There is a group of materials called “superconductors”.
A normal conductor allows the flow of electricity in the form of a current. But even the best conductors resist the flow of current – and this leads to energy losses in the form of heat (think of a laptop or computer getting hot – this is why they have a cooling fan).
A superconductor has zero resistance – this means that a current can flow with zero energy losses. But there’s a catch: a superconductor must be cooled to very low temperatures before it has this property. The best superconductor discovered to date works at -70 degrees Celsius! And this is called a “high-temperature” superconductor!
The discovery of a superconductor which works at room temperature will change the world. Energy could be transported great distances without losses, electronics wouldn’t get hot and waste so much energy, superconducting batteries can story energy forever.
Maybe the coolest thing is the effect on travel. Another property of superconductors is that they repel magnetic fields – this means that a superconductor will float or levitate over a magnet (google superconducting magnetic levitation – you won’t be disappointed). So you can imagine a train that floats above the track and travels without friction on a cushion of air. Magnetically levitating (maglev) trains have already been developed and have reached incredible speeds of more than 600km/h (375mph)!