When.com Web Search

Search results

  1. Results From The WOW.Com Content Network
  2. Cosmic noise - Wikipedia

    en.wikipedia.org/wiki/Cosmic_noise

    Cosmic noise, also known as galactic radio noise, is a physical phenomenon derived from outside of the Earth's atmosphere. It is not actually sound, and it can be detected through a radio receiver , which is an electronic device that receives radio waves and converts the information given by them to an audible form.

  3. Speed of sound - Wikipedia

    en.wikipedia.org/wiki/Speed_of_sound

    The speed of sound is the distance travelled per unit of time by a sound wave as it propagates through an elastic medium. More simply, the speed of sound is how fast vibrations travel. At 20 °C (68 °F), the speed of sound in air, is about 343 m/s (1,125 ft/s; 1,235 km/h; 767 mph; 667 kn), or 1 km in 2.91 s or one mile in 4.69 s.

  4. Line-of-sight propagation - Wikipedia

    en.wikipedia.org/wiki/Line-of-sight_propagation

    The rays or waves may be diffracted, refracted, reflected, or absorbed by the atmosphere and obstructions with material and generally cannot travel over the horizon or behind obstacles. In contrast to line-of-sight propagation, at low frequency (below approximately 3 MHz ) due to diffraction , radio waves can travel as ground waves , which ...

  5. Fry readability formula - Wikipedia

    en.wikipedia.org/wiki/Fry_readability_formula

    A rendition of the Fry graph. The Fry readability formula (or Fry readability graph) is a readability metric for English texts, developed by Edward Fry. [1]The grade reading level (or reading difficulty level) is calculated by the average number of sentences (y-axis) and syllables (x-axis) per hundred words.

  6. NASA offers explanation for bizarre 'trumpet noise' phenomena

    www.aol.com/news/2015-05-22-nasa-attempts-to...

    Eerie noises have been recorded all over the world recently. NASA is now offering up a possible explanation.

  7. Ambient noise level - Wikipedia

    en.wikipedia.org/wiki/Ambient_noise_level

    Ambient noise level is measured with a sound level meter. [4] It is usually measured in dB relative to a reference pressure of 0.00002 Pa, i.e., 20 μPa (micropascals) in SI units. [5] This is because 20 μPa is the faintest sound the human ear can detect. [5] A pascal is a newton per square meter. The centimeter-gram-second system of units ...

  8. Baryon acoustic oscillations - Wikipedia

    en.wikipedia.org/wiki/Baryon_acoustic_oscillations

    The BAO signal is a standard ruler such that the length of the sound horizon can be measured as a function of cosmic time. [3] This measures two cosmological distances: the Hubble parameter, H ( z ) {\displaystyle H(z)} , and the angular diameter distance , d A ( z ) {\displaystyle d_{A}(z)} , as a function of redshift ( z ) {\displaystyle (z ...

  9. AOL Mail

    mail.aol.com

    You can find instant answers on our AOL Mail help page. Should you need additional assistance we have experts available around the clock at 800-730-2563. Should you need additional assistance we have experts available around the clock at 800-730-2563.