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shortly after the bigbang, when the universe was a nonzero amount of time the size of a potato, compared to its current size, how to reconcile that with 'it doe

shortly after the bigbang, when the universe was a nonzero amount of time the size of a potato, compared to its current size, how to reconcile that with 'it doesnt expand into anything'?

fnordpiglet 4y ago
It wasn’t the size of a potato. It was everywhere all at once. There is no three dimensional shape of the universe, no boundary, and edge. Still, between galaxies space is expanding. That means everything below a certain amount of mass density is getting further from every other mass density. Within the mass density space does not expand. We are not getting further away from other stars. But saying the universe was the size of the potato dramatically misses what we believed the universe is today and what the article says. It abstracts the nature of things to what is familiar to you, but misses the actual nature of things. Note the Big Bang is a point in time where all paths started, as stated in the article. It’s a mathematical singularity. It’s not an explosion as you think of it. It was a sudden expansion of all points in space creating vastly more space between the points. But since space has no boundary it didn’t get bigger, and it wasn’t smaller.
- jaywalk 4y ago
  > Note the Big Bang is a point in time where all paths started, as stated in the article. It’s a mathematical singularity. It’s not an explosion as you think of it. It was a sudden expansion of all points in space creating vastly more space between the points. But since space has no boundary it didn’t get bigger, and it wasn’t smaller. This makes zero sense.
  - fnordpiglet 4y ago
    I think PBS space time does a good job explaining these things, but you’re right it doesn’t map to our understanding of how mass and space work in a Newtonian world. These videos give some explanation and link through internally to more details. https://youtu.be/bUHZ2k9DYHY https://youtu.be/bUHZ2k9DYHY https://youtu.be/bUHZ2k9DYHY https://youtu.be/bUHZ2k9DYHY
  - vernon99 4y ago
    And still, it seems this is exactly what the article says and it makes perfect sense to me, so I’m not sure why the parent is downvoted.
    - fnordpiglet 4y ago
      The potato universe conspiracy theory has a big following in HN.
scottmsul 4y ago
There was a point in time where everything in the visible universe was the size of a potato, but the entire universe (beyond the visible edge) is most likely just more matter in every direction indefinitely. Because the universe follows general relativity, space itself behaves like a fluid. When the universe "expands", that's just space itself growing bigger over time.

shortly after the bigbang, when the universe was a nonzero amount of time the size of a potato, compared to its current size, how to reconcile that with 'it doesnt expand into anything'?

fnordpiglet 4y ago

It wasn’t the size of a potato. It was everywhere all at once. There is no three dimensional shape of the universe, no boundary, and edge. Still, between galaxies space is expanding. That means everything below a certain amount of mass density is getting further from every other mass density. Within the mass density space does not expand. We are not getting further away from other stars. But saying the universe was the size of the potato dramatically misses what we believed the universe is today and what the article says. It abstracts the nature of things to what is familiar to you, but misses the actual nature of things. Note the Big Bang is a point in time where all paths started, as stated in the article. It’s a mathematical singularity. It’s not an explosion as you think of it. It was a sudden expansion of all points in space creating vastly more space between the points. But since space has no boundary it didn’t get bigger, and it wasn’t smaller.

jaywalk 4y ago
> Note the Big Bang is a point in time where all paths started, as stated in the article. It’s a mathematical singularity. It’s not an explosion as you think of it. It was a sudden expansion of all points in space creating vastly more space between the points. But since space has no boundary it didn’t get bigger, and it wasn’t smaller. This makes zero sense.
- fnordpiglet 4y ago
  I think PBS space time does a good job explaining these things, but you’re right it doesn’t map to our understanding of how mass and space work in a Newtonian world. These videos give some explanation and link through internally to more details. https://youtu.be/bUHZ2k9DYHY https://youtu.be/bUHZ2k9DYHY https://youtu.be/bUHZ2k9DYHY https://youtu.be/bUHZ2k9DYHY
- vernon99 4y ago
  And still, it seems this is exactly what the article says and it makes perfect sense to me, so I’m not sure why the parent is downvoted.
  - fnordpiglet 4y ago
    The potato universe conspiracy theory has a big following in HN.

scottmsul 4y ago

There was a point in time where everything in the visible universe was the size of a potato, but the entire universe (beyond the visible edge) is most likely just more matter in every direction indefinitely. Because the universe follows general relativity, space itself behaves like a fluid. When the universe "expands", that's just space itself growing bigger over time.