When.com Web Search

Search results

  1. Results From The WOW.Com Content Network
  2. Point reflection - Wikipedia

    en.wikipedia.org/wiki/Point_reflection

    In mathematics, reflection through the origin refers to the point reflection of Euclidean space R n across the origin of the Cartesian coordinate system. Reflection through the origin is an orthogonal transformation corresponding to scalar multiplication by − 1 {\displaystyle -1} , and can also be written as − I {\displaystyle -I} , where I ...

  3. History of Earth - Wikipedia

    en.wikipedia.org/wiki/History_of_Earth

    The first eon in Earth's history, the Hadean, begins with Earth's formation and is followed by the Archean eon at 3.8 Ga. [2]: 145 The oldest rocks found on Earth date to about 4.0 Ga, and the oldest detrital zircon crystals in rocks to about 4.4 Ga, [34] [35] [36] soon after the formation of Earth's crust and Earth itself.

  4. Geological history of Earth - Wikipedia

    en.wikipedia.org/wiki/Geological_history_of_Earth

    Earth formed about 4.54 billion years ago by accretion from the solar nebula, a disk-shaped mass of dust and gas left over from the formation of the Sun, which also created the rest of the Solar System. Initially, Earth was molten due to extreme volcanism and frequent collisions with other bodies.

  5. Lunar Laser Ranging experiments - Wikipedia

    en.wikipedia.org/wiki/Lunar_Laser_Ranging...

    Relativistic transformation of time and space coordinates from a frame moving with the station to a frame fixed with respect to the solar system center of mass. Lorentz contraction of the Earth is part of this transformation. Delay in the Earth's atmosphere. Relativistic delay due to the gravity fields of the Sun, Earth, and Moon.

  6. History of geology - Wikipedia

    en.wikipedia.org/wiki/History_of_geology

    This questioning represented a turning point in the study of the Earth. It was now possible to study the history of the Earth from a scientific perspective without religious preconceptions. With the application of scientific methods to the investigation of the Earth's history, the study of geology could become a distinct field of science.

  7. Bedford Level experiment - Wikipedia

    en.wikipedia.org/wiki/Bedford_Level_experiment

    The Old Bedford River, photographed from the bridge at Welney, Norfolk (2008); the camera is looking downstream, south-west of the bridge. The Bedford Level experiment was a series of observations carried out along a 6-mile (10 km) length of the Old Bedford River on the Bedford Level of the Cambridgeshire Fens in the United Kingdom during the 19th and early 20th centuries to deny the curvature ...

  8. Origin of Australia’s 1,400-year-old mysterious earth rings ...

    www.aol.com/news/origin-australia-1-400-old...

    Mysterious ancient earth rings located on the outskirts of Melbourne were made by Australia’s Aboriginal Wurundjeri Woi-wurrung people hundreds of years ago, a new study finally reveals.

  9. Reflection seismology - Wikipedia

    en.wikipedia.org/wiki/Reflection_seismology

    Crustal studies – investigation into the structure and origin of the Earth's crust, through to the Moho discontinuity and beyond, at depths of up to 100 km. A method similar to reflection seismology which uses electromagnetic instead of elastic waves, and has a smaller depth of penetration, is known as Ground-penetrating radar or GPR.