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| South Pole Diaries 2000/01 |
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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
 
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