Daily Archives: 8th November

Why does metal feel cold?

One adjective commonly used to describe metals, along with the adjectives like “shiny” and “silvery”, is “cold”.

But this doesn’t makes any sense when you take the Zeroth Law of Thermodynamics into account. Over a long enough period, everything in the same location will tend* to the same temperature, so any metal must be at the same temperature as its surroundings.

So why does metal feel cold?

Metals feel cold because they are very good conductors. Both the metal blade and wooden handle of a shovel left out in the Sun will be at the same temperature but the blade will feel colder because the metal is a good conductor: it “sucks” the heat out of your fingers and this heat leaving your fingers is what makes them feel cold.

Fifteen minute timelapse of melting ice cubes.

In the video above identical ice cubes placed on a wooden board and a metal heatsink removed from a broken laptop computer melt at vastly different rates. The wood is a poor conductor and so the ice cube takes a long time to melt; the opposite is true for the metal heatsink.

* I’m using “tend” in the physics sense of “to approach” rather than the general public sense of “to occur frequently” or “to look after”.