Answer to Question 1
Answer: A pan of water rotates at a constant speed and is heated around the edge to represent the equator, and the center is cooled o duplicate the poles. This process causes waves to develop in the pan that are physically similar to those in the atmosphere. The Dishpan Experiment is capable of illustrating the following important characteristics of the Difficulty:
Global circulation: (i) unequal heating from the equator to the poles; (ii) rotation of the Earth; and (iii) turbulent nature of the atmosphere.
Answer to Question 2
Answer: There is always a pressure gradient force across the middle latitudes trying to push the air toward the poles. In the absence of friction, the winds do not blow poleward, but rather blow parallel to the height contours, from west to east. The pressure gradient force is strongest in winter (the height contours are closely spaced), so the upper-level westerlies are strongest in winter. This explains why most midlatitude weather systems migrate from west to east.
Experiment of Lederberg and Tatum demonstrating gene transfer in E. coli
Field experiment on effects of predation on male guppy colouration
Landsteiner's experiment demonstrating the exquisite specificity of the immune system.
Global Warming: Trends and Tensions
The Experiment at Robbers Cave
Global Distribution of Biomes