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Dark Energy Confirmed By Australian WiggleZ Sky Scan
Phoghat writes "An Australian team of researchers scanned the sky using WiggleZ Dark Energy survey and found confirming evidence of Dark Energy. Einstein is correct, as so far, usual."
Meanwhile, the International Space Station is looking for dark *matter* .
here is the actual press release, which (unlike that article) doesn't skip over what they actually did.
The opinions stated herein do not necessarily represent those of anybody at all. Deal with it.
Last part of summary segfaults my internal parser.
Seems like TFA is slightly misleading though. They didn't confirm DARK ENERGY, they provided a bunch of data that confirms the universe is expanding AS EXPECTED PER CURRENT THEORY (and current theory uses dark energy to explain). It isn't like they built a dark energy detector and said "Wow, the readings are off the charts!"
Ok It seems they proof the universe was expanding at an accelerating rate. But does/why it proof the dark energy existence ?
WTF has Einstein to do with this?!
Of course studies of dark energy are deeply conneted to general relativity. But don't throw names like you pretend you know what you are doing.
This is becoming ridiculous, this is like "Well, I drove 100Mi at 50MPH and it took 2 hours, looks like Newton is right again"
how long until
and current theory uses dark energy to explain
The most popular current theory does - there are competitors as well. But, yeah, this is useful because those working on all the theories can keep on going, knowing that they're more likely to be on the right track than they were yesterday.
My God, it's Full of Source!
OUTSIDE_IP=$(dig +short my.ip @outsideip.net)
When I was a kid, TV shows had songs about the alphabet and counting. Apparently, The Wiggles are doing children's edutainment about theoretical physics? Wow...
The cat in the box goes 'round and 'round...
Round and round
Round and round
The cat in the box goes 'round and 'round...
Now let's see if it's dead!
"You're right," Fisheye says. "I should have set it on 'whip' or 'chop.'"
WTF has Einstein to do with this?!
I assume TFS was referring to the cosmological constant - some have figured that Dark Energy is the mechanism behind the lambda* in Einstein's equations.
*someday Unicode will work on Slashdot...
My God, it's Full of Source!
OUTSIDE_IP=$(dig +short my.ip @outsideip.net)
A team of Australian researchers has observed 200,000 galaxies, confirming existing theories about the expansion of the universe. These theories require an unobserved force known as dark energy to account for the expansion of the universe versus contraction that is predicted due to gravitational forces. Dark energy and dark matter have not yet been observed or measured in any way.
Yes. The reason that it was a mistake is that relativity predicts that the universe must be contracting or expanding. Because Einstein thought that the universe was static, instead of actually making the prediction, he added a fudge factor of gravitation repulsion that would keep the universe from collapsing under its own gravity. So he was wrong, because the universe is in fact expanding.
The reason it was the biggest mistake of his life is that adding gravitational repulsion to gravity produces an unstable equilibrium, so it would not have resulted in a steady state even if he was right. All matter would have had to have been equally distributed across the universe, and any perturbation would have caused local clumps that would collapse under gravity. So he incorrectly added his incorrect fudge factor. He was very, very wrong.
There's a reason he called it his biggest mistake. He made an obviously wrong prediction instead of correctly predicting the expansion of the universe. The fact that we now detect a repulsive force has nothing to do with Einstein's prediction except that it's also a repulsive force. It's just coincidence.
What a fool believes, he sees, no wise man has the power to reason away.
Slashdot posts these articles about dark energy every 6 months, but nothing ever makes it to consumers. Let me know when Dark Energy generators are available at my local Home Depot, then I'll be interested.
I don't care if it's 90,000 hectares. That lake was not my doing.
Einstein saw it as a huge mistake, but it wasn't. Current evidence suggests that the value of the cosmological constant is not zero, it's some small positive number. If Einstein had not put the cosmological constant in in the first place, we wouldn't have been able to assign a value to it. His blunder was the assumption of a static universe, not a cosmological constant. The cosmological constant was a leap of physical intuition -- it has a value other than Einstein thought it should have, but so what? He was obviously a bit smarter than most of us :-)
Couple of problems with that:
* Gravitationally-induced time dilation is a local effect--the degree of dilation for an observer depends on the strength of the local gravitational field at that observer's location. And while the universe's expansion does contribute some ongoing changes to the local gravity field strengths at every point throughout the universe, the size of those changes is miniscule compared to the absolute strength of even the earth's gravity at the planet's surface. The observed effects of lambda (cosmological constant, dark energy, whatever) are a whole lot bigger.
* Time dilation works opposite to your description, i.e., the GREATER the local mass density (and therefore the more intense the local gravitational field) the faster time will move relative to the rest of the universe.
* Einstein's GR includes the relativity of time and space in the model, as specific terms OTHER than lambda. Lambda is the part of the model that *cannot* be explained by anything else we already know about.
I know, I know: IHPBT. I needed something to do while my coffee was cooling.
Nope. You're on the right track, but looking at it the wrong way. We can make rough estimates of how far away something is based on how far away it appears to be, what relative velocity/acceleration it appears to have, etc. So something that appears to be 11Mly away could be 20Mly distant.