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Showing posts from October, 2013

Lightning charges Nokia Lumia!

Although it sounds like an advertisement for the mobile company, it is the work of the researchers at the University of Southampton that is creditable. Prompted by the phone company, the researchers attempted to charge a mobile phone using lightning as the source of energy.
Lightning strikes the Earth around 40-50 times per second and each lightning bolt carries anywhere between 1000 - 5000 joules of energy, enough to send a tennis ball at 23,000 km per hour.  While we are aware of the energy potential of lightning, we have never managed to harness this energy because we do not know how to control it (much like Fire was for a man of Stone Age).  Through these efforts, Nokia and The University of Southampton are looking for ways to harness this energy and also charge phones wirelessly. (You can read more about it in our previous post, about wireless charging).
While we might be decades away from harnessing this energy successfully for everyday use, it does make for an interesting vide…

Dancing water on a hot pan - here's why?

Ever wondered why water droplets suddenly start dancing on a hot pan, while they simmer away most of the times.  As if they have a mind of their own, water droplets seem to act like this in a random fashion. Well, you are not the first one to have observed this or to have dismissed it as an random act. In the year 1796, Johann Leidenfrost, found some order in this randomness, which is now known as the Leidenfrost effect.
Image from Wikipedia Initially, as a hot pan reaches the boiling point of water, water evaporates slowly. As temperature increases and goes beyond 100 degrees Celsius, water evaporates immediately, usually accompanied with a hissing sound. As the temperature is increased further, water continues to evaporate quickly, except that the water closest to pan heats up quicker, evaporates and makes a small cushion of vapour between the pan and water droplet. Since, vapour conducts heat poorly, heat from the pan takes much longer to reach and completely evaporate the water d…