Stand Back, I'm Going to Try Science!

[big_bad_al]

My father is a chemical engineer at a large company. He volunteers in an outreach program where the company gives him science demonstrations aimed at precocious elementary schoolers, and he periodically goes to schools and birthday parties and stuff to show how neat science is. One of the kits he does is all about cryogenics, where he gets about a

Comments

[envirobitch]

Thanks for the photo-essay! This looks awesome!

[mikasaur2000]

I think LN2 is capable of turning the O2 in the air into liquid. I don't remember exactly how to do it, but in an issue of Popular Science they explained how to collect liquid O2 to drop onto burning things.

Liquid oxygen make fire go BOOM!

[big_bad_al]

You're absolutely right. Carl von Linde was a German dude in the late 19th century who was working on a cutting edge technology, refrigeration. He experimented with ways to compress air (which heats it up), cool it to room temperature, and expand it again to cool it down (which is pretty much the way modern refrigerators work). but here's the trick he invented: if you then take a second bit of air, compress it, cool it down using the first batch of cool air you made and then expand it again, you can get the new batch even colder than the previous one. You can repeat this process, getting colder and colder, until you get liquid air

[nematic]

more like ml of liquid O2, unless your dad is using weather balloons. 22.4L O2 gas ~ 32 ml liquid. Also, if you do this in the future, I recommend tennis balls - better than raquetballs, the felt helps them keep somewhat of a shape after they are smashed. Also, marshmallows are also fun - when frozen they can be easily ground into a powder, that when warmed up returns to its normal stickiness. Never thought of trying various oils in it though, that looks cool!

[big_bad_al]

Thanks for pointing out that my "ounces" claim is wrong. It's hard to judge how much stuff is inside a deflated balloon. I'll pass along the tip about tennis balls; that sounds promising!

Dad froze some bite-sized marshmallows during the main demonstration, and we ate them cold (since they're mostly air, it takes very little energy to warm them up again so it's safe to feed them to elementary schoolers). They're crunchy.

[mockery0]

http://www.marriedtothesea.com/122308/lets-hear-it-for-chemists.gif