Scientists milk tons of information from things that convey no sense to the rest of us. For example, a ray of light from a distant star is enough to tell them how far the star is, how fast it is moving away from us, what the star is made of, when the star was born, and when it will die.
You and I may kick aside a ‘useless’ piece of broken pottery, but to scientists it is a library of information.
Recently, a group of scientists from IIT-Bombay nosed around in Kunal, Haryana, where the Harappans lived 5,800 years ago, and picked up what they were looking for — shards of pottery. And now they tell us that to make the pottery, the Harappans could raise temperatures between 800 degrees Celsius and 1,000 degrees Celsius.
Leave aside the wonder of how the ancient Harappans achieved such high temperatures — the more intriguing question is, how could the scientists tell so much from just the shards.
Well, the colour of pottery is dependent on temperature. The colour changes from orange to light red at 700-800 degrees C, and dark red at 900 degrees C. The higher the temperature, the more advanced the firing technique.
Using hi-tech instruments such as Fourier transform infrared (FTIR) and X-ray diffraction, the scientists were able to peer deep into the shards and find out all the elements present in them. They also deduced that the Harappans made pottery both by wheel and by hand. They concluded that the Harappans were highly skilled potters.
