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Daily Telegraph London 10.4.2002
View from the lab
Alcohol in space?
Take more ice with it
recommends Prof Steve
Jones
ON an American plane
I was once given a bottle of fizzy
water that bore the caution:
"Small crystals may appear
in this liquid in cold
conditions. These are of no danger to
health and will disappear
upon warming," a statement
reminiscent of the bag
of peanuts that is supposed to
have said "This product
may contain nuts".
Such admonitions sound
absurd (although, given the real
dangers of peanut allergy,
the second is not as silly as it
seems). The famous crystals
are, of course, ice, and to
those of us who prefer
our airborne H2 O in that form
because it dilutes the
other liquid we have just poured
into the glass would
be better served by a health warning
on the gin miniature
(as found on those sold in America).
But ice is less simple
than it seems. Cool water down
slowly in a domestic
freezer and it may stay liquid - until
you give the container
a sharp tap and the whole lot
suddenly goes hard. To
move from one phase to another
- from disorder to order,
liquid to solid, water to ice -
takes energy. Once a
few molecules have been forced
together (a sudden blow
helps) the great shift of state
happens at once, as it
spreads from a single point.
A speck of dust (banned,
no doubt, from bottled water) is
also a great aid in persuading
reluctant molecules to get
together. It acts as
a local nucleus to which they can
attach themselves. That
reduces the endless vibration
intrinsic to the liquid
state, allows them to overcome their
natural disinclination
to join and sparks off the big freeze.
Now comes news that,
far above the heads of even the
determined tipplers of
Business Class, life itself may have
started as an airborne,
albeit dusty, gin and tonic.
Space is like a great
cathedral - a large, cold, empty and
sometimes rather grimy
place. Stardust, now and again,
forms solar systems (our
own included) but, most of the
time, it is just dust.
Just as on Earth, it acts as a centre of
attraction for the other
chemicals that float in minute
quantities through the
heavens. Without such crucial
meeting places in the
almost vacant universe, they would
scarcely ever come into
contact, but upon the tiny
particles - just as in
a bottle of chilled water - the
molecules of the great
void can get together and freeze.
As a result, the grains
are covered with ice and solid
carbon dioxide. They
can also bear other unexpected
elements of the interstellar
cocktail. Certain corners of
the Universe serve up
copious quantities of alcohol. One
single star in the Aquila
galaxy, 10,000 light years from
home, has a cloud of
ethyl alcohol around it big enough
for a bottle of the finest
Gordon's for every person on
Earth, every day for
the next five thousand billion years.
Some new, Earth-bound
experiments hint at a strange
chemistry that may happen
within that great astronomical
brew. In the icy cold
of a Dutch laboratory, a quick blast
of ultraviolet light
of the sort given out by the Sun on to
an artificial version
of the icy and alcoholic stardust (plus,
alas, a dash of ammonia:
an ingredient absent from any
beverage I have ever
tried) and - hey presto - some
unexpected substances
appear.
They are amino acids,
the building blocks of life itself.
Some are identical to
those found in our own bodies. If
polarised UV, whose waves
vibrate in only one plane, is
used in the experiment,
then the new molecules are
twisted to one side,
as is the case for our own amino
acids, but not for those
made by ordinary chemistry
(which gives a mixture
of the two mirror-image forms).
Some of the dustiest
parts of the sky do emit polarised
ultraviolet, which may
explain why the building blocks of
life on Earth lean so
much in one direction (the left, as it
happens).
Lab experiments that
try to mimic the chemistry of space
inevitably involve a
certain guesswork. Nasa's Stardust
probe is now flying through
great clouds of tiny particles
at the edge of the solar
system and collecting them in a
special net. When it
gets back to Earth in 2006 we may
find out just what they
are made of and whether freshly
made versions of our
body chemicals are indeed floating
through the void.
To claim that astral
amino acids actually prove that life
began out there is no
more convincing than to use the
discovery of marble on
some distant planet as evidence
that the Parthenon was
built by aliens. Even so, the
thought surely deserves
contemplation over another glass
of something fizzy as
the flecks of dust left after the Big
Bang rain gently down
outside.
Steve Jones is professor of genetics at University
College London
Last updated April 2002