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Solar radiation pressure strongly affects comet tails. Solar heating causes gases to be released from the comet nucleus, which also carry away dust grains. Radiation pressure and solar wind then drive the dust and gases away from the Sun's direction. The gases form a generally straight tail, while slower moving dust particles create a broader ...
Bartoli in 1876 had derived the existence of radiation pressure from the principles of thermodynamics. Following Bartoli, Boltzmann considered an ideal heat engine using electromagnetic radiation instead of an ideal gas as working matter. The law was almost immediately experimentally verified.
Radiation pressure. The density of the linear momentum of the electromagnetic field is S/c 2 where S is the magnitude of the Poynting vector and c is the speed ...
Pressure gradient: Pressure per unit distance pascal/m L −2 M 1 T −2: vector Temperature gradient: steepest rate of temperature change at a particular location K/m L −1 Θ: vector Torque: τ: Product of a force and the perpendicular distance of the force from the point about which it is exerted
a is the scale factor, G, Λ, and c are universal constants (G is the Newtonian constant of gravitation, Λ is the cosmological constant with dimension length −2, and c is the speed of light in vacuum). ρ and p are the volumetric mass density (and not the volumetric energy density) and the pressure, respectively.
The thermodynamics of a black-body photon gas may be derived using quantum statistical mechanical arguments, with the radiation field being in equilibrium with the atoms in the wall. The derivation yields the spectral energy density u, which is the energy of the radiation field per unit volume per unit frequency interval, given by: [3]
Figures 1 and 2 in A Preliminary communication on the pressure of heat and light radiation, Phys. Rev. 13, 307-320 (1901).. A Nichols radiometer was the apparatus used by Ernest Fox Nichols and Gordon Ferrie Hull in 1901 for the measurement of radiation pressure.
optics, spectroscopy (the ratio of the intensities of radiation exiting through and incident on a sample ... Ratio of plasma thermal pressure to magnetic pressure ...