This is the coolest, spookiest thing I have ever seen. A single photon is caught on film using a camera that shoots at a ridiculously high speed. The image is amazing. The applications are many but surprisingly the study of photons and it's properties was not listed.
What once was impossible is now visible. We can view single atoms and experiments have shown quantum mechanics in action. A hundred years ago Quantum Mechanics was just a bold theory that most physicists thought couldn't be proved with observation. Maybe in another hundred years we will be able to observe the predictions of String theory.