Science:
- Trees are marching north at a rate of about 1 km/year. Kudos to NatGeo for the Ents reference, but boo on the sig fig error (100 km/century = 60 miles/century, not 62, no matter what Google might tell you). Bad NatGeo!
- Oh great. We were told the other day that many renewable energy technologies rely on non-renewable materials. Now Scientific American points out that biofuels are bad for feeding people and combating climate change. Dammit.
- Carl Safina informs us in the NYTimes that "Darwinism Must Die So That Evolution May Live," calling on biologists to stop worshipping Darwin. He refrains from asking biologists whether they've stopped beating their wives. Pharyngula points out some of the many things wrong with Safina's diatribe.
The Internets:
- Firefox 3.2 (or possibly 4.0) will have natural language abilities. Natural language (and the semantic web, its close cousin) is the next big thing that'll happen to the web. It's cool to see it's coming. I mean, I already have a lot of that through fancy Chrome search engines (I should probably blog about how to do that one of these days...), but it's cool that it'll be built in.
- Chris Wilson at Slate is performing memetic research. If you took part in the "25 random things" meme, get thee over there to help them out!
- Microsoft is offering domaing name registration and hosting free for a year, $15/year after that. That's an incredibly good deal, so good that I really don't trust it. If you've thought about setting up a website, check it out and let us know if it feels legit.
- Google plans to offer real-time power-consumption monitoring. I love this idea, particularly the services to warn you of spikes and auto-map those to causes that will grow out of it. Neat.
- Um, Lifehacker? It's built into Reader, we just need to drag that "Note in Reader" link up from "Your Stuff" to our bookmark bar. Why would we download something? Well, ok, I really wanted to find something to make a hotkey out of it, but I'm not sure it's worth the script (especially since I've gotten in the habit of using bookmarklets).
Technology:
Politics:
- Goldman Sachs and Morgan Stanley want to give us our money back. Before you fall down in shock, don't worry, it isn't altruistic; it's because they're afraid they'll get more regulation.
9 comments:
re: "but boo on the sig fig error (100 km/century = 60 miles/century, not 62, no matter what Google might tell you)."
I haven't had the opportunity to research this but you've got me curious. When I do running and racewalking races, a 10K race is 6.2 miles. That would make 100K = 62 miles. For that matter, when I wrote a program to compute race pace I found that 5K was 3.105 miles so that should make 100K = 62.1 miles.
It depends on the precision of the original measurement. In this case, clearly "100 km" was the original measurement, and then they converted that to miles. But the original measurement really could have easily been anything from 90 to 110 km, rounded to 100. When you convert but "unround" the answer, you're implying precision that isn't there.
In the case of a "10k", it's really pretty close to "10.0k", so 6.2 miles might even be a bit below the measured accuracy. Likewise, if you are being precise in your racewalk measurements, 3.105 miles/km COULD be the proper conversion factor. Or, rather... you should always keep lots of digits in your conversion factor, but your final answer should be rounded to the least number of digits in any of your measurements (roughly speaking).
The purpose of this is to avoid implying more precision than you actually have. In the case of the trees, the average isn't REALLY "62 miles/century," it's "about 60 miles/century." 62 implies precision that isn't there.
If you can't tell, this is kinda a pet peeve of mine. It's exacerbated because some professors try to claim that sig figs are a meaningless concept, when they actually have an important meaning. Sure, it's a shorthand form of error analysis, but it's quick and easy and can keep people from creating false meaning.
Ok. It was obvious from the article that the distance was an approximation taken from averages over different species of trees and different areas. Still, if the report said 100k, I can't blame the article for equating it to 62 miles. Even if they had said 60 they would have been implying a degree of accuracy that wasn't supported. It was really something like 60 plus/minus 20.
Well, in sig fig terms, the last digit you report (the 6 in 60 in this case) is taken to be uncertain, while other significant digits are certain (the meaning of "uncertain" can be fuzzy, but usually it's "+/- 5 or so"). So when you say "62 miles," you roughly mean "somewhere between 57 miles and 67 miles." If you say "60 miles," it roughly means "somewhere between 10 miles and 110 miles." Converting from "100 km" ("somewhere between 50 km and 150 km," ie "roughly somewhere between 30 miles and 90 miles") to "62 miles" ("57-67 miles") rather than "60 miles" ("10-110 miles") is adding tons of certainty that isn't there.
I'd be curious to read your take on natural language search with Chrome! I expect that many of the first steps we'll see in semantic search will be vertical. For example at Jinni (http://www.jinni.com) we've developed a semantic search-and-recommendation engine for movies.
Hmmmm.... so we would have something like this:
53<58>63
54<59>64
10<60>110
56<61>66
57<62>67
where 60 has magic multiplier power that its neighbors 59 and 61 don't have? Never thought of it that way, but I'm definitely not a mathematician so my thoughts on numbers pretty much don't count for much. :-)
Phoebe: I don't know if you're a real person or just some sort of spam bot, but my take on natural language (not so much semantic search) in Chrome (and Firefox) is here: http://jonthegeek.blogspot.com/2009/02/firefox-keywords-and-chrome-search.html
Die: The number you're talking about is "60." or "6.0x10^1". Most of the time people aren't picky about noting the difference in popular articles, but you can usually infer it from context. For example, the article was talking about "100 km," pretty clearly not "100. km" (1.00x10^2), nor even significant in the tens digit. The reason I say this is it's talking about km per century, so it's safe to assume that isn't known to a great deal of precision. I'll probably be writing a blog about this for work tomorrow, I'll link it here when it's done...
As promised: http://activeanswers.blogspot.com/2009/02/significant-figures-and-scientific.html
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