The experimental background of quantum theory
... where f is the frequency of the light, and h is the Planck constant. This view, that light behaves a stream of particles, is in sharp contrast with the wave theory! By applying Einstein's photon concept to the photoelectric effect, we can write: hf = Φ + E k . The equation describes that a photon ca ...
... where f is the frequency of the light, and h is the Planck constant. This view, that light behaves a stream of particles, is in sharp contrast with the wave theory! By applying Einstein's photon concept to the photoelectric effect, we can write: hf = Φ + E k . The equation describes that a photon ca ...
The Electromagnetic Spectrum - Warren Hills Regional School District
... The aurora is a near daily occurrence on Earth. Because the intensity of the light in an aurora is low, it can only be seen at night. The most active and brilliant displays usually occur near midnight. The best time to observe the aurora is between 11 p.m. and 2 a.m. In the northern hemisphere, the ...
... The aurora is a near daily occurrence on Earth. Because the intensity of the light in an aurora is low, it can only be seen at night. The most active and brilliant displays usually occur near midnight. The best time to observe the aurora is between 11 p.m. and 2 a.m. In the northern hemisphere, the ...
Light Problems Quiz: Name___________________ SHOW ALL
... [9] The blue color of the sky results from the scattering of sunlight by air molecules. The blue light has a frequency of about 7.5 x 1014 Hz. Calculate the wavelength, in nm, associated with this radiation. ...
... [9] The blue color of the sky results from the scattering of sunlight by air molecules. The blue light has a frequency of about 7.5 x 1014 Hz. Calculate the wavelength, in nm, associated with this radiation. ...
T = 5800 K
... Blackbody Radiation Blackbody = something that absorbs all electromagnetic radiation incident on it. A blackbody does not necessarily look black. Its color depends on its temperature. The Sun and other stars behave approximately like blackbodies. The amount of electromagnetic radiation, with a give ...
... Blackbody Radiation Blackbody = something that absorbs all electromagnetic radiation incident on it. A blackbody does not necessarily look black. Its color depends on its temperature. The Sun and other stars behave approximately like blackbodies. The amount of electromagnetic radiation, with a give ...
Blackbody Radiation
... • The peak emission from the blackbody moves to shorter wavelengths as the temperature increases (Wien’s law). • The hotter the blackbody the more energy emitted per unit area at all wavelengths. – bigger objects emit more radiation ...
... • The peak emission from the blackbody moves to shorter wavelengths as the temperature increases (Wien’s law). • The hotter the blackbody the more energy emitted per unit area at all wavelengths. – bigger objects emit more radiation ...
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.