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Hubble Finds Double Einstein Ring
Einstein Duble brings us news that astronomers using the Hubble Telescope have discovered an extremely rare double Einstein Ring. Occasionally, galaxies or other bright objects are located in such a way that they are behind another galaxy when viewed from Earth. When light from the further galaxy passes a sufficiently massive closer galaxy, the path of the light is bent inward from all sides, creating a "ring" effect. In this case, not one, but two galaxies are directly behind the foreground galaxy, so the gravitational lens produces two distinct rings. Quoting Presscue:
"The distribution of dark matter in the foreground galaxies that is warping space to create the gravitational lens can be precisely mapped. In addition, the geometry of the two Einstein rings allowed the team to measure the mass of the middle galaxy precisely to be a value of 1 billion solar masses. The team reports that this is the first measurement of the mass of a dwarf galaxy at cosmological distance (redshift of z=0.6)."
This is a prime example of the kind of useful knowledge that can be gained with projects like Hubble.
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One of the cool implications becomes clear if you realize this means our galaxy is the 4th galaxy in a line with these three. To someone standing on a planet in that backmost galaxy, 11B Ly away: ...
* The one that's the "foreground galaxy" to us would be the inner ring.
* The one that's the "first ring" to us would be the foreground galaxy for them and
* The Milky Way would appear as the outer ring!
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It seems to me that there must be lots of Double Einstein Rings out there, probably millions of them. We're just not standing in the right place to seem most of them.
And (s)he's got a really big ruler!
Engineering is the art of compromise.
These things line up in space-time as follows: Galaxy 1 is on the line 11 billion years ago, galaxy 2 is on the line 6 billion years ago, galaxy 3 is on the line 3 billion years ago, and the Milky Way is on the line right now.
This does not mean that the reverse is true. It does not mean that there is a line that the Milky Way was on 11 billion years ago, and galaxy 3 was on 8 billion years ago, and galaxy 2 was on 5 billion years ago, and galaxy 3 is on now. Why not? Because galaxies move.
Still, even if not technically correct, it was a really awesome thought by the OP...
As the double ring they found around Uranus
788652 = 2 x 2 x 3 x 3 x 19 x 1153
I was afraid it was a trick to make me click on a link to goatse.cx guy.
That upgrade is on hold. The problems that knocked the latest Atlantis mission back into February have jacked up the schedule. So it was planned for August but now it will be later. I would think that with eol for the shuttle and hubble both rapidly approaching - any more problems or serious delays and it could get knocked from on hold to canceled.
It's hard to believe that's how Micronians are made. Why don't we see it right now by having you both kiss one another?
Brannigan: "What the hell is that thing?"
Kif: "It appears to be the mothership"
Brannigan: "Then what did we just blow up?"
Kif: "The Hubble Telescope"
I'm going to go create my own technology news site, with blackjack and hookers. You know what? Forget the news site.
Don't worry, we can pay for the whole thing by leaving Iraq one or two days earlier. And plus, if you look at it from the financial angle, a space-industrial complex is just as good of an excuse for corporate welfare handouts as the military-industrial complex. The only difference is that if we spent $300 Billion a year on science, we'd probably get something good for humanity out of it.
It's sad that spending money to unravel the secrets of the universe is sneered at (see parent) while large numbers of people and entire news networks (not necessarily including parent) champion spending trillions of dollars to keep poking the middle east hornet's nest (And apparently think that if we keep poking, the hornets will get tired and give up).
And the other problem is the masses of all the galaxies are different. The dwarf galaxy wouldn't act as a lens for them in the same way that the massive galaxy does for us.
Layne
Another article on this double ring find.
Additionally, the astronomers' significant others are annoyed at them for ruining the coffee table by not putting Eincoasters under their Einsteins.
There's a great story about the first person to accurately measure the height of Mount Everest, whose name escapes me at the moment.
His calculations came out to precisely 29,000 feet. Thinking no-one would believe such a round number, he added two feet to make 29,002 feet but was greatly annoyed by the whole thing.
Later it was more accurately measured at 29,029 feet (going from memory here) using lasers or something.
Bubble, bubble, toil and trouble
Hubble finds an Einstein double
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Set him on fire and it will keep him warm for the rest of his life.
for this to occur requires four galaxies to be very close to being colinear, and we have to be in one of the endpoints. Looking at the picture though there are several galaxies visible so I suppose they have quite a few to look at for this. I wonder just how rare it is? As in, is this the first one discovered? I'd asume if there were any other known double E rings it would have been mentioned in TFA. Hard to say how rare something is when you only have one of them to go by.
I work for the Department of Redundancy Department.
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"Convictions are more dangerous enemies of truth than lies."
Seriously, I'm not being hostile with this question. Is your life better for knowing the precise mass of a galaxy which no human will ever visit? I could go out and mass a stone in my back yard rather precisely with a calibrated instrument right now -- that would advance The Sum Of Human Knowledge, insofar as nobody had ever determined the approximate mass of that particular rock before -- but is that knowledge *useful*?
Help poke pirates in the eyepatch, arr.
"The distribution of dark matter in the foreground galaxies that is warping space to create the gravitational lens can be precisely mapped." Really? How can we "precisely map" something that we have never even shown positively to exist yet? The distribution of gravity could be caused my a number of things other than "dark matter". Gravitational disturbance by itself is not evidence for dark matter, any more than it supports at least several other hypotheses.
Yes it is kind of like propaganda to assume dark matter theory is right, but that's the best theory there is. "Dark matter" is just a name for "whatever causes these observations." Whatever it is looks and acts like a gravitational field. Mass produces a gravitational field, so it's assumed to there's some sort of invisible mass, some sort of "dark matter." And they can still "precisely map" the gravitational field, regardless of what is causing it.
And unless you know something physicists don't know, there's not a "number of things" that could cause a gravitational field like that. Interestingly, there is another theory, ether theory, but even the physicist who came up with it says: "We're offering an alternative to the dark matter theory--we're not saying it's wrong. If I had to bet today on which of these theories was correct, I might bet on dark matter."
Light always travels in straight lines. Or to put it another way, light always travels the shortest path from A to B. Or to put it another way, light always travels every path from A to B, but they all cancel each other out except the shortest path. (read Feynman's QED for more) So it can't be curving the light, because that would make the path longer.
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