Memory defines us. Memory is the basis of our sense of self. But how do the structures of the mind store memories? What changes do memories imprint on the brain? …

Albert Einstein shattered previous ideas about time, but left many pivotal questions unanswered: Does time have a beginning? An end? Why does it move in only one direction? Is it real, or something our minds impose on reality?

There are many types of telescopes used in astronomy, but X-ray telescopes offer a view of the cosmos that reveal just how much of a living ecosystem the universe is. …