Scientists believe the universe is comprised of over 95% dark matter and dark energy. Dark matter, which accounts for about 25% of the universe, is matter that cannot be seen as it does not reflect light. Little is known about dark matter. Dark energy, which accounts for over 70% of the universe, is a type of energy that affects the expansion of the universe opposite to matter and energy. Theories for both dark matter and dark energy have been proposed but more research is still needed to fully understand these phenomena.

1. Dark Matter and Dark Energy By: Greg Geanon

2. The Universe This is a more detailed version of what scientists think the universe is comprised of. It’s easy to tell that dark matter and dark energy account for over 95% of our universe.

3. What is Dark Matter? Dark matter is matter in the universe that can’t be seen because it doesn’t reflect visible light. Scientists have determined that dark matter makes up roughly 25% of the universe. Little is known about dark matter. The reason we figured out that it must be there is because there is not enough regular matter to fill the universe.

4. Dark Matter pt. 2 Dark matter cannot be dark clouds of normal matter, nor can they be antimatter because it does not produce the gamma rays when that occur when antimatter interacts with matter. A couple of explanations for what dark matter could be include MACHO’s (massive compact halo objects), or WIMP’s (weakly interacting massive particles). The WIMP’s theory is more popular which states that dark matter is made up of exotic particles like axions.

5. Dark Energy Again, very little is known about dark energy. We know that it exists, because it affects the universe’s expansion, and that accounts for over 70% of the universe. One theory for dark energy is that it is a new type of energy that fills all of space but affects the growth of the universe opposite of matter and energy.

6. Dark Energy pt. 2 Another theory is that Einsten’s theory of gravity is incorrect. This would throw off all of our knowledge of how the universe expands, and that would mean that we would have to figure out a new theory of gravity.

7. Bibliography "2009 April 02 « Ghost Radio." Ghost Radio. N.p., n.d. Web. 3 Feb. 2010. <http://ghostradio.wordpress.com/2009/04/02/>. above, scientists have come up with the composition that we described, ~70% dark energy, ~25% dark matter, and ~5% normal matter. What is dark matter?. "Dark Energy, Dark Matter — NASA Science." NASA Science. N.p., n.d. Web. 3 Feb. 2010. <http://nasascience.nasa.gov/astrophysics/what-is-dark-energy>. "dark matter." www.dsc.discovery.com. N.p., n.d. Web. 2 Feb. 2010. < dsc.discovery.com/space/top-10/strange-univer...>. "dark matter pie." www.ift.uam.es. N.p., n.d. Web. 5 Feb. 2010. < www.ift.uam.es/workshops/DarkMatters/>.