[whataretheysaying] Mary Madigan: Heavy WIMPs and a new frontier

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Posted by Mary Madigan:
Heavy WIMPs and a new frontier
http://whataretheysaying.powerblogs.com/posts/1187620997.shtml


   Via [1]SPACE.com

     Scientists trying to create a detailed inventory of all the matter
     and energy in the cosmos run into a curious problem--the vast
     majority of it is missing.

     "I call it the dark side of the universe," said Michael Turner, a
     cosmologist at the University of Chicago, referring to the great
     mysteries of dark matter and dark energy.

     In fact, only 4 percent of the matter and energy in the universe
     has been found. The other 96 percent remains elusive, but
     scientists are looking in the farthest reaches of space and deepest
     depths of Earth to solve the two dark riddles.

     Einstein's famous equation "E=mc^2" describes energy and matter (or
     mass) as one and the same--maps of the cosmos refer to the
     energy-matter combination as energy density, for short. The problem
     with detecting dark matter, thought to make up 22 percent of the
     universe's mass/energy pie, is that light doesn't interact with it.

     But it does exhibit the tug of gravity.

     Initial evidence for the mysterious matter was discovered 75 years
     ago when astrophysicists noticed an anomaly in a jumble of
     galaxies: The galactic cluster had hundreds of times more
     gravitational pull than it should have, far outweighing its visible
     mass of stars...

     ...Perhaps the biggest mystery of all is dark matter's big cousin,
     dark energy.

     The invisible force is thought to be a large-scale "anti-gravity,"
     pushing apart galactic clusters and causing the unexplainable,
     accelerating expansion of the universe. Turner thinks dark energy
     is the biggest mystery of them all--and quite literally, since
     physicists predict that it makes up 74 percent of energy density in
     the universe.

     "So far, the greatest achievement with dark energy is giving it a
     name," Turner said of the elusive force. "We are really at the very
     beginning of this puzzle."

     Turner described dark energy as "really weird stuff," best thought
     of as an elastic, repulsive gravity that can't be broken down into
     particles. "We know what it does, but we don't know what it is,"
     Turner said.

     While astrophysicists look deep into space to gather more details
     about dark energy's effects, Turner noted that theoretical
     physicists are focusing on explaining how the force actually works.
     And at this point, he joked, any physicist's explanation for dark
     energy is probably good enough to consider.

     "We're at this very early stage, at the crime scene of dark
     energy's existence, if you will," Turner said. "It's a highly
     creative period, and now is the time for ideas."

   We're talking about a new, lawless frontier. Who knows what [2]the
   speed limit is out there?

References

   1. http://news.yahoo.com/s/space/20070820/sc_space/greatestmysterieswhereistherestoftheuniverse
   2. http://www.deanesmay.com/posts/1187355556.shtml