What`s Brewing in the Teapot - Indiana University Astronomy
... •Since nothing can travel faster than light, nothing can escape from inside a black hole •Objects of any mass can (in principle) become black ...
... •Since nothing can travel faster than light, nothing can escape from inside a black hole •Objects of any mass can (in principle) become black ...
How to measure the spin of a black hole -
... spin is rather subtle. The spin itself takes hold very close to the black hole, where the effects of Einstein’s relativity are immense. The strength of the relativistic effects allows us to determine how fast the black hole is spinning. However, black holes are dark voids in the sky, we cannot see t ...
... spin is rather subtle. The spin itself takes hold very close to the black hole, where the effects of Einstein’s relativity are immense. The strength of the relativistic effects allows us to determine how fast the black hole is spinning. However, black holes are dark voids in the sky, we cannot see t ...
AST1100 Lecture Notes
... when a photon with energy E = hν hits an atom, the electron can only absorb the energy of the photon if the energy hν corresponds exactly to the difference between two energy levels ∆E = Ei −Ej . Only in this case is the photon absorbed and the electron is excited to a higher energy level in the ato ...
... when a photon with energy E = hν hits an atom, the electron can only absorb the energy of the photon if the energy hν corresponds exactly to the difference between two energy levels ∆E = Ei −Ej . Only in this case is the photon absorbed and the electron is excited to a higher energy level in the ato ...
Kirchhoff law
... Increasing the temperature increases the intensity at all wavelengths Total area under the curve increases as temperature increases, corresponding to increased total emission as the object becomes hotter. Maximum intensity shifts to shorter wavelengths with increasing temperatures Function defined o ...
... Increasing the temperature increases the intensity at all wavelengths Total area under the curve increases as temperature increases, corresponding to increased total emission as the object becomes hotter. Maximum intensity shifts to shorter wavelengths with increasing temperatures Function defined o ...
Massive Star (10 to 15 times the size of our Sun) Nuclear Fusion
... Theory: the immense gravitational pull from the black hole should tear apart ...
... Theory: the immense gravitational pull from the black hole should tear apart ...
Black body
A black body (also blackbody) is an idealized physical body that absorbs all incident electromagnetic radiation, regardless of frequency or angle of incidence. A white body is one with a ""rough surface [that] reflects all incident rays completely and uniformly in all directions.""A black body in thermal equilibrium (that is, at a constant temperature) emits electromagnetic radiation called black-body radiation. The radiation is emitted according to Planck's law, meaning that it has a spectrum that is determined by the temperature alone (see figure at right), not by the body's shape or composition.A black body in thermal equilibrium has two notable properties:It is an ideal emitter: at every frequency, it emits as much energy as – or more energy than – any other body at the same temperature.It is a diffuse emitter: the energy is radiated isotropically, independent of direction.An approximate realization of a black surface is a hole in the wall of a large enclosure (see below). Any light entering the hole is reflected indefinitely or absorbed inside and is unlikely to re-emerge, making the hole a nearly perfect absorber. The radiation confined in such an enclosure may or may not be in thermal equilibrium, depending upon the nature of the walls and the other contents of the enclosure.Real materials emit energy at a fraction—called the emissivity—of black-body energy levels. By definition, a black body in thermal equilibrium has an emissivity of ε = 1.0. A source with lower emissivity independent of frequency often is referred to as a gray body.Construction of black bodies with emissivity as close to one as possible remains a topic of current interest.In astronomy, the radiation from stars and planets is sometimes characterized in terms of an effective temperature, the temperature of a black body that would emit the same total flux of electromagnetic energy.