Unrevolutionary Scuba Mask

Wow Such Technology

I saw a popular and highly upvoted gallery on imgur, and it bothered me.

It was about this: http://www.yankodesign.com/2014/01/03/scuba-breath/

Dubbed as a "great" advancement in technology, it claims, like the imgur gallery did, to allow humans to breathe underwater without an air tank.

People lie on the internet all the time, but the only thing that really bothers me is popular pseudoscience. This is pseudoscience.

As a physicist and certified diver who enjoys talking about science to the masses, I thought I would take some time to debunk this using concepts everybody can understand.

This is the ocean. The ocean has oxygen. I accessed the World Ocean Atlas's dissolved oxygen data to find out how much. About 0.21 mol O₂/m³. This is the oxygen we need to filter out.

This is a human*. (* actually, this is an Olympian. They are basically super humans.) Humans need air. Every time an adult one takes a breath, it breathes approximately 500 mL of air.

However, we don't have air. All we brought was this. Somebody thought that was a good idea. All of our air needs to come from this. Now, the deeper we go underwater, the higher the pressure is, and the more air we need to breathe in the same volume. Let's assume we're diving 10 meters (~32.8 feet) underwater. And no deeper, because things are only going to get worse from here.

This is the backup equipment you should bring if you want to try this device.

After doing some physics stuff, I found that for EVERY breath you take 10 meters underwater at 25 °C, we would need to filter the oxygen from 190.3 Liters of water (50.3 US Gallons) at 100% efficiency to take a breath. Now, one should note that you need significantly less oxygen than this per breath, but you still need to intake 500 mL of gas to avoid gasping for air.

A quick calculation determines that at slow, controlled breathing rates (12 breaths per minute), the device would need to filter 38 liters of water per second (10 US gallons per second) to meet our required air supply.

I hope you can appreciate just how much (and how fast) water (and everything swimming in it) would have to flow through your face for EVERY breath you take to be able to use this device when it operates at 100% efficiency.

Now, I would be a bad scientist if I didn't try as hard as I damned could to make this thing reasonable. So, I introduce the rebreather.

Rebreathers are devices that abuse the fact that one only uses a fraction of the oxygen breathed in per breath. Instead of exhaling your breath into the water, rebreathers absorb the exhaled carbon dioxide and store the remaining oxygen in a tank to be reused.

While rebreathers can significantly reduce the amount of oxygen our device would need to take in, after more math, I still found the rate at which the device would need to filter water to be wholly unrealistic.

This is not a thing, and will not be a thing. Perhaps even MORE damning to the concept than the reasons I have mentioned is the medical toxicity issues associated with breathing pure oxygen (these issues get exacerbated under water pressure!) However, I focused this exposé on the physical reasons this device is gloriously inconvenient. I encourage readers interested in the medical aspect to look up a study on breathing 100% oxygen.

I hope, if anything, you learned something. Don't take my word for it, learn the physics!

I created an account just to point out how ridiculous this is, and I will now always downvote pseudoscience.

If people enjoy it, I might debunk some other crap I see.

Misc. FAQ - wordy : https://ghostbin.com/paste/8y8t7

I don't own any cats or see any ass, so here's a picture of my lab. The thing in the top right is a muon (of cosmic ray origin) detector.

The big thing is called the El-Vacatron. It's named after a local Mexican restaurant. It makes radiation.

Sitting on the El Vacatron to the left is a hot air rework station. (For reworking solder joints or shrinking heat shrink) Somebody was using it and was lazy, so they set it on the El Vacatron. It wasn't me. OK, it was me.

Don't worry, that's a duck taped lead block in the bottom right over the hinge. It's safe.