I love it when I learn something in class that explains an everyday thing that I have never known how it works before. On Thursday, my Mechanics class (which is usually the most boring class ever) went to the Engineering garage and got to witness a 5 speed manual transmission first hand. It was really cool to see what exactly happens whenever I shift my Swedish Fish in and out of reverse and other gears. I didn't realize how much went into a transmission case.
Here is a picture of the case we looked at.
The gears that have slanted teeth are called helical gears, and the one gear, second from the left, is the reverse gear, and it is a spur gear because it's teeth are straight. There are also two rings used to change which gear is engaged. It was very cool and something I think everyone interested in mechanical things should see.
Another thing I love is when something that most people believe is true, I learn is not from class. Today in Physical Chemistry, P. Chem for short, I learned that those little pumps you buy and put on your soda bottle (yes I do call it soda, not pop!) don't help keep the fizz in. The only way to keep the CO2 dissolved in the soda is to increase the partial pressure of the CO2. The pump increases the total pressure and adds regular air, which has a very little amount of CO2 in it. Now, if you pumped CO2 into the bottle, this would increase the pressure and the amount of CO2 in the bottle, which would then increase the partial pressure of the CO2. This would keep the CO2 dissolved in the soda, thereby keeping it fizzy. But of course this would be inefficient, and my professor finished this explanation by saying that the best thing to do is keep the cap on the bottle as often as possible.