Dark Matter and Dark Energy Essay

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Dark Matter and Dark Energy

Dark Matter and Dark Energy are important. They can help us know how the universe began. These two are the mysteries of the universe; they compose about 90% of the universe. They are mysteries because we believe that they exist but we can’t see them or detect them. People question whether they manifest to be the same thing. Astronomers know very little about their constitution so they cannot assume they are related. Dark Energy is a mysterious force that drives the expansion of the universe. Astronomers states that the universe is expanding and the expansion is accelerating, so the unknown anti-gravity force at work is termed dark energy. Dark energy has important consequences for …show more content…

Once the temperature of the Universe dropped below the neutron-proton mass difference, neutrons began decaying into protons. If the early baryon density was low, then it was difficult for a proton to find a neutron with which to make helium before too many of the neutrons decayed away to account for the amount of helium we see today. So by measuring the He/H ratio today, they can calculate the necessary baryon density shortly after the Big Bang, and, consequently, the total number of baryons today. It turns out that you need about 0.05 M total baryonic matter to account for the known proportion of light isotopes. So only 1/20 of the total mass of the Universe is baryonic matter. This is probably the reason why Astronomers claim that Dark matter must exist to account for the gravity that holds galaxies together. If the only matter in the universe was matter we could directly detect, galaxies would not have had enough matter to have ever formed. The galaxies we observe today would fly apart because they wouldn't have enough matter to create a strong enough gravity to hold themselves together. Dark matter is also responsible for amplifying small fluctuations in the Cosmic Microwave Background back in the early universe to create the large scale structure we observe in the universe today. Astronomers are still in the hunt of the Dark energy and dark matter but they haven’t found none. They are undetectable which makes it

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