Thursday, June 11, 2009

Pointless Scaremongering...

There's an interesting story here. It's true that the orbits of planets in the Solar System aren't quite stable - they're just pretty stable, but that's good enough for us. So I suppose that it is possible that Mars might collide with Earth in about 3 billion years.

But let's get a bit of perspective. According to evolutionary biologists, the most complex organisms alive 3 billion years ago were single-celled organisms too small to see with the naked eye. What people would be like in 3 billion years time is an interesting question, but it's pretty likely we wouldn't be much like we are today. The total of recorded human history is about 10,000 years or so, before which time (if we existed at all), we were living in caves and hitting things with sharp rocks. 1 billion years is 100,000 times as long as that. So the whole of human history, back to back and left to run for 300,000 times. That's how long 3 billion years is.

But that's not the point either. Because even if Jesus hasn't come back by then, our understanding of how stars work suggests that the Sun will by that stage be a fair bit warmer. So much warmer in fact, that many predict that by then the Earth will be too hot to have important things like liquid water on the surface and we'll all be dead anyway, unless we've invented some clever spaceships or something.

This page, for instance, suggests "the end of large surface life on Earth" in about 1.1 billion years due to how the Sun is expected to change with time.

So given that, I don't think that we need worry too much about being crashed into by Mars another 1.9 billion years after the Earth has become uninhabitable.

5 comments:

Casey said...

Either way, the absolute certainty of the extinction of all life on Earth apart from supernatural intervention is what puzzles me the most about extreme environmentalism among atheists.

John said...

Extreme environmentalism, yes. But it makes sense to try to keep the planet habitable for as much of the next 1 billion years as possible.

But yes, if we render Earth uninhabitable through our own actions, but take 1 billion years to do so, then there isn't a big problem with that. The worry among saner environmentalists is that we're doing it somewhat quicker than that.

Casey said...

That's the thing, though. What's a billion years in the grand scheme of things? If all life goes extinct there will be no one around to even remember it ever existed, so what's the point if there's no Creator? If life disappears in 100 years or 1 billion years, it was all pointless, anyway, right?

John said...

Ah yes. Well if you're going down that line, it doesn't actually matter if they die today or in 100 years time either, or what happens during that life...

Casey said...

Yeah, that's what I was getting at. These stories always cause me to ponder what it must be like to be an atheist.