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January 10, 2008 12:18

Double Cosmic Ring of Fire...With a Catch

Posted by Michael Lemonick | Comments (5) | Permalink | Trackbacks (0) | Email This

An embedded pair of "Einstein Rings"—in essence, a cosmic optical illusion./NASA, ESA, and R. Gavazzi and T. Treu (University of California, Santa Barbara), and the SLACS team

The catch is that it doesn't really exist, even though you can see it through a telescope. Or at least, the Hubble can. What you're looking at is a galaxy (brightest spot in the left-hand image) surrounded by the magnified images of two more-distant galaxies that lie right behind it. Because gravity actually bends spacetime, making light rays travel in a curving path, the foreground galaxy's gravitational field distorts the images of the two further objects into what look like rings (the right-hand closeup has the foreground galaxy digitally erased so you can see the rings better).

Einstein himself discussed the idea of "gravitational lensing" in a paper published in the 1930s, but thought they'd never be seen. The first one was found in 1979; they're now a powerful tool in astronomers' arsenals, letting them do everything from detecting planets around distant stars to mapping out the extent of dark matter in and around galaxies.

In short, Einstein was, uncharacteristically, dead wrong.

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Reader Comments (5)

Ernie:

How do we know there are two galaxies behind? Do they look differently in radar or X-ray frequencies? If all you see is the image above, how can you establish there are multiple galaxies involved?

--Good question. I don't know in this case, but in general you take a spectrum of the rings' light (this has been done in the case of other lensed objects); if the spectrum looks like that of a galaxy, you're pretty sure. FYI, tens of thousands of lensed galaxies have been found, though most are less spectacular than this example. But to be strictly accurate, I should have said "it's most likely, given what we know about the universe, that there are two galaxies behind..."
M.L.

Posted by Ernie | January 10, 2008 1:02 PM

13enster:

Either that or the flying spaghetti monster just tapped the lens of the Hubble with one of his noodley appendages!

Posted by 13enster | January 10, 2008 3:39 PM

Brian:

Einstein was wrong about a lot of things.

--True.
M.L.

Posted by Brian | January 10, 2008 11:49 PM

Barton Paul Levenson:

The Flying Spaghetti Monster!!! Get it? It's Flying... It's a Monster... and it's SPAGHETTI!!! Isn't that funny? "Flying Spaghetti Monster." Get it? Get it? Gee, religions are stupid. If God could have created the world, then so could THE FLYING SPAGHETTI MONSTER! Hee hee! Hee hee! Hee hee!

--Actually, BPL, the FSM was created to make fun, not of religion, but of Creationism, with which you also disagree. Just a reality check there.
M.L.

Posted by Barton Paul Levenson | January 11, 2008 6:37 AM

Saint Andeol:

woah . . . damn, I guess we know which of BPL's "Stupid Atheist Tricks" is his least favorite.

oh yeah, and Einstein was wrong about something else too: when he stuck out his tongue at that photographer, he thought "Here's a picture they won't ever be able to sell."

Posted by Saint Andeol | January 11, 2008 10:12 AM

About Eye On Science

TIME contributing writer Michael D. Lemonick fills you in on what's hot, what's cool, what's controversial and what's just plain silly in the world of science. Comments encouraged.