Zacharias janssen and hans janssen biography

Retrieved January 08, from Encyclopedia. Then, copy and paste the text into your bibliography or works cited list. Because each style has its own formatting nuances that evolve over time and not all information is available for every reference entry or article, Encyclopedia. Science Dictionaries thesauruses pictures and press releases Jansen, Zacharias.

Jansen, Zacharias gale. Complete Dictionary of Scientific Biography. Learn more about citation styles Citation styles Encyclopedia. More From encyclopedia. About this article Jansen, Zacharias Updated About encyclopedia. Jansen, Michael E lin. Jansen, Marc C. Jansen, Linda. Jansen, Jan. Jansen, Elly —. Jansen, Dan. Jansen, Cornelius Otto Jansenius.

A year after the death of Janssen's first wife inhe married Anna Couget from Antwerp, who was the widow of a Willem Jansen probably a relative of Janssen. He moved to Amsterdam in November with a profession of a spectacle maker, but was bankrupt by Janssen has been given a death date as late as [ 3 ] although his sister said he was dead in testimony [ 7 ] and his son Johannes declared his parents had died by the time of his marriage in April Zacharias worked for some time in the very competitive and secretive trade of spectacle-making and at one time lived next door to Middelburg spectacle maker Hans Lippersheywho is also claimed to have invented the telescope.

Janssen's attribution to these discoveries is debatable since there is no concrete evidence as to the actual inventor, and there are a whole series of confusing and conflicting claims from the testimony of his son and fellow countrymen. The claim that Zacharias Janssen invented the telescope and the microscope dates back to the year During that time Dutch diplomat Willem Boreel conducted an investigation trying to figure out who invented the telescope.

In his investigation the magistrate was contacted by a then unknown claimant, Middelburg spectacle maker Johannes Zachariassen, the son of Zacharias Janssen, who testified under oath that his father invented the telescope and the microscope as early as and that Hans Lippershey had stolen his father's invention of the telescope. In Boreel's investigation Johannes also claimed his father, Zacharias Janssen, invented the compound microscope in For this to be true Zacharias most likely dates of birth would have made him 2—5 years old at the time some historians concluded grandfather Hans Martens must have invented it.

Other claims have come forward over the years. Physicist Jean Henri van Swinden 's investigation reached the conclusion supporting Janssen and in a collector named Zacharias Snijder came forward with 4 iron tubes with lenses in them purported to be Janssen original telescopes. The confusion surrounding the claim to invention of the telescope and the microscope arises in zacharias janssen and hans janssen biography from the sometimes conflicting testimony of Zacharias Janssen's son, Johannes Zachariassen.

Johannes' various claims include that his father invented the telescope inthat his father invented the telescope inthat in he and his father invented the Keplerian telescope a design using two positive lenses proposed by Johannes Kepler inand that Adriaan Metius and Cornelis Drebbel bought a telescope from him and his father in and copied it. The investigation by William Boreel who may have been a childhood friend of Zacharias Zachariassen added to the confusion over invention.

The people he had the local magistrate interview were trying to recount details 50 or 60 years after the fact and Boreel may have confused the names of spectacle makers from his childhood. He may have also been confused about a microscope built by another optician for Drebbel, claiming it was built by Zacharias Janssen. An investigation begun in in preparation for a memorial to commemorate Janssen as the inventor of the telescope and microscope turned up further problems with the claim including the Lippershey and Metius patent applications, Janssen late date of birth, and no record of him being a spectacle maker before In the years —, Janssen was tried several times for counterfeiting coins.

Leeuwenhoek was a man with many talents, his most important attributes were creativity, power of observation, and ingenuity. Leeuwenhoek was a common man without any fortune or formal education, so he had to work for a living. Leeuwenhoek made simple one lens microscopes. He was not the first person to build a microscope, but the microscopes that he did build were the best ones for that time period.

Leeuwenhoek was the first person to describe bacteria from teeth scrapingsprotozoans from pond waterhelped to prove the theory of blood circulation. Inand detailed his observations in the book "Micrographia. Early compound microscopes provided more magnification than single lens microscopes; however, they also distorted the image more.

Dutch scientist Antoine van Leeuwenhoek designed high-powered single lens microscopes in the s. With these he was the first to describe sperm or spermatozoa from dogs and humans. He also studied yeast, red blood cells, bacteria from the mouth and protozoa. Van Leeuwenhoek's single lens microscopes could magnify up to times larger than actual size.

Single lens microscopes remained popular well into the s, as all types of microscopes improved. Scientists were also developing new ways to prepare and contrast their specimens. Inthe German physician Robert Koch presented his discovery of Mycobacterium tuberculosi s, the bacilli responsible for tuberculosis. Koch went on to use his staining technique to isolate the bacteria responsible for cholera.

Zacharias janssen and hans janssen biography

The very best microscopes were approaching a limit by the beginning of the 20 th century. A traditional optical light microscope can't resolve objects smaller than the wavelength of visible light. But inGerman scientists Ernst Ruska and Max Knoll overcame this theoretical barrier with the electron microscope. He studied electronics at the Technical College in Munich and went on to study high voltage and vacuum technology at the Technical College of Berlin.