enow.com Web Search

Search results

  1. Results from the WOW.Com Content Network
  2. Orders of magnitude (illuminance) - Wikipedia

    en.wikipedia.org/wiki/Orders_of_magnitude...

    Factor ()Multiple Value Item 0 0 lux 0 lux Absolute darkness 10 −4: 100 microlux 100 microlux: Starlight overcast moonless night sky [1]: 140 microlux: Venus at brightest [1]: 200 microlux

  3. C mathematical functions - Wikipedia

    en.wikipedia.org/wiki/C_mathematical_functions

    The type-generic macros that correspond to a function that is defined for only real numbers encapsulates a total of 3 different functions: float, double and long double variants of the function. The C++ language includes native support for function overloading and thus does not provide the <tgmath.h> header even as a compatibility feature.

  4. Computer performance by orders of magnitude - Wikipedia

    en.wikipedia.org/wiki/Computer_performance_by...

    1×10 −1: multiplication of two 10-digit numbers by a 1940s electromechanical desk calculator [1] 3×10 −1: multiplication on Zuse Z3 and Z4, first programmable digital computers, 1941 and 1945 respectively; 5×10 −1: computing power of the average human mental calculation [clarification needed] for multiplication using pen and paper

  5. Apparent magnitude - Wikipedia

    en.wikipedia.org/wiki/Apparent_magnitude

    For example, a magnitude 2.0 star is 2.512 times as bright as a magnitude 3.0 star, 6.31 times as magnitude 4.0, and 100 times magnitude 7.0. The brightest astronomical objects have negative apparent magnitudes: for example, Venus at −4.2 or Sirius at −1.46.

  6. Magnitude (astronomy) - Wikipedia

    en.wikipedia.org/wiki/Magnitude_(astronomy)

    An illustration of light sources from magnitude 1 to 3.5, in 0.5 increments. In astronomy, magnitude is a measure of the brightness of an object, usually in a defined passband. An imprecise but systematic determination of the magnitude of objects was introduced in ancient times by Hipparchus. Magnitude values do not have a unit.

  7. Luminosity - Wikipedia

    en.wikipedia.org/wiki/Luminosity

    The apparent magnitude is the observed visible brightness from Earth which depends on the distance of the object. The absolute magnitude is the apparent magnitude at a distance of 10 pc (3.1 × 10 17 m), therefore the bolometric absolute magnitude is a logarithmic measure of the bolometric luminosity.

  8. Absolute magnitude - Wikipedia

    en.wikipedia.org/wiki/Absolute_magnitude

    For example, the giant elliptical galaxy M87 has an absolute magnitude of −22 (i.e. as bright as about 60,000 stars of magnitude −10). Some active galactic nuclei ( quasars like CTA-102 ) can reach absolute magnitudes in excess of −32, making them the most luminous persistent objects in the observable universe, although these objects can ...

  9. Historical brightest stars - Wikipedia

    en.wikipedia.org/wiki/Historical_brightest_stars

    For example, it omits Gliese 710 which in about 1.35 million years is expected to be close enough to have a magnitude of −2.7, [2] as confirmed by the Gaia spacecraft. [ 3 ] [ 4 ] Star