My head canon for sea-based Kaiju is they have a sack of muscles somewhere inside their body that can expand a cavity, kind of like the diaphragm expands the lungs, except instead of taking in air or water it just creates a volume of vacuum inside of them. This makes them extremely bouyant relative to the surrounding sea pressure, so they rapidly ascend and can casually float like a boat near the surface.
But if they ever want to dive again, they just let that cavity collapse and all their bouyancy goes away.
To get unnecessarily scientific here, that wouldn’t change the overall density of the body, no? Even if there’s now a cavity with vacuum, the matter that was occupying that space just moved somewhere else within the volumes of the body and the overall density remained the same.
Now, if it pushed some matter out, air or water, and created a vacuum cavity, that might work. But I’m not an engineer, so correct me if I’m wrong.
A hundred ton steel ship floats, a hundred ton steel block does not.
Density equals weight per volume. If you increase the volume without increasing the weight, the density will go down.
Exactly my point, the volume doesn’t change in the example provided. Weight and volume stayed the same. We either need to expand Godzilla or it needs to eject some mass.
You’d be right if the cavity is only compressing other organs inside the body without changing the overall volume, but I don’t know why you seem to insist on making that assumption.
I thought it would be clear from my original description, via the analogy with lungs, that the cavity would not squish the internal organs but rather expand the overall volume of the body.
I made that assumption because lungs aren’t really inside, they are pretty close to the surface, so they are easy to expand. If they were inside, they would have to push other organs away.
And regarding increasing the overall volume of the body, I addressed that in another comment. Basically, Godzilla would have to visibly swell by a lot, to have that much buoyancy.
It could be that the swelling is only in the underwater part, but then Godzilla would tip over with any slight movement, because the center of mass would be way above water.
Yes, but birds are very light in general. Most of their volume is feathers and they have a low bone density to boot. As the result, they have a very hard time diving, and have to either dive at high speed or paddle really hard to stay underwater.
And regarding boats, it depends. Do you mean completely empty passenger boats? Then yes, their density is very low by design, because they are mostly empty on the inside. When fully loaded, a commercial cargo vessel, is 80-90% under water.
When fully loaded, a commercial cargo vessel, is 80-90% under water.
Hahaha, no.
While I can’t find a comparable article for cargo ships, cruise ships are 10% underwater. A fully loaded cargo ship can’t be more than 30% as they tend to be stacked far higher than the ship’s sides. Ocean waves would easily swamp a ship that was 80-90% underwater.
My head canon for sea-based Kaiju is they have a sack of muscles somewhere inside their body that can expand a cavity, kind of like the diaphragm expands the lungs, except instead of taking in air or water it just creates a volume of vacuum inside of them. This makes them extremely bouyant relative to the surrounding sea pressure, so they rapidly ascend and can casually float like a boat near the surface.
But if they ever want to dive again, they just let that cavity collapse and all their bouyancy goes away.
To get unnecessarily scientific here, that wouldn’t change the overall density of the body, no? Even if there’s now a cavity with vacuum, the matter that was occupying that space just moved somewhere else within the volumes of the body and the overall density remained the same.
Now, if it pushed some matter out, air or water, and created a vacuum cavity, that might work. But I’m not an engineer, so correct me if I’m wrong.
A hundred ton steel ship floats, a hundred ton steel block does not. Density equals weight per volume. If you increase the volume without increasing the weight, the density will go down.
Exactly my point, the volume doesn’t change in the example provided. Weight and volume stayed the same. We either need to expand Godzilla or it needs to eject some mass.
You’d be right if the cavity is only compressing other organs inside the body without changing the overall volume, but I don’t know why you seem to insist on making that assumption.
I thought it would be clear from my original description, via the analogy with lungs, that the cavity would not squish the internal organs but rather expand the overall volume of the body.
I made that assumption because lungs aren’t really inside, they are pretty close to the surface, so they are easy to expand. If they were inside, they would have to push other organs away.
And regarding increasing the overall volume of the body, I addressed that in another comment. Basically, Godzilla would have to visibly swell by a lot, to have that much buoyancy.
It could be that the swelling is only in the underwater part, but then Godzilla would tip over with any slight movement, because the center of mass would be way above water.
Ducks and other waterfowl have the majority of their weight above the waterline. So do boats.
Yes, but birds are very light in general. Most of their volume is feathers and they have a low bone density to boot. As the result, they have a very hard time diving, and have to either dive at high speed or paddle really hard to stay underwater.
And regarding boats, it depends. Do you mean completely empty passenger boats? Then yes, their density is very low by design, because they are mostly empty on the inside. When fully loaded, a commercial cargo vessel, is 80-90% under water.
Hahaha, no.
While I can’t find a comparable article for cargo ships, cruise ships are 10% underwater. A fully loaded cargo ship can’t be more than 30% as they tend to be stacked far higher than the ship’s sides. Ocean waves would easily swamp a ship that was 80-90% underwater.