1001 things to do with Liquid Nitrogen
In the course of studying physics one is officially taught that liquid nitrogen is simply (and mainly) used
to cool things down to 77K. But everybody who once has observed students in practical courses "working" with this stuff
knows that this is not true.
My intention is now to tell the truth about what is really done with liquid N2 before its
remains are taken and used for cooling.
As we all know liquid nitrogen is mainly used for...making icecream by stirring for example yoghurt under it.
(mind the carpet!; Darmstadt Group)
Roger Carlson comments on this topic
I have pix of making ice cream (with a good recipe), feel free to link
to them if you want:
putting pieces of chalk in it for making little hovercrafts (best on linoleum floors!)
twirling in large basins so that because of its low viscosity you get a
(nearly) infinitly turning maelstrom. It's good fun to watch little
paper-boats floating on it for minutes.
inhaling its fumes because everybody will make eyes on you exhaling.
freezing your partner's chair while he is shortly absent.
for squirting water in it. If you use a spray-bottle you can squirt funny
ice patterns into a basin with nitrogen. My alltime favorite: Helmar's ice-earrings
one word: marshmellows
its nice for cooling a good beer in a basin of water on which the nitrogen is poured
(not much fun to look at, but great fun to drink; Darmstadt Group)
Put on a rubber surgical glove with a hot dog (saussage) stuck in one of the
fingers. Put the hot dog in the liquid nitrogen and then, to the amazement
of your friends, smash your "finger" with a hammer. (Wes Denisson)
Comment: Keep in mind which finger...
Get a pot of boiling water and pour some nitrogen in it. You will watch the
mists of hell shrouding the floor. It's good fun to test how long
you can stand sticking a finger into it - a cool feeling ...
Get about a liter of soap bubble solution hot and pour about a cupful of liquid
nitrogen in it. Bubbles go everywhere! (Wes Denisson)
Break a light bulb, put the filament into liquid nitrogen and turn it on.
Looks cool! (Wes Denisson)
Put a little bit of nitrogen in a can with a plastic snap on lid. We use a
Pringles Chip can. After you pour in the nitrogen seal the lid. The lid will
pop off with a boom and fly off. (David Hutchison)
Blow up a balloon. Put the inflated balloon in the nitrogen. It will deflate,
then take it out and it will inflate as it warms up. (David Hutchison)
A siberian frog frozen in liquid nitrogen shall come to life again if you throw
it back into the water. (Prof. Alois Loidl, who never tried it in public, but
used a wind-up frog of his children instead, for demonstration)
Freeze a can of shaving cream and then peel the can away from the
cream. Put the canless cream into someone's car. Let the oven-like
heat from the car's sitting in the sun defrost the shaving cream.
2 cans will fill an entire car. (Coulter C. Henry, Jr.)
Freeze a banana in liquid nitrogen and use it to hammer a nail. (Wes Dennison)
Here is a small anecdote from Markus Selve (Stuttgart, Germany) I will just quote:
"Wir haben hier nebenbei auch 'ne Anwendung entdeckt.
Eigentlich wollten wir eine wassergefüllte PET-Flasche (Cola)
unter Druck setzen und dann als Rakete hochschießen. Mit Aufpumpen haben wir leider
nur 5 bar erreicht. Deswegen haben wir in die Colaflasche ca. halb mit Wasser gefüllt.
und dann ca 100 - 200 ml LN2 zugegeben und den Deckel geschlossen. Im Deckel war ein
Loch in das wir ein Fahrradventil (nur die äussere Röhre ohne den eigentlichen
Ventileinsatz) gesteckt hatten. Da drin war ein Gummistöpsel. Eigentlich sollte es bei
Erreichen des Enddrucks (was auch immer der hätte sein sollen) den Stopfen rausdrücken
und die Rakete vom Wasserstrahl hochgehoben werden. Es hat aber den gesamten Schraubdeckel
abgerissen. Das Wasser ging ziemlich schnell raus und die Rakete ist immerhin bis zum 7.
Stock (ca. 30m) geflogen."
Here is another quote from Jeeplass (Philadelphia):
As an employee of the Franklin Institute Science Museum in
Philadelphia, Pennsylvania, I had many occasions to use liquid nitrogen in our Hot & Cold show:
One thing we used to do for smaller groups was to freeze a graham cracker and
then eat it. The vapors released through your mouth and nose are quite
dramatic and it really does tintilate your tastebuds! Of course, we usually
waved the cracker around just a little before eating it to be sure no drops of
the really cold stuff linger.
This story was mailed to me by Earl Blodgett (Wisconsin)
For several years our Society of Physics Students
chapter has entertained visiting students with a spectacular liquid nitrogen depth charge.
The term "depth charge" is used because we have a large extremely durable plastic trash can filled
with about 40 cm of water. - After a short safty talk, focusing on the rule of NEVER tightly sealing
a vessel containing liquid nitrogen, we use a long-necked metal funnel to pour perhaps half a liter of
liquid nitrogen into an ordinary 2 liter soda bottle. Then we tightly screw on the cap, and drop it into
the water! - For several seconds, one can hear the bottle expanding! The preferential orientation of the
polymers makes the bottle get longer and longer, rather than a more spherical expansion. However, eventually
the polymers just can't take it anymore, and BOOM! A quite satisfying detonation, sending water, nitrogen
vapor, and bits of plastic high into the air. - The heavy duty plastic can serves to direct the "shrapnel"
upwards, it is lots safer this way versus just setting the bottle on the grass and running away!
(picture 1, picture 2)
Larry Weinstein sent me the following: We have two more demos we use LN2 for here at ODU:
1) Take a 'ringshooter' (used to demonstrate Lenz's Law by placing an aluminum ring around
an AC electromagnet [made by wrapping wire around a long thin iron core - typically 15-20 cm
high and 3 cm in diameter] - the Al ring will jump into the air, a split Al ring and a nonconducting
ring will not move) and demonstrate that the Al ring will jump from the magnetic repulsion. Now
chill the Al ring in LN2. Repeat the demonstration and the ring will jump MUCH higher (since its
resistance decreases substantially at -200 C)
2) Take a thinwalled metal cone, point downward (a sealed metal funnel will work). Fill it with LN2.
Wait. Oxygen will condense out of the air and drip from the tip of the cone. Hold the tip of the funnel
between the poles of a strong magnet. The drops of liquid oxygen will levitate there (if the field is
strong enough) giving a rare good demonstration of paramagnetism. (This demo is courtesy of Sebastian
Kuhn, also at ODU.)
Four suggestions by TOM MILLER (Air Force Research Lab):
(1) Start a show by sticking one end of very flexible tubing
(e.g., latex or tygon) down into a dewar; the heat of the tubing
will cause LN2 to spray out the other end of the tubing, and
you can direct the spray at the audience. After the submerged
end of the tubing is completely frozen (and the spraying stops),
remove from the dewar and whack the frozen end on a table
and watch it break into pieces.
(2) Wrap a long piece of latex tubing around itself and stick
the whole thing into a dewar of LN2 until completely frozen.
Remove and place on a table, and continue with the rest of
your show. After a few minutes, the tubing will slowly start to
move, sometimes crawling across the table.
(3) Stick flowers in LN2 and then crumble them in my hand;
large ones like carnations are best. Sounds simple, but the
kids love it.
(4) I freeze balloons, as you mention, but in a better way.
Blow up a balloon and slip the end of the balloon over the open
end of a test tube, and place the closed end in a dewar full of
LN2. Your breath in the balloon will slowly liquify (10-15 minutes).
When the balloon is completely deflated, lift the test tube out of
the dewar and the audience can see your liquified breath in the
test tube. The tube will frost up, but you can wipe the frost off
with your fingers. Rest the test tube in a beaker, and as time
passes, the balloon will inflate again.
Bob sent me an email reading:
not exactly a *fancy* idea, but I thought it was cool;
bouce (or have a volunteer bounce) a soft, hollow ball. then freeze the ball LN2 style.
using gloves, try to bounce the ball again. The always neat shattering effect will be
accompanied by a loud bang.
also, throwing LN2 from a bucket at a wall - preferably above someone -
creates some interesting effects (the wall will "smoke" for a while)
An email with the following idea comes from Ken Hubbard (da Vinci Middle School, Eugene, Oregon):
I do another "trick" with my middle school students. If you put about 10 ml of LN2 into
a styrofoam cup into a bell vacuum you can see solid nitrogen. The crystalization "puffs" up
very quickly. Really cool to be able to see N as a solid, liquid and a gas.
Something nasty is proposed by Craig Shaw:
fill a small bottle with ln2 then screw the lid on tight. Put in a bag of flour and seal with elastic band. Then run
Åge Guddingsmo from Norway suggested the following:
The other day me and some other students where playing around with Liquid Nitrogen.
I got the Idea to put it in 1/2 l soda bottle and watch it blow. To increase the rate
of heat into the bottle we used water. We used a 10 l bucket with water. It resulted in
an huge explosion, leaving the bucket in small pices over a larger area.
Something for the techies among the readers of this site sent to me by Ralph Lewis Newman-Allen
ya this isnt as quick or as easy to do as most of the fun things on the site..
but a project that someone else accomplished in finaldn i think (not sure where) use a
liquid nitrogen bath to cool a AMD 1ghz cpu and overclocked it to 2ghz.
The guy mentioned, and this is what im hopefully going to accomplish/find out,
that he probobly could have overclocked it further then that but he apparently didnt have
a large enough powersupply.
This is the thing thats curious though. Im no expert in computers just a long
term intermediate user, butas far as i know most of the power goes to your monitor
(about 80% less with an LCD monitor) but even then its still probobly the most.
I wonder how minimal the cpu power drain really is on the system overall and how cost
effective it would be in the long term to just pay a few extra bucks a month, if
thats what it would amount to, for electricity then to buy a new pc system every year.
Of course theres always the cost of the nitrogen compressor too which would prob be a tad expensive.
Ron George from Llanelli, Wales (UK) wrote to me:
I "fry" an egg using LN2. Crack an egg into a frying pan. Pour LN2 over the egg.
It turns into a "fried egg"! When it warms up again, it becomes an uncooked egg once more.
Paul Beauregard is writing:
Pour LN2 on the tile floor with a sweeping action as you walk. It gathers
up dust into a gray mat like felt. It's sort of like using a water hose on
a driveway to push dirt in one direction. Great for 'dusting' under heavy
machinery or instruments. Sweep up the gathered dust at the edges of the
room or the low point in the room and it's gone.
Tish Richey gives an example pour les Chefs
One of my favorite liquid nitrogen demonstrations is to place an egg (raw & in shell)
in container and cover with liquid nitrogen. after the nitrogen has evaporated,
take the egg out smash it with a hammer, it appears to be hard boiled.
As it cools it returns to white and yolk.
Lets hope the fire brigade takes this joke (Dr Lucio Baggio; Univ. of Trento, Italy)
Hide a Dewar into one friend's dorm, drop LN2 around when he is not watching, and
then cry "FIRE". This was told me by a friend of mine, who enjoyed to see the attempts
of the victim to stop the fire...
Richard Mack tells us about effectively cleaning floors:
LN2 also works great for sweeping and cleaning hard floors such as concrete or wood.
Get a couple liters in a container, and dump it on the floor in the direction
you want the debris to travel. It picks up everything in it's wave and if it hits a wall,
the wave will boil off and deposit the junk there. Now all you have to do is go
around the perimeter and sweep up the clutter.
James McSheehy agrees with Richard Mack
LN2 is great for cleaning linoleum or vinyl floors. As it rolls across
the floor and boils, it picks up dirt, dust, and small debris. With a
little practice, the detritus can be sent in a specific direction and
deposited under a lab bench or out the door. Perfect for fast clean-ups
when lab directors decide to visit the worker bees.
Jeremy A. Smith tells us a small story:
At the Gettysburg College Physics department we used to do all kinds of liquid
nitrogen demos to wow visting students. All pretty run of the mill stuff, but
at the end of the spring semester the department head would give the Society
of Physics Students free reign to play with the remaining liquid, as most of
it would dissipate over the summer break anyway.
We did several 'depth charge' style explosions in the fountain that sat in
front of the physics building. Unsatisfied with that we created a liquid
nitrogen cannon with a simple piece of thick cylindrical pipe, capped off
and weighted at one end (we also had free reign of the physics department
metal shop). We would put a small amout of liquid nitrogen in a 16 ounce
plastic bottle, tighten the lid as taight as possible, and placed it upside
down in the cannon. Then we placed a lacrosse ball on top of the bottle...
if you ever noticed, those bottles are concave on the bottem and thus made
perfect resting points for spherical projectiles. We would expediate the
expansion of the gas by pouring some water into the cannon. The explosion
would be very impressive, launching the ball tremendous distances. With a
stop watch and some quick application of basic kinematics we determined we
could get the ball to reach heights of over 40 meters! An impressive show
to say the least. We were never able to find a suitably sized pipe to
create a 2-liter bottle cannon... probably for the better, as we probably
would have tried launching bowling balls or something.
As a side note, we only ever had one mishap. Once we fumbled a bit too long
with the cannon and a bottle exploded in my hand. The most significant
damage was the startle. The concussion was considerable though, numbing my
hand for twenty minutes or so. The only other lasting repercussion was some
scratches from the tattered plastic shards. Lesson to be learned: Physics
fun is not without its hazards.
Another story by Chad Orzel (Physics Department, Union College)
Regarding the "Liquid nitrogen in a Coke bottle" trick,
you really ought to warn your readers to be cautious about
trying that one. I know of a case at MIT where a bored
graduate student put liquid nitrogen in a Coke bottle, and
became alarmed when the bottle started to swell up. He
couldn't get the cap off, so he put the bottle in a restroom
sink, and waited outside the door.
The resulting explosion destroyed the sink, and drove little
slivers of plastic into the walls and ceiling. I've seen
pictures of the aftermath-- the damage was pretty impressive.
Somebody in the same room when the bottle blew could've been
(Of course, since nobody _was_ injured, it's a funny story.
I'm especially fond of the coda, where the campus police
called his advisor at home (the whole thing happened in the
early morning hours), and told him that one of his students
had blown up the lab with nitroglycerin... The advisorm
needless to say, was rather relieved to learn that said student
had only destroyed a bathroom with liquid nitrogen.)
no comment on the following suggestion by Edward Lin (California)
Another trick you can do is to "drink" LN2. since the nitrogen will vaporize
when it gets near your tongue, it will float on an insulating bed of
nitrogen gas and not actually freeze your tongue. You can then blow smoke
and impress your friends. Important Note: dont drink very much at a time
(just a sip) otherwise your skin temperature may eventually get to freezing,
and also do not actually swallow since your epiglotis will seal off your
esophagus and hold the LN2 long enough to freeze the surrounding tissue.
Marshall Hampton has tried the same as above
You can put a little in your mouth (not too much!! - about half a small
spoonful) and let wisps of vapor come out. This is quite safe if you don't
overdo it - like water on a very hot stove, the N2 doesn't wet the surface.
Here is what Ian Hook (Ex. University of New England) mailed to me:
My clumsy physics Lab partner was always knocking over or spilling things.
So naturally when a beaker was spilt all over my Lab note book, I grabbed it
and lifted quickly out of the way.
How does one explain to the lecturer why my entire years work is shattered into
a hundred pieces ?
Luckily the partner did not stay for another year. He noted that a 1 inch diameter
polished steel optical reflector was very dirty. It needed more than just a simple wipe.
Intending to moisten it........ he lost a huge chunk out of the centre of his tongue !
I think he was expelled after a "snap oral test".
Otherwise, it's great fun for the careful.
Another nice trick was mailed to me by Dan Dulek (Stagg High School)
Try taking a ping-pong ball and poking a small hole in it. The hole has to be tangent
to the sphere of the ball. When poking the hole use a pin and the pin should be almost
flat agianst the ball. Basiclly you want a hole in the side of the ball that will cause
the ball to spin. Submerge this ball into the liquid nitrogen and let it fill up.
Place the ball on a table and watch it spin. As the nitrogen goes back to a gas it will
rush out the hole and presto!! It's pretty cool. If it does not spin try placing your
hand on it to warm it to get it started.
Michael L. Clark, PE mailed to me the following text:
One of my favorite demonstrations is to freeze miniature marshmallows and