Comments for Arcsecond http://arcsecond.wordpress.com Playing on the Sea-Shore, Rough Pebbles Welcome Sun, 08 Nov 2009 13:55:50 +0000 http://wordpress.com/ hourly 1 Comment on Freezing in Warm Air by Mark Eichenlaub http://arcsecond.wordpress.com/2009/10/25/freezing-in-warm-air/#comment-339 Mark Eichenlaub Sun, 08 Nov 2009 13:55:50 +0000 http://arcsecond.wordpress.com/?p=1180#comment-339 Cool videos, Seb. Thanks. Cool videos, Seb. Thanks.

]]> Comment on Freezing in Warm Air by Seb http://arcsecond.wordpress.com/2009/10/25/freezing-in-warm-air/#comment-338 Seb Sun, 08 Nov 2009 09:13:40 +0000 http://arcsecond.wordpress.com/?p=1180#comment-338 There's a cool video of superheating water and supercooling beer here: http://www.youtube.com/watch?v=Xsghf1B_5N8 Actually there's tons. Here's another one: http://www.youtube.com/watch?v=wzHXiGdMvkU (BTW thanks for the refutation on Chad's post, Mark!) There’s a cool video of superheating water and supercooling beer here:
http://www.youtube.com/watch?v=Xsghf1B_5N8

Actually there’s tons. Here’s another one:
http://www.youtube.com/watch?v=wzHXiGdMvkU

(BTW thanks for the refutation on Chad’s post, Mark!)

]]> Comment on Multiples Rule for 7 by natalie http://arcsecond.wordpress.com/2008/11/13/multiples-rule-for-7/#comment-335 natalie Thu, 29 Oct 2009 01:45:10 +0000 http://arcsecond.wordpress.com/?p=154#comment-335 where is h 7????? D: where is h 7?????
D:

]]> Comment on Falling Bullets and the Density of Air by Ken Clark http://arcsecond.wordpress.com/2009/10/19/falling-bullets-and-the-density-of-air/#comment-334 Ken Clark Mon, 26 Oct 2009 21:44:31 +0000 http://arcsecond.wordpress.com/?p=1173#comment-334 three matters, one, the bullet is spinning on its axis of travel at about 1400 rpm, not sure that makes much difference, but the big one is the flow over the bullet is supersonic, also, the bullets starting place while on an apparent plane with the landing location, was actually a little ways around a sphere, introducing even more error ;) three matters, one, the bullet is spinning on its axis of travel at about 1400 rpm, not sure that makes much difference, but the big one is the flow over the bullet is supersonic, also, the bullets starting place while on an apparent plane with the landing location, was actually a little ways around a sphere, introducing even more error ;)

]]> Comment on Freezing in Warm Air by Mark Eichenlaub http://arcsecond.wordpress.com/2009/10/25/freezing-in-warm-air/#comment-333 Mark Eichenlaub Mon, 26 Oct 2009 06:27:25 +0000 http://arcsecond.wordpress.com/?p=1180#comment-333 Okay, definitely not due to pressure change. The internet tells me that water freezes only a fraction of a degree cooler at 2atm than 1. As usual for Wikipedia, the <a href="http://en.wikipedia.org/wiki/Supercooling" rel="nofollow">supercooling article</a> is a good place to start. Apparently, Coke once created a super-cooled version of Sprite, but nowadays the project has been put on ice. Okay, definitely not due to pressure change. The internet tells me that water freezes only a fraction of a degree cooler at 2atm than 1.

As usual for Wikipedia, the supercooling article is a good place to start. Apparently, Coke once created a super-cooled version of Sprite, but nowadays the project has been put on ice.

]]> Comment on Freezing in Warm Air by Mark Eichenlaub http://arcsecond.wordpress.com/2009/10/25/freezing-in-warm-air/#comment-332 Mark Eichenlaub Mon, 26 Oct 2009 06:05:11 +0000 http://arcsecond.wordpress.com/?p=1180#comment-332 Damn, Ian. I was hoping you wouldn't even read that post and then I could pose it to you as a puzzle this weekend. Now instead I'm going to be reading tonight trying to figure out what supercooling is. Is this related to how crystals form spontaneously out of solution when you scrape on the edge of the Pyrex with a stirring rod? Damn, Ian. I was hoping you wouldn’t even read that post and then I could pose it to you as a puzzle this weekend. Now instead I’m going to be reading tonight trying to figure out what supercooling is. Is this related to how crystals form spontaneously out of solution when you scrape on the edge of the Pyrex with a stirring rod?

]]> Comment on Freezing in Warm Air by Ian http://arcsecond.wordpress.com/2009/10/25/freezing-in-warm-air/#comment-331 Ian Mon, 26 Oct 2009 02:28:25 +0000 http://arcsecond.wordpress.com/?p=1180#comment-331 I think the pressure change is less likely to be the culprit here than the possibility that the soda was supercooled when you initially removed it from the freezer. A similar thing happened to me once in a mini-mart: I picked a plastic 1L bottle of some colorless carbonated beverage (I forget exactly what) out of the cooler at the back of the store, noticing as I selected it that about a third of the surrounding bottles were frozen. However, the contents of this particular bottle were definitely still liquid. As I walked up to the register to pay, the plastic bottle slipped out of my grip and fell onto the floor. By the time I picked it up a few seconds later the contents had turned to slush. It still hadn't frozen completely (and didn't finish freezing solid), and I assume that's because the heat released in crystallizing a fraction of the liquid warmed the bottle contents up to the freezing temperature. I think the pressure change is less likely to be the culprit here than the possibility that the soda was supercooled when you initially removed it from the freezer. A similar thing happened to me once in a mini-mart: I picked a plastic 1L bottle of some colorless carbonated beverage (I forget exactly what) out of the cooler at the back of the store, noticing as I selected it that about a third of the surrounding bottles were frozen. However, the contents of this particular bottle were definitely still liquid. As I walked up to the register to pay, the plastic bottle slipped out of my grip and fell onto the floor. By the time I picked it up a few seconds later the contents had turned to slush. It still hadn’t frozen completely (and didn’t finish freezing solid), and I assume that’s because the heat released in crystallizing a fraction of the liquid warmed the bottle contents up to the freezing temperature.

]]> Comment on The Renaissance Man Uniform Gravitational Acceleration SMACKDOWN by | Quiche Moraine http://arcsecond.wordpress.com/2009/10/09/the-renaissance-man-uniform-gravitational-acceleration-smackdown/#comment-325 | Quiche Moraine Fri, 16 Oct 2009 15:13:35 +0000 http://arcsecond.wordpress.com/?p=1153#comment-325 [...] Steel Cage Death Match: da Vinci vs. Galileo in The Renaissance Man Uniform Gravitational Acceleration SMACKDOWN [...] [...] Steel Cage Death Match: da Vinci vs. Galileo in The Renaissance Man Uniform Gravitational Acceleration SMACKDOWN [...]

]]> Comment on The Renaissance Man Uniform Gravitational Acceleration SMACKDOWN by Mark Eichenlaub http://arcsecond.wordpress.com/2009/10/09/the-renaissance-man-uniform-gravitational-acceleration-smackdown/#comment-322 Mark Eichenlaub Tue, 13 Oct 2009 10:43:43 +0000 http://arcsecond.wordpress.com/?p=1153#comment-322 According to what I've read elsewhere, he was referring to triangular numbers when he mentioned pyramids. But it does seem like there's a little room for interpretation, based on the tiny bit of text I have. According to what I’ve read elsewhere, he was referring to triangular numbers when he mentioned pyramids. But it does seem like there’s a little room for interpretation, based on the tiny bit of text I have.

]]> Comment on The Renaissance Man Uniform Gravitational Acceleration SMACKDOWN by Paul Murray http://arcsecond.wordpress.com/2009/10/09/the-renaissance-man-uniform-gravitational-acceleration-smackdown/#comment-321 Paul Murray Tue, 13 Oct 2009 06:29:13 +0000 http://arcsecond.wordpress.com/?p=1153#comment-321 Pehaps Da Vinci was right? Maybe by "the degree of its descent" he meant the distance, rather than the time? Obviously, that makes his velocity wrong ... unless he meant total average velocity rather than instantaneous velocity? And a pyramid is three-dimensional, anyway. The pyramidal numbers increase with the cube of n. Was LdV aware that kinetic energy is proportional to the square of the velocity? Is that what he meant by "the power of it's motion"? Pehaps Da Vinci was right? Maybe by “the degree of its descent” he meant the distance, rather than the time? Obviously, that makes his velocity wrong … unless he meant total average velocity rather than instantaneous velocity?

And a pyramid is three-dimensional, anyway. The pyramidal numbers increase with the cube of n. Was LdV aware that kinetic energy is proportional to the square of the velocity? Is that what he meant by “the power of it’s motion”?

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