It was announced today
that scientists have detected gravitational waves, something they
have never previously observed. The gravitational waves were
detected from the extremely rare event of the merger of two black
holes. The detection was made by the very expensive LIGO project.
Although some scientists are speaking as if this is some epic
breakthrough, it may have relatively little meaning in the grand
scheme of things. Buried within the long triumphant announcement in
the Washington Post is this statement: “There is no obvious,
immediate consequence of this experiment.”
One reason why the
detection of gravitational waves may mean relatively little is that
apparently no door has been opened to a new cost-effective method of
astronomy. Let's look at the facts about how much was put into LIGO
and what the output has been so far. More than 600 million dollars has
been invested into LIGO, which required a huge architectural
infrastructure. After years of effort, the project has produced a
single detection of gravitational waves, from a very rare event
involving the merger of two black holes. Does this offer some hope of
some great new method of cost-effective astronomy? Quite the
opposite. A project in which you spend 600 million dollars for a
single observation is millions of times less cost effective than
alternatives. I can spend $1000 on a Celestron telescope, and use it
to make thousands of observations, for a cost of less than one dollar
per observation.
Has the detection of
gravitational waves changed our understanding of the universe? No,
because the existence of gravitational waves was already predicted by
Einstein's general theory of relativity, which almost everyone
already believed in. Has the detection of gravitational waves been a
case of giving some needed support to a tottering theory that people
were starting to question? No, there was already tons of evidence in
favor of the theory of general relativity. A new observational
confirmation for the theory of general relativity is kind of like
giving another billion dollars to Bill Gates.
The interesting questions
in physics and cosmology are questions like these:
Why did the universe
suddenly begin billions of years ago in the Big Bang?
Why are the fundamental
constants of the universe so exquisitely fine-tuned?
Are there any reasons for
believing in a universe beyond our own?
Are there any reasons for
believing in parallel universes?
Why does light sometimes
act like a particle and sometimes like a wave, depending on how we
observe it?
What is this strange thing
called quantum entanglement, and does it point to a far greater amount of connectivity in the
universe than we previously imagined?
Does quantum mechanics
imply a new outlook on consciousness, in which the observer is king?
Why is the universe so
astonishingly ordered on a large scale?
Why is the vacuum of space
relatively empty, when quantum mechanics predicts it should be something totally different, teeming with something like “zero-point”
energy?
Why does the universe have
its particular set of laws that favor the existence of living things?
As far as I can see, the
detection of gravitational waves casts no new light on these
questions.
Is there any chance that
we might be able to do observations like that of LIGO many times more
cost-effectively? Not really. LIGO used a pair of observatories that
each used “ultra high vacuum systems” with an L-shape measuring 4
kilometers (2.5 miles) on each side. There is little prospect of
being able to shrink something like that to something that your local
college can use.
The press stories are
comparing the LIGO project to a moonshot. It's nice that this
particular moonshot has succeeded, and I congratulate the scientists
who achieved this very expensive triumph. But it must be remembered
that from a “science payoff” perspective the moon landing program
was something of a dead-end boondoggle. After paying a king's ransom
for moon rocks, we didn't learn much of anything new. A similar
situation may exist in regard to observing gravitational waves. Just
as going to the moon to pick up rocks is the opposite of a
cost-effective method for geological observations, projects such as
LIGO may be the opposite of a cost-effective method for astronomical
observations.
Postscript: I may note that gravitational waves have no practical use. It's a trillion times easier to use electromagnetic waves for communication, and electromagnetic waves are just as fast; so it's hard to imagine that anyone will ever be using gravitational waves for communication.
Of course, a science mission with no practical benefits may be justifiable if it yields lots of nice visuals, lots of eye candy for the public to enjoy. The mission to Pluto had no practical benefit, but produced some nice visuals. But we have got not a single decent visual from the LIGO project. We could have got better visuals with a $1000 Celestron telescope.
Post-postscript: It turns out the total LIGO cost was more than a billion dollars. John Horgan asks in Scientfic American whether it was worth the money, and quotes a historian of technology who seems to think the funds would have been better spent in other ways.
Postscript: I may note that gravitational waves have no practical use. It's a trillion times easier to use electromagnetic waves for communication, and electromagnetic waves are just as fast; so it's hard to imagine that anyone will ever be using gravitational waves for communication.
Of course, a science mission with no practical benefits may be justifiable if it yields lots of nice visuals, lots of eye candy for the public to enjoy. The mission to Pluto had no practical benefit, but produced some nice visuals. But we have got not a single decent visual from the LIGO project. We could have got better visuals with a $1000 Celestron telescope.
Post-postscript: It turns out the total LIGO cost was more than a billion dollars. John Horgan asks in Scientfic American whether it was worth the money, and quotes a historian of technology who seems to think the funds would have been better spent in other ways.
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