Search results
Results from the WOW.Com Content Network
English: Summary of an Archimedes heat ray. In practice, many more mirrors than shown would be needed, and the results may have been merely soldier sweat, temporary blindness, and confusion rather than fire. The mirrors may have consisted of polished metal and had peep-holes drilled in the middle for use in aiming.
However, "heat" is a technical term in physics and thermodynamics and is often confused with thermal energy. Any type of electromagnetic energy can be transformed into thermal energy in interaction with matter. Thus, any electromagnetic radiation can "heat" (in the sense of increase the thermal energy temperature of) a material, when it is ...
The parabolic model for heat conduction discussed above shows that the Fourier equation (and the more general Fick's law of diffusion) is incompatible with the theory of relativity [7] for at least one reason: it admits infinite speed of propagation of the continuum field (in this case: heat, or temperature gradients).
Thomson's lamp is a philosophical puzzle based on infinites. It was devised in 1954 by British philosopher James F. Thomson, who used it to analyze the possibility of a supertask, which is the completion of an infinite number of tasks. Consider a lamp with a toggle switch. Flicking the switch once turns the lamp on. Another flick will turn the ...
These first Heisler–Gröber charts were based upon the first term of the exact Fourier series solution for an infinite plane wall: (,) = = [ + ], [1]where T i is the initial uniform temperature of the slab, T ∞ is the constant environmental temperature imposed at the boundary, x is the location in the plane wall, λ is the root of λ * tan λ = Bi, and α is thermal diffusivity.
Infrared heating uses infrared lamps, commonly called heat lamps, to transmit infrared radiation to the body that is being heated. When a body with a large surface area needs to be heated, an array of infrared lamps is often used. The lamp commonly contains an incandescent bulb that produces infrared radiation.
Thermal radiation is one of the fundamental mechanisms of heat transfer, along with conduction and convection. The primary method by which the Sun transfers heat to the Earth is thermal radiation. This energy is partially absorbed and scattered in the atmosphere, the latter process being the reason why the sky is visibly blue. [3]
Care should be taken transporting the lamp and replacing lamps. The gases in an HMI lamp are under a very small pressure, but it does increase with temperature. As with quartz-halogen bulbs, care should be taken not to touch the glass directly as skin oils left behind on the envelope can heat beyond the working temperature of the envelope and ...