Convection is the movement in a gas or liquid caused by warm fluid rising and cooler fluid sinking. The moving fluid carries heat with it, so the warmth is not sitting still.

Convection對流 is the movement in a gas or liquid是氣體或液體裡的一種運動，caused by warm fluid rising and cooler fluid sinking由溫暖的流體上升、較冷的流體下沉所造成。 The moving fluid carries heat with it流動的流體會把熱帶著走，so the warmth is not sitting still所以熱不會停在原地不動。

This is how a room warms above a heater, how soup starts to roll in a pan, how some winds begin, and — on a huge scale — how rock in the Earth's mantle slowly turns over. You meet the word in physics and earth science.

This is how a room warms above a heater這就是為什麼房間裡暖氣上方會變暖，how soup starts to roll in a pan湯在鍋裡會開始翻滾，how some winds begin有些風是這樣形成的，and — on a huge scale — how rock in the Earth's mantle slowly turns over而規模放大到極致，就是地函裡的岩石慢慢翻動的原因。 You meet the word in physics and earth science你會在物理和地球科學裡遇到這個字。

Though actually, everyday English stretches it a little: a convection oven is just an oven with a fan that blows hot air around. That fan is not the same thing as warm air rising on its own, but cooks still call it convection because the air is moving and carrying heat.

Though actually不過其實，everyday English stretches it a little日常英文把這個字用得寬鬆一點：a convection oven a convection oven旋風烤箱，is just an oven with a fan that blows hot air around就只是有風扇把熱空氣吹來吹去的烤箱。 That fan is not the same thing as warm air rising on its own那個風扇跟暖空氣自己上升不是同一回事，but cooks still call it convection但廚師還是叫它convection，because the air is moving and carrying heat因為空氣在流動並帶著熱。

Heat also moves by conduction (through a still object, like a metal pan handle) and by radiation (as rays from the sun or a fire). Convection is the 'the fluid itself is moving' way.

Heat also moves by conduction熱也會透過conduction傳導移動，through a still object, like a metal pan handle像是透過靜止的物體，例如金屬鍋柄，and by radiation也會透過radiation輻射，as rays from the sun or a fire像太陽或火發出的光線那樣。 Convection對流 is the 'the fluid itself is moving' way就是「流體本身在動」的那種方式。