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> And of course panspermia isn't new or my idea particularly, but what bugs me is instead of saying there needs to be more evidence, it should be the default as

by hoten 5y ago

> And of course panspermia isn't new or my idea particularly, but what bugs me is instead of saying there needs to be more evidence, it should be the default assumption. Our environment is just not representative of most of the universe even if you ignore non-baryonic dark matter. One might dismiss this by invoking the anthropic principle (a blunt argument, sorry). Most of the universe is void, and planets with no sun have little energy being tossed into their closed system. It seems adding whatever the hell can be found on asteroids into a planet bombarded by energy (a star being most convenient) is a necessary catalyst for life. I'm sure I haven't thought about this as much as you have. What makes you think life can be formed without the presence of a star? Is it simply how much more not-near-a-star places there are?

simonh 5y ago
If panspermia is true, I think it’s most likely life evolved on a planet orbiting a star. It just seems to me that the energy availability and chances of having liquid water are more conducive. That planet then was destroyed or fragments broken off, scattering life enriched matter into star forming nebulae. This seeded more planets, which then broke up scattering more life enriched matter. After several cycles of this you’d end up with life, or at least sophisticated organic molecule enriched matter all over the galaxy.
- perl4ever 5y ago
  >It just seems to me that the energy availability and chances of having liquid water are more conducive. It seems to me the very concept of a "habitable zone" tends to imply liquid water on the surface of a planet is implausible/rare. There's a whole bunch of additional requirements besides distance and temperature, which some people think makes life in red dwarf systems doubtful, and even looking at earth's history, surface dwelling life seems precarious with all the extinction events. And we have Enceladus as an example of the alternative. There must be orders of magnitude more bodies like this, with undersea oceans and some internal warmth, than bodies with surface conditions conducive to life. Perhaps life needs an environment like earth to develop fully, but if 99.x% of the potential habitat for the most basic life is indifferent to our particular conditions, then it seems to me overwhelmingly likely that's where it started.

by hoten 5y ago

simonh 5y ago

If panspermia is true, I think it’s most likely life evolved on a planet orbiting a star. It just seems to me that the energy availability and chances of having liquid water are more conducive. That planet then was destroyed or fragments broken off, scattering life enriched matter into star forming nebulae. This seeded more planets, which then broke up scattering more life enriched matter. After several cycles of this you’d end up with life, or at least sophisticated organic molecule enriched matter all over the galaxy.

perl4ever 5y ago
>It just seems to me that the energy availability and chances of having liquid water are more conducive. It seems to me the very concept of a "habitable zone" tends to imply liquid water on the surface of a planet is implausible/rare. There's a whole bunch of additional requirements besides distance and temperature, which some people think makes life in red dwarf systems doubtful, and even looking at earth's history, surface dwelling life seems precarious with all the extinction events. And we have Enceladus as an example of the alternative. There must be orders of magnitude more bodies like this, with undersea oceans and some internal warmth, than bodies with surface conditions conducive to life. Perhaps life needs an environment like earth to develop fully, but if 99.x% of the potential habitat for the most basic life is indifferent to our particular conditions, then it seems to me overwhelmingly likely that's where it started.