# Tag Info

1

Yes: the insolation can be evened out quite a bit. Tidal locking can be an odd half multiple (like 3:2 of Mercury), the orbit eccentric and inclined. A presentation on the SETI Weekly Seminar Series showed simulations of surface temperature maps and was able to get rather uniform results or at least much smoother gradients than previously supposed. Either ...

1

I suggest to compare human produced heat with the incident heat of the sun which is around 1 kW/m$^2$. The usual comparison is "the sun delivers more heat in an hour than humans use in a day". While such a comparison may not remain accurate forever, a difference in scale of 7000x suggests that even if humans doubled thei energy consumption every 17 years ...

2

Global energy consumption is $5\times10^{20}\ J/yr$ Assume it is all used to power incandescent lightbulbs, so 95% goes to heating the atmosphere The mass of the atmosphere is $5\times10^{18}\ kg$ The heat capacity of air is $1\times10^{3}\frac{J}{kg\cdot °C}$ Assuming all the heat goes to the atmosphere and stays there, using the definition of heat ...

2

Q=mc(t1-t2) You need to calculate C, the specific heat capacity of Earth(as a whole). You need to calculate the specific heat capacity of everything present on, inside earth for that purpose. It might be possible after we advance a bit more further:).

2

Starlight, as emitted by a star, comes in a wide range of colours. For instance see the picture below. Now this is a picture, and pictures can often be tricky with their representation of colour, so you'll have to take my word for it that Betelgeuse does look significantly redder to the naked eye than say Vega until you get a chance to go look yourself on ...

4

The colour of stars as observed by an observer on Earth varies just like the colour of our own Sun, depending on where in the sky the source is relative to the observer. However, the light of stars is generally too faint to notice this as clearly with the naked eye, because we cannot perceive colour for weak light sources.

3

No, Rayleigh scattering models the probability (and angle) of scattering as a function of wavelength and of the particle sizes. All wavelengths travel a long way but the path followed (scatter or nonscatter) varies. Since space is mostly "empty", there's little scattering. Beyond that, your understanding of stars is quite incomplete. THey do in fact have ...

5

What causes sunburns is UV radiation, which damages our skin cells. Heat on the other hand is the same as the one felt when near an incandescent light bulb (doesn't cause sunburns). Most of the UV radiation coming from the sun is absorbed by the earth's atmosphere. During sunset and sunrise the radiation emitted by the sun passes through more air until ...

27

In general, the sun's light (particularly the UV that causes sunburn) has to pass through a lot more atmosphere (or a greater amount of air mass) in the morning and evening to get to a vertical surface than it does when it is at zenith to a horizontal surface. An example is shown in the generalised image below (all graphs are obviously generalised): The ...

0

I would like to expand here on the mechanisms of scattering. Light is scattered by particles in the air which act like dipoles, and oscillate because of the electromagnetic frequency of light. Oscillating dipoles may emit a different frequency. There are two mechanisms of scattering. Rayleigh scattering: This occurs when particle sizes are smaller than ...

2

Space is mostly black, because most of space doesn't have light coming from it for you to see. The moon, being basically a big rock, unsurprisingly does not change this: You would expect that standing on a rock would not affect what you see. Earth is unusual in having a sky because it has an atmosphere. The atmosphere is a bunch of gas that changes the ...

5

In addition to the lack of an atmosphere (the primary reason, already addressed in other answers), something that compounds the effect even further is that the lunar surface is quite reflective, and because the people who are taking the images of lunar surfaces often want to have Earth and/or astronauts in the shots and also be able to make out detail in the ...

12

With the atmosphere of the moon being $10^{14}$ times less dense than that of Earth, there is negligible scattering, so whereas on Earth, approximately 25% of direct solar radiation is scattered around (making the sky light up and appear blue), there is no mechanism for this on the moon, and all light from the sun travels (essentially) unaffected to the ...

22

The moon does have a night and a day, but this isn't as fully connected to your question as you might think. The moon is tidally locked with the earth, meaning that the same side always faces earth. Since the moon also orbits around the earth (with a period of a lunar month), this means each side changes, over the course of a lunar month, between facing ...

3

Wind is a solar powered flow of the atmosphere. The atmosphere is not uniformly heated: different areas have different solar power input. This uneven heating arises because some areas are in daylight, whereas others are in night, and different regions have different amounts of cloud cover and different colored terrain, so the albedo is uneven. Uneven ...

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