When.com Web Search

  1. Ad

    related to: distance to light years calculator converter hours and minutes free

Search results

  1. Results From The WOW.Com Content Network
  2. Light-year - Wikipedia

    en.wikipedia.org/wiki/Light-year

    A light-year, alternatively spelled light year (ly or lyr[3]), is a unit of length used to express astronomical distances and is equal to exactly 9,460,730,472,580.8 km (Scientific notation: 9.4607304725808 × 10 12 km), which is approximately 5.88 trillion mi.

  3. Comoving and proper distances - Wikipedia

    en.wikipedia.org/wiki/Comoving_and_proper_distances

    Comoving distance and proper distance. Comoving distance is the distance between two points measured along a path defined at the present cosmological time. For objects moving with the Hubble flow, it is deemed to remain constant in time. The comoving distance from an observer to a distant object (e.g. galaxy) can be computed by the following ...

  4. Light-second - Wikipedia

    en.wikipedia.org/wiki/Light-second

    The light-second is a unit of length useful in astronomy, telecommunications and relativistic physics. It is defined as the distance that light travels in free space in one second, and is equal to exactly 299 792 458 m (approximately 983 571 055 ft or 186 282 mi). Just as the second forms the basis for other units of time, the light-second can ...

  5. Parsec - Wikipedia

    en.wikipedia.org/wiki/Parsec

    3.261 56 ly. The parsec (symbol: pc) is a unit of length used to measure the large distances to astronomical objects outside the Solar System, approximately equal to 3.26 light-years or 206,265 astronomical units (AU), i.e. 30.9 trillion kilometres (19.2 trillion miles). [a] The parsec unit is obtained by the use of parallax and trigonometry ...

  6. Astronomical unit - Wikipedia

    en.wikipedia.org/wiki/Astronomical_unit

    Light-day: 173 – Distance light travels in one day – Light-year: 63,241 – Distance light travels in one Julian year (365.25 days) – Oort cloud: 75,000: ± 25,000: Distance of the outer limit of Oort cloud from the Sun (estimated, corresponds to 1.2 light-years) – Parsec: 206,265 – One parsec. The parsec is defined in terms of the ...

  7. Speed of light - Wikipedia

    en.wikipedia.org/wiki/Speed_of_Light

    A light-year is the distance light travels in one Julian year, around 9461 billion kilometres, 5879 billion miles, or 0.3066 parsecs. In round figures, a light year is nearly 10 trillion kilometres or nearly 6 trillion miles. Proxima Centauri, the closest star to Earth after the Sun, is around 4.2 light-years away. [89]

  8. Planck units - Wikipedia

    en.wikipedia.org/wiki/Planck_units

    The Planck time t P is the time required for light to travel a distance of 1 Planck length in vacuum, which is a time interval of approximately 5.39 × 10 −44 s. No current physical theory can describe timescales shorter than the Planck time, such as the earliest events after the Big Bang. [27]

  9. Orders of magnitude (length) - Wikipedia

    en.wikipedia.org/wiki/Orders_of_magnitude_(length)

    The centimetre (SI symbol: cm) is a unit of length in the metric system equal to 10−2 metres (⁠ 1 100 ⁠ m = 0.01 m). To help compare different orders of magnitude, this section lists lengths between 10 −2 m and 10 −1 m (1 cm and 1 dm). 1 cm – 10 millimetres. 1 cm – 0.39 inches. 1 cm – edge of a square of area 1 cm 2.