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Monday, October 16, 2017

TWO MONTHS AGO...

TWO MONTHS AGO WE LEARNED SOMETHING NEW ABOUT THE UNIVERSE.

At 08:42 EST on 17 August 2017 the European LIGO--Laser Interferometer Gravitational Observatory--near Pisa detected a gravitational wave emanating from the direction (it would turn out) of a constellation called "thGC 4993," which is 130 million light years distant 
from the Earth.

Think about it: 130 million years ago our planet was still 6 million years away from the Chixtulub Impact. (That's the name of the  estimated 6km wide meteor-collision that--in approximately two seconds--eliminated earth's atmosphere, formed the Gulf of Mexico, caused planetary volcanic eruptions, and ended the Jurassic epoch, along with the dominant life-form at the time: dinosaurs.)

In that moment a pair of neutron stars--dense remnants of collapsed stars--which had been circling one another at increasing velocity exploded in a merger called a "kilonova." Astrophysicists knew of kilonovas because our standard theory predicts their existence, but none had ever been detected before last month.

August marked almost exactly the second anniversary of the first gravitational waves ever detected. The existence of these waves also follow from the General Theory of relativity, but the LIGO instruments were only completed and tested in 2015. That September they proved themselves. Thus a new dimension was added to our physics. Until two years ago the only sensory evidence we had of the universe was light: the radiation-spectrum from x-rays through visible light to infrared. The LIGO detectors added a soundtrack, as it were, to our movie.

Since then astronomers and physicists around the world have been working to coordinate the LIGO instruments with light-gathering instruments, both earth-based and in orbit. In August the system worked.

22 milliseconds--twenty-two thousands of a second--after the Virgo detector in Italy registered the gravitational wave generated by the collision of those neutron stars, the U.S. LIGO observatory in Louisiana recorded it; 3 milliseconds later the one in Hanford WA registered the same impulse. So now we had a planetary triangulation of the arrival of a gravitational wave, set off--remember--when most of the animals on earth were dinosaurs.

But where in the universe did that gravitational wave originate?

Answering this question is the next neat part of this new system. Minutes after that 08:42 hit astronomers were alerted to search a few degrees of the sky for a new object. At this level, however, "few degrees" means billions of radiation-sources across millions of light years. The search began with the NASA "Swift" satellite began scanning some 750 points and soon reported massive ultra-violent radiation from the direction of our NGC 4993 galaxy. With this clue--after having to wait until the day-horizon allowed contact with the enormous telescope-installations in Chile--astronomers began searching the accumulated data for a "transient." That is, a new object in the sky.

In the 9th image, Charlie Kilpatrick found it: a new star next to NGC 4933:


When Kilpatrick sent the images above to Ryan Foley, professor of astronomy at UC Santa Cruz, Foley marveled: "Charlie...is the first human to have seen optical photons from a gravitational event."

So there you have it: the first event in "multimessenger astrophysics:" the field that has been created by this conjunction of physical and optical evidence. This advance is just one consequence of the coordination of science and government: "your tax dollars at work" in the finest sense.

Not only does this news dwarf the pettiness and stupidity of current 
American--not to mention world--politics, it illustrates the highest form of human activity: asking questions rather than seeking "answers" to the trivial problems we create around and for ourselves.

Keep this in mind when you vote...


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