Question: What is quantum physics?

Monique Henson answered on 19 Nov 2015:

Quantum physics is the laws that describe really small things – typically things on the atomic scale or smaller. One of the key ideas in quantum physics is that light is quantized – that means it comes in packets of energy called photons. Each photon carries an amount of energy that depends on its wavelength (color). Photons with a higher wavelength (bluer light) have more energy than those with a smaller wavelength (redder light).

Some of the ideas about quantum physics can seem really weird. Even though they’re really strange, they often turn out to be really useful. Scientists use quantum physics to design better electronics, lasers and medical scanners (like MRI machines).