Re:Venus could have been habitable for billions of years (2019)
by thaumasiotes on Wednesday March 24, 2021 @02:57AM
(#26564278)
I find it kind of weird to have a different word for the same object depending on where it is. As I understand it, Jupiter would be a brown dwarf except that the presence of the Sun disqualifies it.
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Re:Venus could have been habitable for billions of years (2019)
by bregma on Wednesday March 24, 2021 @06:56AM
(#26565613)
Jupiter is orders of magnitude too small to be a brown dwarf. The "brown" implies IR radiation generated by gravitic collapse. If Jupiter was massive enough to generate its own radiance it's unlikely Earth would be around to observe it.
The simplistic solar systems and textbooks in grade school are not just misleading when it comes to scale, but they're really really misleading. Few people really comprehend the scale of things in the universe.
Re:Venus could have been habitable for billions of years (2019)
by thaumasiotes on Wednesday March 24, 2021 @03:45PM
(#26572028)
Scale isn't the right thing to complain about here. Compare https://en.wikipedia.org/wiki/Brown_dwarf :
> most brown dwarfs are slightly smaller than Jupiter (15–20%)
> Brown dwarfs are all roughly the same radius as Jupiter.
The suggestion that Jupiter is "orders of magnitude too small" to be a brown dwarf is obviously wrong in terms of size, but it's also wrong in terms of mass:
> at the low end of the range (10 [Jupiter masses]), their volume is governed primarily by Coulomb pressure