Xi Beta Theta

Friends, I'm going to let you in on a secret: scientists like to have fun. Sometimes, we even tease each other, give each other a hard time. It's hard to believe, I know, but scientists do have personalities.

An XBT thermistor with copper wire attached.
White paper used for contrast.

Allow me to explain. There's one particular instrument for physical oceanography known as an XBT. It's used to measure the temperature in the water column, giving oceanographers an idea of what water masses are present at what depths. The X in XBT stands for Expendable, because an XBT never comes back. It's essentially a thermistor inside a weight with a copper wire attached. You toss it over the back of the ship while transiting. The wire pays out until the weight hits the bottom, and temperature readings are transmitted through the copper wire to a computer on the ship. When you're all done, you snap the copper wire with your fingers and say goodbye to the XBT.

Well, there's a certain tradition surrounding the XBT. Some may call it hazing, but in my mind, hazing is what sororities do to their freshman. It usually involves waking them up rudely in the middle of the night with buckets of cold water and then doing something marginally legal. What we do is much more innocent, much more academic, and much more fun. If you've never fired an XBT before, stop reading now, because otherwise the surprise will be spoiled.

Every first-time XBTer is warned up-front how dangerous the device is. They are told that deploying an XBT is something akin to shooting a rifle, just with stronger kick-back and less opportunity for control. They get dressed up in all sorts of safety gear, marched out to the back deck, and instructed to brace the XBT gun against their shoulder. More experienced lookers-on stand a safe distance away, lest a misfire should send copper wire streaming across the deck. We warn them; we prepare them; we tell them to brace for a nasty kick-back.

Katie launching her first XBT while wearing steel-toe boots,
a life jacket, a hard hat, goggles, ear plugs, and a
headlamp. For the record, only the headlamp was
actually necessary, and that's only because it was dark out.

Friends, all of this is crap. "Firing" an XBT actually involves no fire at all. There is no gunpowder, no trigger, no explosion, and no kick-back. You simply remove the pin, tilt the "gun" forward, and drop the metal ball into the water. The only sound you'll hear is the splash of the thermistor on the ocean surface, and the only danger is that you'll want to sink through the deck for embarrassment.

It's been fun to razz some of the students on their first cruise with XBT nonsense. I was exposed to the initiation rite on a cruise two years ago, so now I get to further the tradition. It's one of the ways we keep cruises entertaining.

Now you know the secret, but if anyone asks, you didn't hear it from me.