Dark Matter


Angel Hansen/Courtney Bawden, Reporter

Recently, a well known theorist, Stephen Hawkings, passed away on March 14, 2018. One of his more known theories was that dark matter in a black hole is densely packed together and surrounded with a circular region of space past which we can not see anything. According to NASA, after the Big Bang, time passed and the first stars were formed; stars formed into galaxies, and galaxies began to cluster together. Bits of matter smashed into each other, and the planets in our solar system began to form around the sun.

It is important to know more about dark matter because with that knowledge, we can better understand our universe and the things within it. According to NASA’s scientists, the space between the galaxies is filled with gas so hot, it can not be seen even while using visible light telescopes. The gas only can be seen as X-rays or gamma rays. Scientists look at that gas and measure how much there is between galaxies in clusters. By doing this, they discovered that there must be five times more material in the clusters than we can detect. The invisible matter that we can’t detect is called “dark matter.”

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Though there is a large possibility that dark matter may not even be made up of the matter we familiar with at all. It may be filled with particles predicted by theory, but scientist have yet to observe that.

Because scientists can’t directly see dark matter, they have come up with other ways to investigate it. Such as using indirect ways to study things, like looking at a shadow and making assumptions about what’s casting the shadow. One of the ways scientists indirectly study dark matter is by using ‘gravitational lensing’.

Light going through a gravitational lens is similar to light going through an optical lens: it bends. When light from distant stars passes through a galaxy or cluster, the gravity of the matter present causes the light to become bent. As a result, the light looks like it’s coming from somewhere else rather than its real origin. The amount of bending helps scientists learn about the dark matter present. Multiple NASA scientists use the Hubble Space Telescope to observe gravitational lensing.

“I think most of what we know about black holes has come from some of the theoretical work that Stephen Hawking has done and in fact there is a kind of radiation that comes out of black holes which is named after him, it’s called Hawking Radiation,” said Zack Pope, a physics teacher at Sedro-Woolley High School.