everyday life - Why do sunbeams diverge even though the sun is …
2014年12月26日 · 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."
How is distance between sun and earth calculated?
2011年2月15日 · 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 ;-).
What is the simplest way to prove that Earth orbits the Sun?
2015年4月17日 · 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.
How does the Earth's orbit change as the Sun decreases in mass?
2020年3月10日 · Now the Sun loses a small amount of mass. The Earth is still traveling at the same velocity, and requires the same centripetal force to maintain the same circular orbit. Unfortunately, the reduced mass of the Sun no longer supplies the required centripetal force. So the Earth is now in a slightly elliptical orbit, passing perihelion.
sun - Why is sunlight spectrum continuous? - Physics Stack …
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 ...
Why is the Sun approximated as a black body at ~ 5800 K?
2019年3月20日 · 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.
How much lux does the Sun emit? - Physics Stack Exchange
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.
How can sunlight be white , but pictures of the sun be orange?
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.
What would happen if Jupiter collided with the Sun?
2018年4月27日 · However, the Sun will accrete $\sim 10^{42}\ \mathrm{kg\ m^2\ s^{-1}}$ of angular momentum, which is comparable to its current angular momentum. The accretion of Jupiter in this way is therefore sufficient to increase the angular momentum of the Sun by a significant amount. In the long term this will have a drastic effect on the magnetic ...
How hot can metal get in sunlight? - Physics Stack Exchange
2015年5月31日 · 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.