What is the temperature of fire?

What is the scale for fire (temperature vs. color)?

• i think yellow fire is the coolest but how does the rest of it go? some people say that blue fire is the hootest while others say it's white. what is it really?

• Answer:

  Hi there, Temperature vs colour goes red, orange, yellow, green, blue, violet. It is simply the spectrum of light (think rainbow) because that is what it is based on. So red light is actually the coolest, and as you go up the temperature scale, you run through the spectrum to violet. White light is a combination of ALL the different colours of light, so something which glows white hot is just releasing all different levels of energy, so it appears white. So in actual fact, blue (or more accurately violet) is hotter, because if something is blue hot, then it is releasing ALL really high levels of energy, but you rarely get anything which is completely blue hot - there is almost always some sort of mixture, and usually, the object glows white tinged with blue (which just means that the object is releasing all different levels of energy, but predominantly or mostly blue!) Just for your interest, the way this works is, when you heat something up, you are exposing it to invisible energy called "infra red" which is just heat. So when you touch something and it feels hot, you are simply sensing infra red energy! This energy is "weaker" than light (so light is actually more energetic than heat), but if you let an object get hot enough, it stops being able to release the heat as just infra red and starts to release it as visible light. The hotter the object gets, the further along the spectrum is the light emitted. Actually, if the object absorbs enough energy it will start to release Ultra Violet (UV) and X-Rays!