Does water stick too but we don’t notice?
In: Chemistry
The real parameter that rules the universe is heat, and heat transfer. Temperature isn’t even “real”. You don’t *feel* cold, you feel heat transfer, specifically heat transferring from you to your surroundings. Likewise, you feel heat transferring to you as warmth.
A key component of how heat moves around is how much heat is present in a thermal mass, and how easy it is for a material to give up heat or receive it.
Water is rather miraculous. It is capable of carrying *a lot* of energy in the form of heat. Skin is likewise miraculous. It is a decent biological heat shield, and does a good job of slowing the heat transfer through it. Humans are still most water, so we still have a decent bit of heat within us, but being as we are warm blooded, we retain heat and control how we release heat very methodically. Skin has the capability to transmit heat relatively slowly, and this is generally a good thing for us.
When you touch an ice cube, the temperature difference between your skin and the ice cube is great. The warmth of your skin immediately moves to the ice, cooling your skin and melting a little bit of the ice. But, as the seconds tick onward, heat from your body tries to heat up your skin again. This take time, because your skin naturally is a decent insulator, and resists how much heat can be passed through your skin to warm it back up.
The ice cube on the other hand, has a layer of cold but liquid water between it and your skin. Water is *really* good at transferring heat, so all the heat your body initially transferred to the ice to melt a bit of it gets transferred deeper into the ice cube. As this happens, heat is leaving the liquid water, and eventually it refreezes next to your skin. When the water was liquid, it could get all cozy with every little ridge or divot in your skin, and when it refreezes solid, it forms a perfect match with your skin and therefore is “stuck” to it. Your skin is also somewhat moist, so some moisture in your skin also cools down and freezes, further “sticking” the ice to your skin. Because your skin sucks at heat transfer, but water is really good at it, your body heat is unable to sustain the energy transfer necessary to keep the portion of the ice cube touching you liquid, and any heat you give the ice cube is unlikely to do anything substantial beyond just melting a tiny bit of water initially.
So, long story short, you end up with ice cubes that “stick” to you .
Latest Answers