57 votes
Accepted

Why is the sky never green? It can be blue or orange, and green is in between!

The sky does not skip over the green range of frequencies. The sky is green. Remove the scattered light from the Sun and the Moon and even the starlight, if you so wish, and you'll be left with ...
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  • 24k
39 votes

If I'm traveling at the same direction and speed of the wind, will I still hear and feel it?

Theoretically no you wouldn't hear or feel anything but obviously in reality not all of the wind is going the exact same direction and speed.
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  • 1,601
39 votes
Accepted

What is this sort of abstract rainbow?

This is not a "rainbow". Quoting from the linked site, "not all colored patches in the sky are rainbows". It instead is a circumhorizon arc. Rainbows are caused by internal by refraction and ...
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  • 39.6k
31 votes

Why is the sky never green? It can be blue or orange, and green is in between!

Note well: What we perceive as color is bit of a tricky subject. This is a different question, one that has been asked and answered multiple times at this site. Per the typical human eye response, ...
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  • 39.6k
23 votes
Accepted

Why does moderately distant lightning sound the way it does: relatively quiet high pitched thunder first, and then much louder low pitched thunder?

I'm not an expert, but I spent some time with references 1 and 2 several years ago. This answer is based on some notes I took. Measurements using the radio waves produced by lightning indicate that ...
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22 votes

Why is the sky never green? It can be blue or orange, and green is in between!

The accepted airglow answer might be technically true, but it does not answer the question! The existence of an additional and very faint source of green light in the atmosphere does not explain the ...
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20 votes

Rainbow in cloud near Sun

There is a full display of these that can occur. The picture here illustrates one of these The names given to the parts of this are seen below. This is a St. Petersburg display. I first saw one 25 ...
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20 votes

Why do rain droplets differ so "much" in size?

The size of a rain drop depends on the process of formation. In principle, condensation of moist air at high altitudes causes tiny drops to form. As soon as those drops get big enough, they start to ...
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  • 117k
19 votes

If I'm traveling at the same direction and speed of the wind, will I still hear and feel it?

To really test the hypothesis, you should ride a balloon: it has no connection to the ground, there is no effect that will make it go slower or faster than the wind. I hear it is a really calm ...
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16 votes

What is this sort of abstract rainbow?

that type of rainbow is created by light refraction within an extended cloud or layer of ice crystals, in which the crystals are similarly-shaped and have been aligned by wind shear so their principal ...
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13 votes

Does a tower bell ringing prevent thunderstorms?

There is enormous energy in a storm, which will be randomly oriented with respect to a bell tower. The energy in the bell's sound will be radially falling with $1/r^2$ and is not directional. The ...
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  • 223k
12 votes

Why is the sky never green? It can be blue or orange, and green is in between!

The hand waving explanation in your question is called Rayleigh scattering Rayleigh scattering results from the electric polarizability of the particles. The oscillating electric field of a light ...
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11 votes
Accepted

Will the upcoming solar eclipse stress the European electrical grid?

Any high slew rate (fast rate of change of power) stresses the grid. Lots of things cause high slew rates. People getting ready for work in the morning, having showers, turning lights and appliances ...
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  • 4,124
11 votes

If I'm traveling at the same direction and speed of the wind, will I still hear and feel it?

Hypothetically, if you were on a flat plain with constant wind speed, and riding at wind speed, the only noises you'd hear are road noise from the chain, tires, gears and engine. Normally, however, ...
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  • 1,543
11 votes

Can we theoretically guide cold air from high altitude down to the needy cities as free AC?

Believe it or not, the air at the bottom of the tube would be just as hot at the air at the same height outside the tube. In air that's well mixed, the temperature decreases as you go up at a rate ...
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  • 9,221
10 votes

What is the explanation of the glory (optical phenomenon)?

Sir Michael Berry seem to suggest that the explanation is now complete in section 6 of this paper: Nature’s optics and our understanding of light published in 2015 in the journal of Contemporary ...
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10 votes

What is the explanation of the glory (optical phenomenon)?

First thing to know is that either the object projecting the shadow or the shadow itself have nothing to do with the formation of the effect. As we shall see below, the fact that the shadow is always ...
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  • 16.5k
9 votes

Why is the sky never green? It can be blue or orange, and green is in between!

I scrolled through the answers expecting to find at least one with a chromaticity diagram, but there are none, so I'm writing my own. Short answer: it simply isn't true that colors are arranged in a ...
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  • 18k
8 votes
Accepted

Is the atmospheric pressure the cause of a planet's surface temperature or is it the temperature the cause of a planet's atmospheric pressure?

Well, to clarify some things first In atmospheric science, or more correct: If you do the math... your only to free Variables are Density and Temperature. The equation of state which gives you the ...
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8 votes

Rainbow in cloud near Sun

That will be a sun dog. I saw one last week. (The sun is over on the left in this picture.)
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8 votes

Why do rain droplets differ so "much" in size?

According to a French researcher, raindrops differ in size because of topological changes they undergo as they fall. They start out spherical when they first form within clouds. Surface tension ...
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  • 8,220
7 votes

Why does moderately distant lightning sound the way it does: relatively quiet high pitched thunder first, and then much louder low pitched thunder?

Air is not a dispersive medium for sound waves. At least, in normal condition. When a lightning is produced, the air is heated up to a very high temperature, creating a shock wave like. The sound ...
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  • 867
7 votes
Accepted

Is the downforce of rain on airplanes negligible?

The impact of new drops even in heavy rain has only a small effect. From force x time = change in momentum $$F\times 1 = 0.021 \times 10^{-3}\times 1000\times 9$$ where the 1000 is for the density of ...
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  • 13.4k
7 votes
Accepted

Does a tower bell ringing prevent thunderstorms?

The question whether ringing a bell on a tower can influence lightning strikes involves two aspects: hypothesizing physical processes which might be relevant, and then figuring out (or measuring) ...
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6 votes

What is the explanation for the elevated levels of iodine-131 near Vermont shown in this video?

Notice that the boundary of the high-fallout region in Idaho, Colorado, Oklahoma, and Illinois is blotchy and blobby and goes gradually from the red through green to blue. However, there is a ...
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  • 74.4k
6 votes

Why does moderately distant lightning sound the way it does: relatively quiet high pitched thunder first, and then much louder low pitched thunder?

Although I am not a thunderstorm expert either, my guess would be, that the reflections of the soundwaves between the atmosphere/clouds and/or ground are responsible for the delay of the low ...
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  • 6,930
5 votes

If I'm traveling at the same direction and speed of the wind, will I still hear and feel it?

If your ears moves continuously as per the wind the relative speed will be zero , and you wont hear it. But this case is ideal but not practical. In reality, your movements wont be as smooth as ...
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  • 51
4 votes

Why is the sky never green? It can be blue or orange, and green is in between!

The sun is technically green because the peak of its black body spectrum is near green wavelengths. When light scatters parallel to the plane of incidence (i.e., during the day time), it is blue-...
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4 votes

Is the atmospheric pressure the cause of a planet's surface temperature or is it the temperature the cause of a planet's atmospheric pressure?

(I have only read the first paragraph of the question) The pressure of Venus's atmosphere is about 90x greater than that on earth. It also happens to be about 90x more dense that that on earth. ...
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