Thursday, October 22, 2009
What is Dark Matter and Dark Energy?
In 1933, Fritz Zwicky averaged the mass of certain galaxies and obtained a value far greater than expected - he determined there was an unseen "dark matter" that allowed for the discrepancy. Dark Matter was determined to be a directly undetectable state of matter with powerful gravitational effects.
But in 1998 an even more shocking discovery revealed that despite this 'dark' matter pulling galaxies together, the universe itself was expanding ... and at an increasing speed. While dark matter was keeping everything together, a stronger force was pushing everything apart! Moreover, galaxies were not being stretched ... instead, more space was being created. The same amount of acceleration of this expansion was observed irrespective of position.
This means that "dark energy" is uniform and also much stronger than dark matter.
It doesn't stop there ... the visible matter, as immense as it is, comprises only 4% of all the matter in the universe - dark matter is believed to take up 21% of the pie, with dark energy taking up an unbelievable 75% of distribution in the universe!
Here's an easy to understand documentary explaining the phenomenon.