Earth: Ctrl-Alt-Del

[Burninator]

Originally Posted by Hemi-Cuda

from my understading, the moon was formed in the first place by a huge asteroid impacting earth and the resulting debris being blown into space. so maybe if something hit the moon we'd get a mini-moon? that'd be kinda neat

Except there is probably a good chance we would all die in the process.

[Locke]

Originally Posted by Burninator

Except there is probably a good chance we would all die in the process.

Well, everything mentioned in this thread doesnt exactly end with a song and dance. Most of this conjecture implies that we all cash out. Although I concure on the mini-moon. That would certainly be novel.

Locke.

[Frank the Tank]

I don't know about you guys, but my favourite planet is the sun! Hey!

[ken0042]

Originally Posted by Hemi-Cuda

from my understading, the moon was formed in the first place by a huge asteroid impacting earth and the resulting debris being blown into space. so maybe if something hit the moon we'd get a mini-moon? that'd be kinda neat

Yeah, but it wouldn't be round though. IIRC the moon is solid, and when it was formed from Earth debris the Earth was a lot more molten than it is now; so as it cooled it formed into a sphere.

But you guys are right; the shockwave of such an impact would likely be enough to rip the atmosphere right off the Earth; so we'd only have a few seconds to enjoy it; depending on what killed us first- the asphyxiation or getting burned to a crisp by the solar radiation.

[Locke]

Originally Posted by Frank the Tank

I don't know about you guys, but my favourite planet is the sun! Hey!

Oh sure Frank, take the easy way out, how many 'the sun isn't a planet' comments are you expecting?

Locke.

[Teh_Bandwagoner]

Originally Posted by Bring_Back_Shantz

Odds/probability are the exact same thing. If the odds of getting hit by an asteroid this year is 1/1000000, then the probability of it happening this year is 0.000001, the exact same thing. The odds/probability of getting hit by an asteroid this year are no different than the are any other year, regardless of how long ago the last one hit.

I have to agree with Shantz, but then again I got a D+ in probability so I could be wrong. But at least I'm not employed at the Verizon call centre.

http://media.putfile.com/Verizon-Bad-Math

[Azure]

Originally Posted by ken0042

(Not that hitting the ocean won't cause damage.)

Well, it would spell the end of the Canucks for a while.

[Locke]

Originally Posted by Azure

Well, it would spell the end of the Canucks for a while.

The only team that wouldnt be destroyed is the Leafs, they wont go away and nothing, it seems, will get rid of them....

Locke.

[ericschand]

Originally Posted by Bring_Back_Shantz

Odds/probability are the exact same thing. If the odds of getting hit by an asteroid this year is 1/1000000, then the probability of it happening this year is 0.000001, the exact same thing. The odds/probability of getting hit by an asteroid this year are no different than the are any other year, regardless of how long ago the last one hit.

Odds and probability are NOT the same thing.

http://en.wikipedia.org/wiki/Odds

ers

[Bring_Back_Shantz]

Originally Posted by ericschand

Odds and probability are NOT the same thing.

http://en.wikipedia.org/wiki/Odds

ers

Well they are both numbers used to describe the same thing and can be used to find each other becasue one is based on the other, so for the purpose of this arguement we an use them as the same thing.

If an asteroid of size X hits earth every million years or so we can say that the probability of it and the odds of it hitting this year do not change, regardless of when the last one hit.

The odds this year are 1/1000000
the probabilty this year is 0.000001

And if one hasn't hit in a million years from now, the odds of one hitting 1million and one years from now will be 1/1000000 and the probability will be 0.000001

And if one hits tomorrow, the odds of one hitting next year will be 1/1000000 and the probabilty will be 0.000001.

[Burninator]

Originally Posted by ericschand

Odds and probability are NOT the same thing.

http://en.wikipedia.org/wiki/Odds

ers

The dictionary says this.

Odds
The ratio of the probability of an event's occurring to the probability of its not occurring.

Probability
The likeliness of a given event occurring: chance, likelihood, odds, possibility, prospect (used in plural).

[Bring_Back_Shantz]

Originally Posted by Burninator

The dictionary says this.

Odds
The ratio of the probability of an event's occurring to the probability of its not occurring.

Probability
The likeliness of a given event occurring: chance, likelihood, odds, possibility, prospect (used in plural).

Either way, they both describe the likelihood of an event occuring and in this instance neither one is changing.

[ericschand]

Originally Posted by Bring_Back_Shantz

Either way, they both describe the likelihood of an event occuring and in this instance neither one is changing.

No. The odds do not change, assuming all other constants are the same,
it will remain the same.

The probability will change, as the amount of time gone by changes, etc.
This probability will draw towards 1. This number is NOT the same as the
odds.

In the example you gave earlier, you forgot that the number of
years has changed (after all, one year has gone by). Your odds
won't change, but your probability will.

In general, the rule is, the more time that passes with an event not
occuring, the probability that the event will occur approaches 1.

I think you are confused by slang, where odds and probability and chances
are the same. In math and statistics they have completely different
meanings.

Another example is the "big one" earthquake they expect in California.
The longer they go without one, the odds remain the same (assuming
the earth doesn't change, which is incorrect), however the probability
of one occurring rises (towards 1 - everybody panic!).

ers

[octothorp]

Originally Posted by ericschand

No. The odds do not change, assuming all other constants are the same,
it will remain the same.

The probability will change, as the amount of time gone by changes, etc.
This probability will draw towards 1. This number is NOT the same as the
odds.

The equation always stays the same. Odds are always equal to 1/(1-p), where p = probability. The odds cannot change without probability also changing. Neither has any account in its equation for the passage of time, except to say that shorter passages of time have lower probabilities and odds than longer passages of time.

[CrusaderPi]

Wouldn't the odds go down as various asteroids crash into the moon or sun or Mars or anything that I'm not living on?

[Cube Inmate]

Good grief...a debate on math when we're talking about asteroids.

Might as well add another voice to the insanity...

1) ericshand: Yes, the cumulative probability function of a regular stochastic process approaches 1 as more time passes (more accurately, as more "tests" occur in this binary problem..."Hit" or "No Hit" in any given year). That doesn't say anything about the probability of an event occurring in any given year, though. The "Big One" is not a valid example here because it will be caused, presumably, by the ever-increasing stresses at the plate boundaries.

Even if a set of lottery numbers has never been called in 50 million draws, the chances of those numbers winning the next draw are no better than any other. On average, with an ever-increasing number of draws, the probability of those numbers eventually winning approaches 1, but there's no impact on a draw-to-draw basis. On the other hand, consider two people: the probability of dying approaches 1 for any two humans, but an 85-year-old has a 50% chance of dying in the next 2 years, whereas a 30-year-old has a 1% chance (I made those numbers up). Some systems have probabilities that change due to past events (e.g. the passage of time); these systems have memory. Others have unchanging probabilities...these are so-called memoryless systems.

2) This raises the question as to whether or not the concept of a devastating asteroid impact qualifies as a memoryless system. As Mr. Pi mentioned, the number of possible impactors decreases over time, thereby reducing the odds of collision (odds/probability...interchangeable in my lexicon). Are there other factors which would cause us to expect asteroid impacts to be fairly evenly spaced? I can't think of any. I'll agree, then, that the odds of getting hit next year are no worse than those of getting hit this year.

So why the confusion?

This is another example of the fallacious "law of averages" being applied. Flip 10 heads in a row, and the human tendency is to feel that we're "due" for a tail. If the coin is actually fair, though, you'll have a 50/50 shot on your next flip. We can also consider the possibility that the 10 heads in a row might actually indicate that we're not using a truly "fair" coin. So, really, the only thing that could happen when we go longer and longer without an impact is that our estimation of the probability of impact might have to go down, but certainly not up.

This post brought to you by your friendly neighbourhood Thread-Killer!

[Flashpoint]

We deserve it.

I for one, welcome our new asteroid overlords.

[Locke]

Originally Posted by Flashpoint

I for one, welcome our new asteroid overlords.

Let the loathing begin.....

Locke.

And yes, I appreciate the irony of my own post.

[Bring_Back_Shantz]

Originally Posted by ericschand

No. The odds do not change, assuming all other constants are the same,
it will remain the same.

The probability will change, as the amount of time gone by changes, etc.
This probability will draw towards 1. This number is NOT the same as the
odds.

In the example you gave earlier, you forgot that the number of
years has changed (after all, one year has gone by). Your odds
won't change, but your probability will.

In general, the rule is, the more time that passes with an event not
occuring, the probability that the event will occur approaches 1.

I think you are confused by slang, where odds and probability and chances
are the same. In math and statistics they have completely different
meanings.

Another example is the "big one" earthquake they expect in California.
The longer they go without one, the odds remain the same (assuming
the earth doesn't change, which is incorrect), however the probability
of one occurring rises (towards 1 - everybody panic!).

ers

First off, cube put it nicely so read his post.
To further his explination, what you're doing is comparing the probability for one year to that of an extended time period say 1000000 years since the last impact which is not logical at all. If an event occurs once every 1000000 then your average wait time for that even to occur will be 1000000 no matter when you start waiting. So no matter how long ago the last event occured, the probability of it hitting this year is the same as any other year because you could say that you're in year 1 of your wait, year 10, year 999999, it doesn't matter.

yes as you take a longer and longer time span the probability (AND ODDS) of an event occuring in that span is going to increase, but saying that changes the chance/probabilty/odds if it changing this year is absolutely false.

[Bobblehead]

Gambler's Fallacy

(I believe this is the technical name for what Cube Inmate was getting at in his discussion of a system and memory. For another interesting discussion, see the Monty Hall problem. Math is really fascinating in the correct context)