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Assyrian soldier diving with an inflatable goatskin bag (ca. 865–860 BC)

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Re: Assyrian soldier diving with an inflatable goatskin bag (ca. 865–860 BC)

#51
post #49

Earlier quoted context omitted.

Swords and armour are heavy.

As soon as you breathed in the air from the skin, you would lose the buoyancy form it and sink to the bottom.

Umm, what do you think happens to the air in that skin when you breathe it? It goes into your body, and continues to provide buoyancy.

Re: Assyrian soldier diving with an inflatable goatskin bag (ca. 865–860 BC)

#52
post #38

Earlier quoted context omitted.

Why have an inflatable goatskin that you're inhaling from for swimming on the surface? Considering the fish next to him it seems more likely the artist left out the boring aspects of holding rocks or whatever to reduce buoyancy.

Did you also consider the horse depicted below the fish?

Horses and the sea have a long history.

Re: Assyrian soldier diving with an inflatable goatskin bag (ca. 865–860 BC)

#54
post #49

Earlier quoted context omitted.

As soon as you breathed in the air from the skin, you would lose the buoyancy form it and sink to the bottom.

Umm, what do you think happens to the air in that skin when you breathe it? It goes into your body, and continues to provide buoyancy.

People exhale too.

Re: Assyrian soldier diving with an inflatable goatskin bag (ca. 865–860 BC)

#55
Using inflated animal skins as floating devices is rather old and widespread tech.

Floats: A Study in Primitive Water-Transport: https://www.jstor.org/stable/2844455

Animal Skin Floats : https://www.iro.umontreal.ca/~vaucher/History/Prehistoric_Cr...

Roman military pontoons made from inflated animal skins: https://www.researchgate.net/publication/291033772_Roman_mil...

Sheepskin rafts are known in China since the Han Dynasty (206 B.C.-220 A.D.)

The Assyrians did use inflated animal skin for their rafts. https://www.researchgate.net/publication/323672056_The_Refle...

By the way, the tech may save your life: https://www.artofmanliness.com/articles/how-to-turn-your-pan...

Re: Assyrian soldier diving with an inflatable goatskin bag (ca. 865–860 BC)

#56
post #41
post #17

Earlier quoted context omitted.

Not regularly and only very shallow so my recall of the details isn’t great. But I do recall asking about even slower breathing and the response was it extracted more oxygen but wasn’t recommended due to the risks of disorientation. I think the 2x was in relation to failing to do slow deep breathing though. As a sanity check 6l of air per minute x 5minutes is 30l which is about the size of your torso. Assuming that b…

> The volume would decrease rapidly with depth but the available oxygen per breath would increase to compensate. > Unless you have something specific to correct? Firstly, how would you bring the highly buoyant bubble of air underwater, in a controller manner? But let's say, for the sake of argument, that you could. Even though the volume of the bubble would indeed decrease with depth (e.g. it would halve at 10m), the…

I am not saying it’s practical or their going to spend time at significant depth. The utility might have been a simple game of who could stay under water longer. That said, spending noticeably longer at 5-10m with an air filled bag weighted down by stones is a very long way from oxygen toxicity or the bends.

As to available oxygen, removal of CO2 is major limitation in the long term and that’s limited by partial pressures so having more available oxygen doesn’t help in the long term. However, the world record for holding your breath is 22 minutes on pure oxygen so if we are talking a 7 minute vs 12 minute dive CO2 is going to be irrelevant.

Re: Assyrian soldier diving with an inflatable goatskin bag (ca. 865–860 BC)

#57

You cannot dive with an inflated goatskin, unless you carry extra weight, like stones.

I think you are right and the depicted soldiers are not diving but floating. Maybe they carried their weapon in the bag, they all seem unarmed. Also I was wondering why they would continuously have to blow air in the sack. Probably they weren’t airtight.

Re: Assyrian soldier diving with an inflatable goatskin bag (ca. 865–860 BC)

#58
post #33

Earlier quoted context omitted.

I would too. Unfortunately, the last Assyrian historians died nearly 3000 years ago.

There are still Assyrians today, they are a persecuted Christian minority in the lands currently disputed between Shia and Sunni factions. https://en.wikipedia.org/wiki/Assyrian_continuity

That was a fascinating article. Thank you!

Re: Assyrian soldier diving with an inflatable goatskin bag (ca. 865–860 BC)

#59
post #49

Earlier quoted context omitted.

As soon as you breathed in the air from the skin, you would lose the buoyancy form it and sink to the bottom.

Umm, what do you think happens to the air in that skin when you breathe it? It goes into your body, and continues to provide buoyancy.

So the person doesn't inhale deeply and hold their breath beforehand, and submerges with empty lungs? That seems, well, not ideal.

Re: Assyrian soldier diving with an inflatable goatskin bag (ca. 865–860 BC)

#60
post #29

Earlier quoted context omitted.

That's about the size of my torso, but I'm fat as hell. I suspect the average ancient swimming warrior was in better shape.

Unless your short your estimate seems odd. The torso is about 1/2 the volume of the average adult and people are close to the density of water of 1kg/l or 2.2lb/l. So 30l would be the expected torso volume of someone weighing ~60kg or ~130 lb. Edit: “47% trunk and neck” so 40% torso would be 75kg and 165lb seems reasonable as a smaller person would also need less air.

30L is 8 gallons. The average torso is somewhat longer than a five gallon bucket, but of course it's much slimmer than a five gallon bucket. An eight gallon bucket, if it existed, would be larger yet. I would question both the assumption that a torso is half the volume of a human and the further assumption that the density of humans is uniform. Obviously the thorax, which contains the lungs, is less dense than the legs, which just have muscles and massive bones with a thin layer of fat.

Sorry it took a while to respond; I got rate-limited this morning.

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