5 ms·

Now calculate the probability of the current Universe arising spontaneously from vacuum.

eanzenberg 8y ago
1
- cpburns2009 8y ago
  This feels anecdotal rather than an actual calculation.
  - TrainedMonkey 8y ago
    Assuming that time moves forward, probability of all events that have already happened is 1. Probability of all events that could have happened, but did not 0. There is an interesting parallel that could be made to quantum states collapsing. Given that the question asks about 'current' universe arising spontaneously from vacuum the probability is 1 because that has already happened. The more interesting question, what is the probability of a new universe similar to our own arising. To the best of our knowledge (which for this type of extrapolation is admittedly flimsy) this is also 1, this just takes a very long time. The expected time it would take (10^10^10^56) is specified on the last row on the "Future of the Earth, the Solar System and the Universe" table.
    - taneq 8y ago
      > Given that the question asks about 'current' universe arising spontaneously from vacuum the probability is 1 because that has already happened. Well, we don't know that. Whatever 'came before' (if that even makes sense) probably wasn't a vacuum with the same rules as we see now.
    - pc86 8y ago
      > Probability of all events that could have happened, but did not 0. Only if you meant "could have happened, but did not, and now for some reason can no longer happen." "All events that could have happened, but did not" would reasonably encompass every event with 1 > P > 0, wouldn't it?
      - TrainedMonkey 8y ago
        What I specifically meant is that to best of our knowledge past is deterministic, but future is not.
  - Florin_Andrei 8y ago
    It's the only case where anecdotal evidence is acceptable. Actually, no. That would be the existence of my own consciousness. Just mine. Not yours. That's it.
  - PhasmaFelis 8y ago
    I am hardly a mathematician, so I'm probably missing something, but I think it makes sense? I believe it's well-established that elementary particles can spontaneously generate through quantum fluctuation. Assuming that this process is uniformly distributed, the probability per unit time of any given structure self-generating is nonzero (if fantastically small). Over a long enough timescale, the probability of any possible event occurring approaches one. If time is infinite, the probability is one. What am I missing?
    - cpburns2009 8y ago
      I meant it more tongue-in-cheek than as a real critique. That being said, such a strong statement should have some backing other than anecdotal evidence I agree with. I'm assuming @eanzenberg said the answer is "1" because our universe clearly exists (from my perspective at least). I'd expect the formula to be similar in nature to the Drake equation [1]. However, I'm neither a mathematician nor a physicist. [1]: https://en.wikipedia.org/wiki/Drake_equation https://en.wikipedia.org/wiki/Drake_equation
- netgusto 8y ago
  Genius.
- ende 8y ago
  Please show your work.
  - deleted 8y ago
    [deleted]
  - eximius 8y ago
- OscarCunningham 8y ago
  They mean probability per second.
  - pjc50 8y ago
    Time is believed to be inside the universe, not outside it; assuming the conventional understanding of spacetime is correct.
f2f 8y ago
it's there at the bottom: 10^10^10^56 "Around this vast timeframe, quantum tunnelling in any isolated patch of the vacuum could generate, via inflation, new Big Bangs giving birth to new universes [...] this is also the time required for a quantum-tunnelled and quantum fluctuation-generated Big Bang to produce a new universe identical to our own, assuming that every new universe contained at least the same number of subatomic particles and obeyed laws of physics within the range predicted by string theory."

cpburns2009 8y ago
This feels anecdotal rather than an actual calculation.
- TrainedMonkey 8y ago
  Assuming that time moves forward, probability of all events that have already happened is 1. Probability of all events that could have happened, but did not 0. There is an interesting parallel that could be made to quantum states collapsing. Given that the question asks about 'current' universe arising spontaneously from vacuum the probability is 1 because that has already happened. The more interesting question, what is the probability of a new universe similar to our own arising. To the best of our knowledge (which for this type of extrapolation is admittedly flimsy) this is also 1, this just takes a very long time. The expected time it would take (10^10^10^56) is specified on the last row on the "Future of the Earth, the Solar System and the Universe" table.
  - taneq 8y ago
    > Given that the question asks about 'current' universe arising spontaneously from vacuum the probability is 1 because that has already happened. Well, we don't know that. Whatever 'came before' (if that even makes sense) probably wasn't a vacuum with the same rules as we see now.
  - pc86 8y ago
    > Probability of all events that could have happened, but did not 0. Only if you meant "could have happened, but did not, and now for some reason can no longer happen." "All events that could have happened, but did not" would reasonably encompass every event with 1 > P > 0, wouldn't it?
    - TrainedMonkey 8y ago
      What I specifically meant is that to best of our knowledge past is deterministic, but future is not.
- Florin_Andrei 8y ago
  It's the only case where anecdotal evidence is acceptable. Actually, no. That would be the existence of my own consciousness. Just mine. Not yours. That's it.
- PhasmaFelis 8y ago
  I am hardly a mathematician, so I'm probably missing something, but I think it makes sense? I believe it's well-established that elementary particles can spontaneously generate through quantum fluctuation. Assuming that this process is uniformly distributed, the probability per unit time of any given structure self-generating is nonzero (if fantastically small). Over a long enough timescale, the probability of any possible event occurring approaches one. If time is infinite, the probability is one. What am I missing?
  - cpburns2009 8y ago
    I meant it more tongue-in-cheek than as a real critique. That being said, such a strong statement should have some backing other than anecdotal evidence I agree with. I'm assuming @eanzenberg said the answer is "1" because our universe clearly exists (from my perspective at least). I'd expect the formula to be similar in nature to the Drake equation [1]. However, I'm neither a mathematician nor a physicist. [1]: https://en.wikipedia.org/wiki/Drake_equation https://en.wikipedia.org/wiki/Drake_equation
netgusto 8y ago
Genius.
ende 8y ago
Please show your work.
- deleted 8y ago
  [deleted]
- eximius 8y ago
OscarCunningham 8y ago
They mean probability per second.
- pjc50 8y ago
  Time is believed to be inside the universe, not outside it; assuming the conventional understanding of spacetime is correct.

f2f 8y ago

it's there at the bottom: 10^10^10^56 "Around this vast timeframe, quantum tunnelling in any isolated patch of the vacuum could generate, via inflation, new Big Bangs giving birth to new universes [...] this is also the time required for a quantum-tunnelled and quantum fluctuation-generated Big Bang to produce a new universe identical to our own, assuming that every new universe contained at least the same number of subatomic particles and obeyed laws of physics within the range predicted by string theory."