Not Scientific Science
Created | Updated Oct 14, 2004
A Spring Called: Drop of Water
Do you know what happens when a drop of water hits a non-absorbent surface? Yeah you're right (if you don't have the answer, please re-read the title of this column), the drop bounces upwards.
A French scientific team from the College de France have studied the scene carefully with a camera that took 40000 images per second. Here are the results:
At first, when it hits the surface, the drop flattens. Then, it bounces up due to the movement energy it had when falling down. The
drop will continue going upwards eventually taking the shape of a needle. Afterwards, the drop falls upon itself, into itself. It thus takes the shape of a pancake (again) but this time, the drop is in midair.
This phenomenon is different to a drop falling on other surfaces as, in this case, the drop crashes on the surface leaving only a small quantity of the water to bounce up. Physicists have also found out that the actual speed of a drop influences its deformation but not the time taken for it to get in contact with the surface. This actually depends upon the mass of the drop.
Anyway why is all this stuff important? Scientists believe that this find may be of interest to the industry. There's a small illustration: Imagine not seeing droplets of rain on your car's windscreen when it is in fact raining cats and dogs outside. Cool, isn't it? Well this may well be possible with these new data obtained by the scientists from the College de France. How though? Easy enough! The period of contact of the raindrops with the windscreen is so minimal that the driver does not even see them!
Water drops bouncing like springs, would you ever have thought of this? No, I'm not sure you would.
Walls Can Cool Themselves!
I always start my column with a question. So why break away from tradition now?
Would you believe that walls can cool themselves when they get hot? (Actually that's 2 questions at the beginning of this column!) Many of you, if not all of you will answer a simple and flat, 'NO'. I would have said so too until I read it with my own eyes (I didn't actually see these walls with my own eyes, no).
The BASF company announced in mid-year that it had managed to do the impossible. The experiments were held in Ludwigshafen, Germany.
Ok, I know you are all interested in reading how these walls in fact 'work' but it's sort of complicated. Anyway I'll try my best. Read on!
The walls are filled with plastic micro-marbles which, in turn, are filled with paraffin wax. Now the wax will melt at a temperature higher than 240C something. Melting, as you might know absorbs energy, which is, in this case, heat. The paraffin wax in the micro-marbles absorbs heat thus cooling their surroundings (they take all the heat away).
Of course, there'll be millions, even billions of micro-marbles full of paraffin in only 1 wall. The walls will seem to absorb heat from their surroundings. A short nap next to one of those during a hot summer day would be great; no need to sit under trees anymore!!!
With this small invention-of-a-genius, we will be able to play computer games without sweating or even go to the toilet and not sweat there!
BASF for its part is not settling down there though. This is an invention for this summer but what will we see next. What will we see next winter? Mystery!
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