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  2. Sidereal time - Wikipedia

    en.wikipedia.org/wiki/Sidereal_time

    Although ERA is intended to replace sidereal time, there is a need to maintain definitions for sidereal time during the transition, and when working with older data and documents. Similarly to mean solar time, every location on Earth has its own local sidereal time (LST), depending on the longitude of the point.

  3. Science fair - Wikipedia

    en.wikipedia.org/wiki/Science_fair

    A science fair or engineering fair is an event hosted by a school that offers students the opportunity to experience the practices of science and engineering for themselves. In the United States, the Next Generation Science Standards makes experiencing the practices of science and engineering one of the three pillars of science education.

  4. Sidereal year - Wikipedia

    en.wikipedia.org/wiki/Sidereal_year

    The sidereal year differs from the solar year, "the period of time required for the ecliptic longitude of the Sun to increase 360 degrees", [2] due to the precession of the equinoxes. The sidereal year is 20 min 24.5 s longer than the mean tropical year at J2000.0 (365.242 190 402 ephemeris days) .

  5. Time standard - Wikipedia

    en.wikipedia.org/wiki/Time_standard

    A sidereal rotation is the time it takes the Earth to make one revolution with rotation to the stars, approximately 23 hours 56 minutes 4 seconds. A mean solar day is about 3 minutes 56 seconds longer than a mean sidereal day, or 1 ⁄ 366 more than a mean sidereal day. In astronomy, sidereal time is used to predict when a star will reach its ...

  6. Synodic day - Wikipedia

    en.wikipedia.org/wiki/Synodic_day

    The synodic day is distinguished from the sidereal day, which is one complete rotation in relation to distant stars [1] and is the basis of sidereal time. In the case of a tidally locked planet, the same side always faces its parent star, and its synodic day is infinite. Its sidereal day, however, is equal to its orbital period.

  7. Solar time - Wikipedia

    en.wikipedia.org/wiki/Solar_time

    On a prograde planet like the Earth, the sidereal day is shorter than the solar day. At time 1, the Sun and a certain distant star are both overhead. At time 2, the planet has rotated 360° and the distant star is overhead again (1→2 = one sidereal day). But it is not until a little later, at time 3, that the Sun is overhead again (1→3 = one solar day). More simply, 1→2 is a complete ...

  8. History of timekeeping devices - Wikipedia

    en.wikipedia.org/wiki/History_of_timekeeping_devices

    The weight-driven mechanical clock controlled by the action of a verge and foliot was a synthesis of earlier ideas from European and Islamic science. Mechanical clocks were a major breakthrough, one notably designed and built by Henry de Vick in c. 1360 , which established basic clock design for the next 300 years.

  9. Anti-sidereal time - Wikipedia

    en.wikipedia.org/wiki/Anti-sidereal_time

    Anti-sidereal time has about 364.25 days per year, one day less than the number of days in a year of solar time, 365.25. Thus each anti-sidereal day is longer than a solar day (24 hr) by about four minutes or 24 hr 4 min. Extended-sidereal time has about 367.25 days per year, one day more than the number of days in a year of sidereal time, 366. ...