Wednesday, June 27, 2007


Silica is a nutrient in the ocean. Silica is used by little phytoplanktons called Diatoms. We like phytoplanktons because they take away all the bad, yucky CO2 we’re pumping into the atmosphere. We want to know about silica so we can know about phytoplanktons so we can know about CO2 uptake (see flow chart below).


I am running samples for Silica today. And I ran samples for Silica yesterday. And I will probably be running Silica samples tomorrow. How do you run Silica samples, you ask? Well, I’ll tell you!

We use a technique called colorimetry. In a nutshell, we add a little bit of our water sample, add a cocktail of hazardous chemicals, pump the mixture into a machine called a Spectrophotometer and presto-chango we get an absorbance reading! Absorbance is a number that makes no sense until it’s put in the context of a standard. Here, let me explain.

Imagine that you are a fancy-pants scientist with a very expensive and very sensitive Spectrophotometer. Your Spectrophotometer has a beam of light built somewhere in its complicated interior. When you stick something in front of that light, the little reader inside the Spectrophotometer says “Hey, that asshole put something in front of me. This is how much my beam of light has changed.” You record this number. Please dismiss any disparaging comments made by your scientific instruments because this senario imaginary and scientific instruments don’t talk. But if they did, they would be grumpy.

Now about this standard business – a standard is just a sample with a concentration that you know precisely. You want to use a couple of standards with different concentrations so you can get a good range of values. In your imaginary lab, you’ll run your standards and say to yourself “A standard with concentration X gave me an absorbance reading of Y”. When you do this for all of your standards you’ll end up with a nice linear relationship between absorbance and concentration. You’ll get yourself a simple equation that you can pop all of your meaningless absorbance readings into and get out very useful concentrations and then make lots of charts and tables and powerpoint presentations with your data.

What we’re dealing with here is described by Beer’s Law. This is a serious scientific law with important implications and has nothing to do you with you doing a keg stand at your frat brother’s 23rd birthday party last year so quit snickering. Beer’s Law relates Absorbance (what your little spectrophotometer reads out) and Concentration (what you are trying to get). Beer’s law says:

I1 / Io = 10^-A. where A = l*c*k (the little ^ tells you that -A is an exponent)

Break it down!

Io is the intensity of the light you start with, I1 is the intensity of the light after it has passed thru your sample (see figure), A is the absorbance (what your instrument reads out), l is the path length of the beam, k is your “absorbance coefficient” (whatever that means), and c is the concentration in your sample (what you want).

In a perfect world you would know all these things. You would know your beam path length and your initial intensity and all that shit. But the big secret is that science is imperfect. Your spectrophotometer is gonna get bumped around and glassware is going to get dropped on it or samples spilled on it or cheeto crumbs mashed into it somewhere. This is why you use the ole’ standards trick 'cause now you can avoid having to use Beer’s Law. See, scientists aren’t perfect either. We just plan ahead because we know how sloppy and clumsy we really are.

Wednesday, June 6, 2007

Shipboard etiquette

Let us turn to the all important science of human relations. Specifically, the science of human relationships while in a confined and isolated environment. Like a boat. There is a lot more to being an oceanographer than throwing big and expensive instruments overboard, you have to know how to cope with crew and fellow scientists while at sea. Both parties are entirely different and usually keep to their own. Here are some helpful hints should you find yourself on a long research cruise or, similarly, being smuggled to China for sweatshop labor. Let these tips guide you so that you won’t be fed spermburgers in the galley, or shanked in the back during your watch shift, or included in the mutter rants of the surly chief engineer. And trust me, they are ALL surly.

* Never throw up in the bathroom. Only throw up overboard. I don’t know why, but if you toss your cookies in the bathroom everyone gets mad at you.

* Front of the boat is the bow, back of the boat is the stern.

* If you’re facing the bow, starboard is on your right, port is on your left. You can remember this because “port” and “left” both have four letters in them.
* Let the captain talk to you. Some are friendly, most are not. Feel out the situation for yourself before you start gabbing about how early it is or how cold you are or how choppy the water is. He’s gonna think you’re a pussy if you start in with the complaints. And he’d be right.

* Anything that looks like a hose is typically important.

* No sandals on deck, hippie.

* No farting on deck. Wait till you’re someplace enclosed and in close proximity to the most annoying member of the science party. Preferable the cold storage room.

* Scientists, as a rule, are more annoying than crew members. Shocking, I know.

* Someone will always know what you’ve been looking at on the community computers. Always

* Don’t press any buttons, especially not if they’re flashing. Tell someone else about it.

* Do answer a phone if it is ringing nearby.

* Don’t talk too much.

* Do get your work done and show up for your watch shift on time.

* Do bring your own alcohol supply IF you are working on a US research vessel.

* Do take advantage of the open bar when working on Canadian, German, or Russian boats (for reals!)

* Don’t eat anything out of ANY refrigerator EVER!

* Don’t accept any compliments/favors/candy from members of the crew unless you intend on sleeping with them.

* Two movies to never put on in the community movie room: Apocalypse Now and Maid in Manhattan. Both will make you extremely unpopular.

* Don’t roll up to the chief engineer with a bunch of bolts in your hand and ask him if they are important. Even as a prank.

* Do get some exercise while you’re at sea. Just look at the crew.

* Don’t eat Doritos while working on the computer.

* Don’t eat Doritos while working with any scientific equipment.

* You know what? Give the Doritos a rest, why don’t you.

* The ocean is a beautiful place and deserves your respect. No peeing off the stern.

There, that should get you through a few days. Let your common sense guide you the rest of the way.