141
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Can stone be "recycled" by melting and cooling it?
It depends on your rock.
Rocks like Granite, with large crystal sizes, are the result of VERY slow cooling and crystallization. So although in theory you could remelt and recrystallize this kind of ...
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Would earthlike planets in other solar systems have well-known Earth gemstones such as rubies, emeralds and sapphires?
Crystal structure is dictated by Gibbs free energy. Once you have the right chemicals and the right conditions, nothing prevents the formation of the desired gems.
The only gems you would not ...
- 301k
109
votes
How much damage to the US would a Yellowstone eruption cause?
EDIT: damn, this got me my first gold badge
Here is a useful source, which is itself based off of this. Here is an ancillary source.
WTL;DR: all the damage
TL;DR:
everything within 80 kilometers ...
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93
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What if a portal is opened from the Mariana trench to the Sahara desert?
The climate of Earth has been roughed up quite a bit last century. But it has no idea what it's got coming with this portal of yours.
Earth turns into Venus.
Update: As R.M. pointed out, the amount of ...
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81
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Is there a scientifically valid explanation for a circle of islands?
An half submerged crater can give you a circular set of islands.
You can choose among various craters:
Volcanic craters, like Santorini
Mountains subsided into the oceans or eroded by changing sea ...
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70
votes
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How could a natural road form across a sea?
Your bridge is an atoll like Kwajalein
The Kwajalein Atoll is one of the largest in the world.
Following the curve of the land, I estimate that the distance from the upper left to bottom right ...
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69
votes
If the Black Sea was disconnected from the Mediterranean, how long would it take to become freshwater?
It would overflow...
As of right now, the Black sea is overflowing with water, leading it to push more water out to the Mediterranean than it receives. This was not necessarily the case during the ...
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67
votes
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What size would a diamond made from a human be?
Before cremation
About 18.5% of the human body is carbon by composition.
One gram is five carats.
The average human being worldwide masses 62 kg. Note that people may be larger in some countries,...
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62
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The erosion problem on floating islands
Nothing. Eventually - over many thousands of years - a floating island will indeed be diminished until it's nothing but dust.
However, individual grains of floating island don't themselves float ...
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60
votes
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A hang glider, sudden unexpected lift to 25,000 feet altitude, what could do this?
Getting caught in a thunderstorm is the most likely cause. This can happen even to experts if they are incautious enough to take risks with the weather.
Here's an example with a paraglider. (I'll see ...
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54
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What would it take for an island to sink and rise yearly and naturally
Give your planet two moons with different orbits, and once a year for about 30-60 days they align on the sides of the planet perpendicular to the twin islands. The tidal forces draw enough water away ...
- 4,262
52
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Physics of a metal-poor world
Could an earth-like planet form without accessible traces of iron
Without iron, you'd need a completely different biochemistry, and would in practice condemn the newcomers to a slow death. Iron is ...
- 55.9k
51
votes
How could a natural road form across a sea?
As long as your local geography/geology permits sand deposition:
a large sand bar/spit
would fulfill all your requirements.
Since I'm the most familiar with the geography of the Baltic, here are three ...
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47
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Is there a scientifically valid explanation for a circle of islands?
For an alternative (to vulcanism) geological process, check out what was discussed in this thread at Earthscience.SE.
Link to Google Map of the affected area.
Basically, a very long ago tectonic ...
- 85.8k
46
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Could terrain like this form on Earth? If so, how?
It seems likely this drawing was inspired by the real Victoria Falls, Zimbabwe and Zambia.
Photographer: De Agostini Editorial/Getty Images
So, yes.
The Victoria Falls are a result of the Upper ...
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46
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How to get blue sand
You want BLUE SAND?
I've got your blue sand on special today, available in the hundreds of thousands of hectares in sunny Namibia.
And we are not talking those feeble green-pretending-to-be-blue sands ...
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43
votes
Realistic geological and chemical composition of an edible planetary surface
The big rock candy planet
A planet is entirely covered in oceans.
Microbial life develops on this planet. This microbial life gains energy by transforming carbon dioxide into sugar.
The ocean ...
- 85.8k
41
votes
If Earth's Core had ALL Of the Heavy Metals
How would this difference affect Earth's overall chemistry?
Not much (but see below). Here's why:
Let's start with some background
The core–mantle differentiation event was the melting event which ...
- 3,858
40
votes
How could a planet have zero surface caves?
Solid is a relative thing
No caves in sand
No caves in water
No caves in magma
No (permanent) caves in ice sheet
No caves in soft soil
No caves in peat bogs
In short:
No caves in anything ...
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40
votes
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How tall can a humanoid creature be without alerting the rest of the planet with earthquakes?
A real answer is a calculus problem that requires many different iffy variables that will be difficult to determine. So I am just going to ballpark it instead. In a lot of places, I have rounded or ...
- 5,673
37
votes
Is there something wrong with my fictional lighthouse?
Lighthouses don't necessarily mean "stay away". They can also mean "you are here".
Your setup is fine if:
theres lots of ship traffic within a few kilometers.
or theres a hazard ...
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36
votes
Evidence of spacetime anomaly in local geology?
There is no evidence of construction in the soil surrounding the house.
A Georgian mansion would have been built on site by craftsmen. They would have done much of their work on the land surrounding ...
- 306k
36
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What conditions would make having them sunken into the ground the predominant way of building large structures?
There is no other option. The underlying rock is limestone, and it has a network of karst caves:
After several attempts to build something on top of the caves, they collapsed causing damage in life ...
- 3,858
34
votes
Can stone be "recycled" by melting and cooling it?
An opportunity here to link up my all time favorite episode of
How It's Made: Stone Wool Insulation. It is exactly melted and recycled rock, being done commercially.
The idea was inspired by "Pele'...
- 306k
34
votes
How could a natural road form across a sea?
You could use a large mid-ocean ridge, like the Mid-Atlantic ridge, and then play around with sea levels. Mid-ocean ridges occur at (divergent) plate boundaries, and can be thousands of kilometers ...
- 102k
34
votes
Can a habitable planet have two separate crusts, both of which can sustain life?
For a given value of 'atmosphere' we already know of one such planet. Well, Moon.
Europa
The smallest moon of Jupiter, Europa is interesting because it is hypothesised that the surface is made ...
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34
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How can I launch a projectile to hit something in orbit, using only geological structures and power sources?
It doesn't seem to be possible using "normal" geology. You'd need a supervolcano to attain the required energies, and "piloting" one with the required precision doesn't look doable.
You need to score ...
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34
votes
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How to explain one side of Super Earth is smoother than the other side?
I'm reminded strongly of Iapetus, a moon of Saturn that has a dramatic two-tone coloring. One hemisphere is quite light, while the other is dark. It almost looks like you dunked half of the moon in ...
- 102k
34
votes
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The erosion problem on floating islands
Vegetation
Thanks to animals and plants you can grow your island. Roots can overhang or pierce the island, getting nutrition out of the water and deposit it on the island in one way or the other. Even ...
- 40.2k
33
votes
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How To Make Earth's Oceans as Brackish as Lyr's
Less land
It's actually pretty easy. There are two ways to make an ocean less salty. The first way is to remove salt, and the second is to add fresh water, both of which are possible, but takes a lot ...
- 40.4k
Only top scored, non community-wiki answers of a minimum length are eligible