I aks you if this reasoning has a base in what we know of universe. There are many articles about so called "vacuum metastability event". As I understand this happens (can happen) with an enormous low probability in every place of the universe. A bubble is produced that then expands with speed of light 'eating' all matter without this matter knowing what is about to happen. (Because we can't have any data in advance from phenomena that are coming towards us with c).

And I understand it like this: Probability of such event can be attribute of the space itself, like every Planck frame has a very tiny probability of going in different vacuum state like in radioactive decay but here is a difference that it once changes has the ability to 'ignite' or 'infect' its neighbors and propagate indefinitely. Or it may be some rare event than could happen only a few times in the history of universe like very energetic collision of particles.

But here is a key thing : universe is VAST. Even very tiny probability on universe volumes becomes certainty. So maybe we live in a universe where some number of this bubbles has been created and are coming towards us. So universe (if we could see faster than light) looks like a growing swiss cheese with bubbles constantly created and growing). And we are simply luck to be in place not yet engulfed by it. An if we were able to get some faster than light information (tachyons ?) we could pinpoint our (that is in our frame, the Earth... of course destroying of whole Solar System would take hours of course) demise to a certain definite time in the future like 1 242 137 331 years + days + seconds.


closed as not a real question by Manishearth Mar 15 '13 at 16:14

It's difficult to tell what is being asked here. This question is ambiguous, vague, incomplete, overly broad, or rhetorical and cannot be reasonably answered in its current form. For help clarifying this question so that it can be reopened, visit the help center. If this question can be reworded to fit the rules in the help center, please edit the question.

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    $\begingroup$ Where is the question in all this? Anyway the thing you are talking about is called "eternal inflation." It has the status of a somewhat dubious conjecture without any experimental support at present. $\endgroup$ – Michael Brown Mar 15 '13 at 15:09
  • $\begingroup$ Question is where is this (may be) a reality or it was ruled out by experimental data. (Question is in first sentence of my post.) $\endgroup$ – rsk82 Mar 15 '13 at 15:12
  • $\begingroup$ @MichaelBrown: Eternal inflation is misleading name... it could be eternal inflation OF THE Universe or WITHIN the Universe. $\endgroup$ – rsk82 Mar 15 '13 at 15:17
  • $\begingroup$ Currently, it's hard to tell what you're asking here. I'll reopen this once you clarify your question. (Ping me in the comments or flag for reopening with a custom flag once you do so) $\endgroup$ – Manishearth Mar 15 '13 at 16:15

You've probably read that the universe is expanding, and that as a result the farther away you look the faster (on average) matter is moving away from the Earth. If you go far enough away the stuff in the universe is moving away from us at faster than the speed of light, and it is therefore causally disconnected from us. By causally disconnected I mean that nothing that happens there can affect the Earth unless it can move faster than light, and of course nothing can.

This means that while your argument is valid, we don't need to worry what happens in the whole universe. We just need to worry about what happens in our bit of it.

From memory, the redshift becomes infinite at 47 billion light years from us, so we would only have to worry if an area of true vacuum nucleated within 47 billion light years of the Earth.

  • $\begingroup$ And I understand this sphere of outward event horizon is coming towards us ? (with what speed?) $\endgroup$ – rsk82 Mar 15 '13 at 15:28
  • $\begingroup$ The 47Gly limit isn't an event horizon in the sense that a black hole has an event horizon. If dark energy didn't exist the 47Glyr cutoff would be constant and not change with time. Dark energy changes this because it is apparently causing the expansion to accelerate, and this will create a real horizon closer to us than 47GLyrs. However, since we don't know what dark energy is it's hard to make predictions about what long term effect it will have. $\endgroup$ – John Rennie Mar 15 '13 at 16:28

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