Lifeboat Foundation

We teamed up with the folks behind BBC World Service’s CrowdScience to answer your questions on one topic — this week it’s all about living underwater.

[Tom Clancy]’s The Hunt For Red October is a riveting tale of a high-level Soviet defector, a cunning young intelligence analyst, a chase across the North Atlantic, and a new submarine powered by a secret stealth ‘caterpillar’ drive. Of course there weren’t a whole lot of technical details in the book, but the basic idea of this propulsion system was a magnetohydrodynamic drive. Put salt water in a tube, wrap a coil of wire around the tube, run some current through the wire, and the water spits out the back. Yes, this is a real propulsion system, and there was a prototype ferry in Japan that used the technology, but really the whole idea of a caterpillar drive is just a weird footnote in the history of propulsion.

This project for the Hackaday Prize is probably the closest we’re going to see to a caterpillar drive, and it can do it on a small remote-controlled boat. Instead of forcing water out of the back of a tube with the help of magic pixies, it’s doing it with a piston. It’s a drive for a solar boat race, and if you look at the cutaway view, it does, indeed, look like a caterpillar.

Instead of pushing water through a tube by pushing water through a magnetic field, this drive system is something like a linear motor, moving a piston back and forth. The piston contains a valve, and when the piston moves one way, it sucks water in. When the piston moves in the opposite direction, it pushes water out.

As swimmers know, moving cleanly through the water can be a problem due o the huge amounts of drag created — and for submarines, this is even more of a problem.

However, US Navy funded researchers say they have a simple solution — a bubble.

Researchers at Penn State Applied Research Laboratory are developing a new system using a technique called supercavitation.

I know it’s an old movie (and it was an even older book before that), but I want to look at the physics of the special submarine drive in The Hunt for Red October. In the story, the Russians build a so-called “caterpillar drive” using hydro-magneto power instead of the traditional propeller. This new drive is way quieter than the traditional type—so quiet that it could sneak up on the United States and blow it up. Spoiler alert: It doesn’t.

Here is the cool part: This magnetohydrodynamic drive, which turns water into a sort of rotor, is a real thing. (Although technically in the book version this drive is something other than magnetohydrodynamic. Quibbles.) In fact, it’s pretty simple to build. All you really need is a battery, a magnet, and some wires. Oh, also this will have to operate in salt water, so you might need some salt. Here is the basic setup.

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The more we learn about the microbiome, the more the pieces are fitting together.

Report that natural gas is just as bad as coal due to rampant methane leaks which cause global heating.

If scientists could find a way to control the process for making semiconductor components on a nanometric scale, they could give those components unique electronic and optical properties—opening the door to a host of useful applications.

Researchers at the Laboratory of Microsystems, in EPFL’s School of Engineering, have taken an important step towards that goal with their discovery of semiconducting nanotubes that assemble automatically in solutions of metallic nanocrystals and certain ligands. The tubes have between three and six walls that are perfectly uniform and just a few atoms thick—making them the first such nanostructures of their kind.

What’s more, the nanotubes possess photoluminescent properties: they can absorb light of a specific wavelength and then send out intense light waves of a different color, much like quantum dots and quantum wells. That means they can be used as fluorescent markers in medical research, for example, or as catalysts in photoreduction reactions, as evidenced by the removal of the colors of some organic dyes, based on the results of initial experiments. The researchers’ findings have made the cover of ACS Central Science.

An apple a day won’t keep the doctor away for much longer. CO₂ pollution is sucking the nutrients out of our healthiest foods. #YEARSproject

Here’s a billion-dollar question. How do we transform our systems of food production and distribution, so that we can produce food much closer to where it’s consumed and therefore reduce food miles, food waste and our impact on the environment?