The typical
astrophysics student is a despondent
individual, already resigned to the fact that he (for they are
rarely female) has made a considerable social and financial error
in following his boyhood dream of being, like
Patrick Moore, an
astronomer. This,
and the mixture of arcane practices and customs that is
astrophysics in general and
AIPS in particular, leads to an unusually rich field of
niche humour in astrophysics coffee-rooms, most of which isn't
actually funny, and all of which is only understood by a handful of
people in the world. Long term residence at at observatories in the
middle of nowhere, particularly
Jodrell Bank, is known to accentuate this
humour problem very quickly - sometimes to such an extent that it
becomes untreatable.
The AIPS experience
For a typical
new postgraduate student (age 21-ish, degree in physics, astronomy
or chemistry), the first encounter with the software that is
AIPS is a strange and
unsettling experience of
Palaeolithic mysticism. Whilst astrophysics students are likely
to be used to
Unix-style
command line
interfaces, nothing will have prepared them for what they are about
to receive. The shock that AIPS is not at all like the software
used to discover alien messages in the
VLA control-room by
Jodie Foster in the film
Contact, is a
heavy blow - the first of many.
The Cookbook
The first
surprise is the
Cookbook. The AIPS manual is
formatted as a cookbook full of
recipes, where
data ingredients are calibrated together to form some kind of
cake (usually an image). Interspersed with these fiendish
recipes are real recipes, often involving bananas. This is
presumably in reference to the pun of AIPS with apes, and is an
indication of the humour that will follow and evolve. The cookbook
of course is littered with small images of apes, and typically has
an ape on the front cover - mimicking the AIPS icon itself, which
is, predictably, an ape.
No Warranty
Upon starting AIPS
for the first time, the condemned student is immediately presented
with a blunt statement of fact: that
AIPS comes with
ABSOLUTELY NO WARRANTY. In the insecure student's mind
this immediately raises the spectre that some kind of disk-wiping
crash is likely and indeed imminent, and panic sets in. This state
of panic is one that remains whenever an astrophysicist is using
AIPS, particularly when tampering with the more intimidating
routines such as
FRING,
CLCAL, or
the mighty
IMAGR (NB those who pronounce IMAGR to
rhyme with "Voyager" still have hope; those who make it rhyme with
"Grrr" are beyond help).
In fact, crashes are exceptionally
rare, and the AIPS "Dump" File (colloquially "ape-shit") is rarely
produced. If one wonders why there was the need to frighten the new
AIPS user with talk of warranties, then one is clearly not an
astrophysicist. The AIPS experience is very much less
WYSIWYG and very much more WYGIWYD
(
What you get is what you deserve).
The
Interferometry Hoax
At some point during the second
postgraduate year it becomes obvious to a typical
VLBI postgraduate that
radio interferometry is an
elaborate hoax (like
gravitational lensing), invented to
keep astrophysics researchers in jobs. This is easily proved by
getting two astrophysicists to stand 100m from a board of small
text, and asking them to tell each other what they see on the
board. The physical process of telling each other what they are
seeing (i.e. Interferometry) does not make the tiny text become
visible at 100m.
Being resigned and accepting kind of people,
the realisation that their PhD is based on a lie is not a great
blow to most astrophysicists; indeed it is a small blow compared to
the numerous painful blows already felt by this time (e.g. that
they will never own a house, or a
Ferrari, or visit somewhere warm that isn't a barren
desert observatory, or visit a mountain that isn't a cold desolate
observatory, or visit
Hawaii for anything other than being in the clouds,
or get to talk to a beautiful
woman). Rather, this realisation inspires the search
for a greater truth: where do the generated images come
from?
AIPS as a gift from God
Images produced from the
recorded observatory data fed into AIPS have been shown to be true
enhancements of that data. So, by the third year of his PhD, the
astrophysicist is chasing the origin of these images. This is only
one possible answer to this conundrum, and that is that AIPS was
written by
God. Every copy of
AIPS contains hidden in its core codes, encrypted by unbreakable
Holy algorithms, an exact copy
of the true and original blueprint of the
Universe as conceived by God Himself in the
moment of the
Big
Bang, approx 15Gy ago.
What AIPS does during the calibration
process is remarkable. It uses the supplied data to extract a
perfect image of the source at infinite resolution from the
Holy Blueprint. Then, the various AIPS routines add, one
after the other, layer upon layer of carefully calculated noise and
image distortion, so as to eventually produce an image of the
quality and resolution that would be predicted from the
cock
and bull theory of VLBI interferometry.
The question then
arises: "Why not refine VLBI interferometry so that the production
of perfect images without noise are allowed". Unfortunately, by
this time, the young astrophysicist has submitted his PhD, got a
tedious job as a software engineer, bought a house, a Ford fiesta,
and is spending his time playing computer games and has forgotten
what he used to know about VLBI. He should consider himself
lucky...
The Future
Using AIPS is liking riding a bike -
you never forget how to do it. Many years in the future, former
AIPS users get cold shivers when the unprovoked thought of
<
tget imagr> pops into their head. At that point the
followup thought is usually:
I wonder if AIPS is finished
yet? (To which the reliable answer is
NO!).