Overview
This lecture traces the evolution of the microscope from early lenses through major innovations in optics and microscopy, highlighting key inventors, discoveries, and technological advancements.
Early History of Lenses and Magnification
- 710 BC: Nimrud lens (rock crystal) used for magnification and focusing sunlight in Assyria.
- 167 BC: Chinese create an early immersion microscope using a water-filled tube and lenses.
- 1000: The first magnifying glass appears; inventor unknown.
- 1021: Al-Haytham's Book of Optics links light, vision, and lens function.
- 13th Century: Lenses improved; simple microscopes and the first eyeglasses by Salvino D'Armate (1284).
Birth and Development of the Compound Microscope
- 1590: Janssen and Martens invent the first compound microscope.
- 1609: Galileo creates a microscope-telescope with concave and convex lenses.
- 1619-1621: Drebbel assembles a two-lens microscope (objective and eyepiece).
- 1625: Faber coins the term "microscope"; first microscopic illustrations published.
- 1645: Objective and eyepiece terms introduced by Schyrleus de Rheita.
- 1661-1664: Power develops transmitted light microscopy; tissue illustration improves.
- 1665: Hooke observes cork cells and publishes "Micrographia."
- 1674: Leeuwenhoek crafts high-magnification lenses, observes microbes, and advances microbiology.
Advances in the 17th-19th Centuries
- Late 17th century: Introduction of light control, microscope slides, binoculars, and Huygens eyepiece.
- 18th century: Tripod stand (Culpeper, 1725), achromatic objective (van Deyl, 1770), wheel of objectives (Sisson, 1776).
- 1830: Lister corrects lens aberrations with a multi-lens system.
- 1834: Fox Talbot invents the polarized light microscope.
- 1840: Chevalier pioneers microphotography.
- 1846: Carl Zeiss founds an optical instrument company.
- 1850: Riddell invents the first working binocular microscope.
- 1872: Abbe formulates resolution limits in optics.
20th Century and Modern Microscopy
- 1903: Zsigmondy invents the ultramicroscope.
- 1931: Ruska and Knoll build the first transmission electron microscope (TEM).
- 1935: Zernike invents the phase contrast microscope.
- 1936: Von Ardenne develops the scanning electron microscope (SEM).
- 1957: Minsky invents the confocal microscope.
- 1981: Binnig and Rohrer invent the scanning tunneling microscope (STM).
- 1986: Atomic force microscope (AFM) invented by Binnig, Quate, and Gerber.
- 1990–present: New microscopes developed for nanotechnology, biomedicine, and materials physics.
Key Terms & Definitions
- Lens — Curved piece of glass or crystal for refracting light and magnifying images.
- Compound Microscope — Instrument with two or more lenses for higher magnification.
- Objective — The primary lens in a microscope closest to the sample.
- Eyepiece — The lens you look through in a microscope.
- Achromatic Lens — A lens designed to eliminate color distortions (aberrations).
- Transmission Electron Microscope (TEM) — Uses electrons instead of light to visualize samples.
- Scanning Electron Microscope (SEM) — Creates images by scanning a surface with electrons.
- Phase Contrast Microscope — Enhances contrast in transparent specimens without staining.
- Confocal Microscope — Uses laser light to create sharp, high-resolution images.
- Atomic Force Microscope (AFM) — Maps surfaces at atomic resolution by physical probing.
Action Items / Next Steps
- Review advancements in microscope technology and their applications.
- Prepare a timeline summarizing key innovations in microscopy.
- Read about the impact of microscopes on biology and nanotechnology.