Category Archives: science education

Nefarious Mad Scientist Scheme: Freezing the Atmosphere

As a demonstration in class this past week, I and one of my henchmen froze a small portion of the atmosphere. 

That’s it in the bell jar.  If it looks like ice floating in liquid, it is.  Before we froze the atmosphere, it needed to be liquified.

The process was amazingly simple.  Once the atmosphere was liquified, all we had to do was boil it.

I call the device the atmosphere-freezinator.

So, unless you want me to freeze the entire atmosphere of the Earth, you’ll deposit.$500 in US currency each month in one of the following offshore accounts-

Excuse me, there’s someone at the door.  I’ll finish delivering this ultimatum once I’ve dealt with them.

Who left this platypus on the doorstep? And why is he wearing a fedora?

Hey, where’d you get that- Urk!

To see more pictures and find out what’s really going on, click the link below (if you’re accessing this from the main page of the blog) to read more:

This demonstration really is pretty simple, but you have to have equipment that can handle extremely low temperatures. 

What we did was take liquid nitrogen, which makes up about 78% of our atmosphere.  We really did boil it, but we didn’t put a flame on it.  (That would have produced a gas under high pressure in a small volume, or what in layman’s terms is called a bomb.  I’m a mad scientist, not a suicidal one.)

Rather, the bell jar is sealed so that it’s airtight.  Once the liquid nitrogen had reached thermal equilibrium with the plexiglass container it was in, we pumped the air out of the bell jar.  You can see the hose to the pump in the bottom of the picture on the right. 

The lower pressure causes the liquid nitrogen to begin to boil.  Boiling is a cooling process.  Most people don’t think it is because they only boil water on a stove, which has a heat source.  The burner replaces the heat the boiling process removes from the water.  If you take a pan of boiling water off the stove, it will boil for a second or two then stop.  That’s because the boiling lowers the temperature.  This is the same principle behind many air conditioning and refrigeration systems.  It’s also the principle behind evaporative cooling, which is why a breeze on a warm day feels cool.

Let me try to explain it this way.  The phase change from liquid to gas requires energy to break the bonds in the liquid.  That energy has to come from somewhere.  In this case it comes from the liquid nitrogen itself.  That lowers the temperature of the liquid nitrogen.  (See, I told you it was a cooling process.) 

Nitrogen becomes a liquid at 77K (-321 degrees Fahrenheit) and a solid at 63K (-346 F).  These temperatures are quite close together, so it doesn’t take much of a drop in temperature for the liquid nitrogen to freeze. 

We were able to freeze the liquid nitrogen completely solid. That’s it below.  You can just see a small amount of liquid nitrogen along the bottom and sides.