Monday, May 23, 2016


"Listening in on the ‘Black Hole Blues,’ the soundtrack of the universe" PBS NewsHour 5/16/2016


SUMMARY:  February saw one of the most important astronomical breakthroughs of the decade, as a team of scientists “heard” gravitational waves -- a key postulate of Einstein’s theory of relativity -- for the first time in human history.  Now, astrophysicist Janna Levin recounts that incredible discovery, and the human drama behind it, in her new book “Black Hole Blues.” Levin joins Jeffrey Brown for more.

JEFFREY BROWN (NewsHour):  The sound lasted about a fifth of a second, but it represented gravitational waves created by the collision of two black holes with the combined mass of about 62 of our suns a billion light years away.

Black Hole Blues and Other Songs from Outer Space” is a story of things extraordinarily small and hard-to-comprehend large, and of the human drama in discovering them.

Author Janna Levin is a physicist and astronomer at Barnard College.  She’s also author of a novel, “A Madman Dreams of Turing Machines.”

So, the blues, we’re sort of in the realm of metaphor here, but the idea is to hear the universe, at least as aspects that we can’t possibly see.

JANNA LEVIN, Author, “Black Hole Blues”:  Yes, most of what we know about the universe really does come to us from light.

And we have telescopes that span the range of light to take pictures of the sky.  This is utterly different.  This is not a form of light.  So when the black holes collided, they were like mallets on the drum.  They rang space-time itself.

JEFFREY BROWN:  But you have got to be able to hear them.

JANNA LEVIN:  Right.  So, you have to be able to record the shape of the drum.

And that’s basically what this experiment did.  It recorded the shape of the ringing drum from two black holes that collided 1.3 billion years ago.

JEFFREY BROWN:  All right, so step back and explain to us as simply as you can, what is a gravitational wave?  And why is it important to our understanding of things?

JANNA LEVIN:  Yes.  Yes.

So, a gravitational wave is really a ripple or a change in the shape of space and time itself.  So, if you were floating near these colliding black holes, you would literally be squeezed and stretched.  And you would experience this squeezing and stretching.  It emanates from this collision.  It causes these ripples in space, kind of like fish swirling in a pond causing water waves.

And then they emanate out.  They travel at the speed of light, even though they are not light.  And eventually they make it here to the Earth.  If you were floating nearby, you might even literally hear the wave, because your ear could respond to the vibrations.
JANNA LEVIN:  Well, I think what people don’t appreciate is, that’s really how science is done.

People think that we just come down with these answers.  As scientists, we are full of answers.  That’s really not what it is like.  Scientists are full of questions.  Sometimes, the questions don’t lead you to the answer, but, sometimes, they do, and there is this great discovery.

But, yes, there is fighting along the way.  There is competition.  There are failures and successes.  And at the end of the climb, some people made it to the summit, and some people didn’t.

NOTE:  The above is the best definition of science I have ever read.

Simulation of Gravitational Lensing GIF by Alain r

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