[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index]

Gamma Ray Bursts

ASTRONOMY NOW / April 1998, p. 11: Berry’s Viewpoint

Who will shield us?

What is the most dangerous threat to the environment - apart from
[...*]? I used to think it was a nearby supernova, the impact of a very
large asteroid, or perhaps a significant change in the Sun's radiation
that could either fry the planet or produce another ice age that might
last 100,000 years. But an even more deadly hazard may be a gamma ray
burster.
Of all the different kinds of explosions in the Universe, gamma ray
bursters are far the most violent. They make supernovae look like squibs
in comparison, for instead of being lethal at about five lightyears like
supernovae, they can destroy most life on a planet from a distance of up
to 3,000 lightyears.
They occur, apparently, at the moment of collision of two close-orbiting
neutron stars - the relics of once shinning stars whose densities have
reached billions of tons per cubic inch. Closer and closer they come,
until, wham!, they merge into a black hole.
A disc forms around the hole, a disc so hot and so dense that it blasts
out jets of energy from its two opposite sides. Far, far away, on a
planet like ours, there comes, a few thousand years later, a single
radiation pulse followed by several months of gamma rays of such
intensity that no animal or planet could survive them unless it lived
deep under the sea.
What should we do on learning that a burster was about to go off within
the 3,000 lightyear danger limit? There would be a few centuries in
which to act, and we would need them, for it would be necessary to
build, as in Arthur C. Clarke's recent novel ‘3001: The Final Odyssey’,
a giant shield, at least as wide as the planet to catch the blast, just
as medieval foemen fended off arrows with their bucklers. It is amusing
to contemplate the public debates about whether and how to build this
shield.
Who is going to pay for it? What shall it be made of? What orbit shall
we place it in? How can we be sure exactly where the Earth will be in
centuries time? What happens if, instead of protecting us, it hits us?
And, more disastrously, why should we support this project? None of our
constituents will be alive when the thing happens, so it won't help our
careers. Anyway, it's probably a lot of science fiction nonsense. Let's
leave it for another generation. Schools and hospitals are a more urgent
priority.
Politicians are simply not interested in long term investments that
outlast their normal attention span of four or five years - the time
until the next election. Which is why I believe, incidentally, that the
long-term colonisation of space will be carried out by private
organisations.
But it may be that not even they will be interested in building the
anti-burster shield. After all, there will be no profit in it, only the
glory of having saved the human race, and there will be no money in
that. And so the future will offer many dangers more deadly than
military crises.

Adrian Berry is Consulting Editor (Science) of the Daily Telegraph.

* Name of politician omitted to prevent politicization of our list.


Best regards,

Bernd

----------
Archives located at:
http://www.meteoritecentral.com/list_best.html

For help, FAQ's and sub. info. visit:
http://www.meteoritecentral.com/mailing_list.html
----------