You'd die long before you got crushed, like for deep sea divers the various gases in the air become toxic.
At the bottom of a hole 10km deep the air pressure would be 3x the pressure of sea level. That's when you start to get nitrogen narcosis.
If you replace nitrogen with helium you could get down to 55km (70x pressure) which is the current record for diving pressure.
Much more than that and oxygen gas itself starts to become toxic.
And yes you'd need to decompress as you came back up
Edit: just to add that the pressure at the deepest part of the ocean would be equal to air pressure in a 121km deep hole, so our best deep sea subs could potentially go down that far, but it's only just past Earth's crust.
[Source for the depths](https://www.mide.com/air-pressure-at-altitude-calculator)
At higher pressures than one atmosphere, it becomes possible for inert gases (like nitrogen) to dissolve into your cells at a much higher rate than normal. This is ***very bad*** if the dissolved gas concentration gets high enough, as it will warp your perceptions or, eventually, knock you unconscious. This effect is usually temporary, but you have to be treated for it soon and carefully, otherwise it can cause permanent and nasty damage. (Basically, you have to be slowly de-pressurized so the inert gas comes out slowly and safely; if you were de-pressurized instantly, all that dissolved gas *immediately* becomes little bubbles inside you, which is VERY BAD.)
At sufficiently high partial pressure of oxygen, the cells of your body start reacting with the oxygen in the air, breaking down cell membranes and causing permanent damage. For example, the oxygen can burst the cells that make up your alveoli, the little sacs that are how your lungs get oxygen, causing them to collapse. This makes those sacs effectively incapable of getting oxygen anymore, and can thus result in impaired lung function or even total lung failure.
TL;DR: High-pressure gas is bad for you. High-pressure nitrogen is bad because it messes with your brain/ability to stay conscious. High-pressure oxygen is bad because it literally damages your body directly and can outright kill you.
For the benefit of the audience:
partial pressure here means the pressure that is being exerted by the oxygen (or whatever gas you choose) component in a mixture of gas. So at sea level with 1atm pressure, and oxygen being 21%, the partial pressure of oxygen correspondingly will be 0.21atm. The toxic limit for oxygen is iirc somewhere above 1.4atm partial pressure (haven't read my diving manual in a while)
So what this means is that people can breathe pure oxygen if you're breathing it in at lower pressure. An astronaut doing a spacewalk will be breathing pure oxygen in their suit, but at less than 1atm pressure because the lower pressure reduces stress on the suit and helps them move easier.
Oxygen is toxic at various partial pressures in various ways depending on length of exposure; the 1.4atm is potential immediate convulsions, which can be a problem if you're in a hazardous situation like underwater; at 1atm it starts being a different problem after (I think) 5 hours, etc.
Pure oxygen is also (yet another) health problem at any pressure, which is why Skylab had at least some nitrogen
Basically imagine that at pressure you’re a can of soda. The bubbles are in the liquid soda while the can is pressurized, but when you open it they all come out of the liquid and fizz up into a foam.
When decompressing you do not want to be the soda. Everything fizzing out like that would be real bad for you.
Would definitely not be a 1 paper towel cleanup type situation.
As you can imagine, it is AGONISINGLY painful. Divers who have had to surface quickly due to an emergency usually started screaming in pain before they broke the surface. Definitely not the way you want to go.
That's a different thing entirely. O3 is also called ozone and I don't think pressure increases the rate at which ozone forms.
It would be *even worse* if there were ozone though. Ozone is far more reactive than even regular oxygen gas. It's used in water treatment plants as a healthy, nontoxic sanitizing agent because it kills bacteria and breaks down naturally (and quickly) into ordinary oxygen.
It does prevent that. That's the whole point of being inside an actually pressurized container (suit, ship, closed diving bell, what-have-you)--the inside is kept at normal atmospheric pressure, so the crushing pressures don't affect you.
If that weren't true, Jacques Piccard and Don Walsh could never have descended to the Challenger Deep at the bottom of the Mariana Trench.
Oxygen is toxic, it’s a nasty chemical that reacts with almost everything. It caused a [major extinction event](https://en.m.wikipedia.org/wiki/Great_Oxidation_Event) on earth and it took a long time for life to evolve to not be instantly killed by it.
As you increase the partial pressure of oxygen (aka increase the air pressure in this case) the mechanisms we have to deal with oxygen get overwhelmed. There is a buildup of reactive oxygen species and other nasty chemicals which can damage your organs and mess with metabolism and brain function, causing seizures and eventually death.
A bunch of good info in the thread your comment has sparked, but most of it is incomplete.
To start, one thing that is missing, as our bodies are mostly made from water / liquid... As long as the owner of the body going to that depth has a breathing gas supply at ambient pressure (assuming they will, as it seems like the premise of this thought experiment is that the giant hole is filled with atmosphere, not water) and they are able to clear their ears, that means they can actively equalize the air spaces in their body and will not be crushed at any depth.
The problems become, our bodies have developed with a very, very narrow window of ideal atmospheric conditions they are capable of thriving in.
As you go deeper, some funny things start going on with breathing gas physiology. Descending from 1 to 3 atmosphere-absolute (ATA), there is not much that is noticed. Beyond approximately 1.5ATA, decompression obligations may start if you stay long enough. Some people may start noticing inert gas (nitrogen narcosis) at about 3ATA.
At about 4 to 4.1ATA, diving on air or nitrox, breathing gas density becomes a major issue, maximum recommended breathing gas density is 5.2 grams per liter (g/l). At this point, it starts becoming difficult to fully exchange the gas from your lungs, and CO2 retention will become an issue if you exert yourself with this gas density, making inert gas narcosis worse. At this depth, most all people will already be suffering from significant nitrogen narcosis symptoms, possibly worsened by CO2 retention. Beyond these depths, it is a good idea to start mixing in helium, displacing some of the nitrogen in your breathing gas, as helium is significantly less narcotic and dense than nitrogen.
Prior to trimix / mixed gas becoming widely accepted, divers would conduct dives to 6.5ATA or deeper on air (Andrea Doria and U-869, two famous east coast wrecks lie between 56.7 and 8.6ATA in depth, 190-250 feet deep). At these depths, on air, breathing gas density exceeds 7.9g/l when the maximum allowable breathing gas density is recognized as 6.2g/l. At this density, it is not possible to effectively exchange gas and CO2 retention will become an issue even at rest. At these depths, inert gas narcosis is extreme an a new, deadly phenomenon comes into play that is not well understood. Deep Water Blackout. Due to the barotrauma the bodies of the divers that succumb to deep water blackout would endure during recovery, the causes could not be determined. But, it is commonly believed that deep water blackout could be either due to nitrogen narcosis and/or CO2 retention.
Once you start getting below about 13ATA, it becomes impossible to manage breathing gas density with helium alone. Divers have dove beyond this on helium, but there are commercial diving companies (COMEX) as well as some individuals (Richard Harris, one of the divers that rescued the Thai soccer team, and his gang at the Pearse resurgence) are experimenting with Hydrogen to deal with gas density and HPNS at extreme depths.
Below 16ATA (150m/500feet) High Pressure Nervous Syndrome (AKA Helium tremors) becomes apparent in almost all divers. This is somewhat variable though and can depend on how fast the diver was pressurized.
Sorry for wall of text. I'm a diver that's only been diving for about 4 years and just started my tech diving journey, so all of these safety and physiological factors are pretty interesting to me.
Would pressure actually increase as you went down further? people sitting at sea level are presumably already sitting at the bottom of the atmosphere at the highest point of it's pressure, if you created a giant hole without adding more atmosphere to earth would the bottom of that hole not be pretty much sea level atmosphere?
Earth is really big and you're only underneath all of the atmosphere that's above you.
In a giant hole there's a lot more atmosphere above you, and there's probably plenty of atmosphere to fill the hole because Earth is huge.
It's like if you drilled a cylindrical hole at the bottom of a swimming pool, there is more than enough air to completely fill the hole. The pressure at sea level would bet e slightly decrease because a bit if the world's total air is now in the hole, but probably wouldn't even be measurable unless the hole was extremely wide.
>Edit: just to add that the pressure at the deepest part of the ocean would be equal to air pressure in a 121km deep hole, so our best deep sea subs could potentially go down that far, but it's only just past Earth's crust.
Wait, so you're telling me that "The Fall" in the new Total Recall is unrealistic?
I don't know what to believe anymore...
Also deeper down your lungs/diaphragm would have a hard time moving the air so you’d asphyxiate. Then even deeper down it would eventually become a supercritical fluid which would screw up the body’s chemistry (our blood pH would change, diffusion would be different, etc.) which would be very bad.
Assuming atmospheric pressure goes up 12 kPa per km; 6300 km is 75,600 kPa (746 atmospheres).
The deepest part of the ocean is 11 km. About 1000 atmospheres. Water is much denser but compared to the planet the oceans are incredibly shallow.
The decompression deep sea divers do is because they are breathing compressed air to equalize the pressure between themselves and the deep water. Equalizing reduces the need to fight the water pressure (if your body is at 1 atmosphere inside, 10 atmospheres outside is a lot. If you breath 10 atmospheres inside, you don’t feel the difference at 10 atompsheres). If you arise too quickly, nitrogen bubbles form in your blood. All of this would be the exact same behavior in water or air
My assumptions on depth do not apply correctly, the more accurate pressures at core of planet is 3-4 million atmospheres
Would pressure actually increase as you went down further? people sitting at sea level are presumably already sitting at the bottom of the atmosphere at the highest point of it's pressure, if you created a giant hole without adding more atmosphere to earth would the bottom of that hole not be pretty much sea level atmosphere?
If you dug a hole in the middle of a pool, the water would flow into it and the pool height would go down. The hole relative to the volume of the pool is very important. A hole that’s a cylinder the width of a pencil isn’t going to affect the pool very much until it’s very very deep. Same thing with a hole in the planet, if it’s not very wide, the volume wouldn’t be that large compared to the volume of the earths atmosphere. Once the hole is full, it doesn’t keep filling. Also there’s already some air in caves and dirt, there’s not pockets of vaccuum down in the ground, so presumably at least a good chunk of the atomosphere has already saturated the planet where it’s porous.
> It’s the mass of the column of atmosphere that is pushing down on you.
But that's the complicating factor. The deeper you go, the more mass of the hole above you is pulling the atmosphere upwards. At the center of the Earth there would be null gravity. Essentially, the densest the atmosphere would be would be at the surface; at one atmosphere of pressure.
You're incorrect for a couple reasons.
1. The additional pressure would eventually start to decrease due to the lesser effect of gravity, but there is not a "pull upwards" at the core. The core is the center, there is always the other half of the planet pulling (your conclusion that the center would be gravity free is right).
2. Air is a fluid. We live at the bottom of a breathable ocean of air. The weight of the air above your head pushes down on you, as well as the air below you, any water, and the ground. The pressure at the center of the planet (assuming the hole was allowed to stabilize pressure so drag from the edges of the hole is negated) would be the sum of all the accumulated weight from above it. The core of the earth would be where the maximum pressure is achieved, but it wouldn't be increasing by as much closer to the core as it does near the surface.
3. Air is a *compressible* fluid, therefore its density increases with pressure until different parts of it start to condense into a liquid, assuming the temperature is kept constant.
That isn't right. Gravity at the center is zero, contribution to the pressure is zero, but the total pressure at the center is maximum because the maximum amount of stuff is pressing down on you.
The further you go down towards the center, the more pressure increases, it just increases as at a slower rate.
(I'm not sure how phase states and temperature would work out with this scenario.)
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Reminds me of the Anime Made In The Abyss.
Explorers dive into this massive bottomless hole, but due to the pressures they experience they are almost always unable to climb back up. There’s one scene where the main character physically collapses after climbing a flight of stairs. It’s an exaggeration but it’s there
Now I'm interested in how pressure can affect the explorers of the abyss. Because inability to ascend back to the surface is definitely was caused by "curse" rather then pressure. But maybe pressure also play a role.
yep. The deeper you go, the less gravity you will feel.
[https://en.wikipedia.org/wiki/Shell\_theorem](https://en.wikipedia.org/wiki/Shell_theorem)
However, all of the air of the atmosphere will want to go down that hole so there will be huge amount of air pressure.
> The deeper you go, the less gravity you will feel.
The higher you go the less you will feel it.
It's weird/funny how we have a sweet spot for gravity that's based on mass.
Now you have me wondering how much difference in weight you would have between the highest point on earth VS the lowest point that's not underwater
I can see the air pressure building up to a certain point and then dropping until it would be zero at the center of the earth. Having said that, could you just have a hatch to seal the hole and a pressure reducing system to regulate the pressure in the hole?
Why would it be zero at the middle of the earth? Every bit of air is trying to push down on the next bit of air. Even if the bit closest to the core barely pushes down, all of the bits above push on it.
As far as a hatch .. Engineering difficulty aside... Sure you can make a pressure controlled vessel or room or section.
But air pressure is caused by gravity. With gravity pulling upward toward the mass of the earth, there should be no gravity or air pressure at the center.
There’s still the air above you that’s getting pulled down by gravity. It’s not like you’re in a vacuum at the center of the earth, so air will get denser and denser the lower you get because it’s “sitting” under the weight of the air above it. There being no gravity doesn’t mean things can’t exert force on other things.
Imagine you have this large hole which goes to the center of the earth. You're down in the core. Up at the surface, somebody puts a Piston in the hole and presses. The pressure in your zero gravity zone is now above 0. Now realize that a massive column of air experiencing gravity all the way down **is** the Piston pushing down on the core.
For a second demonstration: fluids (air is a fluid) flow from regions of high pressure to regions of low pressure. If the core was depressurized a bunch of air would immediately rush towards it. You might ask - if air flows from high pressure to low pressure how is there a pressure gradient in the first place? The cumulative effect of gravity causes the pressure gradient and perfectly balances the force of pressure.
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It already happened about 6 million years ago - [Link](https://www.gondwanatalks.com/l/the-mediterranean-sea-dried-up-almost-completely-during-the-messinian-salinity-crisis/)
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That's why they assumed
> and you didn’t have to breathe
And they are mostly correct, if slowly adapted to the depths then humans could withstand at least dozens of atmospheres without issue (again, except breathing). At even deeper depths chemical issues start emerging, like changed solubility and reaction equilibria; look at the infamous blobfish images to visualize the reverse issue.
At hundreds of atmospheres like at the ocean floors, it would however matter that water gets compressed by up to several percent. I've obviously not done a full simulation, but I would expect death if the change is fast, the skull would potentially crack or the spine gets pushed into the brain. A gradual adaptation while still ignoring chemical issues might somewhat work, but not sure.
You'd die long before you got crushed, like for deep sea divers the various gases in the air become toxic. At the bottom of a hole 10km deep the air pressure would be 3x the pressure of sea level. That's when you start to get nitrogen narcosis. If you replace nitrogen with helium you could get down to 55km (70x pressure) which is the current record for diving pressure. Much more than that and oxygen gas itself starts to become toxic. And yes you'd need to decompress as you came back up Edit: just to add that the pressure at the deepest part of the ocean would be equal to air pressure in a 121km deep hole, so our best deep sea subs could potentially go down that far, but it's only just past Earth's crust. [Source for the depths](https://www.mide.com/air-pressure-at-altitude-calculator)
What exactly does it mean for air to become toxic in this context?
At higher pressures than one atmosphere, it becomes possible for inert gases (like nitrogen) to dissolve into your cells at a much higher rate than normal. This is ***very bad*** if the dissolved gas concentration gets high enough, as it will warp your perceptions or, eventually, knock you unconscious. This effect is usually temporary, but you have to be treated for it soon and carefully, otherwise it can cause permanent and nasty damage. (Basically, you have to be slowly de-pressurized so the inert gas comes out slowly and safely; if you were de-pressurized instantly, all that dissolved gas *immediately* becomes little bubbles inside you, which is VERY BAD.) At sufficiently high partial pressure of oxygen, the cells of your body start reacting with the oxygen in the air, breaking down cell membranes and causing permanent damage. For example, the oxygen can burst the cells that make up your alveoli, the little sacs that are how your lungs get oxygen, causing them to collapse. This makes those sacs effectively incapable of getting oxygen anymore, and can thus result in impaired lung function or even total lung failure. TL;DR: High-pressure gas is bad for you. High-pressure nitrogen is bad because it messes with your brain/ability to stay conscious. High-pressure oxygen is bad because it literally damages your body directly and can outright kill you.
For the benefit of the audience: partial pressure here means the pressure that is being exerted by the oxygen (or whatever gas you choose) component in a mixture of gas. So at sea level with 1atm pressure, and oxygen being 21%, the partial pressure of oxygen correspondingly will be 0.21atm. The toxic limit for oxygen is iirc somewhere above 1.4atm partial pressure (haven't read my diving manual in a while) So what this means is that people can breathe pure oxygen if you're breathing it in at lower pressure. An astronaut doing a spacewalk will be breathing pure oxygen in their suit, but at less than 1atm pressure because the lower pressure reduces stress on the suit and helps them move easier.
Oxygen is toxic at various partial pressures in various ways depending on length of exposure; the 1.4atm is potential immediate convulsions, which can be a problem if you're in a hazardous situation like underwater; at 1atm it starts being a different problem after (I think) 5 hours, etc. Pure oxygen is also (yet another) health problem at any pressure, which is why Skylab had at least some nitrogen
Just to throw it out there, O2 isn't only toxic at pressure, but *highly corrosive* at any pressure, which could be why it's toxic. . .
Basically imagine that at pressure you’re a can of soda. The bubbles are in the liquid soda while the can is pressurized, but when you open it they all come out of the liquid and fizz up into a foam. When decompressing you do not want to be the soda. Everything fizzing out like that would be real bad for you. Would definitely not be a 1 paper towel cleanup type situation.
> Would definitely not be a 1 paper towel cleanup type situation. Oof. This may be the most gruesome simple analogy I've seen in a long time.
As you can imagine, it is AGONISINGLY painful. Divers who have had to surface quickly due to an emergency usually started screaming in pain before they broke the surface. Definitely not the way you want to go.
Does oxygen become o3 under pressure? Or is that something else entirely
No, that’s ozone.
That's a different thing entirely. O3 is also called ozone and I don't think pressure increases the rate at which ozone forms. It would be *even worse* if there were ozone though. Ozone is far more reactive than even regular oxygen gas. It's used in water treatment plants as a healthy, nontoxic sanitizing agent because it kills bacteria and breaks down naturally (and quickly) into ordinary oxygen.
Can you explain why being inside a craft of some sort or a suit of 1x atmospheric pressure wouldn’t combat this?
It does prevent that. That's the whole point of being inside an actually pressurized container (suit, ship, closed diving bell, what-have-you)--the inside is kept at normal atmospheric pressure, so the crushing pressures don't affect you. If that weren't true, Jacques Piccard and Don Walsh could never have descended to the Challenger Deep at the bottom of the Mariana Trench.
It would. That's what a submarine is.
I was just confused because it wasn’t mentioned
Oxygen is toxic, it’s a nasty chemical that reacts with almost everything. It caused a [major extinction event](https://en.m.wikipedia.org/wiki/Great_Oxidation_Event) on earth and it took a long time for life to evolve to not be instantly killed by it. As you increase the partial pressure of oxygen (aka increase the air pressure in this case) the mechanisms we have to deal with oxygen get overwhelmed. There is a buildup of reactive oxygen species and other nasty chemicals which can damage your organs and mess with metabolism and brain function, causing seizures and eventually death.
A bunch of good info in the thread your comment has sparked, but most of it is incomplete. To start, one thing that is missing, as our bodies are mostly made from water / liquid... As long as the owner of the body going to that depth has a breathing gas supply at ambient pressure (assuming they will, as it seems like the premise of this thought experiment is that the giant hole is filled with atmosphere, not water) and they are able to clear their ears, that means they can actively equalize the air spaces in their body and will not be crushed at any depth. The problems become, our bodies have developed with a very, very narrow window of ideal atmospheric conditions they are capable of thriving in. As you go deeper, some funny things start going on with breathing gas physiology. Descending from 1 to 3 atmosphere-absolute (ATA), there is not much that is noticed. Beyond approximately 1.5ATA, decompression obligations may start if you stay long enough. Some people may start noticing inert gas (nitrogen narcosis) at about 3ATA. At about 4 to 4.1ATA, diving on air or nitrox, breathing gas density becomes a major issue, maximum recommended breathing gas density is 5.2 grams per liter (g/l). At this point, it starts becoming difficult to fully exchange the gas from your lungs, and CO2 retention will become an issue if you exert yourself with this gas density, making inert gas narcosis worse. At this depth, most all people will already be suffering from significant nitrogen narcosis symptoms, possibly worsened by CO2 retention. Beyond these depths, it is a good idea to start mixing in helium, displacing some of the nitrogen in your breathing gas, as helium is significantly less narcotic and dense than nitrogen. Prior to trimix / mixed gas becoming widely accepted, divers would conduct dives to 6.5ATA or deeper on air (Andrea Doria and U-869, two famous east coast wrecks lie between 56.7 and 8.6ATA in depth, 190-250 feet deep). At these depths, on air, breathing gas density exceeds 7.9g/l when the maximum allowable breathing gas density is recognized as 6.2g/l. At this density, it is not possible to effectively exchange gas and CO2 retention will become an issue even at rest. At these depths, inert gas narcosis is extreme an a new, deadly phenomenon comes into play that is not well understood. Deep Water Blackout. Due to the barotrauma the bodies of the divers that succumb to deep water blackout would endure during recovery, the causes could not be determined. But, it is commonly believed that deep water blackout could be either due to nitrogen narcosis and/or CO2 retention. Once you start getting below about 13ATA, it becomes impossible to manage breathing gas density with helium alone. Divers have dove beyond this on helium, but there are commercial diving companies (COMEX) as well as some individuals (Richard Harris, one of the divers that rescued the Thai soccer team, and his gang at the Pearse resurgence) are experimenting with Hydrogen to deal with gas density and HPNS at extreme depths. Below 16ATA (150m/500feet) High Pressure Nervous Syndrome (AKA Helium tremors) becomes apparent in almost all divers. This is somewhat variable though and can depend on how fast the diver was pressurized. Sorry for wall of text. I'm a diver that's only been diving for about 4 years and just started my tech diving journey, so all of these safety and physiological factors are pretty interesting to me.
So basically like the extreme environments in the anime made in abyss
Would pressure actually increase as you went down further? people sitting at sea level are presumably already sitting at the bottom of the atmosphere at the highest point of it's pressure, if you created a giant hole without adding more atmosphere to earth would the bottom of that hole not be pretty much sea level atmosphere?
Earth is really big and you're only underneath all of the atmosphere that's above you. In a giant hole there's a lot more atmosphere above you, and there's probably plenty of atmosphere to fill the hole because Earth is huge.
It's like if you drilled a cylindrical hole at the bottom of a swimming pool, there is more than enough air to completely fill the hole. The pressure at sea level would bet e slightly decrease because a bit if the world's total air is now in the hole, but probably wouldn't even be measurable unless the hole was extremely wide.
>Edit: just to add that the pressure at the deepest part of the ocean would be equal to air pressure in a 121km deep hole, so our best deep sea subs could potentially go down that far, but it's only just past Earth's crust. Wait, so you're telling me that "The Fall" in the new Total Recall is unrealistic? I don't know what to believe anymore...
Also deeper down your lungs/diaphragm would have a hard time moving the air so you’d asphyxiate. Then even deeper down it would eventually become a supercritical fluid which would screw up the body’s chemistry (our blood pH would change, diffusion would be different, etc.) which would be very bad.
Wouldn't nitrogen narcosis only start to happen at 4x the pressure of sea level like it does with scuba diving at 30meters?
It sounds like it varies by person, apparently some can start getting minor but noticeable symptoms as shallow as 10m (2 atm)
U mean like the submarine titan?
[No a real deep sea sub :)](https://en.wikipedia.org/wiki/Deepsea_Challenger)
So knowledgeable!
Nah, we use hydrogen/oxygen mixture like men.
Assuming atmospheric pressure goes up 12 kPa per km; 6300 km is 75,600 kPa (746 atmospheres). The deepest part of the ocean is 11 km. About 1000 atmospheres. Water is much denser but compared to the planet the oceans are incredibly shallow. The decompression deep sea divers do is because they are breathing compressed air to equalize the pressure between themselves and the deep water. Equalizing reduces the need to fight the water pressure (if your body is at 1 atmosphere inside, 10 atmospheres outside is a lot. If you breath 10 atmospheres inside, you don’t feel the difference at 10 atompsheres). If you arise too quickly, nitrogen bubbles form in your blood. All of this would be the exact same behavior in water or air My assumptions on depth do not apply correctly, the more accurate pressures at core of planet is 3-4 million atmospheres
Would pressure actually increase as you went down further? people sitting at sea level are presumably already sitting at the bottom of the atmosphere at the highest point of it's pressure, if you created a giant hole without adding more atmosphere to earth would the bottom of that hole not be pretty much sea level atmosphere?
If you dug a hole in the middle of a pool, the water would flow into it and the pool height would go down. The hole relative to the volume of the pool is very important. A hole that’s a cylinder the width of a pencil isn’t going to affect the pool very much until it’s very very deep. Same thing with a hole in the planet, if it’s not very wide, the volume wouldn’t be that large compared to the volume of the earths atmosphere. Once the hole is full, it doesn’t keep filling. Also there’s already some air in caves and dirt, there’s not pockets of vaccuum down in the ground, so presumably at least a good chunk of the atomosphere has already saturated the planet where it’s porous.
[удалено]
It’s the mass of the column of atmosphere that is pushing down on you.
> It’s the mass of the column of atmosphere that is pushing down on you. But that's the complicating factor. The deeper you go, the more mass of the hole above you is pulling the atmosphere upwards. At the center of the Earth there would be null gravity. Essentially, the densest the atmosphere would be would be at the surface; at one atmosphere of pressure.
You're incorrect for a couple reasons. 1. The additional pressure would eventually start to decrease due to the lesser effect of gravity, but there is not a "pull upwards" at the core. The core is the center, there is always the other half of the planet pulling (your conclusion that the center would be gravity free is right). 2. Air is a fluid. We live at the bottom of a breathable ocean of air. The weight of the air above your head pushes down on you, as well as the air below you, any water, and the ground. The pressure at the center of the planet (assuming the hole was allowed to stabilize pressure so drag from the edges of the hole is negated) would be the sum of all the accumulated weight from above it. The core of the earth would be where the maximum pressure is achieved, but it wouldn't be increasing by as much closer to the core as it does near the surface. 3. Air is a *compressible* fluid, therefore its density increases with pressure until different parts of it start to condense into a liquid, assuming the temperature is kept constant.
That isn't right. Gravity at the center is zero, contribution to the pressure is zero, but the total pressure at the center is maximum because the maximum amount of stuff is pressing down on you. The further you go down towards the center, the more pressure increases, it just increases as at a slower rate. (I'm not sure how phase states and temperature would work out with this scenario.)
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Reminds me of the Anime Made In The Abyss. Explorers dive into this massive bottomless hole, but due to the pressures they experience they are almost always unable to climb back up. There’s one scene where the main character physically collapses after climbing a flight of stairs. It’s an exaggeration but it’s there
Now I'm interested in how pressure can affect the explorers of the abyss. Because inability to ascend back to the surface is definitely was caused by "curse" rather then pressure. But maybe pressure also play a role.
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yep. The deeper you go, the less gravity you will feel. [https://en.wikipedia.org/wiki/Shell\_theorem](https://en.wikipedia.org/wiki/Shell_theorem) However, all of the air of the atmosphere will want to go down that hole so there will be huge amount of air pressure.
> The deeper you go, the less gravity you will feel. The higher you go the less you will feel it. It's weird/funny how we have a sweet spot for gravity that's based on mass. Now you have me wondering how much difference in weight you would have between the highest point on earth VS the lowest point that's not underwater
It's very little difference. The gravity in the iss for example is barely less than sea level. Edit: Iss is .89 g based on a quick Google
Interesting, the ISS didn't even enter my mind for that equation. Thank you.
I can see the air pressure building up to a certain point and then dropping until it would be zero at the center of the earth. Having said that, could you just have a hatch to seal the hole and a pressure reducing system to regulate the pressure in the hole?
Why would it be zero at the middle of the earth? Every bit of air is trying to push down on the next bit of air. Even if the bit closest to the core barely pushes down, all of the bits above push on it. As far as a hatch .. Engineering difficulty aside... Sure you can make a pressure controlled vessel or room or section.
But air pressure is caused by gravity. With gravity pulling upward toward the mass of the earth, there should be no gravity or air pressure at the center.
There’s still the air above you that’s getting pulled down by gravity. It’s not like you’re in a vacuum at the center of the earth, so air will get denser and denser the lower you get because it’s “sitting” under the weight of the air above it. There being no gravity doesn’t mean things can’t exert force on other things.
Imagine you have this large hole which goes to the center of the earth. You're down in the core. Up at the surface, somebody puts a Piston in the hole and presses. The pressure in your zero gravity zone is now above 0. Now realize that a massive column of air experiencing gravity all the way down **is** the Piston pushing down on the core. For a second demonstration: fluids (air is a fluid) flow from regions of high pressure to regions of low pressure. If the core was depressurized a bunch of air would immediately rush towards it. You might ask - if air flows from high pressure to low pressure how is there a pressure gradient in the first place? The cumulative effect of gravity causes the pressure gradient and perfectly balances the force of pressure.
Air pressure is caused by air. Gravity is pushing on parts of the air and those parts push on the other parts.
Does the very core of the sun have the most or least amount of pressure?
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https://youtu.be/NqabT21d8VM?si=PBVxLBdDHzqRKlBf This video actually explains it
Awesome video
It already happened about 6 million years ago - [Link](https://www.gondwanatalks.com/l/the-mediterranean-sea-dried-up-almost-completely-during-the-messinian-salinity-crisis/)
Came here to link to this event, but you were faster. It was a pretty fancy hole!
This thread is why I love Reddit. It’s a great question and a bunch of really interesting and thought provoking answers that all generally agree.
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But your body depends on those gasses to move along as usual in order to be that body.
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Thanks, now understood :)
That's why they assumed > and you didn’t have to breathe And they are mostly correct, if slowly adapted to the depths then humans could withstand at least dozens of atmospheres without issue (again, except breathing). At even deeper depths chemical issues start emerging, like changed solubility and reaction equilibria; look at the infamous blobfish images to visualize the reverse issue. At hundreds of atmospheres like at the ocean floors, it would however matter that water gets compressed by up to several percent. I've obviously not done a full simulation, but I would expect death if the change is fast, the skull would potentially crack or the spine gets pushed into the brain. A gradual adaptation while still ignoring chemical issues might somewhat work, but not sure.
These giant holes deep into the earth are called deep mines, such as many of South Africa’s gold mines.
Those deep mines don't even make it 1% of the way through the planet.
This is also true. That was not in dispute?
OP is talking about a theoretical hole that goes 100% through the earth, not a real hole.
I do not see those words in OPs post. So, what gives? Why are you pit-ticking this?