The Diamond Thermometer

Cold as a diamond. The older generation may still remember Chris Norman s song titled Some Hearts are Diamonds from 1986. In esoteric texts, cold diamonds are often contrasted with fieiy mbies. 

There are very well established natural laws, ealled the laws of thermodynamies, working behind the scenes. Along with a few other features, these laws state that objects in contact with each other, absent arty external heating or cooling, will reach a state called thermal equilibrium, in whieh their temperatures will be eqtral. Under normal kitchen conditions, half an hoirr is more than errough to reach this thermal equilibrimn, so all objects in contact with air will have identical temperatiues. Why then, do they feel so different  

There are two key scientific facts here. First, the human body heats itself, and usually maintains a temperature aroimd 36 °C. So a human hand is usually warmer than the air in kitchen. If you touch something, you begin to heat it at the same time. A piece of ice melts in human hands much faster than ice left alone. However, this does not itself explain why you feel one object cold and another warm. A second important phenomenon is heat conduction. Heat is the disordered movement of 

Returning to diamonds, the high thermal conductivity of diamonds is certairrly mysterious. In physics, a rale called the Wiedemann-Franz law states that the electric conductivity of a substance is proportiorral to the thermal conductivity. Briefly put, this law says that good thermal condrrctors are good electrical conductors attire same time. Strictly speaking, this is orrly true for metals. The best coimteiexarrrple 

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