How Hot Electrons Get Cool
It’s a hot summer day. You desperately want something cold to drink, but unfortunately, your bottle of root beer has been sitting in a hot car all day. You put it into a bucket full of ice to cool it down. But it’s taking forever! How, you wonder, could you speed the process up? The same question is important for understanding how electronic devices work, and how we can make them work better by controlling the temperature of the electrons that power them. Read on to find out what a bottle of root beer in a cooler full of ice and a nanowire in a vat of liquid helium have in common!
Use a laser pointer to measure the thickness of your hair!
Have you ever wondered how scientists can accurately measure the size of very small objects like molecules, nanoparticles, and parts of cells? Scientists are continually finding new ways to do this, and one powerful tool they use is light scattering. When an incoming beam of light hits an object, the light "scatters," or breaks into separate streams that form different patterns depending on the size of the object. This incoming light might be visible light, like the light we see from the sun, or it might be higher-energy light like X-rays. The light from commercial laser pointers, it turns out, is perfectly suited to measure the size of a human hair!
Ketchup and oobleck and slime, oh my!
Why do so many fluids behave counterintuitively? Many substances in our lives – like oobleck, slime, or Silly Putty – don’t quite behave the way we expect a fluid to, despite some fluid-like properties. These substances fall into a special category: non-Newtonian fluids. Scientifically, this term is a bit of a catch-all for any substances that have a complicated relationship between their apparent viscosity and the force applied to them.