What problem in physics would you like to be solved?

A total understanding of time.

although, i think when we really understand time, it will lose some of its mysticism, and people will be surprised by why we thought the way we did.

The obvious ones are the important ones. Unifying macro and micro phenomena (that is to say reconciling quantum mechanics with cosmology), and finding the Higgs Boson.

@pdworkin: Sorry to report that Milo just ate the Higgs’.

He’s a piggy, not a kitty.

True, but he is working on the unified field theory in his spare time.

(If you get lonely, open the window and yodel towards the NW.)

Creating/harvesting antigravity

Look up a Faraday Motor

A magnetic field and a current running at right angles produces a force at right angles to both the current and the field. In real life the wire is pushed one way and the magnet is pushed the opposite way, in accordance with Newton’s Third Law, “Every action has an equal and opposite reaction.” In a Faraday Motor the magnet is glued or bonded to the rotor and it still turns. In the videos linked above you can clearly see that there is no force in a direction opposite to the rotation of the disk. So where is the equal and opposite reaction?