-
Asked by Chickenophile to Steven on 16 Jun 2015.
-
Steven Thomson answered on 16 Jun 2015:
The weird forces I talk about in my profile are the crazy quantum mechanical effects that happen to small particles at low, low temperatures. We have liquids that can run up the side of a glass, against gravity, and spill out onto the desk. Other liquids can go straight through the bottom of a solid glass, sneaking through tiny subatomic gaps.
Some particles do crazy thing. Imagine running into a wall – you’d bounce off it and land on the floor, right? But electrons can be fired into microscopic ‘walls’ and they ‘quantum tunnel’ right through them. Sometimes electrons can be in more than one place at once, and sometimes they communicate with each other faster than the speed of light, which is really weird.
I help figure out how and why these happen in magnetic materials, and how to use them. The main challenge in my field is something called superconductivity, which is when materials become perfect conductors of electricity, way better than normal metals. It only happens at really low temperatures, though. It’s got something to do with the quantum weirdness I mentioned above, all stemming from electromagnetic interactions, but no one really understands quite why it happens. If we figure out why, we can design better superconductors that work at higher temperatures, meaning more efficient energy generation and faster computers. (And even levitating trains, believe it or not!)
-
Comments
Chickenophile commented on :
Why do you need low temperatures for these crazy forces to take effect? @Steven
Steven commented on :
We need low temperatures because these forces are amazing, but very weak.
In most materials at normal temperatures, thermal fluctuations (a fancy term for heat) destroy all the weird quantum behaviour. Heat is the movement of particles: the hotter the material, the faster and more erratic the movement of the particles in it.
When materials are at normal temperatures, the particles inside them are shaking around like crazy and they’re hard to control. The quantum behaviour gets totally wiped out by the random movement of the particles due to heat. We cool the materials down because when we do this, the particles move slower and slower. Eventually, once it’s cold enough, all the motion from the heat is gone, and the only motion left is due to quantum mechanics. That’s when the weird stuff starts happening!
Ideally, we’d like to design new materials where we don’t need to keep them cold to study the quantum mechanics – this is a really hard challenge, but we’re working on it!