A quasar (contraction of QUASi-stellAR radio source) is an extremely bright and distant active galactic nucleus. They were first identified as being high redshift sources of electromagnetic energy, including radio waves and visible light that were point-like, similar to stars, rather than extended sources similar to galaxies. There is now a scientific consensus that a quasar is a compact halo of matter surrounding the central supermassive black hole of a young galaxy.
Vacuum energy is an underlying background energy that exists in space even when devoid of matter (known as free space). The vacuum energy results in the existence of most (if not all) of the fundamental forces – and thus in all effects involving these forces, too. It is thought (but not yet demonstrated) to have consequences for the behavior of the Universe on cosmological scales.
In particle physics and quantum chemistry, antimatter extends the concept of the antiparticle to matter, whereby antimatter is composed of antiparticles in the same way that normal matter is composed of particles. Antimatter sounds like the stuff of science fiction, and it is. But it’s also very real. Antimatter is created and annihilated in stars every day. Here on Earth it’s harnessed for medical brain scans.
A micro black hole, also called a quantum mechanical black hole and inevitably a mini black hole, is simply a tiny black hole for which quantum mechanical effects play an important role.
In cosmology, the cosmic microwave background radiation is a form of electromagnetic radiation discovered in 1965 that fills the entire universe [1]. It has a thermal 2.725 kelvin black body spectrum which peaks in the microwave range at a frequency of 160.2 GHz, corresponding to a wavelength of 1.9 mm. Most cosmologists consider this radiation to be the best evidence for the Big Bang model of the universe.
In astrophysics and cosmology, dark matter is matter of unknown composition that does not emit or reflect enough electromagnetic radiation to be observed directly, but whose presence can be inferred from gravitational effects on visible matter. According to present observations of structures larger than galaxy-sized as well as Big Bang cosmology, dark matter accounts for the vast majority of mass in the observable universe.
An extrasolar planet, or exoplanet, is a planet beyond the Solar System. As of October 2007, the count of known exoplanet candidates stands at 257.[1] The vast majority have been detected through various indirect methods rather than actual imaging.[1] Most of them are massive giant planets likely to resemble Jupiter.
In physics, a gravitational wave is a fluctuation in the curvature of spacetime which propagates as a wave, traveling outward from a moving object or system of objects. Gravitational radiation is the energy transported by these waves. Important examples of systems which emit gravitational waves are binary star systems, where the two stars in the binary are white dwarfs, neutron stars, or black holes.
Galactic cannibalism refers to the process by which a large galaxy, through tidal gravitational interactions with a companion, merges with that companion, resulting in a larger, often irregular galaxy. The image above is from a simulation of Andromeda and our galaxy colliding, an event that will take place in about 3 billion years. The most common result of the gravitational merger of two or more galaxies is an irregular galaxy of one form or another, although elliptical galaxies may also result. It has been suggested that galactic cannibalism is currently occurring between the Milky Way and the Large and Small Magellanic Clouds. Streams of gravitationally-attracted hydrogen arcing from these dwarf galaxies to the Milky Way is taken as evidence for this theory.
Neutrinos are elementary particles that travel close to the speed of light, lack an electric charge, are able to pass through ordinary matter almost undisturbed, and are thus extremely difficult to detect. Neutrinos have a minuscule, but non-zero, mass too small to be measured as of 2007.
