What is Quantum Gravity? | COSMOS in a minute #25

Quantum gravity is the hardest problem in physics. It's the attempt to unify the two pillars of modern physics: quantum mechanics and general relativity. It's the study of how gravity works at the quantum level, where the laws of physics are very different from what we experience in everyday life. One of the biggest challenges in quantum gravity is that gravity is the weakest force in nature. It's so weak that it's impossible to study for particles in the lab. We can only see its effects on very large objects, like planets and stars. Scientists have been working on quantum gravity for decades, but they haven't been able to come up with a complete theory. So it remains one of the biggest unsolved mysteries in physics, one that scientists are determined to solve. For more videos of Cosmos in a minute, follow The Secrets of the Universe. #cosmosinaminute