Why do we have nose bleeds at heights?

Of course the Law of Conservation of Matter and Energy applies to all matter, including man. When a man dies, portions of his body, which are combustible are burnt on the funeral pyre and mix with the atmosphere. Sixty to 70 per cent of man is water. On the pyre, this water converts itself into steam. Calcium, phosphorous, iron, copper, sodium and other chemicals in the body are left behind. The soul certainly cannot be weighed on scales.

My mother not only washes rice three times before cooking, she also cooks rice in a lot of water and then throws the extra water away. When I tell her that the method destroys all the nutrients from rice, she refuses to listen. How can I convince her?

Nirmala Redkar, Naupada, Thane

Well, all the nutrients are not lost when the water, in which rice is cooked, is thrown away. Starches, vitamins of the B group and vitamin C are soluble in water. Rice has a negligible vitamin C content. It is likely that along with some starch, most of the vitamins of the B group are lost when the water, in which the rice is cooked, is thrown away.

If your mother cooks rice in a pressure cooker, she has to add two cups of water for every cup of rice so that there would be no extra water to throw away. If she does not have a pressure cooker, she may have to add about two and a half cups of water for every cup of rice. After a couple of attempts your mother can know the exact amount of water to be added.

It is certainly not advisable to throw away the water in which rice is cooked.

Why do we start bleeding from the nose, at times, when we reach high altitudes?

–Abhishek Singh, Pune

This happens because at high altitudes, the atmospheric pressure is low. It is lower than the pressure within the body. As a result, blood tends to ooze out of the blood vessels in the nose.

Why does the bottom of a vessel appear to be raised when it is filled with water?

— Carol Fernandes, Vasai (West)

This is due to a phenomenon called refraction. Light travels at a different speed in different mediums, like air and water. In fact, in the water light travels at different speeds. For instance, light travels much faster in deep water than in shallow water.