Physics is Phun! (really...)

I am retired. It's kind of like a never-ending weekend.  I don't know the date.  (Sometimes I'm not even sure what day it is!)  But I taught high school for 30 years--biology for a bunch of years and physics for the last several.

I'm telling you this because I love physics. Physics explains the world.  It's the rules of nature.  It's the why and the how.  I love that.

You might think it would take away the magic and wonder of a rainbow to know that it's only refraction and diffraction of light.  Or that you could no longer enjoy the magnificence of voices raised together in song if you understood the way pitch works together with resonance to cause air particles to vibrate your eardrum.  But I've always believed it's easier to appreciate things if you know how they work.  I think I see the beauty even more.  To borrow from Paul Hewitt, one physics guru, richness in life is not only seeing the world with wide open eyes, but knowing what to look for.

Here are some really, really cool physics phacts:
-Ignoring air resistance, a bullet fired from a gun and a bullet dropped at exactly the same time from the same height will hit the ground at EXACTLY the same time. (The horizontal component and vertical component of a projectile are independent of each other, and the vertical acceleration of each bullet is due to gravity, pulling each bullet down equally!)
-Centripetal force keeps an object moving in a circle, while the absence of force causes an object to leave that circle.  (When I was in high school, I was taught that centrifugal force did this...but now I know it's the object's own inertia that makes it move off in a straight line path!)
-If you get a cup of coffee to go and you like cream, you should put the cream in before you leave the restaurant to keep it hot; if you wait until you get to work to add the cream, the coffee will have cooled off even more and you'll have lukewarm coffee!
-A large lake will never freeze. (4 degree C water is more dense than any other water, so it sinks under the warmer water.  The entire lake would have to reach 4 degrees before any of the water could eventually reach 0 degrees and freeze.)
-Winds blow off the ocean toward the shore during the day, but off the shore and toward the water at night. (Convection currents are produced by uneven heating and cooling...the land is warmer than the water in the day and cooler than the water at night, so the direction of air flow reverses from day to night!)

Okay.  I hear some of you leaving.  Sorry, but I really, really love physics.  And I think if you could go back and do it again, you would too!

Physics is Phun!!!