The history of the dark matter dates back to 1932 when it was discovered by an
astronomer named Jan Oort. He discovered dark matter by taking the measurements of a
star�s movements. Through the believed influence of gravity on the star he discovered
something very odd. He discovered that the mass was twice as large as it should be.
In 1933 a man named Fritz Zwickey discovered almost the same thing as Oortz.
Fritz was actually measuring the dynamics of clusters and galaxies at the time of the
discovery. He found when observing these galaxies that only ten percent of the total mass
could be accounted for.
Unfortunately this theory was never seriously looked at again until the nineteen
seventies. At this point in time astronomers and physicists started realizing that this
mysterious matter could account for many of their observations about space and the
universe.
Dark matter today is a difficult and competitive search. The more scientist
discover the more they realize how they do not know. The task is especially difficult
,because what they are observing is thought to be invisible, still the search continues.
Dark matter is believed to make up ninety percent of matter in the universe. It is
called dark matter, because it does not radiate (see appendix a). This matter seems to have
no glow that can be detected in the electromagnetic spectrum. It seems to only reveal its
existence through its gravitational pull.
It is believed that dark matter could be various substances or phenomenas. Some
believe it could be ultrafaint stars, black holes or cold gas (see appendix b). Others simply
believe it is merely a substance we do not know how to study. The majority of physicists
and astronomers seem to be shifting towards the belief that dark matter is a substance
called MACHOs or massive astro physical compact halo objects.
can be seen. Dark matter is often the explanation for inexplicable events in space. For
example astronomers can often predict the path of a star, but when its movement changes
in some way there must be something pulling or pushing it. The gravitational pull of dark
matter may be the explanation for this phenomena.