"How do you measure the height of Mt. Everest??", they asked me. Confidently, I set about telling them that i would use trignometry, get the angle of elevation, the distance of my view pt from the base of the mountain, and, thus, get the height. They weren't satisfied. I told them, you can measure the boiling pt ofwater, or the value of 'g', or the atmospheric pressure at the peak and, since you know how these quantities vary with height, and their values at sea level, you can get the height. But, they were not pleased. Then, they asked me if I had heard of the sextant. I said no. Then, they asked me if I could estimate the boiling point of water on top of the Everest. I told them I donot know the expression for how it varies with altitude. They asked me if I could make a rough estimate - " 30, 40, 60, 99...? What would it be?" I said - "70 - 80?? probably, 70??" The questioner looked at me and said -" Not bad. It is wrong, but not very wrong. It is important for a scientist to be able to estimate. Esp; in the kind of field you have chosen."
I came home, looked it up on the net. I guess I can start investing in the stock market now :D
P.S. While discussing with NiNa, I also estimated the boiling pt of water at Bangalore to be 95deg C and, found out it was 94.6 :D