What is a true vacuum? what is an energy barrier? why would I die in a true vacuum? (I don't think it's the same as dying because there isn't any air or air pressure)[/quote'] To the best of my knowledge, and understand I am just a tech, not a phycist, here is how I understand it:

 

Could they already exist but not be visible? Yes.

 

What exactly is a "true vacuum? The best answer I can give is by way of analogy. Supposed you lived on top of a hill. That "peak" is our present universe. A true vacuum would be more like the bottom of the hill, with less energy/mass or more importantly, less inconnection between the two.

 

Some have speculated that because we live at this peak, inertia exists. In a true vacuum, (as I understand it) inertia would be altered, or even non existent.

 

Remember that energy is ability to do work, or ability to move physical objects a specific distance. A set amount of energy moves a certain mass a certain distance. In a true vacuum, it would take a different amount of energy to affect the same thing. (I cannot remember if it is more or less.)

 

What is an energy barrier? It is not a physical wall or like a force field. When looking at things like the inside of atomic nuclei, it takes a certain amount of energy to overcome the attraction of the nucleus, to expel a neutron or proton. Once it is separated, then far less energy is required move that particle a distance. That initial energy requirement is called an energy barrier.

 

Why would you die in a true vacuum. One of the points they stress is that in such a place, the laws of physics as we understand them break down. Different rules apply. Since the human body is dependent on what laws of physics apply, how chemicals interact with each other, changing those rules will change the chemistry. The probability is that such a change would be highly detrimental. There are all kinds of way you could die, including suffocating. Its not that there would be no air, its that because of the rule changes, your body cannot process the oxygen in the same way.

 

Anyway, don't take this as gospel. There is a question that if such regions did exist, whether they could ever be connected to this one anyway.

[Bucky]

Re: What is Vacuum Decay like?

 

Wouldn't it depend on how fast it was travelling?

Hmm.. You know you might have a point here.

 

Special Relativity tells us that as particles get faster, time, for the particle, slows down. This is why particles that decay very quickly are still able to reach the earth, when otherwise, they should have decayed high in the atmosphere.

 

So the faster the black hole, the slower it decays (violently) in OUR frame. It would appear to decay slower than if it were standing still. (Well still relative to us.)

 

So the question becomes, what is the slow down factor for a particular speed?

[Dr. Anomaly]

Re: What is Vacuum Decay like?

 

So the question becomes' date=' what is the slow down factor for a particular speed?[/quote']

The equation is t = t0 [1 – (v/c)^2]^1/2

 

Taking c = 2.9975 x 105 km/sec, we get:

 

%c Time Compression

0.000 1

0.050 1.001

0.100 1.005

0.200 1.021

0.250 1.033

0.300 1.048

0.400 1.091

0.500 1.155

0.750 1.512

0.800 1.667

0.866 2

0.900 2.294

0.950 3.203

0.970 4.113

0.980 5.025

0.990 7.47

0.995 10.013

0.996 11.474

0.997 12.92

0.998 15.819

0.999 22.366

 

So at .866c, you only have a time compression of 2 -- you're moving half as fast as the outside universe. At .999c, the compression factor is just over 22, or about 1 day for the outside universe seems like 1 hour for someone moving at .999c

 

So you can see that unless you're moving at an absurdly high fraction of light speed (much higher than a "mere" .999c), you're not going to have a sufficient relativistic effect to slow down time enough to make quantum black holes last any appreciable length of time.

[Bucky]

Re: What is Vacuum Decay like?

 

The equation is t = t0 [1 – (v/c)^2]^1/2

 

Taking c = 2.9975 x 105 km/sec, we get:

 

Okay, the mass of the electron is equivalent to 0.510998918 MeV. On an experiment a couple years ago, we routinely accelerated these babies to 50 GeV. We had a mass increase of almost 100,000 fold. (97847.565)

 

So, using m/m0=1/[1-(v/c)^2]^1/2, where m/m0=~100,000, we get a (v/c) or % C= 0.9999999994999999998749999999375 (roughly).

 

Using the above formula, we get t=31,622.7766.

 

Now granted, electrons are not a whole ship, and we are not the biggest machine on the planet. There are other, more powerful accelerators out there. But this is a substantial fraction of the speed of light. Now whether it counts as "absurdly high fraction of light speed (much higher than a "mere" .999c)," I am not so sure.

 

Do you have decay times for microscopic black holes?

[Nyrath]

Re: What is Vacuum Decay like?

 

Do you have decay times for microscopic black holes?

http://library.thinkquest.org/C007571/english/advance/core8.htm#end_cal

[Dr. Anomaly]

Re: What is Vacuum Decay like?

 

Using the above formula' date=' we get t=31,622.7766.[/quote']

Accelerating an electron to that velocity is one thing...accelerating a micro black hole (which would mass somewhere near the same as a small mountain) is quite another.

[Bucky]

Re: What is Vacuum Decay like?

 

Accelerating an electron to that velocity is one thing...accelerating a micro black hole (which would mass somewhere near the same as a small mountain) is quite another.

Oh yeah. Unless the black hole is charged. And of course this is even assuming these micro black holes would last long enough to be accelerated.

 

But that part might be unnecessary anyway. When Brookhaven started up their RHIC, it was feared that it would produce black holes. (A fear that really did not make a whole lot of sense to me. [And their team of experts as well] A black hole made from a few nuclei would still have the gravitational pull of only a few nuclei.) How that collider worked was taking heavy ions (gold) and smashing into each other. While the mass may change, the momentum does not simply vanish.

 

So here is the idea. You build black holes by smashing two beams of particles into each other. But you design the beams such that the momentum does NOT cancel completely. You can do this by accelerating one beam greater than the other, or using different massed ions in each beam.