How does gravity affect pressure under water?
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How different would being under water in Europa differ from being under water on Earth? Would it be possible to dive deeper on Europa with a submarine than on Earth and by how much?
gravity astrophysics atmosphere europa
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up vote
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How different would being under water in Europa differ from being under water on Earth? Would it be possible to dive deeper on Europa with a submarine than on Earth and by how much?
gravity astrophysics atmosphere europa
In order to answer this you'd need to know the density of Europa's oceans, which I don't believe anyone knows. Water pressure is created by the weight of the column of water above the depth in question, and this is directly related to its density. But if one assumes the density to be about equal to Earth's oceans, then the diving depth would simply be the ratio of Earth's and Europa's gravity (Earth = 9.78, Europa = 1.314).
– BillDOe
7 hours ago
@BillDOe How compressible do you think water is?
– Rob Jeffries
7 hours ago
@BillDOe Why do you think there would be a meaningful difference in density? (Obviously, if you get deep enough you'll start seeing effects but long before you get appreciable compression you'll get phase changes.)
– Loren Pechtel
47 mins ago
add a comment |
up vote
4
down vote
favorite
up vote
4
down vote
favorite
How different would being under water in Europa differ from being under water on Earth? Would it be possible to dive deeper on Europa with a submarine than on Earth and by how much?
gravity astrophysics atmosphere europa
How different would being under water in Europa differ from being under water on Earth? Would it be possible to dive deeper on Europa with a submarine than on Earth and by how much?
gravity astrophysics atmosphere europa
gravity astrophysics atmosphere europa
edited 32 mins ago
user22a6db72d7249
1032
1032
asked 8 hours ago
Muze
697118
697118
In order to answer this you'd need to know the density of Europa's oceans, which I don't believe anyone knows. Water pressure is created by the weight of the column of water above the depth in question, and this is directly related to its density. But if one assumes the density to be about equal to Earth's oceans, then the diving depth would simply be the ratio of Earth's and Europa's gravity (Earth = 9.78, Europa = 1.314).
– BillDOe
7 hours ago
@BillDOe How compressible do you think water is?
– Rob Jeffries
7 hours ago
@BillDOe Why do you think there would be a meaningful difference in density? (Obviously, if you get deep enough you'll start seeing effects but long before you get appreciable compression you'll get phase changes.)
– Loren Pechtel
47 mins ago
add a comment |
In order to answer this you'd need to know the density of Europa's oceans, which I don't believe anyone knows. Water pressure is created by the weight of the column of water above the depth in question, and this is directly related to its density. But if one assumes the density to be about equal to Earth's oceans, then the diving depth would simply be the ratio of Earth's and Europa's gravity (Earth = 9.78, Europa = 1.314).
– BillDOe
7 hours ago
@BillDOe How compressible do you think water is?
– Rob Jeffries
7 hours ago
@BillDOe Why do you think there would be a meaningful difference in density? (Obviously, if you get deep enough you'll start seeing effects but long before you get appreciable compression you'll get phase changes.)
– Loren Pechtel
47 mins ago
In order to answer this you'd need to know the density of Europa's oceans, which I don't believe anyone knows. Water pressure is created by the weight of the column of water above the depth in question, and this is directly related to its density. But if one assumes the density to be about equal to Earth's oceans, then the diving depth would simply be the ratio of Earth's and Europa's gravity (Earth = 9.78, Europa = 1.314).
– BillDOe
7 hours ago
In order to answer this you'd need to know the density of Europa's oceans, which I don't believe anyone knows. Water pressure is created by the weight of the column of water above the depth in question, and this is directly related to its density. But if one assumes the density to be about equal to Earth's oceans, then the diving depth would simply be the ratio of Earth's and Europa's gravity (Earth = 9.78, Europa = 1.314).
– BillDOe
7 hours ago
@BillDOe How compressible do you think water is?
– Rob Jeffries
7 hours ago
@BillDOe How compressible do you think water is?
– Rob Jeffries
7 hours ago
@BillDOe Why do you think there would be a meaningful difference in density? (Obviously, if you get deep enough you'll start seeing effects but long before you get appreciable compression you'll get phase changes.)
– Loren Pechtel
47 mins ago
@BillDOe Why do you think there would be a meaningful difference in density? (Obviously, if you get deep enough you'll start seeing effects but long before you get appreciable compression you'll get phase changes.)
– Loren Pechtel
47 mins ago
add a comment |
1 Answer
1
active
oldest
votes
up vote
6
down vote
accepted
For a liquid, hydrostatic pressure is $rho g h$ where $rho$ is density (this is always the same for all water) g is gravitational acceleration and h is depth.
The gravitational acceleration on Europa is 1.3 (compared with 9.8 on Earth). But on Europa there is 20km of ice floating on the water.
As a rough estimate, the gravity in Europa is 1/10 that on Earth, so the pressure at the bottom of the ice/top of the water would be comparable to the pressure at 2km in the Earth's Oceans.
Since we can build submarines that can operate at 10km, we could reasonably suppose that we could operate submarines down to about 100km on Europa, which takes us to the rocky surface. However we have no way to pass through 20km of ice crust to reach the water layer. Building the submarine may be the easy part!
2
A hot submarine could melt its way through, a bit like a dark stone on a glacier ;-)
– Chappo
5 hours ago
Nice answer. Is 20 km of ice a pretty good estimate? I thought it was a lot less certain.
– userLTK
4 hours ago
1
@Chappo Yup. Put a nuclear reactor (not merely a RTG) on board, melt your way down.
– Loren Pechtel
46 mins ago
add a comment |
1 Answer
1
active
oldest
votes
1 Answer
1
active
oldest
votes
active
oldest
votes
active
oldest
votes
up vote
6
down vote
accepted
For a liquid, hydrostatic pressure is $rho g h$ where $rho$ is density (this is always the same for all water) g is gravitational acceleration and h is depth.
The gravitational acceleration on Europa is 1.3 (compared with 9.8 on Earth). But on Europa there is 20km of ice floating on the water.
As a rough estimate, the gravity in Europa is 1/10 that on Earth, so the pressure at the bottom of the ice/top of the water would be comparable to the pressure at 2km in the Earth's Oceans.
Since we can build submarines that can operate at 10km, we could reasonably suppose that we could operate submarines down to about 100km on Europa, which takes us to the rocky surface. However we have no way to pass through 20km of ice crust to reach the water layer. Building the submarine may be the easy part!
2
A hot submarine could melt its way through, a bit like a dark stone on a glacier ;-)
– Chappo
5 hours ago
Nice answer. Is 20 km of ice a pretty good estimate? I thought it was a lot less certain.
– userLTK
4 hours ago
1
@Chappo Yup. Put a nuclear reactor (not merely a RTG) on board, melt your way down.
– Loren Pechtel
46 mins ago
add a comment |
up vote
6
down vote
accepted
For a liquid, hydrostatic pressure is $rho g h$ where $rho$ is density (this is always the same for all water) g is gravitational acceleration and h is depth.
The gravitational acceleration on Europa is 1.3 (compared with 9.8 on Earth). But on Europa there is 20km of ice floating on the water.
As a rough estimate, the gravity in Europa is 1/10 that on Earth, so the pressure at the bottom of the ice/top of the water would be comparable to the pressure at 2km in the Earth's Oceans.
Since we can build submarines that can operate at 10km, we could reasonably suppose that we could operate submarines down to about 100km on Europa, which takes us to the rocky surface. However we have no way to pass through 20km of ice crust to reach the water layer. Building the submarine may be the easy part!
2
A hot submarine could melt its way through, a bit like a dark stone on a glacier ;-)
– Chappo
5 hours ago
Nice answer. Is 20 km of ice a pretty good estimate? I thought it was a lot less certain.
– userLTK
4 hours ago
1
@Chappo Yup. Put a nuclear reactor (not merely a RTG) on board, melt your way down.
– Loren Pechtel
46 mins ago
add a comment |
up vote
6
down vote
accepted
up vote
6
down vote
accepted
For a liquid, hydrostatic pressure is $rho g h$ where $rho$ is density (this is always the same for all water) g is gravitational acceleration and h is depth.
The gravitational acceleration on Europa is 1.3 (compared with 9.8 on Earth). But on Europa there is 20km of ice floating on the water.
As a rough estimate, the gravity in Europa is 1/10 that on Earth, so the pressure at the bottom of the ice/top of the water would be comparable to the pressure at 2km in the Earth's Oceans.
Since we can build submarines that can operate at 10km, we could reasonably suppose that we could operate submarines down to about 100km on Europa, which takes us to the rocky surface. However we have no way to pass through 20km of ice crust to reach the water layer. Building the submarine may be the easy part!
For a liquid, hydrostatic pressure is $rho g h$ where $rho$ is density (this is always the same for all water) g is gravitational acceleration and h is depth.
The gravitational acceleration on Europa is 1.3 (compared with 9.8 on Earth). But on Europa there is 20km of ice floating on the water.
As a rough estimate, the gravity in Europa is 1/10 that on Earth, so the pressure at the bottom of the ice/top of the water would be comparable to the pressure at 2km in the Earth's Oceans.
Since we can build submarines that can operate at 10km, we could reasonably suppose that we could operate submarines down to about 100km on Europa, which takes us to the rocky surface. However we have no way to pass through 20km of ice crust to reach the water layer. Building the submarine may be the easy part!
answered 7 hours ago
James K
31.9k247104
31.9k247104
2
A hot submarine could melt its way through, a bit like a dark stone on a glacier ;-)
– Chappo
5 hours ago
Nice answer. Is 20 km of ice a pretty good estimate? I thought it was a lot less certain.
– userLTK
4 hours ago
1
@Chappo Yup. Put a nuclear reactor (not merely a RTG) on board, melt your way down.
– Loren Pechtel
46 mins ago
add a comment |
2
A hot submarine could melt its way through, a bit like a dark stone on a glacier ;-)
– Chappo
5 hours ago
Nice answer. Is 20 km of ice a pretty good estimate? I thought it was a lot less certain.
– userLTK
4 hours ago
1
@Chappo Yup. Put a nuclear reactor (not merely a RTG) on board, melt your way down.
– Loren Pechtel
46 mins ago
2
2
A hot submarine could melt its way through, a bit like a dark stone on a glacier ;-)
– Chappo
5 hours ago
A hot submarine could melt its way through, a bit like a dark stone on a glacier ;-)
– Chappo
5 hours ago
Nice answer. Is 20 km of ice a pretty good estimate? I thought it was a lot less certain.
– userLTK
4 hours ago
Nice answer. Is 20 km of ice a pretty good estimate? I thought it was a lot less certain.
– userLTK
4 hours ago
1
1
@Chappo Yup. Put a nuclear reactor (not merely a RTG) on board, melt your way down.
– Loren Pechtel
46 mins ago
@Chappo Yup. Put a nuclear reactor (not merely a RTG) on board, melt your way down.
– Loren Pechtel
46 mins ago
add a comment |
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In order to answer this you'd need to know the density of Europa's oceans, which I don't believe anyone knows. Water pressure is created by the weight of the column of water above the depth in question, and this is directly related to its density. But if one assumes the density to be about equal to Earth's oceans, then the diving depth would simply be the ratio of Earth's and Europa's gravity (Earth = 9.78, Europa = 1.314).
– BillDOe
7 hours ago
@BillDOe How compressible do you think water is?
– Rob Jeffries
7 hours ago
@BillDOe Why do you think there would be a meaningful difference in density? (Obviously, if you get deep enough you'll start seeing effects but long before you get appreciable compression you'll get phase changes.)
– Loren Pechtel
47 mins ago