The microscope

In time, the microscope made the existence of a whole tiny world irrefutable. This amazing device was invented in the 1590s, probably either by Hans Janssen, working with his son, Zachariah, or by Hans Lippershey, all of whom were eyeglass makers in Middelburg, the Netherlands.

Robert Hooke's microscope

Robert Hooke's microscope

The microscope was possibly a byproduct of the invention of the telescope, and it definitely benefited from the fact that a great many people were wearing eyeglasses by the end of the 16th century.

The compound microscope, multiple lenses in a tube, like the device Robert Hooke used to make his famous study of cells, was invented before the simple, single-lens model like the one Anton van Leeuwenhoek used when he discovered microorganisms.

The Nobel Committee has awarded four prizes for microscopes, the most recent three for Physics:

  • Richard Zsigmondy won in Chemistry in 1925 for his development in 1903 of the ultramicroscope, which allowed him to view objects that were below the wavelength of light.
  • Frits Zernike won in 1953 for his invention in 1932 of the phase-contrast microscope, which makes colorless or transparent objects visible.
  • Ernst Ruska won in 1986 for the electron microscope, a superior design for magnification that he developed in 1938.
  • Gerd Binnig and Heinrich Rohrer won in 1986 for inventing the scanning tunneling microscope in 1981.  This amazing instrument makes the atoms in an object visible — in three dimensions!

Image courtesy of Wikipedia Commons

Anton van Leeuwenhoek

Anton van Leeuwenhoek was a linen merchant in Delft, the Netherlands, whose passion for science helped make him one of the most important figures in the history of microbiology.

Van Leeuwenhoek saw his first microscope, in use in the fabric trade, in 1653, and he soon bought one of his own. He read Robert Hooke's Micrographia, and it reportedly enthralled him.

Anton van Leeuwenhoek

Anton van Leeuwenhoek

By 1668, he was grinding lenses for his own simple microscopes and looking at every tiny thing he could find. Those two things — his boundless curiosity and the fact that he kept improving his lenses — were critical to his discoveries.

Van Leeuwenhoek was the first to identify microorganisms, notably protists and bacteria, and the first to describe red blood cells and sperm.

Van Leeuwenhoek's discoveries were documented in letters he wrote to Henry Oldenburg, secretary of the Royal Society of London, between 1673 and Van Leeuwenhoek's death in 1723. The letters made him famous, and the Royal Society made him a fellow in 1680.

Over the course of his lifetime, van Leeuwenhoek made at least 500 microscopes. The few that survive are little more than powerful magnifying glasses. However, he developed his own technology for making them, and he never revealed the secrets of their power and brightness.

Portrait by Jan Verkolje from Wikimedia Commons

A first look at the small world

In 1665, the Englishman Robert Hooke published an amazing book called Micrographia that contained some of the first peeks at a world that was too small to see with the naked eye.

Micrographia, published when Hooke was 30, was the first publication of the Royal Society of London, and the first scientific best-seller. The diarist Samuel Pepys called it "the most ingenious book that I ever read in my life."

Hooke made the illustrations himself, based on what he had seen through a microscope he had built. Looking at a slice of cork, he saw divisions that reminded him of monks' cells in a monastery, and that is what he called them, "cells."

Cork drawing by Robert Hooke

Robert Hooke's drawing of cork cells

Hooke was born on the Isle of Wight, home-schooled and then apprenticed as an artist. He went on to Oxford at a time of unprecedented scientific activity, and he impressed his teachers with his ability to design and execute experiments: He built the vacuum pumps for Robert Boyle, who would demonstrate that gases all act in more or less the same way.

Hooke himself described how springs work in a treatise that gave rise to "Hooke's law" of elasticity. He was also an architect, and worked to help rebuild London after the Great Fire of 1666.

Hooke would probably be more famous than he is had he not quarreled with Isaac Newton over some of their overlapping discoveries. When the scientific community took sides in the dispute, Hooke was shunted aside.

His writings on fossils showed amazing rigor and originality. In the face of a scientific community that considered fossils a "sport of nature," Hook argued correctly that they were the remains of extinct organisms.

Image from Wikimedia Commons