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Posts Tagged ‘light bulb

For now we see through a glass, darkly…

A computer simulation shows how invisible dark matter coalesces in halos (shown in yellow). Photograph: Science Photo Library, via The Guardian

For all the bright clutter of the night sky, the stars and planets that we see are only about 4% of what’s there.  The balance, scientists believe, is dark matter– an invisible substance that plays a critical role in existence via the gravitational force that it exerts.  The Swiss astronomer Fritz Zwicky postulated dark matter in 1933, when he noticed that a distant cluster of galaxies would fall apart were it not for the extra gravitational pull of some mysterious unseen mass in space.  Since then, astronomers and cosmologists have wrestled with the idea– and with the challenge of verifying dark matter’s existence.

Now, The Guardian reports, that challenge may have been met:

In a series of coordinated announcements at several US laboratories, researchers said they believed they had captured dark matter in a defunct iron ore mine half a mile underground. The claim, if confirmed next year, will rank as one the most spectacular discoveries in physics in the past century.

Tantalising glimpses of dark matter particles were picked up by highly sensitive detectors at the bottom of the Soudan mine in Minnesota, the scientists said.

Dan Bauer, head of the Cryogenic Dark Matter Search (CDMS), said the group had spotted two particles with all the expected characteristics of dark matter…

“If they have a real signal, it’s a seriously big deal. The scale on which people are looking for dark matter is vast,” said Gerry Gilmore at Cambridge University’s institute of astronomy. “Dark matter is what created the structure of the universe and is essentially what holds it together. When ordinary matter falls into lumps of dark matter it turns into galaxies, stars, planets and people. Without it, we wouldn’t be here,” Gilmore said…

Read the whole extraordinary story here.

As we slip off our shades, we might it was on this date in 1879 that Thomas Edison first privately demonstrated incandescent lighting at his laboratory in Menlo Park (or “the other Menlo Park,” as it’s known out here in your correspondent’s neck of the woods…)

Illustration from Edison’s patent application