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Asteroids and Stuff


Rainbowtrout

Will we "get rekt" in the next century?  

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  1. 1. Will we "get rekt" in the next century?



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http://www.express.co.uk/news/nature/507480/Asteroid-Strikes-Earth-Damage-Nasa-Destruction

Thoughts on this? I think that we should be okay. Firstly, the title seems exaggerative (that better be a word, and that point means nothing) Secondly, civilisation might do well in the event of an impact (or not). On the other hand, it's been a while, to my knowledge, that an asteroid hit the Earth with civilisation-destroying power. Statistically, it's more likely now than 30 MYA. Interesting.

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If you don't have a source that's not the express, I'm going to say it's probably based on a misunderstanding of something. Their journalistic standards aren't exactly stellar.

As you suspected:

http://www.slate.com/blogs/bad_astronomy/2014/09/07/debunking_no_asteroid_swarm_is_headed_for_earth.html

Phil Plait:

"at about 18:00 UTC, a small asteroid named 2014 RC will harmlessly pass by the Earth, though at the close distance of very roughly 40,000 km. I wrote all about it a couple of days ago… and also warned that you can expect a bunch of breathless and fact-free YouTube videos about it, claiming it would hit us. I was so, so close. The very day I posted that, a ridiculous article appeared in the UK tabloid Express, claiming that the Earth “faces 100 YEARS of killer [asteroid] strikes starting 2017." How do I phrase this? That claim is really really really really really wrong. Really. The author of this article, Nathan Rao, has a history of writing reality-impaired articles; for example, in August he wrote a piece suggesting the Supermoon might kill everyone on Earth. This led to a less-than-satisfying exchange of tweets between Rao and me (and many others), with him trying to defend his writing, and ended with me telling him, “Whatever helps you sleep at night.â€Â
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If you don't have a source that's not the express, I'm going to say it's probably based on a misunderstanding of something. Their journalistic standards aren't exactly stellar.

True. I did think about the legitimacy of the source. A quick Google, praise be thy Lord's name, revealed nothing more. But, as Sky_Walker said, if this makes the UK realise that space is more than an empty place, with nothing of use, could be fun. Brian Cox is the public outlet to space, yet not so much effect... Public demonstration time?

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99%* or more of asteroids have to have originated within our solar system. Earth is a planet, and to become one, and continue as one, it needs to remove obstacles. So 99% of the asteroids will have already hit us or have been deflected in the last 3.5 billion years or more. That's right, 3.5 billion years, a long time and long enough to clear the way safely. For the other 1% or less left they are small enough to not be a worry.

For the other other 1% of asteroids not originating from within our own solar system, but passing by, they have an astronomically small chance (see what I did there!? ;) ) of hitting. So they'll already miss. For a KSP related example of this, try "hitting" the sun in KSP. It's not easy, right? Even though it's a massive gravity well, because of the effect of gravity and the extra energy required. Adding to that it's size relative to the rest of space. (See http://what-if.xkcd.com/109/ for other reasons it's so hard to "hit" something)

We are safe** . :)

* All figures are wild estimates, but within the acceptable margin of error for a forum post I guess.

** I take no responsibility for that rock about to hit us, but in all reasonableness, we will still survive better than most other things that can happen...

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On the whole, I've found out where not to get my news from. If I see unnecessary capitals in a title, away it goes!

Haha, good call :P

The first address to verify claims of asteroid strikes should always be NASA's impact risk tracking table. It's updated at least once a week and rates known objects with near earth passes by the Palermo and Torino scales, lists the number of potential impact scenarios, and gives the total commulative risk of any of these scenarios actually happening. The list looks 100 years into the future.

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This article was by the same guy who said the "supermoon" was going to destroy civilisation.

The Daily Express has about as good a news source as my toilet paper. Probably less, because my toilet paper doesn't deliberately make stuff up, or blame everything on immigrants and the poor.

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Generally, getting news about science from publications such as this (Even CNN) is disappointing. Always look for this information, at the very least, on scientific publication websites such as sky and telescope for example. There are many out there!

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On the other hand, it's been a while, to my knowledge, that an asteroid hit the Earth with civilisation-destroying power. Statistically, it's more likely now than 30 MYA. Interesting.

If you flip a coin for a while and come up with 100 heads in a row, is it more likely that the next throw will give you tails? /rhetorical question

Or did you mean something different, such as "there are more potential impactors around now, then 30 MYA"?

PS On the poll - we didn't get rekt in several centuries before, so there's two alternatives. We've been incredibly lucky and it's been a long time coming (small likelihood), or we're unlikely to get rekt in the space of a century. In the absence of new info my vote's "no".

Edited by LLlAMnYP
typos
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If you flip a coin for a while and come up with 100 heads in a row, is it more likely that the next throw will give you tails?

That's actually an excellent way to tell between science-minded people, and the posers who merely pretend to think scientifically :)

The correct, rational and scientific answer being of course that it's a lot more likely you'll get heads on the 101st throw.

(Whoever intend to flame me about this: don't bother. You are wrong, you just don't know it yet.)

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That's actually an excellent way to tell between science-minded people, and the posers who merely pretend to think scientifically :)

The correct, rational and scientific answer being of course that it's a lot more likely you'll get heads on the 101st throw.

(Whoever intend to flame me about this: don't bother. You are wrong, you just don't know it yet.)

It's usually assumed that the coin is unbiased, to be fair. In that situation, the 101st flip is still a 50:50 chance, regardless of what the previous 100 results are.

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Aaaaand you lose :) You are brave to try, though.

100 'heads' in a row falsify any and all of the untold assumptions you made that support your "50:50" hypothesis, with a huge margin of confidence. Even if the coin really is unbiased.

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That's actually an excellent way to tell between science-minded people, and the posers who merely pretend to think scientifically :)

The correct, rational and scientific answer being of course that it's a lot more likely you'll get heads on the 101st throw.

(Whoever intend to flame me about this: don't bother. You are wrong, you just don't know it yet.)

Actually note my two examples: One is about us flipping a coin 100 times, the other is us not getting killed by an asteroid in a century several times over the course of human existence. They are completely opposite in nature.

If you know with a certainty of unity, that the coin is unbiased, then the next flip will be 50:50 in any case. That was a counterargument to the statement of the original post "statistically, it's more likely now, than 30 MYA". Basically if there's a certain fixed chance of something happening and the game has "no memory", then regardless of a winning streak beforehand, you'll still stand the same chance of winning or losing in the next round. So just because we haven't had a major impact in 30M years, doesn't mean that we've got it coming to us now (or not).

EDIT: However, off the hand, we may or may not know the probability of a major impact in a hundred-year timeframe. The point is, that just because it didn't happen for a while, doesn't mean that the probability has changed. The next paragraph deals with estimating this probability.

Suppose, on the other hand, that we don't know whether the coin is biased or not. In that case after 100 heads in a row, I'd bet precisely 100:1 that the next outcome will also be heads (as you said, by a huge margin of confidence, the coin is biased). Similar logic follows: we haven't had a major impact in over 300'000 centuries. I'd bet 300'000:1, that we won't have a major impact in the coming century.

And, of course, to speak with any real authority on the coin problem we have to first set our prior probabilities of the coin being biased or not.

Edited by LLlAMnYP
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Or maybe the 100 heads streak falsifies even our understanding of probabilities ;)

Face it: if your theory isn't falsifiable, it's not scientific. And if it is falsifiable, then the 100 series is more than enough to falsify it, regardless of what you conjure up in its support (unbiased coin or not), because however likely sounding it still can't dent the crazy odds, and however improbable you make the alternative sound it'll still be vastly more probable than the "just a coincidence" explanation. This is a fun thought experiment in this way.

Agreed with you on the risk of impact, though, because it's vaaaastly more likely than actually getting 'heads' 100 times in a row. Paradoxical ! With a mere 20 series of 'heads' you have the right answer, I'm just pushing past the limit of sanity for giggles.

Edited by Jesrad
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Aaaaand you lose :) You are brave to try, though.

100 'heads' in a row falsify any and all of the untold assumptions you made that support your "50:50" hypothesis, with a huge margin of confidence. Even if the coin really is unbiased.

Actually, statistically speaking, 100 heads in a row is just as likely as any other combination of heads and tails. All of them have a probability of 1/(2^100)

Of course, scientifically speaking, if heads comes up 100 times in a row, you're going to suspect that something fishy is going on, but that doesn't have any effect on the basic laws of probability.

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Of course. This has been covered in a recent article here: http://www.askamathematician.com/2014/08/q-how-many-times-do-you-need-to-roll-dice-before-you-know-theyre-loaded/

So when doing a test make sure you establish when the test starts and stops ahead of time.

For all you know, this winning streak could have been in the middle of a series of 2^100 rounds.

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