Why is it that if we wet our fingers before putting out a candle, we don’t get burned, but if we grab a hot pan out of the oven with a wet oven mitt, we get burned?
In: Physics
This is two different things: thermal mass and conductivity.
The moisture you give your fingers to put out the candle provides them with enough thermal mass to absorb the energy from the candle, without dramatically changing the temperature of the water (the water can absorb a lot of energy without changing temperature) Also the water is a better conductor than your skin, so it spreads the energy across the liquid much better.
When you wet an oven mitt, you turn what should be insulating you from the heat into a better conductor, and the heat travels through the water in the glove to burn your hand.
I learned a similar lesson after bringing socks to the beach to help walk across the hot sand. I went back to our house at one point and thought it would be “really smart” if I dipped the socks in the cool pool water before heading back on the burning sand to our site. Big mistake.
You don’t even need to wet your finger to put out a candle. I never did and it barely feels warm.
Warmth and temperature are not the same thing.
A candle might be a few hundred degrees, but it doesn’t radiate (much) thermal energy. The wet on your hand will be enough to quell that intense – but small- energy source.
But the hot pan, despite having a lower temperature, is larger, and had more thermal energy in its metal/Pyrex structure. That abundance of heat is enough to shluck through a wet mitt through conduction. The heat from the over pan cannot be quelled by a soggy mitt, so instead that thermal energy agitates the water, making it hot, and soon enough the heat conducts through.
A good mental thought experiment that could help with understanding is to ask “How much volume of water will it take to cool down this hot object?” Framing a question like that makes you begin to consider the energy content of the hot object, not necessarily its temperature.
In fact, it is known that the temperature at the hottest part of a candle’s flame can be up to 2,500 °F, yet the flame could be put out by a single drop of water. Hence a wet finger is protected when touching a candle flame. But you can imagine that a hot pan out of the oven will be barely affected by a drop of water. The hot pan has tremendously more energy content than a flaming candle.
So THAT is why I burned my hand 5 minutes ago making pizza. The glove was wet. I didn’t know you get burnt that way. Thanks
Oh dude. I was drunk and stoned a few weekends ago and grabbed a red hot cast iron pan with my bare fucking hand. The skin is still peeling off
If you take an iron pan out of the oven and throw water on it, it will immediately will turn to steam. FWOSSH! The same thing happens when you put a damp mitt on it. The water in contact with the metal will turn to steam very quickly and hit your fingers super hot. It depends on the ratio of the metal type, how hot it is and how much water the mitt is holding. If you have a lot of water and low heat, you are fine as the water can take it without turning too hot or even flash into steam. But if you have lots of heat and low water, the water will be “overwhelmed” and burn you.
Because the heat stored energy in the pan is magnitudes greater than that in a candle, and the conductivity of metal is vastly greater than a wick.
This dude wants to know why you can’t just blow out a bonfire but you can a birthday candle
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