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1590 BCE
First Microscope
Hans and Zacharias Janssen make the first microscope by placing two lenses in a tube -
1286 BCE
First Specticals
The art of grinding lenses is developed in Italy and the first spectacles are made to improve eyesight. They consisted of two framed glasses or crystal stones -
First Compound Microscope
A father son team named Hans and Zacharias Janssen invented the first compound microscope. They realized when they put lenses on the top and bottom of the tube and looked through it, object would become magnified. -
First use of term "Cells"
Robert Hooke was the first to view and describe cells and name them. He used a slice of cork using a microscope and saw tiny boxes, which he thought looked like small rooms and he started calling them cells. . -
Micrographia
Robert Hooke studies objects with his microscope and publishes his result in Micrographia. A cork was able to float in water -
Disaprove Spontaneous Generation
Francesco Redi demonstrated that the maggots in meat does not prove spontaneous generation but from eggs laid on the meat by flies. -
First reflecting telescope
Isaac Newton built his first reflecting telescope in the UK. -
Single-lens microscope
Anton Van Leeuwenhoek used single-lens microscope to view tiny organisms which are not visible to the unaided eye in pond water. This was the first time scientist were able to view microscopic living things. He also named cells " Animalcules" -
Bacteria Discovery
Anton Van Leeuwenhoek discovered bacteria. -
Hooke's Inventions
Robert Hooke invented the universal joint, the iris diaphragm, a respirator, an anchor escapement and balance spring for clocks. -
Charles Hall Invention
Charles discovered that by using a second lens of different shape and refracting properties, he could realign colors with minimal impact on the magnification of the first lens. The invention of the achromatic lens. -
John Needham
He published his own experiments which he boiled broth hoping to kill anything inside. He attempted to provide evidence supporting spontaneous generation. He supports S.G -
Lazzaro Spallanzani
Lazzaro reviewed both Redi and Needham's experiments and concluded that the heating of broth did not kill everything inside. He proposed that microbes move through the air and that they could be killed through boiling -
Lenses reducing chromatic effect
An important discovery is that lenses combining two types of glass could reduce the chromatic effect, with its disturbing halos resulting from differences in image. -
Joseph Jackson
Joseph Jackson Lister reduces the problem with spherical aberration by showing that several weak lenses used together at certain distances gave good maginifying without blurring the images. -
Cells Are Living
Matthias Schleiden and Theodor Schwann studied plant and animal cells and were able to view the nucleus. Through their studies they concluded that all living things were made up of cells and that a cell is the smallest unit of organization of a living thing. These ideas formed the basis for cell theory. -
Basic unit of life
Cells were finally the basic unit of life -
Rudolf Virchow
Rudolf studied cellular pathology and proposed that all cells come from other cells. They do not appear spontaneously. This explains how living things grow and reproduce. -
Louis Pasteur
Louis designed a procedure to test whether sterile nutrient broth could spontaneously generate microbial life. The broth did not show signs of life until he broke off the neck of the flask allowing dust and microbes to enter. -
Abbe Condenser
Abbe's work on a wave theory of microscopic imaging made possible the development of a new range of 17 microscope objectives. From here on microscopes were designed based on sound laws of physics. This Abbe Condenser is mounted below the microscope and controls the lights passing through -
Cell mitosis and chromosomes
Walter Fleming discovered cell mitosis and chromosomes. -
August Kohler
He figured out an unparalleled illumination system that is still known as Kohler illumination. Using double diaphragms, the system provides triple benefits of illuminated specimen. This can almost achieve an almost perfect picture. -
19th-20th Louis Pasteur & Robert Koch
Louis Pasteur invented pasteurization, while Koch discovered his famous postulates: the anthrax bacillus, the tuberculosis bacillus and the cholera vibrio. -
Ultra-microscope
Richard Zsigmondy develops the ultra-microscope and is able to study objects below the wavelength of light -
Viewing unstained cells
Frits Zernike discovered he could view unstained cells using the phase angle of rays. -
First electron microscope
Max Knoll and Ernst Ruska invented the first electron microscope that blasted past the optical limitations of the light. Knoll and Ruska built a transmission electron microscope- one that transmits a beam of electrons through the specimen. -
Phase-contrast microscope
Frits Zernike invents the phase-contrast microscope that allows the study of colorless and transparent biological materials. -
Electron Microscope
Ernst Ruska develops the electron microscope. The ability to use electrons in microscopy greatly improves the resolution and expands the borders of exploration. -
Stanley Miller & Harold Urey
Miller and Urey simulated hypothetical conditions present on the early Earth in order to test what kind of environment would be needed to allow life to begin. The experiment is considered the classic experiment on the origin of life. ( Water, methane, ammonia and hydrogen. ) They created a cycle of compounds through glass tubes and flasks. They did not create life from non life but they did show the basic compounds of life could be derived from non living compounds -
Lynn Margulis
She made the first discovery of endosymbiosis. Her endosymbiotic theory of eukaryotic cell development is the concept of how life originated on earth. She also said that different types of bacteria, through “symbiogenesis”, formed more complicated single organisms. -
Scanning tunnel microscope
Gerd Binnig and Heinrich Rohrer invent the scanning tunneling microscope that gives three-dimensional images of objects down to the atomic level.