Can the water pressure be so high in some places underwater that gas bubbles will be trapped in place, unable to rise up?
In: 5
No. Water pressure doesn’t stop things from moving. It might squish the bubbles down quite a bit and even make them dissolve into the water but not freeze in place.
Bubbles rise because gases are typically less dense than water so gravity forces water above the bubbles to come downward (forcing the bubbles upward). In order for a bubble to stay down, it’s density would have to be equal or greater than water.
No. Gases (well most of them), no matter the pressure will be lower density than water and so still rise.
There may be some substances that at high enough pressures can still form a gas bubble but with a density greater than water, there are some weird things out there, but I’ve never heard of one.
What will normally happen instead is that if the pressure is high enough the bubble will collapse and the gas with be absorbed into the water. This is what happens with fizzy drinks, the pressure is high enough that the carbon dioxide is absorbed into the water. Once the pressure is released the gas starts to reform bubbles.
In some conditions of low temperature/high pressure water in combination with rising methane from underlying sources, water can form a *methane clathrate*. The methane is trapped in an icy cage of linked water molecules via hydrogen bonding.
These methane clathrates are stable and can be set alight in air – burning ice. Concerns about oceanic warming causing catastrophic methane release from clathrate deposits seem to have abated somewhat, but the climate-change driven release of methane from melting permafrost is still present and a growing issue.
Yes, but for air that would require something in the order of 10000 atmospheres, or roughly 100km of water depth. So not on this planet. You would also need to add a lot of additional air until the water is saturated and stops dissolving it.
If you allow other liquids and gases, it becomes quite feasible. See this video of Cody: https://www.youtube.com/watch?v=AsP4yMY-a6U
Furthermore, an air bubble can be held in place under water e.g. by sound pressure. One particularly interesting instance is “single bubble sonoluminescence”, which (extremely simplified) uses sound to create a light-emitting bubble of steam and air. The first step is to [trap an air bubble in a spherical flask by sound](https://www.science.org/cms/10.1126/science.279.5355.1322/asset/e6ce1fe2-c05b-4f04-9a15-c21d42565635/assets/graphic/1322-1.gif). Either that or the vapour bubble then looks like [this](https://upload.wikimedia.org/wikipedia/commons/thumb/9/91/Single_bubble_cropped.jpg/800px-Single_bubble_cropped.jpg).
Maybe it helps more to think that heavier things get pulled downwards *more*, sliding under the less dense thing. Then the less dense thing gets squeezed upwards.
Water pressure, and pressure of any fluid, is exerted basically evenly in every direction*. Because of that, no matter how high the pressure, the bubbles will always rise up so long as their density is lower than the surrounding fluid. Suction cups take advantage of the pressure by making it so it only pushes from the top, pinning the cup down.
*There is a very tiny difference, but the pressure is actually higher below instead of above the bubble. That’s why it rises. It happens because pressure of a liquid increases as you go further down.
The pressure isn’t just pushing the bubbles down, it pushes equally on all sides. If the pressure inside the bubble is less than that of the surrounding water, then the bubble gets compressed down until the internal pressure matches the external pressure. It’s just a balancing of forces.
Buoyancy is a phenomenon that actually has very little to do with pressure, and the amount of buoyant force you experience is dependent on the mass of the fluid you displace, which is dependent on the volume you occupy and the density of the fluid you’re in.
If you want to change the buoyancy of an object by changing the pressure, you need to make sure that the object in question compresses differently than the fluid around it. Like a Cartesian diver has a little air bubble in it, so when you increase the pressure, the air bubble is compressed more than the surrounding water, causing the diver to have more density than the surrounding water, and sink until pressure returns to normal.
Yes, sort of. Throttling is the general term. The bubbles can constrict flow for a short time, forcing pressure to increase upstream until it overcomes the blockage created by the bubble. This is more or less how many geysers operate.
The bubbles will not permanently block flow. The bubbles will generally compress as pressure increases and then get carried along with the flow, but can sometimes produce vapor lock for short periods. The system will not stop dead and ignore the existence of the blockage (the fluids will still be impelled to move, and since there is blockage, pressure rises until it exceeds the capacity of the blocking mechanism to prevent additional movement).
It does sometimes occur that there is only a partial blockage created by formation of a bubble and the bubble remains in place, restricting, but not stopping, flow. This sort of thing happens in pipes all the time.
Latest Answers