When.com Web Search

Search results

  1. Results From The WOW.Com Content Network
  2. Heat lightning - Wikipedia

    en.wikipedia.org/wiki/Heat_lightning

    Heat lightning (not to be confused with dry thunderstorms, which are also often called dry lightning) is a misnomer [1] used for the faint flashes of lightning on the horizon or other clouds from distant thunderstorms that do not appear to have accompanying sounds of thunder.

  3. Atmospheric refraction - Wikipedia

    en.wikipedia.org/wiki/Atmospheric_refraction

    Atmospheric refraction of the light from a star is zero in the zenith, less than 1′ (one arc-minute) at 45° apparent altitude, and still only 5.3′ at 10° altitude; it quickly increases as altitude decreases, reaching 9.9′ at 5° altitude, 18.4′ at 2° altitude, and 35.4′ at the horizon; [4] all values are for 10 °C and 1013.25 hPa ...

  4. Heat deflection temperature - Wikipedia

    en.wikipedia.org/wiki/Heat_deflection_temperature

    The heat distortion temperature is determined by the following test procedure outlined in ASTM D648. The test specimen is loaded in three-point bending in the edgewise direction. The outer fiber stress used for testing is either 0.455 MPa or 1.82 MPa, and the temperature is increased at 2 °C/min until the specimen deflects 0.25 mm.

  5. Infrared heater - Wikipedia

    en.wikipedia.org/wiki/Infrared_heater

    Electrical infrared hair dryer for hair salons, c. 2010s. A heat lamp is an incandescent light bulb that is used for the principal purpose of creating heat. The spectrum of black-body radiation emitted by the lamp is shifted to produce more infrared light. Many heat lamps include a red filter to minimize the amount of visible light emitted.

  6. Distortion (optics) - Wikipedia

    en.wikipedia.org/wiki/Distortion_(optics)

    In geometric optics, distortion is a deviation from rectilinear projection; a projection in which straight lines in a scene remain straight in an image.It is a form of optical aberration that may be distinguished from other aberrations such as spherical aberration, coma, chromatic aberration, field curvature, and astigmatism in a sense that these impact the image sharpness without changing an ...

  7. Amazon Just Knocked 25% off the Dyson Supersonic Hair Dryer ...

    www.aol.com/amazon-just-knocked-100-off...

    For example, in past sales, you could get a Dyson Supersonic with all five attachments for $349, almost a full $100 cheaper than some stores that offer it for $320 to $420. Best Buy

  8. Distortion - Wikipedia

    en.wikipedia.org/wiki/Distortion

    Distortion occurs when the transfer function F is more complicated than this. If F is a linear function, for instance a filter whose gain and/or delay varies with frequency, the signal suffers linear distortion. Linear distortion does not introduce new frequency components to a signal but does alter the balance of existing ones.

  9. Chromatic aberration - Wikipedia

    en.wikipedia.org/wiki/Chromatic_aberration

    In optics, chromatic aberration (CA), also called chromatic distortion, color aberration, color fringing, or purple fringing, is a failure of a lens to focus all colors to the same point. [ 1 ] [ 2 ] It is caused by dispersion : the refractive index of the lens elements varies with the wavelength of light .