Cosmology 101: Dark matter
November 6, 2010 by Actaphysica
Filed under Physics Videos
Please visit and join to learn more. www.astronomy.com In this series I give you an overview of important ideas in the area of cosmology. This video is the second in the series, and focuses on dark matter. Using various detectors and research methods, astronomers have determined that the stuff we see in space — stars, gas, and dust — amounts to less than 5 percent of the universe. This stuff is ordinary matter, and it’s made up of protons, neutrons, and electrons. Scientists call ordinary matter “baryonic matter” because protons and neutrons are subatomic particles called baryons. So if ordinary matter is only about 5 percent of the universe, what’s the other 95 percent? Well, about 23 percent is something called dark matter. The remaining 72 percent is a mysterious pervasive force called dark energy. I’ll explain more about dark energy in my next video. Alright, back to dark matter. This mysterious mass is a type of matter that doesn’t emit, absorb, or reflect any type of light (so, for example, it doesn’t emit X rays or absorb infrared radiation). Dark matter is therefore invisible. If it’s invisible, how do astronomers have any idea it’s there? Dark matter interacts with ordinary matter through gravity. Its gravitational interaction is how astronomers first found out dark matter exists. In 1933, a Swiss astrophysicist by the name of Fritz Zwicky first proposed dark matter’s existence. While studying the Coma galaxy cluster, he found that the galaxies’ gravity alone was …
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![The Dark Matter & Dark Energy [1/5]](http://i.ytimg.com/vi/rLmcbjLVPKc/default.jpg)
@alaric63 (…Cont’d) Furthermore, the evidence for DM now comes from multiple types of observation and arguments all converging on one solution. We even have maps of it, created through detailed grav lensing observations. That and the rotations of galaxies, plus detailed analysis of the behavior of cluster collisions like in the Bullet Cluster, put DM in the arena of observational data. It used to be only a prediction of the consensus model, made by Rubin. But no longer. This isn’t the 1990s.
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@alaric63 You are making no sense. We know that the corona of the sun is hotter than the surface. While this was a surprise, it’s not a deep mystery. We know that it has to be plasma streams heating up the wispy corona. However, with the instruments available to us in the past, it has not been possible to observe them directly. The recently launched SDO helps. And the IRIS mission should be able to see them clearly. But none of this calls into question the sun’s fusion power source. (Cont’d…)
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I cannot find the article I was reading right now, if it’s important, let me know and I’ll dig deeper…lol
I believe it was either the Chandra or one of the sattelites sent out to take pictures of the sun.
through the thin surface in the images I saw it was easy to see that is was dark (cool) inside.
I believe this has been touched on by various supporters of the Plasma Model which as you know is somewhat controversial.
Or rather, disregarded as it don’t fit the ‘current model’.
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@alaric63 First, which images are you referring to? To the best of my knowledge it is a well known fact that the core of a star is significantly hotter than its surface due to the gravitational pressure with the star.
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Cosmologist were ‘pretty confident’ that the Sun is a giant nuclear ball too, but I cannot support their confidence in the face of real scientific evidence, using the Scientific Method. Because the theory fails under the weight of said evidence.
Excellent images show the sun to be cooler inside.
This dark matter and energy thing is more of the same.
It is erroneous.
And therefore, propaganda.
In my opionion.
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trippy
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Maybe a possible explanation for difficulty in detecting the dark matter on earth is the relative Size and Scale in order for them to be effective.
A good example: the graviton particle, under the scale of sub-atomic level it has almost puny to no effect on other particles, but gravitons(responsible for gravity) have huge effects on the scale of cosmic size matter such as star, planets, galaxies..etc.
The dark matter could be something that works relatively in large(Comic) scale only.
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Dear Wonderers,
My name is Mark Maloney; I would like to invite you to visit my website Epluribusunum56. com. There you will find entirely new physics and cosmology, called Proto-space and DSFF, which are the formational mechanics composing all aspects composing our universe. The best way to learn something new is to securitize it looking for errors. I welcome your opinions.
Sincerely, Mark Maloney
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Photons must have a certain amount of energy to be absorbed by an electron. A photon with a little too much energy to be absorbed by one electron and not enough to be absorbed by another would be invisible to all electrons and everything else. However such photons still have energy so they would interact with matter and each other through gravity.
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@WizardTom2 yes they kind of have…
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First rate summary. Excellent
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And please please!!!!! for FSM’s sake no one claim that dark matter is god!! Ok? And we’re cool. Lol
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if anyone can explain to me plz when you look at space that darkness between the stars what’s that called
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@mikefromspace hay do u think that its tackion energy? dark matter i mean. i really would like to work this thing out. thanks mate.
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@mikefromspace if there is no dark matter then its anti matter….get it? well do you get it? no matter. no matter? you cant see anti matter because ther is no matter. some might say because its dark. invincible no light no matter. just flow, like wind. all matter is disturbed by this even you. dark matter might just be flow vortex like. it holds all things together with flow
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