Stephen Hawking thought a form of string theory could be our best bet for a 'theory of everything'.
While we know that dark matter exists, we have no idea what it is. Luckily, there is no shortage of suggestions.
Running the world's largest particle accelerator requires a lot of energy, but it could reveal the secrets of the universe.
Subatomic particles have shaped and continue to shape our universe but despite perfect predictions by physicists, the theory about unseen particles is still wrong.