RT @NOLAnews: Divorce-ban movement in California is satirical response to gay-marriage ban http://bit.ly/78ByIBTue, 01/12/2009 - 2:43am | by Dr. Gunn
WOOHOO!!! Time to sedate that eye by systemic admin of EtOH ;-) RT @LabSpaces: I PASSED MY DEFENSE :) Thanks for all of the support guys!Tue, 01/12/2009 - 2:42am | by Dr. Gunn
mrgunn: WOOHOO!!! Time to sedate that eye by systemic admin of EtOH ;-) RT @LabSpaces: I PASSED MY DEFENSE :) Thanks for all of the support guys!
@communicating Thought you might have. I guess there are tons of small obvious things, depending on your perspective.Tue, 01/12/2009 - 2:41am | by Dr. Gunn
mrgunn: @communicating Thought you might have. I guess there are tons of small obvious things, depending on your perspective.
Follow humbly wherever and to whatever abyss Nature leads, or you shall learn nothing. -T.H. Huxley
We've spent a little bit of time talking about dark energy, including what we think of it, how we first discovered it, and how we knew that there wasn't just something out there blocking the light. It seems to be the latest abyss that Nature is leading us, so we needed to look beyond the type Ia supernova data and see what else the Universe was telling us.
(Image credit: Don Dixon.) So what do we do? First off, we can try to measure how much matter is in the Universe independent of anything else. How do we do this? We use the most accurate method available, of course. This means taking giant surveys of galaxies and clusters of galaxies, combined with a knowledge of gravity.
(Image credit: the 2dF galaxy redshift survey team.) Then you take this actual clustering data and you compare it with simulations of Universes with different matter compositions. You take a Universe with 10% matter, then you take another one with 20%, 30%, 40%, etc., and see which one matches the Universe you actually have in front of you.
(Image credit: Millenium Simulation.) From clustering data, we can tell that the Universe has somewhere between 25 and 30% of its energy in the form of normal matter. Independent of any supernova data, we learn that most of the energy in the Universe is not normal matter.
So what's the rest of it? We need the cosmic microwave background to tell us that.
(Image credit: WMAP team.) These tiny little fluctuations tell us a tremendous amount about what's in our Universe. Moreover, they tell us whether space in the Universe is curved positively like a sphere, flat like a sheet of paper, or curved negatively like a saddle.
These three different curvature cases would lead to the hot and cold spots looking different from one another, and the differences are striking. BOOMERANG was able to tell these cases apart.
Only the middle case -- a flat Universe -- holds up to the data. In fact, the limits are that if the Universe is curved, the amount of curvature is less than 2% of the total energy density. So we have not only supernovae, but clusters of galaxies and the cosmic microwave background too, all pointing towards the same Universe. One where it's spatially flat, full of about 25-30% matter, and where the remaining 70-75% is some mysterious form of energy. Seriously, all these different data sets point towards the same conclusion:
The Universe is mostly full of dark energy, which would need to exist even without the supernova data! It's a very unusual thing for all of these different sources of data to come in all at once, like they have over the past decade, and all support the same conclusion.
But this is what we've got, and it's supported from every angle. So take Huxley's advice, and follow Nature into the abyss of dark energy, or -- the horror -- you shall learn nothing.
Also check out the featured ScienceBlog of the week: Applied Statistics
Where Does My Money Go? - http://www.wheredoesmymoneygo.org/wdmmg-a...
See original: Pierre Lindenbaum: Where Does My Money Go?
How do you describe nanotechnology in 24 seconds, or even in 7 words? Tough challenge, but Professor Wade Adams, Director of the Richard E. Smalley Institute for Nanoscale Science & Technology at Rice University rose to it with aplomb at this year's Ig Nobel awards.
Here's the transcript of the achievement, ...
RT @jwyg: Would love more comments on @okfn's 'Where Does My Money Go?' (#wdmmg) alpha prototype: http://ur1.ca/gwiwTue, 01/12/2009 - 2:34am | by Dr. Gunn
mrgunn: Who dat!! RT @whatwereeating: off to run errands before the saints game starts! who dat!
Visualizing the East Anglia Climate Research Unit Leaked Email Network | Computational Legal Studies http://ff.im/ceUrDTue, 01/12/2009 - 2:32am | by Dr. Gunn
mrgunn: Visualizing the East Anglia Climate Research Unit Leaked Email Network | Computational Legal Studies http://ff.im/ceUrD
@communicating Or send tweets to my timeline from people I'm not following. Neither twitter nor clients are "ready for business".Tue, 01/12/2009 - 2:30am | by Dr. Gunn
mrgunn: @communicating Or send tweets to my timeline from people I'm not following. Neither twitter nor clients are "ready for business".
Liked "Internet Evolution - Mathew Ingram - Social Media Help Generate Science 2.0" http://ff.im/ceNzvTue, 01/12/2009 - 2:12am | by daniel
EvoMRI: Liked "Internet Evolution - Mathew Ingram - Social Media Help Generate Science 2.0" http://ff.im/ceNzv