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I think (somebody correct me if I'm wrong) that all we really need is our sun, and to not be swallowed in a black hole or something. Eg. if we lost our own blac

I think (somebody correct me if I'm wrong) that all we really need is our sun, and to not be swallowed in a black hole or something. Eg. if we lost our own black hole, or a hole got punched in our galaxy (not where we are), or our solar system got slung out of the galaxy (intact)- we'd be fine, right?

wahern 4y ago
There are other interstellar objects like comets, asteroids, planets, and dwarf stars roaming around that could take us out at any moment, directly or indirectly. A blackhole isn't much different than any of those in terms of consequence. The same process that would fling a blackhole around can fling anything around, and in theory primordial blackholes could be as small as most of those other objects.
- barbazoo 4y ago
  Is there a chance that there's something out there so fast that we wouldn't see it coming early enough, and big enough to significantly impact us? Like 2023 BU earlier this year that almost hit us less than a week after discovery.
  - 20after4 4y ago
    Yes it's one of the most significant existential threats to life on earth. Probably #2 after self-inflicted environmental destruction.
    - theyamo 4y ago
      Nuclear war is probably more likely.
  - wahern 4y ago
    The chance is >0, but beyond that it's just speculation--some of it very fancy, but speculation all the same. For example, for awhile there was a theory that mass extinction events were correlated to the solar system's orbit as it passed through the galactic plane. That model, which is now largely rejected (per Wikipdia), predicted periodic relative increases and decreases in event rates across time spans down to several millions of years, but pinning down hard numbers was highly suspect even then--among other reasons, our solar system has only completed a couple dozen orbits since forming. We just don't know enough to be able to say anything reliable except in broad, abstract terms with little meaning or substance. I'm squarely in the multi-planet advocacy camp, but IMNSHO if I or anyone else starts throwing around figures, conclusions, or even deductions, beware.
    - barbazoo 4y ago
      What you're saying is it could be over at any moment. Cool, cool, ...
  - deafpolygon 4y ago
    There's a chance it already has, and we're just ghosts walking around unaware of our own demise.
    - barbazoo 4y ago
      That would explain so much

wahern 4y ago

There are other interstellar objects like comets, asteroids, planets, and dwarf stars roaming around that could take us out at any moment, directly or indirectly. A blackhole isn't much different than any of those in terms of consequence. The same process that would fling a blackhole around can fling anything around, and in theory primordial blackholes could be as small as most of those other objects.

barbazoo 4y ago
Is there a chance that there's something out there so fast that we wouldn't see it coming early enough, and big enough to significantly impact us? Like 2023 BU earlier this year that almost hit us less than a week after discovery.
- 20after4 4y ago
  Yes it's one of the most significant existential threats to life on earth. Probably #2 after self-inflicted environmental destruction.
  - theyamo 4y ago
    Nuclear war is probably more likely.
- wahern 4y ago
  The chance is >0, but beyond that it's just speculation--some of it very fancy, but speculation all the same. For example, for awhile there was a theory that mass extinction events were correlated to the solar system's orbit as it passed through the galactic plane. That model, which is now largely rejected (per Wikipdia), predicted periodic relative increases and decreases in event rates across time spans down to several millions of years, but pinning down hard numbers was highly suspect even then--among other reasons, our solar system has only completed a couple dozen orbits since forming. We just don't know enough to be able to say anything reliable except in broad, abstract terms with little meaning or substance. I'm squarely in the multi-planet advocacy camp, but IMNSHO if I or anyone else starts throwing around figures, conclusions, or even deductions, beware.
  - barbazoo 4y ago
    What you're saying is it could be over at any moment. Cool, cool, ...
- deafpolygon 4y ago
  There's a chance it already has, and we're just ghosts walking around unaware of our own demise.
  - barbazoo 4y ago
    That would explain so much