What is the cosmological constant? How is the expansion of the universe related to quantum fields? How does a vacuum energy produce accelerated expansion?
What is a quantum state? How can two particles share the same state? What is entanglement, and does it really allow for faster-than-light communication?
Were the dark ages really dark? What is a perturbation, and how did they grow in the early universe? When the first stars awoke, what happened?
What does momentum have to do with rockets? Why are nozzles so dang important? What is a “potent mixture”, anyway?
What is the so-called “OMG Particle”? Where could it possibly come from, and how are magnetic fields involved? How can we detect these cosmic rays?