Dark Matter

Nearly 50 years ago, Fritz Zwicky realized that clusters of galaxies consisted predominantly of matter in some nonluminous form. The search for dark matter has dominated cosmology for half a century. Precise measurements were obtained over 20 years ago, when dark matter was first mapped in galaxy halos. Only recently has the existence of dark matter over much larger scales than even galaxy clusters been confirmed.

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What is the Universe Made Of?

One of the key questions that needs to be answered by astrophysisits is what is really out there? And of what is it all made? Without this understanding it is impossible to come to any firm conclusions about how the universe evolved.

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Dark Matter: Hidden Mass Confounds Science, Inspires Revolutionary Theories

Once upon a time a bit more than 100 years ago many scientists believed that seemingly empty space wasnt empty at all, but was filled with a substance called luminous ether. This mysterious stuff, never seen in any laboratory on Earth, was thought to explain how gravity from one celestial body could affect another.

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What is Dark Matter?

We believe that that the Universe is critically balanced between being open and closed. We derive this fact from the observation of the large scale structure of the Universe. It requires a certain amount of matter to accomplish this result. Call it M.

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Cosmic collision reveals dark matter

New observations of a great big cosmic collision provide the best evidence yet that invisible and mysterious dark matter really does exist.

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Dark matter detected in cosmic crash

Astronomers say fresh imagery of a powerful collision of galaxy clusters supports the idea that dark matter is something totally separate from ordinary matter.

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Wormhole

In physics, a wormhole is a hypothetical topological feature of spacetime that is basically a 'shortcut' through space and time. Spacetime can be viewed as a 2D surface, and when 'folded' over, a wormhole bridge can be formed. A wormhole has at least two mouths which are connected to a single throat or tube. If the wormhole is traversable, matter can 'travel' from one mouth to the other by passing through the throat. While there is no observational evidence for wormholes, spacetimes-containing wormholes are known to be valid solutions in general relativity.

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Journey to A Black Hole

We must know where to find a black hole before we can travel to it. But how can we find black holes? Although they do not emit any light, they do reveal themselves in other ways.

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What Happens if You Fall Into a Black Hole?

The world's largest scientific instrument, the Large Hadron Collider, was switched on in Switzerland on Wednesday. A few people worried that the LHC would cause the world to be swallowed up by a black hole, especially when it starts to operate at full force in the spring. What would happen if you fell into a black hole?

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Beyond Big Bang Cosmology

The Big Bang model is not complete. For example, it does not explain why the universe is so uniform on the very largest scales or, indeed, why it is so non-uniform on smaller scales, i.e., how stars and galaxies came to be.

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Big Bang

Tests of Big Bang Cosmology

The Big Bang Model is supported by a number of important observations, each of which are described in more detail on separate pages:

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Big Bang Cosmology Primer

The steady state theory of cosmology claims that the Universe simply exists without changing with time. This theory presents many physical as well as philosophical difficulties. Evidence suggests that the Universe is expanding. While there are ways to explain expansion in a steady state universe, few astrophysicists believe this theory, because there is little evidence to support it. As the first widely held theory about the Universe it is included here for historical completeness.

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Big Bang Theory - The Premise

The Big Bang theory is an effort to explain what happened at the very beginning of our universe. Discoveries in astronomy and physics have shown beyond a reasonable doubt that our universe did in fact have a beginning. Prior to that moment there was nothing; during and after that moment there was something: our universe. The big bang theory is an effort to explain what happened during and after that moment.

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What is Cosmology?

Cosmology is one of the most exciting disciplines in all of physical science. It is concerned not so much with individual stars or galaxies in their own right, but rather with the properties of the Universe as a whole: its origin, evolution and eventual fate.

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What is Astrophysics?

Astrophysics is the branch of astronomy that deals with the physics of the universe, including the physical properties (luminosity, density, temperature, and chemical composition) of celestial objects such as stars, galaxies, and the interstellar medium, as well as their interactions. The study of cosmology is theoretical astrophysics at scales much larger than the size of particular gravitationally-bound objects in the universe.

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