South Pole Diaries 2000/01

   

   


Wednesday 13th December 2000

From Paolo Calisse.....

The instrument is still working fine and collecting his data, unaware of the passionate debate that started at UNSW about the following question: which is the best strategy to measure Dome C atmospheric transparency at 350 micron wavelength?

To understand why people should spend days on such a cryptic issue, instead of chatting about sex or cricket (soccer for my countrymen), you have to understand that scientists are really just kids that have never grown up, with the only relevant difference that their toys are a bit more expensive and provided by taxpayers, not their parents.

If you work in the field, and I like that, or spend years in labs worldwide, sooner or later you'll get it. It is a continuous game to show your colleagues you are the smartest, the more competent, the more "quick-witted" (I hope I have accurately copied this strange word from the Collins Italian-English Dictionary). Not only for career problems, as if you were interested in money and success, you would be opening a layer office, not wasting your time in the freezing cold. Just because you can't avoid it. Is part of our nature.

I have a theory about science, still not popular like the Popper's one to tell the truth, that the two most important engines for mankind's restless progress are laziness and childishness.

The importance of laziness is evident. Suppose you are a Neanderthal man pushing a squared stone, several hundred kilos heavy, to make your bed a bit more attractive for the girl (actually a bit hairy) who has agreed to meet you after sunset. Thinking requires a bit less energy than pushing a stone, so you sit panting on it for a while and start to think about how the hell to do the job with less effort and, above all, within due time, without loosing all of your energy (Prozac was not available at that time).

Under these conditions, it is quite easy to understand how you can invent the wheel, the rope, and a lot of other funny and useful things, just because you are so tired of destroying your backbone just to do what Mother Nature asked you to try to do tonight.

Think now about childishness. This is a little bit harder to explain, but one of the most powerful engines to make your lazy brain do work, is to do something not alone but with a colleague, like to develop a new instrument. At the beginning, you start dressing your best smile, but it is likely, that after some time you will have to decide if the hole for that damned screw should be done there or 5 mm to the left. Despite the fact that it is exactly the same in most of the cases, you can easily start to argue with that ignorant mate of yours, trying to demonstrate something which is impossible to demonstrate, clinging to your ideas as if it had suddenly become the most important thing in the world, exactly like a 5 year old kid could feel respect that flat balloon that never touched up to the moment the neighbor's son comes home to play with him and start getting it.

But this is the way science makes progress. Forget about sages, white hairy scientists with a visionary views of the future, it is just a question of pure humanity, I mean, childishness.

So, the instrument is acquiring his data, not informed about the harsh battle ensuing via email between here and several offices at the University of New South Wales. Everybody has an excellent point of view, and is asking to me to change the observing strategy (that means to make some adjustment on the instrument control program) following their suggestions.

The friendly atmosphere, the ingenuous jokes of the past are quickly over and everybody searches in others email for certain signs that the problem is no longer just about science progress, but a personal vendetta against him.

The problem is that we have to measure, to say it roughly, how much radiation is emitted from the sky at a given wavelength, actually, 350 micro-metres. Yes, the sky emits radiation, infrared light, light, otherwise it would be completely dark, and we are here because of that (also the daily blue color is quite a different phenomena with respect to the thermal emission we are measuring, that doesn't expire at night). This radiation is important, because it can tell us, and a possibly not very interested world, if this is the outstanding site we hope to build an infrared astronomical observatory on.

Well, the instrument we use here, the SUMMIT, features a rotating mirror, that allows US to look at different directions above the horizon. If you look just over your head, the beam will travel across the atmosphere, collecting all the radiation emitted by it, that represents just a lot of unwished noise for the never satisfied astronomer. If you look toward the horizon, the instrument will look toward a thicker layer of atmosphere. This is why, for example, the sky is more foggy toward the horizon than toward the zenith (the, I guess, Arabian word for "directly above your head" or something like this).

By looking in different directions above the horizon, you can "easily" compute how transparent the atmosphere is. You can't do it with just one measurement though, because two different parameters determine how much radiation is emitted by the sky: the opacity and a sort of "average" sky temperature. A warmer body radiates more than a cold, and a more transparent body is emitting, for definition, less radiation than an opaque one. You have to get both the parameters out of your data, that can easily be done by looking at, at least, two different directions through the atmosphere as, these two parameters play a slightly different role at different elevations above the horizon.

The problem is "how much easier" can the job be done. Up to about fifty years ago, it didn't matter, there were no computers available anywhere, and scientists spent days and days just manually computing and verifying the theories behind the small amount of data available. It was natural that the main effort was to find the less elaborated way to reach the goal.

Today, computers allow us to think in a different way. As soon as you start reflecting on how to explain a natural phenomena, or to measure some physical quantities, or to design a washing machine, your trained brain starts thinking of the most complex and absurd strategies, relying on the good, "old" computer to extract the needed information from a mess of cryptic data. This approach brought with it, in my opinion, a sort of laziness - again - in the contemporary scientist. No more time spent to "simplify" your models, your instrument, or your observing strategy: just let the PC do the job.

This removed, according to many people, a sort of elegance in most contemporary experiments. Opening the door that unveils natural laws, scientists are now more like a horde using heavy rams, with respect to the delicate and light passpartout used by the sharpest "thefts" of the past.

On the other side, present successes in contemporary science are just not even imaginable without a stack of PCs on any serious office desk. Yes, indeed, just like Bill Gates' property (Ed - I think Bill Gates uses a I-Mac now though).

In the end, we have two parties: John Storey, siding for an "old fashioned" observing strategy, robust, tested and easy to be done and analyzed. Michael Ashley and Michael Burton on the other side, pushing for a more complex, and probably powerful, observing strategy, that will require a lot of painful efforts from some disgracefulles at the uni to analyze data.

And, in the middle, a poor, frozen astronomer at Dome C, the typical "last wheel of the cart" (actually, I don't know if this phrase is used in English like in Italian), expected to actually do the job.

Who will win the game?

The answer, hopefully, tomorrow.

Paolo