# Tag Info

## Hot answers tagged hypothetical

28

That would have many consequences. For example the Coriolis force would change the sign. Thus wind around pressure systems would switch the direction from north and south hemisphere, but also the Ekman spiral in the ocean would be affected. Surface heating at sloped terrain will different, as the sun would rise in the West. This would change thermal induced ...

28

Just to add some further discussion to @Pont and @fre0n excellent answers. The problem of the water needed to submerge the world during the Genesis flood have been discussed for centuries. The narrative could seem legit as traces of marine condition can be seen even in high mountains. The Biblical flood was the most logic explanation for marine fossils ...

23

there is not enough existing water inside this geosystem IMO for such a thing to occur. Let's see these figures here: One estimate of global water distribution Oceans, Seas, & Bays 1,338,000,000 -- 96.54% of all water this figure means that most of the existing water at the global scale is seawater. Sea floor is quite irregular, with some abyss like ...

23

I'll try to put time scales on each of these events. The Sun as a red giant - 5 to 6 billion years$^1$ The Sun is currently on the main sequence, which means that it's a "full grown" star - think of it as being middle-aged. It's been on the main sequence for around 4 to 5 billion years, and in 5 to 6 billion years, it will leave the main sequence. Most ...

22

Depending on the assumptions you make, the Moon would suddenly have a retrograde orbit. If the moon had a retrograde orbit, it would have tremendous consequences. Retrograde orbits tend to become less distant over time, meaning the moon would either be much closer to the Earth with huge tidal effects or come more close in the future. At some point, the Moon ...

20

The "precipitation rate" part is easy to answer, at least to a first approximation. We have 40 days and nights (960 hours) in which to raise sea level above the peak of Mount Everest (let's round up and call it 9000m). Thus, we need a precipitation rate of around 9000/960 =~ 9.4 metres per hour. For comparison, the largest rainfall ever recorded over an hour ...

18

The lowest reaches of an aurora is ~100 km in the air. Your problem won't be the ionized gas, it'll be that the air pressure is close to zero. Also, aurora are very diffuse, with at most a few glowing molecules per square centimeter. I'm not sure at that density that you could tell you were actually in something. If you're in a spacesuit to survive the ...

15

Atmospheric escape is a topic with a long research history. It is complex and is being addressed with both measurements and simulations. For example, the question of atmospheric escape is still actively researched at Mars, and the MAVEN (Mars Atmosphere and Volatile Evolution) spacecraft mission is for example dedicated to this topic. Mars is a planet ...

14

Let's assume that the earth didn't suddenly stop spinning (because intertia and conservation of angular momentum would do all sorts of "interesting" things that are deserving of a What-If answer), and stipulate that the earth slowed down gradually, or possibly that it was never spinning in the first place (although I'm sure this would have all sorts of other ...

14

Let me first correct a small misconception. Where you are talking about 'the magma ocean', you are implying that one exists. This is in fact false. There is no 'magma ocean' in the Earth at the moment (and it has been like that for several billions years). The lavas you see erupting in volcanoes are not coming from a magma ocean. They are coming from either ...

12

Since atmospheric retention is largely dependent on escape velocity and temperature, removal of the Earth's magnetic field should not have a greatly noticeable effect, as current research shows that Earth's magnetic field changes the location of atmosphere loss due to the solar wind rather than eliminating it. Earth's temperature is not likely to change ...

12

The answer is No, the Earth would not remain in any recognizable form without the Sun. There would still be a husk of a dead planet with a small amount of energy coming from the residual heat of the core which might be able to sustain chemosynthetic life in small colonies. However, this is a pretty minor amount of energy compared to what we usually ...

10

The best place to ask this question is going to be at xkcd: http://what-if.xkcd.com/ but I will give it a shot. I'm not a geophysicist, but I'll try to give you a reasonable enough answer. As you said, making such a hole is not possible. However, let's try to think what if some magical force made a hole 1 km wide and then suddenly released it. This is ...

9

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 and night, respectively. This means, in summer one hemisphere completely faces the Sun with 24h daylight a day causing extreme hot summers. The temperatures in ...

9

This is covered in an episode of the National Geographic TV series Aftermath called "When The Earth Stops Spinning". It's also covered by "If the Earth Stood Still: Modeling the absence of centrifugal force" by Witold Fraczek of Ersi, a GIS software company. The Earth is not round, but bulges at the equator. The diameter at the equator is 43km more than ...

9

Even the extremely dim light of the aurora is accumulated from massive volumes of air. This means that a small volume of air emits almost no light by itself. If you were in the middle of a filament you might not even know it! (Likely it would be visible as increased local skyglow, but would be invisible against the Earth.) Secondly, the aurora are ...

8

The Earth is as it currently is and has been since most of the Phanerozoic (542 Ma), the Eon of life, because of some important (not exhaustive) characteristics presented here, being: its inclination (causes seasons) its mass (gravity) its rotation (regulate a temperate climate) its revolution trajectory around the sun (latitudinal seasonality) its internal ...

8

The average global warming due to greenhouse gases corresponds to a 33 Kelvin temperature increase. If you remove all greenhouse gases the average global temperature would then decrease 33 Kelvin (from 288K to 255K). You might want to check out: http://www.nasa.gov/topics/earth/features/co2-temperature.html which estimates the CO2 portion of global ...

8

You've missed a number of calamities: Everything dies because all plant life dies from ever decreasing levels of CO2 in the atmosphere. This is projected to happen within less than a billion years. Everything dies because the oceans boil away and the Earth becomes Venus 2.0. This is projected to happen within one or two billion years due to increased ...

7

Too much tilt will cause extreme seasons, and that will lead to an extreme climate. For a planet with a tilt of 90˚ - that is, lying on its side - the Arctic and Antarctic circles coincide with the equator, and there are neither tropical nor temperate zones. Seasons are extreme indeed; over nearly half the planet the Sun would never set during the summer, ...

6

According to a recent Scientific American article, in about a half-billion years the Sun will have expanded enough and the Earth's orbit decayed enough that Earth will no longer be in the "habitable zone". (Earth is already on the inner margin of that zone.) (Of course, humans will destroy things far sooner than that.) BTW: For folks interested in this it'...

5

1.Given the amount of water on Earth (including all the water as liquid, solid, and gas, in all possible places: the atmosphere, the surface, and underground), is there enough water to flood the whole earth until ‘all the high mountains… were covered’? Yes. According to Massive 'ocean' discovered towards Earth's core A reservoir of water three times the ...

4

This has sat untouched for a while, so I did a quick search and found this article which sums it up nicely. They key factors with regard to earth science would be: 1) Less extreme tides. The tides would only be linked to the sun and would not be as strong. They would also peak at noon. This has obvious implications for any coastal processes that rely on ...

4

If we consider that by "Assume daily cycle and convection and so on operate as usual" you meant that all heat transport from/to the pole remain as it is today. Then, we can do a back of the envelope calculation. This calculation will at least give you an order-of-magnitude answer, and we can then consider everything that would affect the result. Currently ...

4

As others have pointed out, you cannot really touch it as such. What you can do, potentially, is to fly through it on a sub-orbital flight. It might be beautiful; indeed, aurora is from a large volume, so you would likely see it all around you. However, you will be bombarded with charged particles, because that's what the aurora borealis is — the solar ...

4

My best estimate on what would happen is the following: - At the twilight zone there would be tremendously fierce and constant windstorms as the heavier cold air rushed from the dark side to displace the lighter air warmed by the Sun. - Additionally, the wind patterns would generally align themselves towards and away from the twilight zone. - Over a ...

4

Popular science has a good write up on this. In short, everything on the surface is doomed in a year or two. Life in the Oceans would last several hundred thousand years. After that, it's probably just microorganisms living near vents at the bottom of the ocean. http://www.popsci.com/node/204957

4

It's not that hard to make an estimate. CO2 traps about 2 watts per square meter. Direct sunlight at 1 Astronomical Unit is about 1,360 watts per square meter, but spread out over the earth, average night and day it's about 1/4th of that about 340 watts per square meter. (note, Casey's point is valid, it's probably better to use the number of watts that ...

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