4 ms·
> It's about as renewable as solar, which is to say, we will eventually run out - but at that point the heat death of the universe is a more pressing concern.
by krisoft 5y ago
> It's about as renewable as solar, which is to say, we will eventually run out - but at that point the heat death of the universe is a more pressing concern.
Nitpicking:
The sun is expected to stop fusing helium in about 8x10^9 years [1].
The heat death will occur in around 1.7x10^106 years [2]. (if at all, there are some uncertainties around that)
Which means that while they are both far, the heat death as predicted is much much further than the other. In short, the heat death of the universe won't be a pressing concern at all when we run out of solar.
1: https://en.wikipedia.org/wiki/Black_dwarf#Future_of_the_Sun https://en.wikipedia.org/wiki/Black_dwarf#Future_of_the_Sun
2: https://en.wikipedia.org/wiki/Graphical_timeline_from_Big_Bang_to_Heat_Death https://en.wikipedia.org/wiki/Graphical_timeline_from_Big_Ba...
- Aeolun 5y agoIt’s oddly reassuring to know that we’ll actually have some time to stay a spacefaring civilization after the sun runs out.
- Smithalicious 5y agoI wonder, does the sun /have/ to run out? Could we find a bunch more hydrogen from outside the solar system and dump it into the sun to recharge it?
- throwntoday 5y agoAssuming we possesed that capability it seems like it would be simplet to build a dyson sphere around another star and setup shop on a nearby planet.
- infogulch 5y agoStars fail when the elements in their cores stop releasing net energy when fused. This crossover occurs at iron. Adding more mass will just make it's death more violent. Also the sun contains 99% of the mass of the solar system. The remaining 1% includes Jupiter. I'm not sure how much effect we can have when only leveraging 1% of 1% of the solar systems mass.
- Out_of_Characte 5y agoI also wonder how one removes mass from the sun. Its the biggest gravity well in the solar system and our biggest power source is the sun itself.
- zozbot234 5y agoProper management of star lifetime actually requires the opposite approach: subtract mass from the star, so that the star "core" where actual fusion happens can steadily mix with a larger fraction of the remaining mass. The harvested mass can then be stored away as gas-giant planets, and used for miscellaneous purposes.
- Teever 5y agoThis is fascinating. Do you have any recommendations for sources so I can learn more about megascale engineering projects to maximize the life of a star?
- Jerrrry 5y agowarning: Isaac Arthur is like crack to sci-fi/intellectuals. binge at your own risk: https://www.youtube.com/watch?v=pzuHxL5FD5U https://www.youtube.com/watch?v=pzuHxL5FD5U
- deadbeeves 5y agoI remember reading some time ago that after the Sun runs out there's only enough energy in a state fit for fusion for like one or two more generations of stars in the universe, and after that the universe will go dark forever.
- dysfunction 5y agoThat may be true, but it's worth noting that the length of a "generation" of stars varies wildly depending on the type of star. Stars like our Sun might only live 10 billion years or so, but red dwarfs live 100 billion years or more so we could presumably live around them long after all the Sun-like stars have burned out.
- matthewdgreen 5y agoCan't we dump matter into black holes to draw things out for a while even after that?
- deadbeeves 5y agoFrom where are you getting the energy to do that?
- matthewdgreen 5y agoIf you have a bunch of matter (dead stars, planets, interstellar dust) is there some fundamental reason this can't be dumped into accretion disks, etc. in an energy-positive way?
- NeutronStar 5y ago
- stjohnswarts 5y agoI suspect human will have LONG since destroyed themselves by the time the sun dies, probably before we're spacefaring and out of the solar system.