What is it? Seriously, do you know?
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So, dark matter? Have you heard the term, never heard the term? You know what, it doesn't matter. Because even if you do know what dark matter is, I'm still going to be explaining it in this article. But seriously, why would you've clicked on this article if you knew what dark matter was? Anyway, enough with me asking you questions. What is dark matter? Let's find out.
I'm getting all of my information from NASA, so here it is: for a while after the Big Bang, the universe was kind of empty. Then, through time, stars formed, they made galaxies, and galaxies made clusters of galaxies. What holds it all together, though? Gravity. Gravity, gravity, gravity. In some clusters, the space between the galaxies is filled with super hot gas that can only be seen as x-rays or gamma rays. Scientists will look at the gas and measure how much there is between galaxies in clusters. When they did this, they found that there must be five times more material in the clusters than we can detect. That invisible matter that we can't find is called "dark matter."
People don't really know what dark matter is, mainly what it's not. According to NASA, "Dark matter may not be made up of the matter we are familiar with at all. The matter that makes up dark matter could different. It may be filled with particles predicted by theory but that scientists have yet to observe." Since we can't really see it, scientists have found other ways to learn more about it.
According to Hubblesite, "A gravitational lens can occur when a huge amount of matter, like a cluster of galaxies, creates a gravitational field that distorts and magnifies the light from distant galaxies that are behind it but in the same line of sight. The effect is like looking through a giant magnifying glass. It allows researchers to study the details of early galaxies too far away to be seen with current technology and telescopes." How does this connect? Well, when light passes through a gravitational lens, the gravity of the matter present in the galaxy or cluster causes the light to bend. The amount of bending helps scientists learn about the dark matter that's there.