Dry ice chips w/interesting flow patterns

Buy dry ice in the Seattle area at QFC supermarkets. It's about $1.00 per pound, in the seafood section. Bring a styrofoam cooler. Otherwise check your yellow pages under Dry Ice, or phone various supermarkets.

Dry ice creates water-fog droplets which become trapped in the viscous thin "boundary layer" of air above a dark water surface. LOOKS COOL! Long ago at the U. of Rochester we had nerd parties with the SF society, gamers, etc. I'd supply a block of dry ice as one major piece of entertainment. (Makes big booms when, ahem, misused.) Finally I built some official equipment: painting a cookie sheet black. Years later I used this phenomenon to demonstrate the gas clouds around rotating comet nuclei. Also see a weird electrostatic effect:

THREADLIKE ELECTRIC WIND
http://www.youtube.com/watch?v=NX3dVpK23xo

http://amasci.com/weird/unusual/airthred.html

Category:

Science & Technology

Tags:

• science
• physics
• demo
• amasci
• demonstration
• co2
• dry
• ice
• comet
• nucleus
• nuclei
• solar
• system

[SBxxxStudios]

Hey I am from the Seattle area (Issaquah to be exact). I am actually going to QFC to get dry ice in a few hours. About what is the size of a 1-lb block of dry ice?

[wbeaty]

@SBxxxStudios I think 1lb is perhaps two cups? Since it's only $1/lb, I usually buy five or ten or 15 lbs.  Links to more experiments at bit.ly / 9Q2s7l

[drjustian]

Wonderful, I like it. The phenomena of rotating ice chips that do not sink is due to gas around the ice chips, true. However, the question is "why is that so?" It is so because, in addition to the gas the water tension helps support the ice chip. The water's surface tension is viscous, rather that inertial, allowing the lighter gas to support the ice chip. I think. Signed, David Justian. My theory of viscosity is at "David Justian" on YouTube.

[wbeaty]

Gas is viscous too: boundary layers remain trapped against surfaces. The higher it's viscosity, the thicker is the layer.

When the surface is large and the mass of the chip is small, the gas buoyancy wins over the weight.

[AmerB87]

wth, why does my comment always end up at the top when i hit reply to another comment, shouldn't it be under that comment if i hit the reply button?

[wbeaty]

> wth, why does my comment always end up at the top

Looks like a bug.  It seems random. And... that's why I always include your text in my response. Otherwise responses aren't connected.

[neomaster911]

no he is a computer simulation.

[MonsterEnergyMan]

STFU if you don't like it. What is he pushing? You are the one pushing the closed-minded bs on everyone else, so shut it.

[LegoOndWoWNerd123]

Hvy do you hold the dry ice with your hands thats not good :)

[Emomoz]

Why you reminded me of cookies :(

[zack95clark]

I really enjoy this guys videos

[Ivanlamperouge]

wonderful

[JaySeeAndWe]

@WrathWolfAngel you can pick it up with bare hands you just have to keep moving your hand and move really quick

[Caskader]

Very important: a big OLD cookie sheet and a big OLD pot of water!

[WrathWolfAngel]

well that's cool and all by wth, if you know so much about dry ice then YOU should know your not gonna use ur bare hands to pick it up -_-