6 ms·
Well, it's "at least" 500m, but is probably much more[1]: "Determining the ages of such small stars is difficult because they evolve so slowly over their lif
by stupidcar 10y ago
Well, it's "at least" 500m, but is probably much more[1]:
"Determining the ages of such small stars is difficult because they evolve so slowly over their lifetimes of trillions of years but it is estimated to be in excess of a half a billion years and is probably much more."
And abiogenesis occurred on Earth within about 500m years of the Earth's formation, so life can clearly arise pretty quickly. It's complex, multi-cellular life that seems to be hard part. Although this is based on our observations of a single example.
[1] http://www.drewexmachina.com/2016/05/03/habitable-planet-reality-check-trappist-1/ http://www.drewexmachina.com/2016/05/03/habitable-planet-rea...
- hughes 10y ago> trillions of years This is off by several orders of magnitude. Like estimating the age of your neighbor to be somewhere around 400,000 years old.
- dwaltrip 10y agoUh? I think it's widely accepted that our best models of small stars are fairly well understood, and predict that they will continue to fuse hydrogen in their cores for more than a trillion years.
- kakarot 10y agoReferring to an average of 1-2 trillion years as "trillions of years" is either misleading, uninformed, lazy, or a combination of the 3. When dealing with hard science it's important to choose your descriptors wisely. Most readers will not follow up.
- lutorm 10y agoUh, "1-2 trillion" IS "trillions". I'm not sure how you can make that out to be misleading. Stating "trillions" in lieu of "tens of trillions" or "hundreds of billions" might be misleading, but this is not.
- kakarot 10y agoIt seems the rest of HN disagrees with me, but when I hear "trillions" I think in plurality of trillions, a handful maybe, but afaik these things don't really live past 2 trillion years
- Retra 10y agoThat's because that number is a reference to a plurality of years, not a plurality of trillions.
- kakarot 10y agoIf you say so, I guess I'm just wrong about this. Thank you for trying to clarify for me, instead of just downvoting me into oblivion like everyone else.
- Retra 10y agoI don't think you're "just wrong," there's definitely some ambiguity. You can use "trillions" to denote the scale or magnitude of a value and also to denote a denomination.
- kakarot 10y agoI definitely think it's a an interesting case of context, because if you say a quantity "could even be in the hundreds" it is unambiguously stating it could be within the singular hundreds. But change that into "is in the hundreds" and suddenly you aren't so sure. Even the term "hundreds" alone seems to carry less ambiguity than its superiors, thousands, billions, etc. The higher the quantity, the more imprecision when using the plural form. I guess I was just trying to encourage a little more precision when talking astronomically, though retroactively I see that I could have been less of a dick about it.
- hughes 10y agoAh, my bad. I thought the model was in reference to the current age of the star, not the expected duration of fusion.
- sampo 10y agoThat is not talking about the age, but about the possible life span, into the future.
- tokipin 10y agoI'd be surprised if there isn't other microbe-like life in our own solar system. And the path from microbial to "complex" life is just a matter of whether the environment provides enough energy to support it (nearby sun + photosynthesis in our case). This is because cellular communities will always have certain niche advantages (homeostatis etc). Complex life developed on Earth because it is advantageous in a physics/evolutionary sense, not because the universe accidentally slipped on a banana. Complex life is only an "accident" in that the search algorithm took a while to find the maxima. Otherwise it's just a matter of running the search long enough, and for that all you need is a star.