Minute Physics: What is Dark Matter?
Minute Physics provides an energetic and entertaining view of old and new problems in physics -- all in one minute! In this episode, we discuss Dark Matter, an exotic type of matter we know...
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Have you ever had the feeling that there's something bigger out there, something youcan't see? Well there is – it's called Dark Matter.Dark matter is spread throughout space, engulfing the Milky Way and all other galaxies. It'sfour times more common in the universe than visible matter, yet we've never seen or directlyobserved it!So how do we know it's there? Because of gravity. A galaxy is like a giant merry-go-round thatall the stars are riding. In order to stay on, each star has to hold on tight (that'swhere gravity comes in), otherwise it'll fly off into space.The problem is, the force of gravity from all the stars we can see isn't strong enoughto hold galaxies together – all the stars should...
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Have you ever had the feeling that there's something bigger out there, something youcan't see? Well there is – it's called Dark Matter.Dark matter is spread throughout space, engulfing the Milky Way and all other galaxies. It'sfour times more common in the universe than visible matter, yet we've never seen or directlyobserved it!So how do we know it's there? Because of gravity. A galaxy is like a giant merry-go-round thatall the stars are riding. In order to stay on, each star has to hold on tight (that'swhere gravity comes in), otherwise it'll fly off into space.The problem is, the force of gravity from all the stars we can see isn't strong enoughto hold galaxies together – all the stars should...
