If you can trap and drown a fly, you can then cover the dead fly with salt, which will suck the water out of the fly, and bring the “resurrected” fly back to life.
The relevance here: it is surprisingly difficult to drown a fly, because the weird hairs around their bodies create an air bubble around them, which protects them. A fly in a bubble of air can survive for at least 20 minutes underwater. Released, they will float to the surface inside this bubble and fly away.
Don’t ask how I know.
Why am I not surprised?
Can’t say I condone this, it seems rather cruel.
I was playing devil's advocate for a bit, there are much crueler things one can imagine. Freezing and unfreezing like this has been the dream in much of sci fi. And it doesn't cause any harm or difference at the end?
...The buoyancy provided by superhydrophobicity scales
with surface area, while the mass of a ship scales with
volume, so this can only ever work for roughly coin-sized
Precisely because it can result in excellent comments like the current top comments on the article.
Providing an opportunity for experts to exercise critical analysis is a good thing and an excellent teaching/learning opportunity.
Fresh or saltwater, any vessel is subject to corrosion and the accumulation of grime (or worse, like barnacles). In the demo video, note that the demonstrator is using gloves and isn't even touching the "coin" directly, but using tweezers.
1) either engrave the inner surface of metallic parts in airplanes or spatial stations with a microscopic pattern allowing the recognition ot metal scrapes stolen or found in the sea after an accident (hours count and you could be searching in the wrong area). This could accelerate a lot the identification of the remains and help identifying corpses found next to some metallic part. Many metallic parts are hollow and as long as the pattern is placed in inner surface (inside a tube for example) would not create any problem with dirt, paint or gloss of the final product. That could be a real application.
2) or try to engrave the outer surface to make the airplane surface smoother without losing too much efficience and properties. I assume that this in hands of a competent engineer could reduce a little the noise emited by the airplane.
3) same as point one, but for guns and weapons would be also really useful
> The [metal floats because they use] bursts of lasers to "etch" the surfaces of metals with intricate micro- and nanoscale patterns that trap air and make the surfaces superhydrophobic, or water repellent.
Anything with tiny pores put on the sea will either be covered in life in weeks, or will need anti-fouling painting to avoid rust and life (distroying the effect), or this pores will be filled with lime and mud in no time. A ship hull that is not easily cleanable and can't be polished is creating many new problems.
I could be wrong but translating this to the real life applications seems really complicated to implement. Specially when you can just create a sealed metal box filled with multiple air cameras or a buoy.
My question with this, is that if an air bubble is formed against the surface of the material and thus the water is not touching the surface.. how does the life inside the water attach itself to the surface which it does not touch?
If something gets into even one pore and starts displacing air, that would be enough to break equilibrium, right?
If you are completely engulfed in air you're like a diver underwater achieving neutral buoyancy, the same kind of thing as a perfectly balanced balloon. So you're floating in air rather than on air.
Huh? Half the article talks about how they maintain buoyancy while submerged and why that's important.
You don't need a boundary, and it wouldn't help you if you did. You still need to displace the same amount of air.
The only way on/in makes a difference is if you have some way to prevent the fluid from going around you. You'd have to be tightly jammed inside a tube for that.
The tech. described in TFA sounds like something that would make for an awful bottom coat, since such surfaces tend to promote growth by providing something attachable.
Would be nicer to just point lasers and the existing cans or glass bottles and be done with it.
So I would prefer nanoengineering to manipulate surface tension.
Nanotoxicity is a very poorly understood field and any nanomaterials are at the very least likely to flake away bits that are similar to asbestos.
One is only relevant at hundreds of degrees, so it's a pan problem and not a can/bottle problem.
The other is a separate chemical that's sometimes used in the production, and the solution is simply to not use that chemical.
So not perfect, but pretty good!
If it were that simple then they would already not be using it
Yeah, did you read the link? "several manufacturers have entirely discontinued its use"
But also your statement isn't really true as a general rule. Sometimes it's very straightforward to avoid an ingredient but it costs half a penny extra.
And after a week these etchings will be covered by sealife and won't work anyway.
I do see your point. This is easier to envision on a smaller scale in production, however. In theory, if it works for a small vessel, it should also work for a larger one. Although I don't see large sea-bearing vessels changing any time soon.
Either way, innovation is cool...and it always starts somewhere.
Another way to think about it is specific weight. Ships have fewer kilograms per cubic meter than water does so they float. When pierced they start filling up with water which makes their specific weight go up and eventually become more kilo per cubic meter than water. At that point the ship sinks.
But why so complicated? A 10cm metal hull seems much safer than a 5mm opening with hydrophobic coating.
Also with a chamber system ship's can be made pretty robust and almost unsinkable.
In practice this is something that's actually done quite a bit. Fill a lot of air spaces in a boat with foam and you get to the point where if your boat fills with water you can simply pull the plug in de bottom of the boat and it will un-sink itself most of the way. You see this for example on small sailboats, the only caveat being you can't be on the boat as it's un-sinking since you'd weigh it down.
That said, seems to me that foam is a lot cheaper and easier than micro-engineering every surface on the boat.
Also, an "unsinkable flotation device" can be made out of styrofoam?
There are other ways of trapping air between two pieces of metal.
I wonder how this compares against a sandwich of metal-bubble-wrap-metal. Or with styrofoam, or an injectable foam. It would also float. It would also withstand multiple punctures. I imagine it is cheaper than etching metal.
Come to think of it: they better make sure this bubble isn't influenced by some trivial chemicals, otherwise they don't need explosives to sink a ship...