darkmatterandenergy

DARK MATTER

theoretical matter that is undetectable by its emmitted radiation, but is detectable by its gravitational effects on visable matter

Dark matter is postulated to explain the flat rotation curves of spiral galaxies and other evidence of "missing mass" in the universe. According to present observations of structures larger than galaxies, as well as Big Bang cosmology, dark matter and dark energy account for the vast majority of the mass in the observable universe.

Implied by rotational speeds of galaxies, orbital velocities of galaxies in clusters, gravitational lensing, and temperature distribution ofhot gas in galaxies.

4% of the universe is visable matter 22% of the universe is hypothetically dark matter 74% of the universe is dark energy

often times considered to be term for human ignorance similar to that of marking "terra incognita" (unknown land) on a map.

The vast majority of the dark matter in the universe is believed to be nonbaryonic, which means that it contains no atoms and that it does not interact with ordinary matter via electromagnetic forces

DARK ENERGY

Dark energy is the most popular way to explain recent observations that the universe appears to be expanding at an accelerating rate.

It is known to be very homogeneous, not very dense and is not known to interact through any of the fundamental forces other than gravity.

theoretically creates negative pressure