Random Story – Playing with mercury

This is just an odd little story from my life.

I was a physics major in college back in the 90’s.  On the physics floor of the science building there was a room which I think was meant to be a study room for majors: there were bookshelves with old science books, a blackboard and a computer hooked up to the internet.  But I think it largely ended up being used as random storage.  In fact, it was where they kept the radiation sources.  These were little plastic disks that held alpha emitters, which would only be dangerous if you ate them.  Alpha particles can be stopped with a sheet of paper, but these were kept in this thing on the countertop built out of lead bricks with a sheet of lead for a roof.  (Side note, those lead bricks made excellent doorstops.)

Anyway, one day I was poking around near the lead bricks and I found a puddle of mercury.  Apparently a thermometer or two had broken.  I told one of the professors, and he put it in a little square, glass jar, maybe half-an-inch on a side and two inches tall.  I don’t know if he didn’t know what else to do with it, but he left the jar in the room. 

I stopped in to use the computer the next day and I found the jar, and I started playing with it.  I quickly found two odd things.  First, when you sloshed the mercury against the glass, there was a metallic ting sound.  Which is not the kind of sound you expect from a liquid.  I mean, if your milk goes “ting,” you have an issue. 

The second odd thing was the weight.  Setting on the counter, the mercury barely covered the bottom of the glass jar.  When you picked it up, you assumed that most of the weight was the glass.  But when you shook it, you could feel the mercury throwing its weight around.  For a brief moment it would be in midair, and then it would slam into the top or bottom of the jar and you could feel it jerk because something heavy had slammed into it. 

I would sit there at the computer shaking this glass jar for minutes just to hear the tings and feel the weight shifting just because it was so weird.