can u use the stuff in air dusters.i think its either liquid nitrogen or carbon nioxide.

illegal nah ,
just beg the local high school ( may only work if you are a student in a cool teachers class though

To buy liquid nitrogen all you have to do is go to a welding store. Like Norco for example. It's not illegal, just like dry ice isn't...

No we use it as a sheilding gas for welding. You can a) Buy some at a welding supply shop b) Use Liquid Helium to cool gaseous nitrogen c) Buy a $20,000 LN2 machine d) Get some from a local dermatology lab.

illegal? OF COURSE NOT, it's just nitrogen...

you cannot liquify nitrogen with dry ice. Not aware of any retail source that will sell liquid nitrogen to tourists. I suspect someone knows someone who works in a research lab.

Liquid Nitrogen is -320 degrees below 0 Fahrenheit , or - 195.5 Celsius. Very cold stuff, I have worked with this often. (You should see what it does to a frog)

You can liquify nitrogen just like you do freon, with a compressor. Don't think you can do this with anything you can buy at Home Despot. You could probably pull it off, if you were interested in spending the money and time. I have other fish to fry. Practically speaking, you need a commercial source, or know someone who works in a hospital or science lab. We used to play with the stuff. And yes, it's really hard on frogs..

You can actually stick your hand in a vat of liquid nitrogen for a few seconds. This is true because your hand is so warm it causes the liquid nitrogen to evaporate. Pretty cool(bad pun), eh?

Also if this might help with the dilemma of finding liquid nitrogen, It is often used in the manufacture of aircraft parts (tubes and gaskets, I believe). If you work in a aircraft parts factory, you might be able to score some.

not illegal, just rare.

no, not rare, just mostly used for "scientific" purposes...

but seriously, where did you get it? i know how to make it out of gaseous nitrogen, but i don't have that either

Judging from the background in the video I would say a School of some type, no doubt a Science Lab.

Use dry ice... I think that's what he meant anyway... It's frozen (liquid) Nitrogen...

No it's not. Dry ice is solid (frozen) carbon dioxide. Not the same thing at all.

Ur right... two different things... I guess it hadn't occurred to you that gasses have to first go into a liquid state before they freeze. That's chemistry for ya... go figure...

No, not all do. Dry Ice skips the liquid state. See the attached link of google it.
http://www.school-for-champions.com/science/matter_states_pressure.htm

Actually, CO2 at 1 atm. will go into liquid phase. The catch is that is is very unstable and only stays in liquid form if pressurized.

in a fire extenguisher the c02 goes through sublimination which is liquid-solid instantly and can only stay liquid if pressurized.

I know it's been six months but I feel a comment is necessary for all the junior chemists out there.  Sublimation is the transition from solid to gas, bypassing the liquid phase.  It's what dry ice (solid carbon dioxide) does, and is most easily demonstrable by dropping a chunk in water and observing the bubbles coming off of it. 

CO2 fire extinguishers precipitate a dry ice "snow" created when the gaseous CO2 in the extinguisher dumps its heat as the pressure drops.  This snow then sublimates into the gaseous phase. 

As for where to find liquid nitrogen, first educate thyself.  It's very (very) cold and can cause severe thermal injuries if not handled properly (this means thick gloves, approved goggles, possibly facial protection, and tongs).  LN2 also expands to about 700 times its volume when it boils off, meaning placing it in a sealed container creates risk of explosion, and allowing it to boil off in a small, sealed room creates risk of suffocation.

It's not rare, toxic, or illegal.  It can be had at a gas or welding supply shop for probably around the price of milk.

Finally,an educated reply.We purchased ours from Air Products,which sells all sorts of welding gasses.We also used it in metalforming.A place I used to work made stainless steel fittings.In order to bend them to 90 degress without splitting,we threw them in a foam cooler with a couple inches of liquid nitrogen.Then they bend like copper.Another shop I worked at we chilled titanium bars so they could be machined easy.Once they got to room temperature the tooling would quickly wear down.

well, know i know where to get gaseous nitrogen now, but thanks anyway. hooray for air compressors!

How do you make it liquid?

Short answer you COOL air, google it or see below link.
http://www.pa.msu.edu/sci_theatre/ask_st/092894.html

I was having a brain fart on this whole topic... my apologies to all...

dont know

What leads you to that conclusion?

Wow! I don't even remember posting that! After watching it though I can see it is a rocket. It doesn't even seem like me to say it like that. very unusual.