enow.com Web Search

Search results

  1. Results from the WOW.Com Content Network
  2. Spherical coordinate system - Wikipedia

    en.wikipedia.org/wiki/Spherical_coordinate_system

    Particular care must be taken to check the meaning of the symbols. The mathematics convention. Spherical coordinates (r, θ, φ) as typically used: radial distance r, azimuthal angle θ, and polar angle φ. + The meanings of θ and φ have been swapped—compared to the physics convention. The 'south'-direction x-axis is depicted but the 'north ...

  3. Unpolarized light - Wikipedia

    en.wikipedia.org/wiki/Unpolarized_light

    the set of all polarization states are then mapped to points on the surface of the so-called Poincaré sphere (but of radius P), as shown in the accompanying diagram. In quantum mechanics and computing , a related concept is the Bloch sphere .

  4. Astronomical unit - Wikipedia

    en.wikipedia.org/wiki/Astronomical_unit

    In the 2nd century CE, Ptolemy estimated the mean distance of the Sun as 1210 times Earth's radius. [36] [37] To determine this value, Ptolemy started by measuring the Moon's parallax, finding what amounted to a horizontal lunar parallax of 1° 26′, which was much too large. He then derived a maximum lunar distance of ⁠64 + 1 / 6 ⁠ Earth ...

  5. 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.

  6. Magdeburg hemispheres - Wikipedia

    en.wikipedia.org/wiki/Magdeburg_hemispheres

    Sound did not transmit through the sphere, indicating that sound needed a medium in order to be heard, while light did not. [ 2 ] The first artificial vacuum had been produced a few years earlier by Evangelista Torricelli and inspired Guericke to design the world's first vacuum pump , which consisted of a piston and cylinder with one-way flap ...

  7. Earth radius - Wikipedia

    en.wikipedia.org/wiki/Earth_radius

    Earth radius (denoted as R 🜨 or R E) is the distance from the center of Earth to a point on or near its surface. Approximating the figure of Earth by an Earth spheroid (an oblate ellipsoid), the radius ranges from a maximum (equatorial radius, denoted a) of nearly 6,378 km (3,963 mi) to a minimum (polar radius, denoted b) of nearly 6,357 km (3,950 mi).

  8. Radiation pressure - Wikipedia

    en.wikipedia.org/wiki/Radiation_pressure

    Laser light interacts with a glass sphere: the radiation pressure force causes it to vibrate. The presence of a single molecule on the sphere disturbs that (thermal) vibration, and the disturbance in the sphere's motion can be detected in the oscillator spectrum on the left.

  9. Specific rotation - Wikipedia

    en.wikipedia.org/wiki/Specific_rotation

    The CRC Handbook of Chemistry and Physics defines specific rotation as: For an optically active substance, defined by [α] θ λ = α/γl, where α is the angle through which plane polarized light is rotated by a solution of mass concentration γ and path length l. Here θ is the Celsius temperature and λ the wavelength of the light at which ...