4 ms·

> But in 1967, three physicists at the Hebrew University in Jerusalem realized that when the core of a dying star is very heavy, it won’t gravitationally collap

by rc_kas 7y ago

> But in 1967, three physicists at the Hebrew University in Jerusalem realized that when the core of a dying star is very heavy, it won’t gravitationally collapse into a black hole. Instead, the star will undergo a “pair-instability supernova,” an explosion that totally annihilates it in a matter of seconds, leaving nothing behind. “The star is completely dispersed into space,” the three physicists wrote. Does this mean that maybe the big bang was just a unstable pair that did what they describe?

NikolaeVarius 7y ago
The big bang might as well be the almighty space chicken laying an egg for all we care before the moment space-time became a concept worth talking about
- jacobush 7y ago
  Sometimes referred to as "God". :)
  - earthscienceman 7y ago
    You know. I get why this is down-modded... but in the end it's actually a beautifully succinct description of exactly why god is compelling to some people. (Obligatory, "as an atheist" disclaimer)
    - chousuke 7y ago
      As far as I can tell It's compelling because people tend to dislike uncertainty and making up stories and hypotheticals can feel like knowing. I don't have an issue with that per se, but the pretend "knowledge" tends to get intertwined with all sorts of claims that actually matter, and that bothers me.
    - jacobush 7y ago
      It's funny it gets downmodded too, considering it wasn't even argument, only an observation. But I'm not here only for upvotes. If my score gets too high I get worried. Edit: Thanks! Can we go a little lower plz.
magicalhippo 7y ago
Not really. Lee Smolin has a nice accessible writeup on the Big Bang here[1], what we typically mean by "the Big Bang" and how we seek to replace the Big Bang concept with something better. [1]: https://www.edge.org/response-detail/25371 https://www.edge.org/response-detail/25371
ben_w 7y ago
No. The “pair” in “pair instability collapse supernova” refers to positron-electron pair production. Specifically, it refers to the situation where the star is hot enough that some of the photons inside it turn into positron-electron pairs which (because conservation laws) move slower than the original photon in the brief time before the positron is annihilated, and therefore contribute less pressure, which causes the start to collapse and get hotter, causing more photons which have the energy to create positron-electron pairs. The big bang was too big to be a star, at all. If all the matter had been in the same place, it would’ve spontaneously turned directly into a black hole, if not for inflation, which I think is not yet well understood but had effects including causing spacetime to expand by an amount which makes “a lot” seem like “almost nothing” in comparison.
gpderetta 7y ago
To further clarify what other have been replaying: the big bang was not an explosion.

by rc_kas 7y ago

NikolaeVarius 7y ago

The big bang might as well be the almighty space chicken laying an egg for all we care before the moment space-time became a concept worth talking about

jacobush 7y ago
Sometimes referred to as "God". :)
- earthscienceman 7y ago
  You know. I get why this is down-modded... but in the end it's actually a beautifully succinct description of exactly why god is compelling to some people. (Obligatory, "as an atheist" disclaimer)
  - chousuke 7y ago
    As far as I can tell It's compelling because people tend to dislike uncertainty and making up stories and hypotheticals can feel like knowing. I don't have an issue with that per se, but the pretend "knowledge" tends to get intertwined with all sorts of claims that actually matter, and that bothers me.
  - jacobush 7y ago
    It's funny it gets downmodded too, considering it wasn't even argument, only an observation. But I'm not here only for upvotes. If my score gets too high I get worried. Edit: Thanks! Can we go a little lower plz.

magicalhippo 7y ago

Not really. Lee Smolin has a nice accessible writeup on the Big Bang here[1], what we typically mean by "the Big Bang" and how we seek to replace the Big Bang concept with something better. [1]: https://www.edge.org/response-detail/25371 https://www.edge.org/response-detail/25371

ben_w 7y ago

No. The “pair” in “pair instability collapse supernova” refers to positron-electron pair production. Specifically, it refers to the situation where the star is hot enough that some of the photons inside it turn into positron-electron pairs which (because conservation laws) move slower than the original photon in the brief time before the positron is annihilated, and therefore contribute less pressure, which causes the start to collapse and get hotter, causing more photons which have the energy to create positron-electron pairs. The big bang was too big to be a star, at all. If all the matter had been in the same place, it would’ve spontaneously turned directly into a black hole, if not for inflation, which I think is not yet well understood but had effects including causing spacetime to expand by an amount which makes “a lot” seem like “almost nothing” in comparison.

gpderetta 7y ago

To further clarify what other have been replaying: the big bang was not an explosion.