Sun - The Flat Earth Wiki
The Sun's electromagnetic radiation which is received at the Earth's surface is predominantly light that falls within the to show their relation to direct illumination. Earth is the third planet from the Sun and the only astronomical object known to harbor life. Earth's axial tilt (or obliquity) and its relation to the rotation axis and plane of orbit. The axial tilt of the Earth is approximately ° with the axis. All celestial bodies in the Solar System, including planets such as our own, orbit around the Solar System's centre of mass. The sun makes up % of this mass which is why the centre of mass is extremely close to the sun. Earth's orbit is the trajectory along which Earth travels around the Sun. In the 16th century, Nicolaus Copernicus' De revolutionibus presented a full.
This is caused by the tilt of the Earth's axis, and also by changes in the speed of its orbital motion around the Sun produced by the elliptical shape of the orbit. The principal effects of this east-west oscillation are variations in the timing of events such as sunrise and sunset, and in the reading of a sundial compared with a clock showing local mean time. As the graph shows, a sundial can be up to about 16 minutes fast or slow, compared with a clock.
Since the Earth rotates at a mean speed of one degree every four minutes, relative to the Sun, this minute displacement corresponds to a shift eastward or westward of about four degrees in the apparent position of the Sun, compared with its mean position. A westward shift causes the sundial to be ahead of the clock.Earth's motion around the Sun, not as simple as I thought
Since the main effect of this oscillation concerns time, it is called the equation of time, using the word "equation" in a somewhat archaic sense meaning "correction". The oscillation is measured in units of time, minutes and seconds, corresponding to the amount that a sundial would be ahead of a clock. The atmospheric extinction brings the number of lux down to around The total amount of energy received at ground level from the Sun at the zenith depends on the distance to the Sun and thus on the time of year.
It is about 3. This is higher than the efficacy of source of most artificial lighting including fluorescentwhich means using sunlight for illumination heats up a room less than using most forms of artificial lighting. Multiplying the figure of watts per square metre by 93 lumens per watt indicates that bright sunlight provides an illuminance of approximately 98 lux lumens per square meter on a perpendicular surface at sea level.
The illumination of a horizontal surface will be considerably less than this if the Sun is not very high in the sky. Averaged over a day, the highest amount of sunlight on a horizontal surface occurs in January at the South Pole see insolation. However, the radiance at the centre of the sun's disk is somewhat higher than the average over the whole disk due to limb darkening.
Because of its vastly increased surface area, the surface of the Sun will be considerably cooler 2, K at its coolest than it is on the main sequence. Eventually, the core will be hot enough for helium fusion; the Sun will burn helium for a fraction of the time it burned hydrogen in the core. The Sun is not massive enough to commence the fusion of heavier elements, and nuclear reactions in the core will dwindle.
Its outer layers will move away into space, leaving a white dwarfan extraordinarily dense object, half the original mass of the Sun but only the size of Earth.
Sunlight - Wikipedia
Sun Size comparison of the Sun and the planets The Sun is the Solar System's star and by far its most massive component. Its large massEarth masses which comprises Hotter main-sequence stars are more luminous. The Sun's temperature is intermediate between that of the hottest stars and that of the coolest stars.
The oldest stars contain few metals, whereas stars born later have more. This high metallicity is thought to have been crucial to the Sun's development of a planetary system because the planets form from the accretion of "metals". Along with lightthe Sun radiates a continuous stream of charged particles a plasma known as the solar wind. This stream of particles spreads outwards at roughly 1. The interaction of this magnetic field and material with Earth's magnetic field funnels charged particles into Earth's upper atmosphere, where its interactions create aurorae seen near the magnetic poles.
The heliosphere and planetary magnetic fields for those planets that have them partially shield the Solar System from high-energy interstellar particles called cosmic rays.
The density of cosmic rays in the interstellar medium and the strength of the Sun's magnetic field change on very long timescales, so the level of cosmic-ray penetration in the Solar System varies, though by how much is unknown.
The first, the zodiacal dust cloudlies in the inner Solar System and causes the zodiacal light. It was likely formed by collisions within the asteroid belt brought on by gravitational interactions with the planets. This region is also within the frost linewhich is a little less than 5 AU about million km from the Sun.
Terrestrial planet The inner planets. From left to right: EarthMarsVenusand Mercury sizes to scale.
Orrery showing the motions of the inner four planets. The small spheres represent the position of each planet on every Julian daybeginning July 6 aphelion and ending January 3 perihelion. The four terrestrial or inner planets have dense, rocky compositions, few or no moonsand no ring systems.
They are composed largely of refractory minerals, such as the silicates—which form their crusts and mantles —and metals, such as iron and nickel, which form their cores. Three of the four inner planets Venus, Earth and Mars have atmospheres substantial enough to generate weather; all have impact craters and tectonic surface features, such as rift valleys and volcanoes.
The term inner planet should not be confused with inferior planetwhich designates those planets that are closer to the Sun than Earth is i.
Mercury has no natural satellites; besides impact craters, its only known geological features are lobed ridges or rupes that were probably produced by a period of contraction early in its history.
Hypotheses include that its outer layers were stripped off by a giant impact; or, that it was prevented from fully accreting by the young Sun's energy.