3 ms·

If perpetual motion machines don't exist, what powers earth's natural systems?

2 points by yamrzou 3y ago

richardjam73 3y ago
William Hope Hodgson's story "The Night Land" 1912 is set when the sun goes out and the systems powering the earth are dying.
westurner 3y ago
Earth's rotation > Origin: https://en.wikipedia.org/wiki/Earth%27s_rotation#Origin https://en.wikipedia.org/wiki/Earth%27s_rotation#Origin : > Earth's original rotation was a vestige of the original angular momentum of the cloud of dust, rocks, and gas that coalesced to form the Solar System. This primordial cloud was composed of hydrogen and helium produced in the Big Bang, as well as heavier elements ejected by supernovas. As this interstellar dust is heterogeneous, any asymmetry during gravitational accretion resulted in the angular momentum of the eventual planet. [58] > However, if the giant-impact hypothesis for the origin of the Moon is correct, this primordial rotation rate would have been reset by the Theia impact 4.5 billion years ago. Regardless of the speed and tilt of Earth's rotation before the impact, it would have experienced a day some five hours long after the impact. [59] Tidal effects would then have slowed this rate to its modern value. Solar energy: fission, fusion; [thermal] radiation,: https://en.wikipedia.org/wiki/Solar_energy https://en.wikipedia.org/wiki/Solar_energy Circumstellar habitable zone: https://en.wikipedia.org/wiki/Circumstellar_habitable_zone https://en.wikipedia.org/wiki/Circumstellar_habitable_zone : > In astronomy and astrobiology, the circumstellar habitable zone (CHZ), or simply the habitable zone, is the range of orbits around a star within which a planetary surface can support liquid water given sufficient atmospheric pressure. [1][2][3][4][5] The bounds of the CHZ are based on Earth's position in the Solar System and the amount of radiant energy it receives from the Sun. Earth > Hydrosphere, Atmosphere: https://en.wikipedia.org/wiki/Earth https://en.wikipedia.org/wiki/Earth : > Earth's hydrosphere is the sum of Earth's water and its distribution. Most of Earth's hydrosphere consists of Earth's global ocean. Nevertheless, Earth's hydrosphere also consists of water in the atmosphere and on land, including clouds, inland seas, lakes, rivers, and underground waters down to a depth of 2,000 m (6,600 ft). Gravity: https://en.wikipedia.org/wiki/Gravity https://en.wikipedia.org/wiki/Gravity

2 points by yamrzou 3y ago

William Hope Hodgson's story "The Night Land" 1912 is set when the sun goes out and the systems powering the earth are dying.

westurner 3y ago

Earth's rotation > Origin: https://en.wikipedia.org/wiki/Earth%27s_rotation#Origin https://en.wikipedia.org/wiki/Earth%27s_rotation#Origin : > Earth's original rotation was a vestige of the original angular momentum of the cloud of dust, rocks, and gas that coalesced to form the Solar System. This primordial cloud was composed of hydrogen and helium produced in the Big Bang, as well as heavier elements ejected by supernovas. As this interstellar dust is heterogeneous, any asymmetry during gravitational accretion resulted in the angular momentum of the eventual planet. [58] > However, if the giant-impact hypothesis for the origin of the Moon is correct, this primordial rotation rate would have been reset by the Theia impact 4.5 billion years ago. Regardless of the speed and tilt of Earth's rotation before the impact, it would have experienced a day some five hours long after the impact. [59] Tidal effects would then have slowed this rate to its modern value. Solar energy: fission, fusion; [thermal] radiation,: https://en.wikipedia.org/wiki/Solar_energy https://en.wikipedia.org/wiki/Solar_energy Circumstellar habitable zone: https://en.wikipedia.org/wiki/Circumstellar_habitable_zone https://en.wikipedia.org/wiki/Circumstellar_habitable_zone : > In astronomy and astrobiology, the circumstellar habitable zone (CHZ), or simply the habitable zone, is the range of orbits around a star within which a planetary surface can support liquid water given sufficient atmospheric pressure. [1][2][3][4][5] The bounds of the CHZ are based on Earth's position in the Solar System and the amount of radiant energy it receives from the Sun. Earth > Hydrosphere, Atmosphere: https://en.wikipedia.org/wiki/Earth https://en.wikipedia.org/wiki/Earth : > Earth's hydrosphere is the sum of Earth's water and its distribution. Most of Earth's hydrosphere consists of Earth's global ocean. Nevertheless, Earth's hydrosphere also consists of water in the atmosphere and on land, including clouds, inland seas, lakes, rivers, and underground waters down to a depth of 2,000 m (6,600 ft). Gravity: https://en.wikipedia.org/wiki/Gravity https://en.wikipedia.org/wiki/Gravity