Questions tagged [atmospheric-science]

The study of the composition or dynamics of the gaseous layers around planets, often applied to questions on Earth's atmosphere but can be applicable to all planets & moons in the solar system.

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92
votes
8answers
91k views

Why does the atmosphere rotate along with the earth?

I was reading somewhere about a really cheap way of travelling: using balloons to get ourselves away from the surface of the earth. The idea held that because the earth rotates, we should be able to ...
42
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5answers
10k views

Why does the sky change color? Why is the sky blue during the day, red during sunrise/set and black during the night?

Why does the sky change color? Why is the sky blue during the day, red during sunrise/set and black during the night?
6
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1answer
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At what altitude would the air be too thin to carry a sound wave?

A related question When does an aerobraking space craft create a sonic boom? has spawned a couple of answers, but so far no compelling answers. It is a common belief that in space there is no sound,...
5
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1answer
1k views

Can a hovering helicopter travel half the globe in 12 hours? [duplicate]

Suppose we have a helicopter that is able to stay stationary in flight for extended periods of time. If such a helicopter stayed at point A in the sky for 12 hours straight, would it reach the other ...
64
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3answers
46k views

Why is the sky not purple?

I realise the question of why this sky is blue is considered reasonably often here, one way or another. You can take that knowledge as given. What I'm wondering is, given that the spectrum of ...
24
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4answers
13k views

The Density of Clouds

Clouds are made up of tiny water or ice droplets, depending on temperature. This implies that cloud density is greater than that of dry air. Why don't clouds sink through their surrounding atmosphere ...
41
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2answers
14k views

Why is the sun brighter in Australia compared to parts of Asia?

Background: I've lived in Philippines for several years, and visited other parts of Asia occasionally (Singapore, Indonesia, Hongkong). I just moved to Western Australia a few months ago and I ...
53
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5answers
31k views

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

I, like everybody I suppose, have read the explanations why the colour of the sky is blue: ... the two most common types of matter present in the atmosphere are gaseous nitrogen and oxygen. These ...
23
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5answers
148k views

Why does the road look like it's wet on hot days?

Often, I'll be driving down the road on a summer day, and as I look ahead toward the horizon, I notice that the road looks like there's a puddle of water on it, or that it was somehow wet. Of course, ...
124
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15answers
34k views

Is the butterfly effect real?

Is the butterfly effect real? It is a well known statement that a butterfly can, by flapping her wings in a slightly different way, cause a hurricane somewhere else in the world that wouldn't occur if ...
24
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5answers
54k views

Why less temperature at high altitude

Why there is always cold at high altitudes. e.g. at peak of mountains. Also as we go high from sea level, temperature starts decreasing. Why is it?
15
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4answers
34k views

How does carbon dioxide or water vapour absorb thermal infra red radiation from the sun?

We are all told at school water vapour and carbon dioxide are the top two greenhouse gases, and that they absorb thermal infra red radiation, trap heat and warm up the Earth. My question is how do ...
18
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2answers
2k views

What is the safe distance to a supernova explosion?

In other words, what stars near the Sun may have an impact on the Solar system equilibrium or the Earth life if they become supernova ? Is SN 1987 A too far ?
3
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2answers
3k views

Why is the atmosphere transparent in the visible spectrum?

One of the great 'coincidences' in physics is that the Sun happens to shine most brightly at exactly the wavelengths our eyes can see; it's an easy explanation that our eyes evolved to make the most ...
20
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5answers
16k views

Can helium disappear from Earth?

Helium is lighter than air, so it should fly off from Earth. Is it possible that in the future we will run out helium?
24
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12answers
10k views

Why do spacecrafts take off with rockets instead of just ascending like an aircraft until they reach space?

I guess it's not a very educated question, but I never quite understood why spacecrafts have to shoot up and can't just reach space by simply continuing an upwards ascent like an airplane.
13
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3answers
750 views

Extended sound of thunder

Why does the sound of thunder last several seconds even when lightning lasts for only fraction of a second?
13
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1answer
3k views

From how high could have Felix Baumgartner jumped without disintegrating like a shooting star?

Today Felix Baumgartner jumped from 39 kilometres high and reached the earth safely. Just considering friction, from how high can a human jump? I expect that from a certain height, he would have ...
30
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1answer
3k views

Using nuclear devices to terraform Mars: Elon Musk's nuclear proposal? [closed]

Elon Musk has recently suggested Using nuclear devices to terraform Mars. In the past, comet related ideas were mooted, but Musk seems, to me anyway, to be a man in a hurry and perhaps his idea has ...
28
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3answers
7k views

Why doesn't rain fall down in streams (as opposed to drops)

Why is it that raindrops don't collide and 'stick together' on their descent to Earth, arriving in streams rather than separate drops?
7
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3answers
18k views

Atmospheric pressure experiment using a cup with a fluid to hold a glass plate

When I was in high school, my teacher did an experiment to show the power of atmospheric pressure. Experiment: Prepare a glass bottle, fill with water, put a glass plate on the bottle, make sure ...
4
votes
1answer
367 views

Do atmospheric physics prevent hot air balloons from ascending over 60,000ft?

I was reading the altitude records for hot air balloons on Wikipedia, and noted that the max hot air balloon altitude was about 60,000ft. It didn't really say if there was a reason why. I know that ...
41
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10answers
24k views

Why can't we see gases?

I am not sure what causes gas molecules to be invisible.This question may look silly but I really want to know the story behind it.
12
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2answers
7k views

What is the temperature of the clear night sky from the surface of Earth?

Before you all jump in with 2.73 K or thereabouts, this is more of an experimental question. It will obviously depend on humidity and radiation being scattered back towards the surface of the Earth. ...
3
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2answers
6k views

Can someone explain to me the concept of atmosphere opacity?

On this diagram, why is the atmospheric opacity shaped as it is? If we are able to see lights due to low atmospheric opacity, why can't we see radio waves, when the atmospheric opacity is so low for ...
14
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6answers
8k views

Can low-gravity planets sustain a breathable atmosphere?

If astronauts could deliver a large quantity of breathable air to somewhere with lower gravity, such as Earth's moon, would the air form an atmosphere, or would it float away and disappear? Is there a ...
9
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1answer
2k views

What are the white lines in some nuclear bomb test photos?

What are those white lines connecting the ground to the sky on the left side of this photo? I've see these before in the nuclear bomb test films too. They're apparently already in place upon ...
8
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3answers
1k views

Why does the air pressure at the surface of the earth exactly equal the weight of the entire air column above it

Why does the air pressure at the surface of the earth (resulting from collisions of molecules on the surface of the earth which has to do with the velocity of the particles) exactly equal the weight ...
8
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3answers
6k views

What determines the apparent radius of the rainbow?

Let's say I know how to compute the apparent radius of a rainbow from the viewpoint of the observer: take a photo of the scene, measure the distance to a known reference object, and its dimensions. ...
9
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2answers
12k views

Purple doesn't occur in rainbow - or does it?

Usually, when asked whether the purple color exists rainbows, an answer similar to this is given: The purple color is perceived by human eyes via the activation of both red-sensitive and blue-...
1
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1answer
925 views

Would a pipe from the surface to the Earth's exosphere suck all atmosphere to the space? [closed]

If I built a tube from Earth's surface to the exosphere, would all the air be sucked out to space? If this pipe reached to a big planet, like Jupiter, would its gravity through the pipe suck our ...
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2answers
5k views

Why the pressure of atmosphere doesn't crush you when you e.g. walk outside?

Why the pressure of atmosphere doesn't crush you when you e.g. walk outside? I mean the density of air is $1.26 kg/m^3$, so with $100 km$ above us, it exerts much pressure on you when you walk outside....
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vote
3answers
727 views

Pressure and altitude

I am going to ask a simple question, for sure. The pressure with respect to the altitude is given by this formula Where sea level standard atmospheric pressure p0 = 101325 Pa sea level standard ...
41
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9answers
18k views

Why is air not sucked off the Earth?

People said outside earth is a vacuum. But the air does not get sucked from the Earth's surface. Some said it is due to gravity and some said the speed of air molecules are not high enough to escape....
41
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2answers
4k views

Cause for spikes in Trinity nuclear bomb test

In Richard Rhodes' book, The Making of the Atomic Bomb, I was reading about the Trinity nuclear test. High speed photos were taken and this one is from <1ms after the detonation. The book mentions ...
13
votes
9answers
23k views

How come gas molecules don't settle down?

If the earth's gravity exerts a net downward gravitational force on all air molecules, how come the molecules don't eventually lose their momentum and all settle down? How is the atmosphere is still ...
22
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2answers
19k views

Is there an upper frequency limit to ultrasound?

Wikipedia has this diagram of the acoustic frequency spectrum: Is there an upper limit to the frequencies you can transmit through the air? Are they absorbed more and more at higher frequencies, ...
10
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3answers
11k views

Can open, unsafe nuclear fusion reaction burn the atmosphere?

I happened to hear people saying that the nuclear fusion bomb tests could set the atmosphere on fire. I have some serious doubts about that - but I have no facts. Nuclear fusion reaction requires $15*...
13
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5answers
20k views

Does the moon affect the Earth's climate?

So, this morning I was talking to a friend about astronomical observations, and he told me that lately there has only been good weather when there was a full moon in the sky, which was a shame. I ...
8
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5answers
31k views

Why is the sky of the moon always dark?

Why is the sky of the moon always dark compared to the sky of the earth, doesn't it have day and night like earth?
5
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1answer
380 views

How to correctly calculate the colour of the sky?

It is well-known that the sky is blue due to Rayleigh-scattering. What bothers me though is the question how to actually calculate the spectrum of the scattered sunlight. Yes, use one of the formulas ...
6
votes
3answers
10k views

Could the sky on a planet theoretically be any color?

The sky on the Earth is blue. Could the color of the sky on a planet with an atmosphere be of any color theoretically? Which colors are the most likely? I think it would be really awesome to have ...
3
votes
4answers
7k views

What experiments prove the greenhouse effect?

What experiments prove that heat can be "trapped" by a layer of material with suitable optical properties, such as carbon dioxide? I've read a little on Wikipedia but I've got only some names, not the ...
25
votes
1answer
994 views

Causes of hexagonal shape of Saturn's jet stream

NASA has just shown a more detailed picture of the hexagonal vortex/storm on Saturn: http://www.ibtimes.com/nasa-releases-images-saturns-hexagon-mega-storm-may-have-been-swirling-centuries-1496218 ...
20
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4answers
31k views

How Earth protected from the gamma rays generated by Sun?

Sun is generating energy by nuclear fusion. And nuclear fusion will emit energy in the form of gamma rays. Normally earth's ozone filtering the Ultraviolet radiation. And magnetic fields of earth ...
15
votes
2answers
628 views

Why is Jupiter so sharply defined?

In photographs of Jupiter, the limb seems extremely definite. Being a gas giant, my naive self thinks that the atmosphere should have a more gradual cut off, creating a hazy effect similar to that on ...
15
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4answers
7k views

Why can't CO$_2$ mix back with the liquid after a soda bottle has been shaken?

If you shake a soda bottle before opening it, and then open it, you get the fizz. That is the compressed CO2 releasing to the atmosphere which is at comparatively low pressure value. Two questions (...
11
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2answers
5k views

Is the Earth gaining or losing mass over time?

The earth presumably loses mass because molecules of the atmosphere disassociate and fly off into space where the solar wind carries them away. On the other hand the earth gains mass because ...
10
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1answer
1k views

Why doesn't the percentage of oxygen in Earth's atmosphere diminish significantly with altitude?

According to numerous sources online, the percentage of oxygen is approximately the same at sea level and 10,000 meters. Since oxygen is heavier than nitrogen, shouldn't the percentage of oxygen ...
6
votes
1answer
428 views

How does the 11-year solar cycle alter the cosmic ray flux?

Looking at a flux vs. time graph of secondary cosmic rays (e.g. from a neutron station: www.nmdb.eu/nest/search.php can plot you some. I just tried for example Moscow, from 14 Oct 1951 to today, ...