Where are we humans in terms of size in our universe? Have you thought about this question? Our dimensions are much smaller than those of our world- it in turn is much smaller than our solar system, which in turn is much smaller than our galaxy, etc. We are much bigger than ants, and they in turn are far bigger than bacteria and viruses, while atoms in turn are smaller yet. What are the known upper and lower limits of size in our universe? Are we near the upper or lower ends of the size scale, or near the middle? If so, why would this be? Why couldn’t we be extremely tiny as compared to what we are, or extremely large? Are there physical advantages of scale that must be considered? Why is the universe so large? Why are atomic nuclei, quarks, etc., so small? What units do we use to measure large and small? Are some units of measure more useful and convenient than others? Many questions of this sort that you may not have considered will be discussed.

Dr. Penney is a retired medical school professor of physiology and biochemistry. During the past 7-8 years, he has given dozens of presentations to school groups, libraries, and astronomy societies on science, history, astronomy, biology, paleontology, and other subjects.