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Ever wondered why clouds can be white and fluffy like cotton on bright sunny days and dark and gloomy when it’s gonna rain?
My mum used to tell me that was cos the clouds absorbed all that dirt in the skies, turning it really dark and dirty. (That’s also why she says it’s not a good idea to get yourself wet standing in the rain)
So are the clouds dirty just before it rains? Well, not really.
The truth is, when you look at clouds, the extent of their brightness (or greyness) depends on how much light is reflected into your eyes. The more water droplets there are in the skies, the more light is absorbed such that less light can reach your eyes –> hence darker clouds. When there isn’t a lot of water droplets in the skies, most of the light can be reflected into your eyes and you see the the clouds are white.
When there is a lot of water droplets in the skies, they block off a lot of light, hence causing the clouds to look dark. And because there is a lot of water droplets in the skies, it is more likely that dark clouds signify that it’s going to rain!
I found a more scientific explanation in this site here: do read it for better insight!
It was raining again today and my feet got wet. The wet straps rubbing my feet made me think of a question I had some time back – Why is it that wet socks make it a lot easier for a person to get abrasion?
Searching online, I discovered this site which did a great job answering my question.
Heat, moisture and friction all play roles in the formation of blisters, and each heightens the severity of the others, thereby creating a Blister Cycle. Excess heat signals the body to produce sweat to lower the skin’s temperature through evaporative cooling. Wet socks increase the amount of friction (stickiness) on the skin’s surface which soften and weaken the skin. Linear or torsional movements create shearing forces which subsequently cause the skin and inner tissue to tear apart. This separation soon fills with fluid to form a blister.
Now my question is answered. =) Hurrah for the internet.
I was looking through Instructables.com and came across this:
I used to make this when I was really young. You just fold a piece of paper into that shape and flick it really hard. It makes really loud noises and scare the wits out of anybody nearby. Such fun!
And now for a bit of physics while we are at it: How does this work?
Basically, when the centre-fold of the paper gets flicked out, it moves at a very fast rate and pushes the air in front of it away quickly. This creates a shock wave which can be really loud.
Just yesterday, I read an online news that a ‘surfer dude’ with no university affiliation have published a paper about a theory of everything.
Not string theory mind you. A different one that marries gravitational field, Quantum Mechanics, Electromagnetism etc using E8. I admit I do not exactly understand what he is trying to say, but it is said that if his theory can actually predict ‘new particles’ which we can test and confirm then this might just be THE theory of everything.
Just a note la. If anyone’s interested to read his paper, it can be accessed through here: http://arxiv.org/abs/0711.0770
Have fun reading! (it’s 31 pages long) Gimme a summary *points to ‘comment’ link* when you are done with it okay?
Oh ya, the surfer dude’s name is A. Garrett Lisi.
I just came across this really interesting game (still in ‘beta’) called crayon physics and what it does is that it allows you to draw 2D images and see how they would behave if they were subjected to physics (or in this case gravity)
Basically you have a ball and stars. You are suppose to make the ball touch the stars by drawing shapes with ur crayon cursor so that the ball rolls towards the star without dropping down.
It’s really quite fun and you can download other levels when you become bored of the basic 4 levels found in the game.
The only thing I don’t like about it (for now) is the fact that you can’t draw much beyond rectangles and well… rectangles. The newer version (purported to come soon) looks really promising. Seems like you can draw all kinds of shapes and even cars. Fun stuff!
To play, download the game here
For more physics gaming delights, try:
For other experimental games, try:
I have yet to play the games found in the latter website yet, I sure will do so really soon! Meanwhile, I can’t wait for the Crayon Physics Deluxe game to be finished!