Polarised Sunglasses
Not only do they filter light, they do it selectively by filtering out only light reflected from flat surfaces. You stare at a body of water. The sun's reflection disappears but the light from the objects under the water comes through loud and clear.
You're staring through your windscreen while driving. The sun's light reflected off the dirt on the screen if filtered out while the light everything else outside comes through.
Not only do they do this but they require no batteries! Let's say we didn't have polarised materials. How many billions would the military send trying to develop such fantastic devices which we can buy for a few bucks from any discount store?
Thermos Flasks (Dewar Flasks)
They keep hot things hot and cold things cold all using the principles of thermodynamics. No CFCs, no greenhouse-generating power, just a chamber surrounded by a vacuum (or at least a chamber with lower pressure).
How much of modern science owes a thank you to the humble thermos? All those cool experiments you see on tv with liquid nitrogen. How do they store it? In a termos flask. How many picnics and family outings are made so much better by a hot cup of (slightly weird tasting) tea or a cool drink protected from the elements by a thin wall of nothing.
Simple devices, leveraging science and making the world a better place.
I totally agree with the polarised sunglasses. But the thermos flask... An issue I have.. Though a great idea, it is somewhat misleading in its size. Great inventions to me are only any good when they become practical and the thermal flask is ALLWAYS just too small to hold enough soup for the picnic. Though it looks large enough for the whole family, somebody always has to miss out.
ReplyDeleteBack to the drawing board I say!