Skeletons by Zalasiewicz Jan; Williams Mark; & Mark Williams

Author:Zalasiewicz, Jan; Williams, Mark; & Mark Williams [Zalasiewicz, Jan & Williams, Mark]
Language: eng
Format: epub
Publisher: Oxford University Press, Incorporated
Published: 2018-01-15T00:00:00+00:00

6

Mini-skeletons

To a Tudor physician covered head to foot in thick clothing doused in vinegar, and wearing a beaked mask, avoiding disease carried by airborne vapours was a serious business. Little was known about the vectors of disease, and little about how to cure it, and absolutely nothing was known about the microscopic world that was its cause. When Queen Elizabeth I of England was ‘diagnosed’ with smallpox in 1562, she was given the most advanced medical treatment known to the physicians of England at that time: being wrapped from head to foot in a red blanket. Apparently it worked, though no one could be sure why. The tiny virus that carries the smallpox disease is no more than 400 nanometres in maximum length, and there are one million of those nanometres in a single millimetre. The smallpox virus then, is much, much too small to see with the naked human eye.

What then, is the smallest object that the naked human eye can resolve? In good natural light, the eye can see objects somewhat less than 1 mm in size, and probably about one-tenth that, which is around 100 000 nanometres. Human vision can struggle to see the breadth of a single strand of hair. That is nowhere near small enough to resolve the smallpox virus. But it does mean that long ago, people had already recognized tiny, millimetre-long objects swimming in their drinking water. The indigenous Mogollon people of New Mexico, for example, noticed the minuscule ostracods (seed shrimps) that inhabited their lakes and streams, and depicted them ‘swimming’ on their pottery 1000 years ago. To see beyond the breadth of a hair, into a world of unseen skeletons, humans had to wait another 600 years, for the invention of the microscope.

Download

Copyright Disclaimer:
This site does not store any files on its server. We only index and link to content provided by other sites. Please contact the content providers to delete copyright contents if any and email us, we'll remove relevant links or contents immediately.