Gravity runs the Universe. This free online course explains why, exploring gravitational waves, black holes and the Big Bang. What is gravity? This fundamental force is the common theme between concepts as intriguing as the Big Bang, black holes, dark energy, space-time, gravitational waves and the expansion of the Universe. If these concepts pique your interest, this free online course is for you. It doesn’t require any background in physics or mathematics, just a simple curiosity about the Universe and our place in it.