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1500 questions
100
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6 answers
How can a storm drop 40 inches (1 metre) of rain?
Hurricane Harvey dumped more that 20 inches (500 mm) of rain over a large region, with 40+ (>1000 mm) in some spots... and much more expected.
How is that possible?
Does the atmosphere really hold that much water?
Or is it getting repeatedly…
William Jockusch
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3 answers
Impossible or improbable? Hurricane crossing the equator
No known hurricane has ever crossed the equator. Hurricanes require the Coriolis force to develop and generally form at least 5° away from the equator since the Coriolis force is zero there.
Are the physics of the earth and tropical systems such…
DrewP84
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83
votes
7 answers
What place on Earth is closest to the Sun?
What is the location on Earth that is closest to the Sun?
I've seen this question asked many times, and answered in varied and contradictory ways:
The most common answer is “the summit of Chimborazo volcano in Ecuador”. This volcano is the point on…
Camilo Rada
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78
votes
21 answers
Are there any saltwater rivers on Earth?
I'm curious if there are any saltwater rivers on Earth. These would presumably arise if a saltwater lake had a river outlet to the ocean.
However, all the saltwater lakes I looked at (Caspian Sea, Dead Sea, Great Salt Lake Utah), apparently don't…
DrZ214
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64
votes
6 answers
Why does lightning strike from the ground-up?
The enlightening image below is of a lightning strike slowed down at 10,000 frames per second. It can be seen that the most intense flash produced from the lightening occurs in the direction from the ground up. Why does this final "ground-up"…
Kenshin
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58
votes
5 answers
How many trees would I have to plant to solve Global Warming?
According to NASA, causes of the Earth's greenhouse effect include water vapor, carbon dioxide, methane, nitrous oxide, and CFCs. Carbon dioxide gets the most press, and NASA's page says:
Carbon dioxide (CO2). A minor but very important component…
philipthegreat
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54
votes
3 answers
How much oil is created each year?
We all know that oil is an essentially nonrenewable resource over human time scales. However, I am currently working on an activity for high schoolers that teaches them to predict how long humans can continue extracting oil before running out (and…
Kupyn
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5 answers
What started the US Dust Bowl of the 1930s, and could it happen again?
Most of us know about the Dust Bowl: the huge storms of dirt and dust that swept across America in the 1930's. But what I'm wondering is...
What actually triggered the start of the Dust Bowl?
Is it very likely that it will occur again?
I've often…
Azzie Rogers
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50
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14 answers
Why is the pond in my backyard not frozen when it is -15 °C (5 °F) outside?
I am in O'Fallon, Missouri and today it is -15 °C (5 °F) outside. I was taught water freezes at 0 °C (32 °F). I could understand if it was exactly 0 °C (32 °F) that the water might not be turning to ice, but how can it be 15 °C (27 °F) below water's…
Seth Kitchen
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49
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3 answers
How do 'greenhouse gases' let heat in, but not let it out?
That honestly doesn't make any sense to me. How could heat pass through a gas one way but not the other? Its not like our upper atmostphere has a bunch of doors that can only open one way. To me, that seems to fly in the face of everything I've been…
user13471
47
votes
5 answers
How is the mass of the Earth determined?
According to textbook knowledge, the mass of the earth is about $6 × 10^{24}\,\mathrm{kg}$. How is this number determined when one cannot just weight the earth using regular scales?
Kenshin
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47
votes
7 answers
How high must one be for the curvature of the earth to be visible to the eye?
I would like to ask that at what distance from the Earth's surface the curvature of the Earth is visible. What layer of the atmosphere is this?
I've noticed that at the height of 9-12 Km (the view from from aeroplanes) it is not visible.
Mani
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47
votes
5 answers
Why do snowflakes form into hexagonal structures?
Snowflakes are known to form into pretty hexagonal structures. The image below shows a variety of such structures that are possible (although by all means not an exhaustive list):
What is the mechanism for snowflakes forming into these delightful…
Kenshin
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45
votes
2 answers
Why is NaCl so hyper abundant in the ocean?
Why is sodium chloride far and away the most abundant salt dissolved in ocean water? Its two constituent ions do have a very high frequency in the crust of the earth, but they are far from the most common. Chlorine is (according to Wikipedia) the…
Fraser Orr
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44
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6 answers
Are Richter-magnitude 10 earthquakes possible?
The largest earthquake since 1900 according to the United States Geological Survey (USGS) was Richter-9.5 magnitude quake in Chile in 1960. Are magnitude 10 earthquakes possible? If so, what is the most likely frequency of such earthquakes, and…
blunders
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