Humboldt-Universität zu Berlin - Faculty of Mathematics and Natural Sciences - Experimental Particle Physics

Dark Matter

GravitationslinseNumerous observations have led to the hypothesis that, besides the well-known visible matter of which we all consist, an as yet unknown type of matter must exists.  Observations of the rotating velocity of stars provide further evidence for this hypothesis.  Without this unknown form of matter the rotational velocity of stars should decrease with increasing distance from the centre of the galaxy, however, this is not what is observed.  Similarly, neither the dynamics of galaxy clusters nor the gravitational lens effect, in which light is focussed by mass like a lens, can be explained by visible matter.

The so-called Dark Matter cannot be observed directly because of its extremely weak interaction with electromagnetic radiation.  It can only be seen indirectly in its gravitational effect on visible matter. Computations show that around 90% of the matter in our universe is Dark Matter.  Despite this, however, Dark Matter has not yet been proven to exist.

Matter | Dark Matter | Higgs-Particle | 4th Generation | Heavy Quarks