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The site deals with the consequences of Newton's work; it disregards relativity, string theory, etc.
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G × MSun = 1.32712440018×1020 N m2 kg-1 (HS 20031230 news:s.p.p)
G = (6.674215±0.000092)×10-11
m3/kg/s2 ( Jens
H. Gundlach and Stephen M. Merkowitz);
Earth's mass : (5.972245±0.000082)×1024 kg
& Sun's mass : (1.988435±0.000027)×1030
kg (G
& M)
Hubble constant : 70.4 ± 1.4 km/s / Mpc (68%) (WMAP, 2010)
Age of Universe : 13.75 ± 0.11 × 109 years (68%) (WMAP, 2010)
Planck density, 5.1×1096 kg/m3
Age of Solar System : 4.5685 × 109 years
Average radii : Earth : mean 6371 km, equatorial 6378 km, polar 6357 km; Moon 1739 km
Earth circumferences : polar 40007.863 km, equatorial 40075.017 km (WGS84 / Kaese))
Geosynchronous orbit radius : 42.164 Mm (authority?) ( → ~ 36 Mm high)
Standard Earth gravity : 9.80665 m s-2 (CGPM 3, 1901)
Standard atmospheric pressure at sea level : 101.325 kPa (CGPM 10, 1954)
Angles from Earth Orbit : Equator 23.4° ; Moon Orbit 5.2°
Eccentricity of Earth's orbit : currently 0.0167
Power of Sun : 3.86×1026 watts
Solar Constant : ~ 1361 W/m2.
Solar wind dynamic pressure averages ~ 2 nPa at Earth; solar radiation ~10 µPa
Measurements and Units - see in Kaye & Laby Online.
Gravitational binding energy : U = 3GM2/5r
Moment of Inertia : I = 2Mr2/5
Now in The Geometry of Ellipses.
This section mentions advanced subjects that I recall comparatively little of.
There are relativity FAQs.
A part of my Astronomy / Astronautics 3 calculates relativistic travel.
Note - this is really not my subject - needs checking. Was there not a third confirmation of Einstein?
Presumed to be that of light. Newtonian gravity is instantaneous; making the speed finite introduces unwanted differences; proper relativity removes those.
The advance of the perihelion of Mercury is largely explained by Newtonian gravity. But there is a residual advance of 43" of arc per century, explained by Einstein's relativitistic gravitation.
Light passing near a massive body is deviated by gravity. Eddington's 1919 trip confirmed Einstein's relativitistic prediction of 1.74" of arc for Sun-grazing rays, twice the Newtonian value.
In that fashion, the Sun "focuses" light from infinity at a distance of 550 AU (the angular radius of the Sun as seen from there is 1.74"). Galaxies can focus more distant ones. Focusing is not lens-like, but it can magnify and intensify.
Light reaching a massive body is gravitationally blue-shifted, and vice versa. This is not the Hubble-related shift; it can be shown locally by using the Mössbauer effect.
Even classically, light cannot escape from a body which is sufficiently large and concentrated, as judged by 2GM/rc2; but General Relativity is needed to attempt a full explanation of Black Holes.
One can enter a sufficiently large Black Hole unharmed, but cannot leave it nor survive long. A Black Hole must contain a singularity. Black Holes evaporate, big ones more slowly. When a large enough star runs out of fuel, it must collapse to a Black Hole?
The Universe - the Big Bang, inflation?, expansion/crunch?, flatness?, dark matter/energy?, cosmology?.
Galaxies - Always black holes at their centres?
The Milky Way - our Galaxy - centre in Sagittarius, a supermassive black hole (Sgr A*) orbited by many star-sized ones within ~ 1 pc.
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