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Discussion in 'The latest one!' started by JoergS, May 26, 2013.
One more "scientific" episode...
Why don't you shoot the beer bottle in abaout 6000m high then is the beer ice cold.
You only have to make a very strong slingshot!
Since i personaly do not drink beer can you do something with a bottle of coke next time??
giant mousetrap for men, beer can as bait.
I really liked this video, and I learned from it as well. I knew that rubber grows warmer when stretched, but I had no idea it becomes colder when released.
Thermodynamically speaking, this makes sense. Gas under pressure heats up, and then once the pressure vessel has cooled and you expel the gases, you can freeze many things solid. A tensed rubber band is under pressure of a different sorts, but it's still pressure, yes? Releasing the pressure after the pressure vessel has cooled to ambient temperature will cool the vessel down past ambient.
Jorge, I think you should repeat this using the same band, but with a greater stretch distance. See if the heating and cooling effect increases. Also, since rubber tends to be a somewhat poor thermal conductor (regular vulcanized in one test maxed out at 0.15 W/mK,) varied thickness of bands might affect heating/cooling capability/time.
I so need one of those Laser thermometers. Or better yet the new thermal IR camera built into the exact same form factor that keeps popping up in ads in my e-mail. Then I could repeat this and see the entire band's thermal profile change!
Most excellent experiment to conduct with rubber.
Indeed rubber does behave like a gas. The thermal effects stem from the entropy/enthalpy effect. Relaxed rubber has all of the loooong polymer chain molecules in chaotic bundles. Stretching it out to full length brings order into that chaos. This ALWAYS creates heat. Releasing the band means the molecules snap back to the state of chaos. This creates the cooling effect.
When, say, water evaporates, the same thing happens - the orderly molecules in the liquid are spreaded into chaos. This creates cold. When you compress the steam back into water, the opposite effect happens. That is why we sweat - the sweat evaporates, which cools the body down.
The new aspect of my little invention: There is no other cooling device that works with a material that does not change it's aggregate condition in the process.
Looks Great but it would be great When you can heat up your food too.
The next "sYrvival" Tool
Awesome, i cant wait to see that Texas slingshot.
Poor Mrs. Channel, pushing the beercooler-lever hole day long in summertime...no.
Another way: Wrap a wet cloth around the can and slingshoot it to your buddy standing 20m in front of you. The water on the cloth will vaporize fast in the airstream and vaporization will cool your beer. Back and forth until the beer temperature is ideal.
So both of you have training and Mrs. Channel has time to make sandwiches and go for more beer.
In warm countries they used porous amphoras since a long time, cooling the water...
To heat up your food,
Put it under your Shirt when you pump!
Mr. Sprave? Did you Devolve your channel format?