Heat changes the shape of matter and when a solid is heated, its atoms vibrate more intensely and push each other farther apart. This causes the object to expand, not just in one direction, but uniformly in volume. In this case, the metal ball grows slightly after being heated by Prof. Lewin. Then Lewin places the hot ball on the cool ring and heat flows from the hotter object (the ball) to the colder one (the ring): ❄️ As the ball cools, it contracts. 🔥 As the ring warms, it expands. Eventuall