De Niro x Pacino, and one of the all time great movie scenes. The iconic Heat (1995) is now streaming on Netfix UK/IE. | Netflix

What is heat, really? 🌡️ We usually think of heat as just “warmth” — like when it’s cold and someone says “turn up the heat.” But in physics, heat has a very specific meaning. Heat is the transfer of energy that causes a temperature change. And that energy can move in three different ways: 🔥 Conduction When a hot object touches a cooler one, energy flows through direct contact — from hot to cold. 🌬️ Convection This happens in liquids and gases. Warmer material rises, cooler material sinks, an