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Space Phenomenon
Dark Matter
The examination of the movement of the Galaxies that the visible part of the Galaxy is not moving in a manner consistent with the amount of material that can be detected. It is believed therefore that there is an unseen amount of matter that is pulling on the visible part of the Galaxy. Dark Matter is an often encountered phenomenon of the Star Trek Universe but sadly few times is the material treated correctly. To discuss dark matter and why we do not see it, it is appropriate first to discuss why we see normal matter.
|
Type |
Composition |
Evidence |
Contribution to W |
|
Visible Matter |
Ordinary Matter |
Telescope Observation |
0.01 |
|
Baryonic Dark Matter |
Massive compact halo objects and MACHOs |
Nucleosynthesis and deuterium abundance |
0.05 |
|
Nonbaryonic Dark Matter |
Axions mass neutrinos WIMPS |
Galactic speed in cluster |
0.3 |
|
Cosmological “dark matter” |
Energy of freespace |
Flat cosmos from microwave background radiation |
0.6 |
When light shines on an object it either passes through the material, a process referred to as transmission. In such a case, we would not be aware of the existence of the material. An example could be oxygen; when looking across a room one is not aware of the oxygen in between. Light can bounce off an object and it is this reflection that gives objects their observed colour. Other frequencies being absorbed. Absorption is the final way light can be affected by matter. Absorbed frequencies are not seen.
Dark matter is dark because it transmits light. If it absorbed light like many of the dark matter nebulas seen in Star Trek, Cathexis (Brannon Bragga & Joe Menosky 1995). If the matter absorbed light then it would be conspicuous by its camouflaging of what was behind it. In addition, if matter absorbs energy it heats up which would mean that the electrons would be promoted higher in their shells giving off photons of energy. Thus making the once dark matter quite visible or in the least detectable. The reason we know of its existence is not due to the fact that we can see it but because its gravity perturbs the orbit of the stars around the Galaxy. The matter also causes peculiar movement of the Galaxy through the Inter Stellar Medium and finally contributes to the initial formation of the universe after the Big Bang. (Smoot 1994)
Cold Interstellar clouds are called dark nebulae. These are significantly different to dark matter nebulas. The cold interstellar clouds called dark nebulae appear as dark areas in the sky obscuring background stars. At the turn of the century E.E. Barnard and are such called Barnard Objects. Work in the 1940s by Dutch-American astronomer Bart Bok, labelled around 200 small dark patches as Bok Globules. A typical dark nebula contains a few thousand solar masses of gas and dust but with a volume of around 10 parsecs. The internal temperature of the cloud is so low at this point there is no resistance to the gravitational field strength of the cloud. These dark nebulae often start to contract under their own weight. Many of these areas are believed to be the birth place of protostars.