Diatoms are single-celled planktonic algae that are vital to ocean ecology. They account for about 40% of marine photosynthesis, and are a major component of the base of the marine food chain. Centric diatoms are disc or tube-shaped organisms. When seen from one end, they look like circles—for which the circumference can easily be calculated using pi. Pi, the ratio of a circle's circumference to its diameter, approximates to 3.1415.The circumference of this centric diatom with a diameter of 150 micrometers is (pi X 150 micrometers), or 471.2 micrometers. In addition to the centric diatoms, other organisms with radial symmetry include jellyfish, sea anemones, some plants and adult sea urchins, and starfish.
Pi Day is on Saturday, March 14, 2015 or 3/14/15
The fossil diatom was isolated from a sample of diatomite retrieved from Dunkirk, Maryland by Bill Dailey, PhD, University of Pennsylvania. The specimen was mounted on a microscope slide and photographed using a specialized light microscope (Jamin-Lebedeff Interference microscope).
Stephen Nagy, MD, Montana Diatoms, Helena, MT