osmie: (Default)
I posted a long time ago (and don't want to bother looking up the link right now and am grateful to [livejournal.com profile] koppermoon for looking up the link for me) about my frustration with narratives which are created to explain a statistical inevitability. I remember citing the examples of bisexuals in straight relationships, and of mathematicians who appear most productive in their youth.

Well, here's another such narrative debunked: women and men are equally good at chess; women just play it less often.

In particular, the ratings of female chess masters & grandmasters in Germany are almost exactly what you'd expect from comparing a larger group with a smaller one. Of the 120,000 ranked German chess players, just 7000 are women -- but if you picked 7000 chess players at random, instead of by gender, you'd get a rating distribution which is 96% identical. In fact you'd expect the highest rating to be somewhat lower than Judit Polgar's, but even that matches the narrative that she's the best female chess player in history.
osmie: (Default)
I posted a long time ago (and don't want to bother looking up the link right now and am grateful to [livejournal.com profile] koppermoon for looking up the link for me) about my frustration with narratives which are created to explain a statistical inevitability. I remember citing the examples of bisexuals in straight relationships, and of mathematicians who appear most productive in their youth.

Well, here's another such narrative debunked: women and men are equally good at chess; women just play it less often.

In particular, the ratings of female chess masters & grandmasters in Germany are almost exactly what you'd expect from comparing a larger group with a smaller one. Of the 120,000 ranked German chess players, just 7000 are women -- but if you picked 7000 chess players at random, instead of by gender, you'd get a rating distribution which is 96% identical. In fact you'd expect the highest rating to be somewhat lower than Judit Polgar's, but even that matches the narrative that she's the best female chess player in history.
osmie: (Default)
http://news.bbc.co.uk/2/hi/science/nature/7423184.stm

Actually, what I find most wonderful about this is that the monkeys' arms were only immobilized, not harmed in any way. That means the monkeys could move their robot limbs separately from their flesh ones. Which suggests that this technology doesn't just replace amputated limbs: it adds brand new ones. Prehensile tails! Centaur legs! Doc Octopus! We're on our way!
osmie: (Default)
http://news.bbc.co.uk/2/hi/science/nature/7423184.stm

Actually, what I find most wonderful about this is that the monkeys' arms were only immobilized, not harmed in any way. That means the monkeys could move their robot limbs separately from their flesh ones. Which suggests that this technology doesn't just replace amputated limbs: it adds brand new ones. Prehensile tails! Centaur legs! Doc Octopus! We're on our way!
osmie: (Default)
...might find [livejournal.com profile] rjl20's latest utility tremendously useful.
osmie: (Default)
...might find [livejournal.com profile] rjl20's latest utility tremendously useful.
osmie: (Default)
I'd been wondering where to find maps showing how much of the earth would be inundated by various levels of sea level rise.

Today I found them.

This is a Google Maps hack showing sea levels from +0m (current) to +14m, at one-metre increments. It's based on NASA satellite terrain measurements, which means that downtown cores with lots of tall buildings might throw off the data -- and it doesn't take tidal effects into account, so "dry" areas might still be subject to tidal flooding -- but it's a pretty useful & interesting tool.

(Note that the current worst-case estimates, if the entire Greenland and West Antarctic ice sheets melt, range up to a 70m rise. However, this kind of melting would almost certainly be associated with a thermohaline stall, with the effect of packing brand new glaciers across the North Atlantic ... so I think some kind of negative feedback would kick in before we reached that level of inundation. 30m I could see, but I'm skeptical* of 70m.)

(EDIT: In conversation with an actual climate scientist this afternoon, I learned that the thermohaline stall is more of a boogeyman than a threat. There will always be bizarre annual fluctuations during a time of climatic crisis, but the Gulf Stream is driven as much by trade winds as by ocean salinity. While it would certainly shut down if enough fresh water were dumped into the oceans all at once, as when the retroglacial ice dams broke 11,000 years ago and allowed a lake half the size of Canada to flow into the North Atlantic, even the fastest glacial & iceberg melt wouldn't make much of a difference. So maybe a 70m rise is realistic after all.)


*In the real definition of "skeptical," meaning that I'm open to being convinced as more information comes in. I dislike that the word's been co-opted in climate change discussions to mean "wilfully blind."
osmie: (Default)
I'd been wondering where to find maps showing how much of the earth would be inundated by various levels of sea level rise.

Today I found them.

This is a Google Maps hack showing sea levels from +0m (current) to +14m, at one-metre increments. It's based on NASA satellite terrain measurements, which means that downtown cores with lots of tall buildings might throw off the data -- and it doesn't take tidal effects into account, so "dry" areas might still be subject to tidal flooding -- but it's a pretty useful & interesting tool.

(Note that the current worst-case estimates, if the entire Greenland and West Antarctic ice sheets melt, range up to a 70m rise. However, this kind of melting would almost certainly be associated with a thermohaline stall, with the effect of packing brand new glaciers across the North Atlantic ... so I think some kind of negative feedback would kick in before we reached that level of inundation. 30m I could see, but I'm skeptical* of 70m.)

(EDIT: In conversation with an actual climate scientist this afternoon, I learned that the thermohaline stall is more of a boogeyman than a threat. There will always be bizarre annual fluctuations during a time of climatic crisis, but the Gulf Stream is driven as much by trade winds as by ocean salinity. While it would certainly shut down if enough fresh water were dumped into the oceans all at once, as when the retroglacial ice dams broke 11,000 years ago and allowed a lake half the size of Canada to flow into the North Atlantic, even the fastest glacial & iceberg melt wouldn't make much of a difference. So maybe a 70m rise is realistic after all.)


*In the real definition of "skeptical," meaning that I'm open to being convinced as more information comes in. I dislike that the word's been co-opted in climate change discussions to mean "wilfully blind."
osmie: (Default)


In the days before SQL, having a surname of "New" used to perform much the same trick. I had no credit rating until the mid-1990s because my name kept nuking the software.
osmie: (Default)


In the days before SQL, having a surname of "New" used to perform much the same trick. I had no credit rating until the mid-1990s because my name kept nuking the software.

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