A while back, I pointed out a paper in the Relativity section of PF that claimed to have a description of Special Relativity that is meant for "school-going children". It seems that such activity is a popular one for researchers at the Tata Institute of Fundamental Research in Mumbai, India. Another person from that same institution has written another physics paper meant for the same audience. This time, it is on the Brownian motion. So again, if you know of any 12 to 16-year olds (or if you are one), see if you can comprehend what is being said here: http://arxiv.org/abs/physics/0412132 Zz.