The temperature of regular stuff is basically just a measurement of jiggliness of the atoms and molecules that make that stuff up.More jiggling,higher temperature,Less jiggling,lower temperature.Of course,when something's at a high temperature,it feels hot,and when something's at a low temperature,it feels cold.Right?mmmjhyyaaanot exactly.
If you touch a piece of metal and a book that have been sitting in your fridge,the metal will feel much colder than the book-Derek of veritasium did a great video on this,But you really have to try it for yourself to believe it!The metal and the book are honestly at the same temperature,as measured by a thermometer,but the metal FEELS colder.
This isn't just a trick of the mind,though,we experience the metal as "colder"than the book for a very physical reason:Metal is a conductor,and paper is an insulator,so the ENERGY,or jiggliness of the molecules in our hands,is absorbed more quickly by the metal than by the book.Even though the book and the metal are at the same temperature,the metal causes the temperature of our hands to go down faster and thus,we experience the metal as being colder,because the temperature of our hands is what we really feel.
It's like how,technically,a mercury thermometer really only measures its own temperature,And you can only indirectly measure temperatures of other things by putting them in thermal contact with it.Similarly,the thermo receptive nerves in our skin,can only directly measure the temperature of the skin itself and not of anything else.
So when we touch something,we don't feel its temperature,but rather,we feel its effect on our skin:that is,how much and how quickly it transfers thermal energy-that's the jiggling of molecules-to or from us.The capacity to transfer thermal energy is also,why a blast of steam from your stovetop,can feel so much hotter than a blast of hot dry air from your oven,even though the oven has a higher temperature:water vapor transfers more molecular jiggling to your skin than air by itself.
In fact,it's tempting to say that "hot"and "cold"are fundamentally different concepts from "high temperature"and "low temperature",even though we usually use the words interchangeably."Hot"really means "it gives off a lot of energy",while high temperature means"it has a lot of energy"and as anyone who's tried fundraising knows,just because somebody has a lot of something,doesn't necessarily mean they give a lot of it away.
实际上冷热和温度高温度低 是两个截然不同概念的说法听起来更有道理，尽管我们经常将二者混为一谈，“热”意味着“物体向外传递很多能量”，而温度高则意味着“物体所含能量高” 正如每个曾筹过款的人都知道的，一个人所拥有的东西多，并不一定意味着他们给予的多。