I can’t even begin to explain–or even understand for myself–how I got to be reading up on these things, but here are some things I’ve read about recently that I think are fascinating:

• MagLev Trains, which, instead of having wheels riding on metal rails, levitate on electromagnets. MagLev trains have reached speeds exceeding 300mph.
• The biggest obstacle with train speed now is air drag. And when air is harshing your mellow, what else is there to do but move into a vacuum? Vactrains, which don’t actually exist in production yet, are trains running in vacuums — tunnels “evacuated” of air — eliminating air drag and are predicted to be able to move around 5,000 mph.
• MagLev trains depend on superconducting magnets. I had assumed that superconductors were materials that were excellent conductors, which is partially correct. In actuality, superconductors have zero resistance. (Not “really small” resistance, but exactly zero resistance.) Seemingly like a lot of things that turn everything I thought I knew about science on its head, superconductors only exist when cooled to absurdly low temperatures approaching absolute zero, but this isn’t as big of a hurdle as one might assume, and they’re apparently common in scientific settings. Since they have no resistance, it’s possible to “close the loop” and have them just retain their strong magnetic charge.
• Superfluids are the liquid equivalent of superconductors, having absolutely no viscosity. The details are way, way over my head, but superfluids can do things like climb the walls of their containers and leak out. Here’s a more approachable introduction.
• Biochar is charcoal mixed into soil. It’s popular now because it’s a good means of ‘sequestering’ carbon rather than releasing it into the atmosphere. But, incidentally, it’s excellent for soil. It comprises one of the major components found in terra preta, extremely fertile soil found in the Amazon basin.
• Continuing on the super- line of thinking, there are superhydrophobes, substances which are exceptionally good at causing water (and other substances) to bead off. A common example is the Lotus effect, named after the Lotus plant. Water won’t stick to Lotus leaves, but, more interestingly, nothing really does: dirt and such are suspended on the surface. When water hits the leaves, the water droplets pick up the other contaminants, leaving the plant uncannily clean. There are countless obvious uses of superhydophobicity in real life, such as clothing. (Car wax?) Sto Corporation sells Lotusan paint, which claims to biomimic the Lotus plant.
• Aerogel is interesting, too. The nickname “solid smoke” is somewhat fitting its construction, though it’s not literally smoke. They’re the least-dense solid known, and are exceptionally good thermal and conductive insulators.