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" The first full day of the World Science Festival came to a conclusion Thursday night with &amp;quot;The Dark Side of the Universe,&amp;quot; in which festival co-founder Brian Greene, along with other prominent experts and award-winning journalist John Hockenberry, probed the mysterious nature of the dark matter and dark energy that make up most of our universe. Scientists agree that the universe is indeed expanding, at an increasing rate. But according to astronomy, that doesn&amp;#039;t make sense, and that&amp;#039;s where dark matter and energy come in. Here are four ways the experts who spoke Thursday night are investigating these unseen phenomena. Dark Matter WIMPs (Weakly Interacting Massive Particles) &amp;amp;amp; XENON100 Experiment While WIMPs are still theoretical at this point, but physicists are keen to prove their existence because their weak interaction with ordinary matter makes them excellent dark matter candidates. Elena Aprile, professor of physics at Columbia University, has been trying to observe this interaction with her XENON100 experiment in Italy. The detector is composed of a refrigeration unit filled with 161 kg (355 pounds) of liquefied xenon, and the hope is that a WIMP&amp;#039;s energy will penetrate the surface and interact with the xenon. Unfortunately, Aprile hypothesizes, there is only one reaction per year per ton of dark matter, so catching WIMPs takes a lot of patience. While Aprile&amp;#039;s project detected six possible WIMPs in 100 days from January to May of this year, three turned out to be electronic noise, and two more were found to be detection errors resulting from the radioactive nature of the experiment. And with the other five ruled out, there wasn&amp;#039;t sufficient evidence to support the idea that the final possible find was truly a WIMP. Gravitational Lensing Einstein predicted that the gravity of large objects could bend light to a noticeable degree. This is evident in a solar eclipse when the rays of the sun bend around the moon going toward Earth, and it&amp;#039;s also one of the ways that scientists can detect the presence of dark matter indirectly. Katherine Freese, physicist and professor at the University of Michigan, studies far-off stars to see how their light is distorted on its path to Earth. Findings by her and other scientists studying gravitational lensing suggest that there must be much more dark matter than ordinary matter in the universe to account for the large distortion that appears. Dark Energy Studying Supernovae An astrophysicist at the Lawrence Berkeley National Laboratory and professor at the University of California, Berkeley, Saul Perlmutter was one of the scientists behind the discovery of the accelerating universe that shook the astronomy world. His team observed a large cluster of galaxies, attempting to spot a supernova in a distant galaxy. By observing where these supernovae came from, Perlmutter and his team also saw how much that particular cluster of galaxies had changed since that explosion. Gathering evidence from other supernovae showed an even more interesting result: The expansion of the universe was decelerating up until five billion years ago, but is now rapidly expanding, caused by the fact that dark energy makes up about 70 percent of the universe. Perlmutter is collaborating with research teams from seven countries to continue measuring the universe&amp;#039;s rate of expansion.  Multiple Universes Perhaps the wildest of the theories represented on stage was Brian Greene&amp;#039;s mention of the possibility of multiple universes, something he wrote about in great detail in his recent book The Hidden Reality. Greene explains that when the Big Bang occurred and the universe began to form as pockets of gas opened up, other pockets could have opened up alongside ours, potentially creating other universes. Perhaps, he says, our universe was one of the fortunate ones that ended up with just the right amount of dark energy to forge stars and galaxies, and eventually foster human life. Thus, we may be living in a Goldilocks universe. "^^<http://www.w3.org/2001/XMLSchema#string>
<http://www.popularmechanics.com/space/deep-space/a6686/4-ways-scientists-are-trying-to-figure-out-dark-matter-and-dark-energy/>