eftychia: Me in poufy shirt, kilt, and Darth Vader mask, playing a bouzouki (vader)
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posted by [personal profile] eftychia at 06:20pm on 2007-03-14 under ,

Huh. According to Wikipedia, a human skydiver can actually go as fast as a Peregrine falcon. I'd thought our terminal velocity in our most streamlined position was slower than that. Interesting. Not likely to ever be useful information for me, but still interesting.

Has something I'm allergic to already started blooming really aggressively, or am I coming down with a nasty bug? (And the fibro pain is being especially bad. Breakfast today was determined not by what I felt like eating nor what I thought I ought to eat for good nutritional balance, but entirely based on what was high enough in the fridge for me to reach without bending over.)

This morning's poll generated some results I found surprising, but the whole point was to find out whether there would be such surprises, so that makes it a successful experiment. It would be interesting to try again with a more random sample set. It would also be interesting to see how much slight changes in phrasing change the results (my guess is that in at least some sample populations the effect would be large).

Some of the comments got me thinking about the problem of certifying/licensing scales for commercial use in locations well away from the Earth's surface. And whether there are any scales certified for commercial use in mobile applications. (Measuring accurately with a moving vehicle would be problematic, of course, but I'm thinking of "set up shop here on Tuesdays, there on Thursdays, and at a different event each weekend" situations.) Do they require use of a balance scale, or just certify a spring scale as "close enough as long as you don't go more than ______ miles from where we certified it"? The answer to the mobile applications question is probably on the web, once the curiosity itch gets strong enough to motivate me to search for it. The off-planet problem probably won't be addressed, except by science fiction authors, until/unless space travel becomes commonplace enough that retail commerce starts being conducted up/out there. (Again, a balance scale seems to make the most sense to me, but I can see some bureaucrat mandating different package labelling for products intedended to be sold on the moon, and American space travellers having to memorize a list of different lb<->kg conversion factors (or recipe adjustments) for the various places they go, instead of just making it simple and using mass, just so stuff can still be sold 'by weight'.)

Physics for pessimists:

"There is no gravity, the Earth just sucks."

"Man, everything sucks, not just Earth. F=(Gm1m2)/r2, y'know."

"Feh. It might as well be gravity."

[ETA: It occurs to me that that might be a good starting place for explaining the difference between weight and mass (to pessimists): mass is how much something sucks; weight is how much the thing is being sucked on ...]

There are 2 comments on this entry. (Reply.)
 
posted by [identity profile] garnet-rattler.livejournal.com at 01:56am on 2007-03-15
Even the mediocre spring scales that they certify for vegetables and such are (generally) good anywhere in the territory of the country they were certified in, and often world-wide, with the caveats that you only use them within their rated range and with the seals intact.

Earth's gravity is not Entirely flat, but reasonably close enough for most places. I only know of one or two spots where the difference from the average is more than a small fraction of a percent, and even fewer if you compensate for altitude (farther from the core, lower pull).

I do have a gravitic anomaly map for the US and Caribbean if you'd be interested. I might even be able to find the USGS site I got it from ... ;-) Note that I really liked that psuedo-explanation for mass and weight!
 
posted by [identity profile] madbodger.livejournal.com at 05:43am on 2007-03-18
1) humans are quite hydrodynamic. I subscribe to the theory that this is partially due to the fact that we were aquatic for a while.


2) Did you head about the fellow how demonstrated relativistic gravity effects with some cesium clocks on a mountaintop? Said it was the best 22ns he ever spent with his kids.

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