You dont know the power of the dark side
Posted on 11/24/2005 10:08:26 AM PST by PatrickHenry
The genius of Albert Einstein, who added a "cosmological constant" to his equation for the expansion of the universe but later retracted it, may be vindicated by new research published today in the journal Astronomy and Astrophysics.
The enigmatic "dark energy" that drives the acceleration of the Universe behaves just like Einstein's famed cosmological constant, according to the Supernova Legacy Survey (SNLS), an international team of researchers in France and Toronto and Victoria in Canada, collaborating with large telescope observers in Oxford, Caltech and Berkeley. Their observations reveal that the dark energy behaves like Einstein's cosmological constant to a precision of 10%.
"The significance is huge," said Professor Ray Carlberg of the Department of Astronomy and Astrophysics at the University of Toronto. "Our observation is at odds with a number of theoretical ideas about the nature of dark energy that predict that it should change as the universe expands, and as far as we can see, it doesn't."
"We have set ourselves a very challenging goal - to distinguish whether the dark energy can be explained by Einstein's cosmological constant or whether a new physical theory is needed." Says Dr Isobel Hook of the University of Oxford, "So far our results are consistent with Einstein's cosmological constant, but the best is still to come. The first year results already represent the largest homogeneous set of distant supernovae, but over the full five years of the survey we will improve our precision more and more. Our goal is a measurement of the nature dark energy that will be a true legacy for years to come."
She added "Before dark energy was being considered, Einstein invented the 'cosmological constant' to make his equations fit with his ideas about the Universe, but later regretted it, calling it his biggest blunder'. Now we know he may have been closer to the truth than he realised."
The Supernova Legacy Survey (SNLS) aims to discover and examine 700 distant supernovae to map out the history of the expansion of the universe. The survey confirms earlier discoveries that the expansion of the universe proceeded more slowly in the past and is speeding up today, apparently driven by some unknown form of energy. Since scientists don't know much about this mysterious new form of energy, they call it "dark energy."
The researchers made their discovery using an innovative, 340-million pixel camera called Megacam, built by the Canada-France-Hawaii Telescope and the French atomic energy agency, Commissariat à l'Énergie Atomique. "Because of its wide field of view - you can fit four full moons in an image - it allows us to measure simultaneously, and very precisely, several supernovae, which are rare events," said Pierre Astier, one of the scientists with the Centre national de la recherche scientifique (CNRS) in France.
"Improved observations of distant supernovae are the most immediate way in which we can learn more about the mysterious dark energy," adds Richard Ellis, professor of astronomy at the California Institute of Technology. "This study is a very big step forward in quantity and quality."
Study co-author Saul Perlmutter, a physics professor at the University of California, Berkeley, says the findings kick off a dramatic new generation of cosmology work using supernovae. "The data is more beautiful than we could have imagined 10 years ago - a real tribute to the instrument builders, the analysis teams and the large scientific vision of the Canadian and French science communities."
The SNLS is a collaborative international effort that uses images from the Canada-France-Hawaii Telescope, a 3.6-metre telescope atop Mauna Kea, a dormant Hawaiian volcano. The current results are based on about 20 nights of data, the first of over nearly 200 nights of observing time for this project. The researchers identify the few dozen bright pixels in the 340 million to find distant supernovae. They acquire spectra using some of the largest telescopes on Earth-the Frederick C. Gillett Gemini North Telescope on Mauna Kea, the Gemini South Telescope on the Cerro Pachón mountain in the Chilean Andes, the European Southern Observatory Very Large Telescopes (VLT) at the Paranal Observatory in Atacama, Chile, and the Keck telescopes on Mauna Kea.
In the UK the work has been done by Dr Isobel Hook and her student, Justin Bronder, in Oxford. Their focus has been on obtaining spectra with Gemini to measure redshifts and confirm the supernova types. Only certain types of supernovae are useful for cosmology, namely those classed as "Type Ia" which they identify by particular signatures in their spectra.
The "queue" observing mode used at Gemini and VLT is ideal for this project. When they find good supernova candidates from CFHT they send instructions over the internet to the staff at Gemini and VLT, and they take data for them when the weather conditions are right for the program. The instruments used on the Gemini telescopes for this project are the GMOS - the Gemini Multi-object spectrographs - built in the UK (by the UKATC and University of Durham) and Canada.
"Only the world's largest optical telescopes - with diameters of eight to 10 metres - are capable of studying distant supernovae in detail by examining the spectrum," said Dr Isobel Hook.
The current paper is based on about one-tenth of the imaging data that will be obtained by the end of the survey. Future results are expected to double or even triple the precision of these findings and conclusively solve several remaining mysteries about the nature of dark energy.
The research was funded by the Canada-France-Hawaii Telescope, the Particle Physics and Astronomy Research Council (PPARC), the Commissariat à l'Énergie Atomique (CEA), Centre National de la Recherche Scientifique (CNRS), Institut National des Sciences de l'Univers du CNRS, the Natural Sciences and Engineering Research Council of Canada, the National Research Council of Canada's Herzberg Institute of Astrophysics, the Gemini Observatory, the W. M. Keck Observatory and the European Southern Observatory.
So they say. Just you wait until I announce my anti-gravity powered, perpetual motion, FTL drive & time machine that I've been working on -- alone! -- in my la-BOR-a-tory.
Only in cosmology and high-energy physics.
Cheers!
Yes, I agree, the model is screwy. Ill accept a certain amount of weirdness- the dead/alive quantum cat in the box, but like you say, 90% of the universe's mass invisible. That should send up a cosmological red flag. The Chinese say that confusion is the first step to wisdom, so this is a good thing.
After pondering string theory for awhile, I realized it wasn't worth pondering.
Just make sure you are saved by the blood of Jesus, and obey His commandments. Then you will have the mind of God throughout eternity, and have a detailed understanding of how all this stuff works.
You dont know the power of the dark side
Have you ever wondered if the CAT in the box wonders if YOU exist? Esp at FEEDING TIME? Really though, your questions are answered at cheniere.org as to vacuum energy and how its tapped by the MEG. If you want to hear how time and gravity are over running matter wave energy I can fill in the blanks for you. W=P
What is it about dark matter that exists only in the deepest recesses of the universe? Like superstrings in multi-dimesional matrices, energertically closed to us here and now. Very compelling. Though theory without experiment remains theory.
I was hoping in my older age, I would not find this interesting.
Fudge is dark. Dark matter + dark energy = fudge factor.
And theory with experiment (or observation of a predicted phenomenon) remains theory. Although, the more supporting experiments and observations there are, the more confidence we have in the theory.
Thanks for the ping!
Dark energy is what everybody feels in the morning when they don't want to get up and go to work. Out in space there is more of it because God's work isn't done...
Ironic, because Einstein called the cosmological constant the biggest mistake of his career.
Are you kidding? Have you ever taken a calculus class? Just curious...
No and no. Are you?
I'm just saying, there is so much more to math than just algebra. If you ever get a chance, take some calculus classes or real analysis. Higher math really can describe the universe!
Admittedly, there does seem some probability that we're not actually here, communicating. But....
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