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Cuneiformist
The Imperfectionist
USA
4955 Posts |
 Posted - 07/17/2007 : 11:59:43
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Over on the New York Times Science section is this interesting piece. It starts out with the rather interesting lede:| In 1993, J. Richard Gott III computed with scientific certainty that humanity would survive at least 5,100 more years. At the time, I took that as reason to relax, but Dr. Gott has now convinced me I was wrong. He has issued a wake-up call: To ensure our long-term survival, we need to get a colony up and running on Mars within 46 years. |
It's actually quite fascinating, and Gott's use of the Copernican Principle to forecast things is interesting if, in some cases, a bit useless.
Still, as someone who-- rationally or no-- is a fan of the idea of human space travel, I am curious to read more of Gott's work on this.
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dv82matt
SFN Regular
760 Posts |
Posted - 07/17/2007 : 12:50:34 [Permalink]
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Originally posted by Cuneiformist
Over on the New York Times Science section is this interesting piece. It starts out with the rather interesting lede:| In 1993, J. Richard Gott III computed with scientific certainty that humanity would survive at least 5,100 more years. At the time, I took that as reason to relax, but Dr. Gott has now convinced me I was wrong. He has issued a wake-up call: To ensure our long-term survival, we need to get a colony up and running on Mars within 46 years. |
It's actually quite fascinating, and Gott's use of the Copernican Principle to forecast things is interesting if, in some cases, a bit useless.
Still, as someone who-- rationally or no-- is a fan of the idea of human space travel, I am curious to read more of Gott's work on this.
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Interesting indeed. But the Copernican Principle seems to me like one of the least useful ways of making a forcast. Useful for putting things in context perhaps but it should only be used when better methods and data are not available. |
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Dave W.
Info Junkie
USA
26022 Posts |
Posted - 07/17/2007 : 14:08:57 [Permalink]
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All Gott is saying is that if a phenomenon ends completely randomly - that is, without being able to predict it in any way - then you can use his method to figure out when it's going to end to whatever degree of accuracy you like. Gott uses a 95% confidence level, because, the article says, it is "the scientific standard for statistical significance." But that's only true of medicine, generally. Physicists tend to want to see 99.9% confidence levels, which would widen the ranges Gott offers considerably.
For example, any unpredictable phenomenon that's been in existence for 127 days has a 99.9% chance of continuing for anywhere between three hours and 348 years. Compare with Gott's 95% prediction about Bill Clinton staying in office for between three days and 13.6 years after his first 127 days.
These SFN forums have been around for six years, three months and 3 days, so I can predict with extreme confidence (99.999% likelihood) that the SFN will continue to use this customized Snitz software for anywhere between 33 minutes and 6,268 centuries. Go ahead and write that down, so we can check my prediction in 626,901 years.
Thus, it certainly isn't "scientific certainty" that humanity will survive another 5,100 years. It's only 95% certain. (Besides which, I calculate that 2.5% of 200,000 is 5,000 and not 5,100 - unless he's decided that humanity has been here for 204,000 years... [shrug] we can run with that.) So we're 99% confident that humanity will last another 2,040 years, and we've got 99.9% confidence it'll go another 204 years. In fact, we can run the math in reverse and state that we have a 99.99951% confidence that Homo sapiens will still exist on this date next year (while sadly, there's only an 84.047% chance that the SFN software will last that long).
But it's clear that he's pulled a bait-and-switch of his methodology when it comes to putting a colony on Mars. Rather than saying we've got 95% confidence that our space program will continue for anywhere between 14 months and 1,794 years, Gott assumes that we've just begun the second half of its lifetime, and so doubles the current lifetime to predict the end. By such reasoning, Bush will be in office for another 6.5 years (argh!), the Iraq war will last another 52 months, and human beings will lose the ability to farm in another 10,000 years.
More importantly, by the same reasoning, an hour after landing, Mars colonists should consider themselves dead or otherwise off-planet in another hour. So why go? |
- Dave W. (Private Msg, EMail)
Evidently, I rock!
Why not question something for a change?
Visit Dave's Psoriasis Info, too. |
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BigPapaSmurf
SFN Die Hard
3192 Posts |
Posted - 07/17/2007 : 14:56:52 [Permalink]
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As absurdly difficult as it will be to overcome our stupid actions on Earth in the coming centuries it will be far eaiser to correct or deal with any problem we have here than it will be to colonize Mars or anywhere else.
The total habitat destruction issue will need to be addressed eventually, this will probably mean a new way of mapping the solar system for all small bodies and not a successful Mars colony any time in the next 200 years. Perhaps an underground colony on Mars might work, but then it would have to be easier than an underground colony on Earth. If we could just get some of that prime Sun surface real estate. |
"...things I have neither seen nor experienced nor heard tell of from anybody else; things, what is more, that do not in fact exist and could not ever exist at all. So my readers must not believe a word I say." -Lucian on his book True History
"...They accept such things on faith alone, without any evidence. So if a fraudulent and cunning person who knows how to take advantage of a situation comes among them, he can make himself rich in a short time." -Lucian critical of early Christians c.166 AD From his book, De Morte Peregrini |
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HalfMooner
Dingaling
Philippines
15831 Posts |
Posted - 07/17/2007 : 16:11:14 [Permalink]
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I like the idea of a Mars colony, though I worry that I might end up like the Viking Greenland colony, especially if it is cut off from earth. And its survival on its own would be the whole point, in this scenario of a dead earth.
Gott's prediction of how long humans will be around seems to be based upon the premise that things are not getting much more dangerous. We don't know that. Who knows if synthesizing world-killing viruses may not be a simple kitchen operation in a hundred years, or if some total mass-conversion technique might make super-bombs available to every teen?
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“Biology is just physics that has begun to smell bad.” —HalfMooner
Here's a link to Moonscape News, and one to its Archive. |
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Ricky
SFN Die Hard
USA
4907 Posts |
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Cuneiformist
The Imperfectionist
USA
4955 Posts |
Posted - 07/17/2007 : 18:22:37 [Permalink]
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Originally posted by Dave W.
But it's clear that he's pulled a bait-and-switch of his methodology when it comes to putting a colony on Mars. Rather than saying we've got 95% confidence that our space program will continue for anywhere between 14 months and 1,794 years, Gott assumes that we've just begun the second half of its lifetime, and so doubles the current lifetime to predict the end. By such reasoning, Bush will be in office for another 6.5 years (argh!), the Iraq war will last another 52 months, and human beings will lose the ability to farm in another 10,000 years. |
Good. I wondered about that, too. That is, why suddenly assume that it's 50% and not use the first- or last-5% as he had before? I guess more reading is required. That or it's just a bunch of rubbish, and John Tierney, who was a total hack op-ed columnist for the Times for awhile, couldn't be bothered to question some of the assumptions more before writing a column on it. |
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Dave W.
Info Junkie
USA
26022 Posts |
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dv82matt
SFN Regular
760 Posts |
Posted - 07/17/2007 : 22:08:14 [Permalink]
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The Copernican Principle is really just a formalization of the adage that something that has been around for a long time is likely to continue to be around a bit longer, as in, "The pyramids have been here for a long time so they'll still be here tomorrow."
Anyway the Copernican Principle is easy to misapply and by using math may give an appearence of rigor or precision that isn't really warranted. It's really just a best guess type of calculation barely better than nothing at all.
T = time existed so far
C = chance of correct prediction
R1 = lower end of prediction range
R2 = higher end of prediction range
Formula:
R1=T*(1-C)
R2=T/(1-C)
For T = 100
Chance Range
%100 0 - infinity
%99.9 0.1 - 100,000
%99 1 - 10,000
%95 5 - 2,000
%50 50 - 200
%5 95 - 105.263...
%1 99 - 101.010...
%0.1 99.9 - 100.100...
%0 100 exactly |
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Colonization imperative
