I have been working on a four step program to introduce the law of supply and demand to economists:

1) The candidate economist must go to a library. There he or she will notice spheres sitting on wooden stands. These represent the planet we live on: Earth. Spheres like Earth are by definition finite; they only hold just so much stuff. Economists are required to memorize this key point and say it over and over, “The Earth only holds just so much stuff because it’s a sphere,” until he or she can remember it without peeking at notes.

Next, the economist is ready for his or her very first BIG scientific experiment! The economist is advised to stay calm, and be sure to get a good night’s sleep before attempting the following:

2) Put a piece of cake on a plate.
3) Eat the cake.
4) See if you still have the cake.

Economists aren’t used to empirical science and will typically have to do the experiment (steps 2 through 4) at least a few times before the implications finally sink in.

Isn’t science fun?

Office printers consume energy and may even pose a health risk. But the hand-powered RITI Printer, designed by Jeon Hwan Ju, is different.

Power comes from the user, who has to pull the printer head back and forth as the paper is pulled through. Cleverly, the printer also does away with expensive ink cartridges, instead making use of waste coffee.

The printed product definitely smells of coffee, which some evidence suggests could help reverse the effects of sleep deprivation. Also, there is no word yet on how long a coffee-printed document will remain readable.