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When you look 'at the world' (i.e. to the horizon) on a clear day, unlesss the sun is at a very low angle, the surface of your eye is not illuminated directly by the sun, only reflected sunlight from the atmosphere, ground and objects. The 32,000-100,000 lux figure is referring to a horizontal surface illuminated directly by the sun.
The continuous spectrum of the visible photosphere of the Sun is attributable to the radiative equilibrium of the $\mathrm{H}^{-}$ ion. This has been recognised for at least 80 years ( Wildt 1939 ). This ion forms by the attachment of a free electron (with a continuous spectrum of energies) to a hydrogen atom, emitting a continuous spectrum of photons in the process.
Feb 15, 2011 · Another way of calculating the earth - sun distance is to look at the centrifugal and the gravitational force. This solution assumes that one already knows the mass of the sun, but thats a different problem ;-).
Mar 13, 2017 · The sun puts out about 8% of its energy in UV (which does the damage), about 44% in visible, and the rest in IR. A standard incandescent puts out effectively no UV, 10% visible and the rest in IR. Halogen lamps can be operated at higher temperatures with a reasonable lifetime, and produce some UV, with perhaps 15% visible.
A nonrotating Sun would also beget the observed anomalous precession, whose non-Newtonian component almost wholly arises from the inverse cubic term in the effective potential coming from the solution of the Einstein Field Equations for the Schwarzschild Metric. This metric assumes the central body (Sun in this case) is stationary and nonrotating.
Jul 10, 2014 · The reason is that at the temperatures of the sun's core production of the next stable step (carbon) is many orders of magnitude slower than helium production. Many. Right now the density and temperature of the core are regulated by the energy input of helium production and the the energy loss mechanism of radiative transport.
The article seeks to explain the increasing Earth-Sun separation (orbit-averaged separation, as in semi-major axis), and a large part of it is focused on the expansion of the universe. Now Ben Crowell gave a great explanation here as to why the effect of cosmic expansion only comes in with the third time-derivative of the scale factor, noting that the effect is "undetectably small."
Dec 4, 2012 · The Earth is 1AU from the sun (by definition!) so the sun is only 1/122 of the diameter in Voyagers sky. That means it would appear as large as stars appear to us on Earth by eye. The light from the sun though spreads out with the area of the sphere, so the square of the distance. This means that at voyager it is only 1/(122*122) = 0.007% as ...
May 31, 2015 · If the building is located in Hammerfest, Norway the metal might get warm to the touch. If it's on the sun-facing side in Las Vegas you may find it gets hot enough to cause burns. A definitive answer is not possible. If people can touch it easily the temperature is a concern. If it's out of reach, don't worry about it. The iron isn't going to melt.
The orbital energy of two bodies is defined as the energy required to separate them to infinite distance: $$ E = E_1 + E_2= \mu \frac{v^2}{2} - \frac{ G m_1 m_2 }{ r } = \mu \left( \frac{v^2}{2} - \frac{ G m_2 }{ r } - \frac{ G m_1 }{ r }\right) = - \frac{ G m_1 m_2 }{ 2 a } = - \frac{ G m_1 m_2 (1+e) }{ 2 d } $$ where: $ \mu $ is the reduced mass, v is the relative (heliocentric) velocity, r ...
