https://en.wikipedia.org/wiki/TRAPPIST-1
Too young star for alien life hopes?
It's somewhat counterintuitive, but the bigger a star is, the faster it uses up its fuel, despite having much more of it. As size increases, the rate of fusion in the star's core increases such that the extra fuel isn't enough to prevent the lifespan from shortening. In fact, a common type of supernova occurs in stars that are at least 8 times the size of the sun, burn through their fuel in less than 100 million years, and then go out in style.
Crash course astronomy has some great videos on this stuff: https://youtu.be/PWx9DurgPn8
What's the upper bound on their estimate for TRAPIST-1's age?
Current estimations for the age of the Universe are around 12 to 14 billion years, which isn't much compared to a trillion year life span of such a star.
"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."
[1] http://www.drewexmachina.com/2016/05/03/habitable-planet-rea...
This is off by several orders of magnitude. Like estimating the age of your neighbor to be somewhere around 400,000 years old.
Stating "trillions" in lieu of "tens of trillions" or "hundreds of billions" might be misleading, but this is not.
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.
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.
Not necessarily -- life on Earth may have arisen a remarkably short time after accretion, perhaps even in the first few hundred million years. See this old HN discussion: https://news.ycombinator.com/item?id=10415212
But we can also say that Earth was cool enough for liquid water 4.4G years ago, and there are some findings suggesting microbial life already 4.1G years ago. So only 300 million years, at maximum.