Superconducters

Introduction to Resistance

The reason why super conductance is a cool topic to learn about is because of electrical resistance (link here). Electrical resistance is basically what causes things to wear out and devices to need to be replaced. You can "feel" it or see properties of it if you've ever felt a circuit, or even a laptop that's extra hot after long periods of use. It can easily be thought of as the obstacles that prevent water from flowing in a pipe, with water being the electrons. The material that the pipe is made of could present issues, as well as the size and shape of the pipe. For the most part, water will flow more slowly through a pipe than it would without a pipe.

The problem of electrical resistance has a lot of potential to create really cool electrical devices for the future. It's somewhat analogous to friction from physics 1 in the sense that it slowly leaches energy from a system until it reaches zero. Just like how without friction, you could kick a ball around the world without it stopping or slowing down, without electric resistance, you could create a circuit that would have a current flowing forever. This has really cool practical applications and could create all sorts of new technology for the future- imagine devices that didn't need to be charged, or super low energy prices. More on this later.

How a Superconducter Works

When you lower the temperature of a metal, its resistance will decrease. You could demonstrate this by taking a basic circuit and freezing it- because of ohm's law, the bulb would start to glow brighter since there is a lot more current flowing through. (V=IR, lowering R will raise I which will raise brightness). For most materials, taking them to absolute zero (or really close) will cause the resistance to decrease to almost zero, but not quite. However, some materials, superconductors, lose all resistance to current. The difference between "almost zero" and "actually zero" is enough to give rise to some cool properties of superconductors.

Obviously, having to cool something down to absolute zero, or very close, creates a lot of problems from a research standpoint alone. Some superconducters can exist under their particular critical temperature.