Heat moves from one place to another in three main ways: conduction, convection, and radiation. Knowing how these methods work helps us understand how we can feel heat even if we don't touch something directly.

1. Conduction

• What is it?: This is when heat travels through direct contact between materials.
• Example: Think about when you put a metal spoon in a bowl of hot soup. The heat moves from the soup to the spoon.
• Important Point: Conduction works best in solids, especially metals. This is because metal particles are packed closely together.
• Fun Fact: Copper is one of the best conductors of heat, with a measure called thermal conductivity of about 400 W/m·K.

2. Convection

• What is it?: This type of heat transfer happens in liquids and gases. Heat moves when hot parts of the fluid rise and cooler parts sink.
• Example: When you heat water, the hot water at the bottom rises to the top, causing a movement in the water.
• Important Point: Convection needs the fluid to actually move around.
• Fun Fact: The rate of heat transfer in convection can change based on how fast the fluid is moving and the temperature difference. This is described by Newton's law of cooling.

3. Radiation

• What is it?: Unlike the first two methods, radiation doesn’t need things to touch or a material to pass through. It moves heat using invisible waves.
• Example: The warm feeling you get from the sun is because of radiant heat.
• Important Point: Every object gives off and takes in thermal radiation, depending on its temperature and surface.
• Fun Fact: The Stefan-Boltzmann Law shows how this works. It tells us how much power a hot object gives off.

In short, while we often think of heat through touch, radiation lets us feel warmth from afar. This shows the amazing ways heat can travel between different objects.