Jonathan,
Congratulations on getting your 10th community vote! The last part of my trilogy "This Is Physics" has been stuck at 9 votes for a few days, and since you left a comment (and presumably a vote) on part 2, I am trying my luck with you! The last part of my video deals with the incompatibility of General Relativity and Quantum Mechanics, and lists some of the open questions (but by no means all) that Physics will have to tackle in the future. I hope you enjoy it! Here's the direct link:
Thank you, and good luck in the contest!
Marc