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24 votes
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What is the fastest the Earth has ever spun?

The speed of rotation of Earth is controlled by its angular momentum. And the conservation of angular momentum is a very serious law of physics (perhaps even stricter than conservation of mass). So in ...
Camilo Rada's user avatar
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14 votes
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Plate Tectonics: Is it possible to have an ocean-continent divergent boundary

The oceanic plates are themselves formed from the divergent boundary, so probably not. Even if a new rifting occurred exactly at the boundary, the result would eventually be that the ocean floor ...
user2821's user avatar
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11 votes

Are old geophysics textbooks useful?

Mathematics and computer science are exact sciences. If something is discovered and known, it is not wrong. With time, there may be better or new ways of doing something, but the old stuff is still ...
Gimelist's user avatar
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11 votes
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Diamond at the core of Jupiter

I would think this is questionable, though we don't have a definitive answer yet. We usually think Jupiter has a roughly solar composition, which according to the solar abundance measurments of ...
AtmosphericPrisonEscape's user avatar
11 votes

Eclipse, Hurricanes, Earthquake....Related Events?

The occurrences of Hurricanes, Harvey, Irma, Katia and Jose, east of Mexico and a magnitude 8.1 earthquake southwest of Mexico within a few weeks of the American solar eclipse of August 21, 2017 are ...
Fred's user avatar
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10 votes

Carbon dioxide on Mars, Venus and Earth

Firstly, Mars is farther away from the sun than Venus or Earth, so it gets less heat from the sun. Secondly, Venus & Earth are volcanically active, whereas Mars is volcanically inert. Thirdly, the ...
Fred's user avatar
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10 votes
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Is there any evidence for higher air pressures in the geological past?

Yes, there is. But the data is still very sparse and errors are large. Past atmospherics pressures have been estimated by at least three different methods: Isotopic composition of fluid inclusions ...
Camilo Rada's user avatar
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9 votes

What sort of climate zones would be present if Earth was tilted like Uranus?

A paper on this topic just appeared: Multiple Climate States of Habitable Exoplanets: The Role of Obliquity and Irradiance. In case of 90° obliquity, summer and winter would appear together with day ...
Barlach's user avatar
  • 91
9 votes
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How far up do you have to go before most of the atmosphere is below you?

Roughly 5.5 km, although the exact value depends on the weather. All you need to do is to solve the hydrostatic equation and find the height at which the pressure is 50% of the height at sea level (...
gerrit's user avatar
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9 votes

How far up do you have to go before most of the atmosphere is below you?

It turns out that the answer is a bit simpler than you think. Atmospheric pressure (neglecting small weather variations) is due to the weight of the column of air above a given point. If we divide ...
Chris W's user avatar
  • 91
9 votes
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Does the global temperature vary daily (hotter and colder days)?

The site http://www.karstenhaustein.com/climate.php comes closer to answering your main question with a daily anomaly graph: Indeed it's still not the actual average temperature... and I too was ...
JeopardyTempest's user avatar
8 votes

What time and date is the sun directly overhead a given place on Earth?

Having the sun directly overhead can happen only between the Cancer and Capricorn tropics. That is, only the places between 23.5° of latitude north and 23.5° of latitude south. On the Cancer tropic (...
Camilo Rada's user avatar
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8 votes
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What "g" would be needed to keep helium on Earth?

Atmospheric escape is the loss of planetary atmospheric gases to outer space. You'd never be able to contain ALL of any gas forever by gravity. Ultimately you end up in the rarefied atmosphere where ...
MaxW's user avatar
  • 511
8 votes

Which physical parameters can we actually measure to confirm the existence of the Greenhouse Effect (GHE)?

The physical parameters you need to measure to confirm the existence of the greenhouse effect are few and simple. Measure the electromagnetic properties of constituent molecules in the atmosphere. ...
casey's user avatar
  • 14.2k
8 votes

Do scientists ever make rock vapor in a laboratory? If so, is it ever used to study planetary or lunar formation?

Not quite "rock vapour", but scientists do study gas-rock interactions. Some of that is used to understand processes forming in the moon. For example, this paper looked at volatile metals (...
Gimelist's user avatar
  • 23.1k
8 votes

Is it possible for tsunamis to occur on deep water planets?

Tsunami are caused by sudden changes in the sea floor. An earthquake that causes a slump or surge in the seabed can cause a tsunami. Tsunami travel as shallow water waves; they have a wavelength ...
James K's user avatar
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7 votes
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How do tectonics work on other planets?

It's a huge field of research and a lot of interesting studies have been published over the years, but also a lot of speculation. Models and theories are mostly based on surface structures observed by ...
user2821's user avatar
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7 votes
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What are Ordovican trace fossils, and what do they look like?

Trace fossils are marks or things left behind by living things do their thing, they are indirect remains of organisms, coprolites (poop), footprints, egg shells, ect. If we found a fossilized beehive ...
John's user avatar
  • 6,931
7 votes

How would a world entirely covered in oceans get the nutrients to support life?

If the planet is geologically/volcanically active hydrothermal vents are a way by which nutrients, in the way of minerals and chemicals, can enter the ocean. Certain types of bacteria can consume the ...
Fred's user avatar
  • 24.7k
6 votes

How does water still exist on the Earth?

Lava doesn't destroy water it evaporates it into steam. This steam rises high into the atmosphere, cools and condenses into rain which it falls back onto the Earth's surface where it gets hot again, ...
userLTK's user avatar
  • 5,857
6 votes

Mechanism for Pluto's young surface

Prior to the New Horizons flyby, a popular model for Pluto’s surface involved frost migration. Delsanti & Jewitt (2006) explain that at different points during the year, there should be seasonal ...
HDE 226868's user avatar
6 votes

How would a world entirely covered in oceans get the nutrients to support life?

On an ocean planet, nutrients can come either from space or from the bottom of the ocean, where they can leak from the crust trough different processes, perhaps with the help of submarine volcanoes or ...
Camilo Rada's user avatar
  • 17.7k
6 votes
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How do you stop the Australian wildfires?

As of 7 January 2020, the total area burnt by the fires in the whole of Australia is 8.4 million hectares (21 million acres; 84,000 square kilometres; 32,000 square miles. That is equivalent in area ...
Fred's user avatar
  • 24.7k
6 votes

Why is the Lunar crust anorthite?

A base-level justification is that calcium is much more abundant than sodium or potassium - about 10 times in bulk earth, and double in the crust. Since the moon is thought to have formed as a result ...
desander's user avatar
  • 415
5 votes
Accepted

Was there once a glacier over Starcke national park in Queensland Australia?

That region forms part of the North Australian Craton and the underlying bedrock is in the order of 1.8 billion years old. The bedrock appears to be overlain by the Isa Superbasin during a period of ...
norman_h's user avatar
  • 176
5 votes

What natural phenomena increase stratospheric ozone?

Like BarocliniCplusplus said, ozone is generated when you have a single free oxygen atom. This can come from photolysis of O2 in the upper stratosphere, or photolysis of ozone itself, or photolysis of ...
Jareth Holt's user avatar
  • 1,381
5 votes

Will the Earth ever stop rotating?

Strictly speaking, the Earth will never cease to rotate in the technical sense... not while Earth is intact at least. No matter what the Earth might eventually become tidally locked with, whether the ...
seanion's user avatar
  • 51
5 votes

Which physical parameters can we actually measure to confirm the existence of the Greenhouse Effect (GHE)?

Reality is not as simple as your thought experiment The problem with your thought experiment is that, even though you are holding sunlight intensity identical between your two planets, there are too ...
kingledion's user avatar
  • 3,376
5 votes

How can scientists measure chemical composition on other planets?

Scientists can measure the chemical composition of the atmosphere of other planets using spectroscopy. Each molecule in the atmosphere absorbs and re-radiates at specific frequencies of light that ...
f.thorpe's user avatar
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