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If you want your eyes to receive 32000~100000lux, you need to stare at the sun in a sunny day.If you stare at the ground in a sun-exposure area, your eyes receives much less than 32000 lux. If you stare at a shedded ground in a sunny day, your eyes receive slight less than 10000lux. human eyes could not tolerate 32000lux more than 5 secounds.
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 ;-).
The Sun has actually set/risen and we see it due to the way light is bent across the atmosphere. Apparently due to coincidence of the size and distance of the sun, its exactly the same size - so if we see 50% of the sun, the sun is 50% below the horizon. So, I understand all this, so here is my question :
Mar 20, 2019 · The sun is considered a black body, not only from the perspective of the Earth but from any perspective. The sun's intensity spectrum is roughly the one of a perfect black body minus absorption by the sun's atmosphere and the Earth's atmosphere depending of where we measure the spectrum. See the sunlight article on wikipedia.
May 31, 2015 · Stefan-Boltzmann: J = σT4 J = σ T 4. To lose 1 kW over 1 m 2 requires a temperature of. T = 1000 5.67 ⋅10−8− −−−−−−−−√4 ≈ 364 K T = 1000 5.67 ⋅ 10 − 8 4 ≈ 364 K. This assumes only the surface facing the sun loses heat by radiation: in other words this is only valid for a black surface mounted on a good insulator.
Aug 27, 2015 · Incandescent light bulbs (the ones with a filament) operate similarly to the sun - they emit light because the filament heats up, and when objects heat up they emit a lot of light. If you put your hand in front of an incandescent light bulb you will feel a lot of heat, because most of the light it emits is infrared.
Nov 26, 2014 · 13. The Sun does not rise, it is the horizon that goes down. You say that Sun rises in the East (with a certain degree of oscillations due to the tilt of the axis) just because the Earth spins from West to East. The revolution affects the difference between sidereal time and solar time, and makes the solar day ≈ 4 ≈ 4 minutes longer.
The Sun is white, but the reason why it is white is because your brain adjusts the white balance to make the totality of all the ambient light illuminating the objects you see, white. Now, the Sun is too bright to look directly at safely, but around dusk or dawn you can sometimes see by accident a glimpse of it, and it then looks red.
Dec 26, 2014 · The same applies to the beams of light above them. The Sun is very far away and the beams are pretty much parallel, but they're pointing towards you, and perspective makes them appear to converge towards the vanishing point - which in this case is the Sun's location in the sky. The technical term for these beams is "crepuscular rays."
Apr 17, 2015 · If we assume the Sun orbits the Earth, the math says that the Sun should be much less massive than the Earth. If we assume the Earth orbits the Sun, the opposite is true. Either way we can get an estimate of the mass of the Sun. We know from other tests that the Sun is more massive than the Earth, so therefore the Earth orbits the Sun.
