# Underwater physics



## Ireth (Nov 28, 2014)

I have a couple of questions about planned scenes for my WIP that focuses on merfolk. I'll try to keep things concise.

1) In one scene, the MC is imprisoned in a holding cell deep under the ocean. There's a large stone blocking the door, and a small window in one wall. How would water pressure affect the MC's attempts to escape? Given that merfolk are much stronger than humans, could she possibly push or roll the stone away from inside the cell? Or would it be wiser to squeeze out through the window?

2) Regarding the window question above, if said window is just barely wide enough to admit her, could she or someone helping her make things easier by lubricating the edges of the window somehow (similar to using butter to slide a too-tight ring off your finger)?


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## Queshire (Nov 28, 2014)

If the people who caught the MC are natives to the underwater would then I feel like they would know to account for the environment and the strength of the merfolk when they put the stone there. I feel like the window would be better. I think lubricating the window would work. Some sort of slime or goo? Sorry, I don't know enough to offer anything aside from my opinion.


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## Ireth (Nov 28, 2014)

Well, the MC's captors are merfolk as well, so naturally they'd plan out their holding cells accordingly. I was leaning toward the window as an escape route anyway. Now I just need to figure out what kind of slime/goo would lubricate the window best... The novel is set on our own Earth, with the only significant alteration of reality being the merfolk, so I can't really cheat with made-up plants and such.


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## Queshire (Nov 28, 2014)

How about something like mashed up slugs or other bottom dwellers?


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## Ireth (Nov 28, 2014)

Ooh, that could work! Thanks!


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## B-Raan (Nov 29, 2014)

Just so you now, algae is incredibly slippery!


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## psychotick (Nov 29, 2014)

Hi,

Is the inside of the cell filled with water as well as the outside? If so water pressure makes no difference since it's the same on both sides. If there's air inside the chances are the pressure would be trying to push the stone inwards into the cell. 

As for underwater slime, have you seen the goo that hagfish can release?

Cheers, Greg.


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## wordwalker (Nov 29, 2014)

Agreed, water pressure shouldn't matter. Now if there were no window and the rock was wedged in water-tight (and some of the water in the cell pumped or magicked out?) the water would help seal the "door" in, but not with this scenario--and that would leave the prisoners using up all the air in the water anyway, same as an airtight room.

A related question: have you thought about why your merfolk use windows at all? Some of the surface reasons still apply (ventilation, a view outside), but a major historical one was that sunlight was the only really decent light source we had until gaslights. And we had a thread a while back about merfolk light sources-- I think our options included better night vision, "shining undersea cities" with their own lights, and sonar and other lightless options. So the more your merfolk rely on the third, or the second (if they have sea-lamps for every room, not just big ones out in the "streets"), the less they'd assume they'd need windows.


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## Ireth (Nov 29, 2014)

Good points, wordwalker. Sonar is a moot point, since my MC is deaf and uses sign language to communicate with her pod members. They use the same sign language with her, and spoken words when they address others. The MC has a translator around for the duration of the story, useful when they encounter others who don't know their pod's sign language.

Better night vision is definitely an option. I'd also considered bio-luminescence -- does anybody know if an anglerfish's light would stay lit if it were removed from the fish and stuck on a merperson's wall somewhere for a lamp? Are there any other bio-luminescent creatures I could use?


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## psychotick (Nov 29, 2014)

Hi,

Loads of fungi and algae are bioluminescent.

Cheers, Greg.


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## stephenspower (Nov 29, 2014)

Following the thought of why a window, I would ask, What's the cell made out of? Cut stone? Why? And where did it come from? I like that a big stone is used as a door, but how is it held in place? Perhaps a better cell would be crevice in a reef in a which the stone would sit on (ideally the edges of the hole would be worn down so the rock could sit in the crevice like an egg in a cup, with the crevice too deep for the merman to use his legs to lift it off). I don't know what the world is like above the waves, but what if you used a sunken ship or sub retooled as a jail? That could be the basis for the reef, in fact, which might give the prisoner tools for escape that his jailers wouldn't expect.

As for light, what do the merman need it for? Why would a jailer want a prisoner to have light?


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