Dark energy and dark matter may not exist after all
Scientists propose new theory that could reshape our understanding of the universe.
Tue, Jun 15, 2010 at 11:42 PM
An artist’s conception of how dense knots of dust in otherwise normal galaxies dim the light of a dark-gamma ray burst. (Photo: NASA)
One of the greatest mysteries of the universe is dark matter and its puzzling sister, dark energy. Dark matter is considered to be the glue that holds galaxies together. It is thought to make up 22 percent of the universe’s mass-energy budget. We have never been able to see it, but experts think it exists because of the gravitational pull it places on everything else, according to Space.com. Dark energy is believed to make up 74 percent of the universe’s mass-energy budget and is thought to be the reason the universe is expanding. That means only 4 percent of the universe is made up of planets, asteroids, moon and us.
This recipe is how scientists generally believe the universe is structured. But now some experts are saying dark energy and dark matter might not exist at all. Space.com reports that data from a telescope examining dark matter has yielded some interesting discoveries. Scientists study dark matter and dark energy by measuring the glow of light in space thought to be left over from the Big Bang. This light is called the cosmic microwave background (CMB), and scientists have been using a spacecraft called the Wilkinson Microwave Anisotropy Probe (WMAP) to learn more about it.
But some scientists have recently calibrated their WMAP observations a little differently. Astrophysicist Tom Shanks of Durham University in England decided to focus his attentions on the CMB. As he told Space.com, “It's such an important thing — the microwave background. All the results in dark energy and dark matter in cosmology hang on it, and that's why I'm interested in checking the results."
And so, Shanks and graduate student Utane Sawangwit examined the WMAP data by using distant astronomical objects in the WMAP data itself that were emitting radio light. Usually, scientists use Jupiter to calibrate their data. What they found was more smoothing than usual through the telescope. Smoothing is what happens when you look at images through a telescope, much like how stars twinkle when their light passes through the Earth’s atmosphere.
Why is this important? It could mean that the fluctuations measured in the intensity of the CMB radiation are smaller than thought. And as Space.com reports, the size of these fluctuations is key to supporting the existence of dark matter and dark energy. According to Shank, this means we may not need dark matter or dark energy to explain CMB observations.
Other astronomers are quick to disagree with Shanks and his theory. Mark Halpern of the University of British Columbia is a WMAP team member. As he told Space.com, "These are weak sources, so many of them must be averaged together to obtain useful measurements. None of them move with respect to the CMB … This method is inferior to our main approach." But Shanks stands by his observations. More spacecrafts are being launched to take more observations of the CMB, and he’s eager to see what they will find.
For further reading: