Fahrenheit & Celsius (#57/#56)

Fahrenheit

Daniel Gabriel Fahrenheit was born on May 24, 1686 in Danzig in the Polish-Lithuanian Commonwealth. Fahrenheit came from a family of merchants, but in 1701, both of Fahrenheit's parents died from eating poisonous mushrooms. After this, Fahrenheit moved to Amsterdam to begin training to become a merchant himself.

While in Amsterdam, Fahrenheit became interested in natural science and began studying and experimenting in the field. Fahrenheit also began to travel throughout Northern and Central Europe. While travelling, Fahrenheit met many notable members of the scientific and Enlightenment communities, including Gottfried Leibniz, co-developer of infinitesimal calculus, and Ole Romer, who made the first quantitative measurements of the speed of light.

In 1717, Fahrenheit settled in The Hague as a glassblower who specialized in making barometers, altimeters, and thermometers. Fahrenheit also lectured in chemistry in Amsterdam. In 1724, Fahrenheit created a scale to record temperature based on three points. These three points were the lowest point on the thermometer, or 0 Fahrenheit (F), the freezing point of water, or 32 F, and body temperature, which he calculated to be 96 F. The system was later changed so that the difference between the freezing and boiling points of water was exactly 180 F. 

Celsius

Anders Celsius was born on November 27, 1701 in Uppsala, Sweden. Unlike Fahrenheit, Celsius came from a family of scientists. Celsius's father and maternal grandfather were astronomers, and Celsius's paternal grandfather was a mathematician. Celsius studied at the Uppsala University and in 1730, Celsius became a professor there.

Celsius published many works in several fields of study. In one study conducted, he was the first to suggest that there was a connection between the appearance of the aurora borealis and changes in the magnetic field of the Earth, which was later proved to be correct. He also was part of the 1736 expedition to Lapland to measure the length of a degree along the meridian. This expedition, when compared to similar measurements from Peru, proved Isaac Newton's theory that the Earth was ellipsoid, rather than completely round, and flattened at the poles. Celsius was also one of the first people to measure the magnitude, or brightness, of certain stars, and, even with the equipment he used, Celsius was quite accurate.

Celsius is most famous for his creation of the temperature system that was named after him. Celsius understood that the boiling point of liquids was not simply dependent on heat but on pressure as well, so using a standard pressure (the pressure at sea-level), Celsius created a thermometer. At the standard pressure, the thermometer would read 100 Celsius (C) at water's melting point and 0 C at its boiling point. A year after his death, the system was reversed so the 0 C would be freezing and 100 C would be boiling.

The End

Fahrenheit died in The Hague on September 16, 1736 and is buried there at Cloister Church. Celsius died on April 25, 1744 of tuberculosis soon after co-founding the Royal Swedish Academy of Sciences. Fahrenheit's system of temperature measurement was widely accepted throughout the world and is still used by the general population of the United States, Belize, and in parts of the United Kingdom and Canada. Celsius's system, when published, replaced Fahrenheit's system in all but the above stated regions. The Celsius system has also become the standard measurement system for the majority of scientific studies, and the Kelvin System is based off of that of Celsius. Fahrenheit and Celsius are on our list because they create the first systems to measure temperature without just say "It's cold." or "It's hot."

Dimitri Mendeleev (#59)

Background

Dimitri Ivanovich Mendeleev was born on February 8, 1834 near Tobolsk in Siberia. There is no consensus on how many siblings Mendeleev had, but all sources agree that the number was at least eleven. Dimitri's father supported the family by teaching fine arts, politics, and philosophy, but after some time, Mendeleev's father became blind and lost his teaching position. Mendeleev's mother was forced to restart her family's abandoned glass factory, but when he was thirteen, Mendeleev's father died and the glass factory was destroyed in a fire, so Mendeleev was sent to study at the Gymnasium in Tobolsk.

In 1850, Mendeleev's family moved to St. Petersburg and Mendeleev began to attend the Main Pedagogical Institute. After graduation in 1855, Mendeleev contracted tuberculosis and moved to the Crimean Peninsula to recover his health. While away, Mendeleev became the science master of the Simferopol gymnasium No. 1, but returned to St. Petersburg in 1857.

On April 27, 1862, Mendeleev married Feozva Nikitichna Lescheva with whom he was married to until 1882, when he became obsessed with Anna Ivanova Popova. Mendeleev divorced Lescheva and married Popova.

Career in Science

Mendeleev studied several areas in science including the capillarity of liquids and the science behind spectroscopes. In 1864, Mendeleev became a professor at Saint Petersburg Technological Institute and at Saint Petersburg State University. In 1865, Mendeleev became a Doctor of Science and achieved tenure two years later. Mendeleev is widely credited as being the man who helped Saint Petersburg become an internationally recognized center of chemistry. He is also said to have been the man who brought the metric system to Russia.

In 1869, Mendeleev was writing a book on chemistry and, while doing so, organized a table of  the 56 known elements based on atomic mass, weight, and chemical properties. This was the first periodic table ever created. Mendeleev also predicted the existence of three chemicals that would make his table make more sense. These predicted elements did exist as gallium, germanium, and scandium. The periodic table was widely expanded upon as more knowledge came in concerning the elements and their properties.

Mendeleev went on to formulate new state standards for the production of vodka in 1893 while working as the Director of the Bureau of Weights and Measures. He also helped to investigate the properties of petroleum and found the first oil refinery in Russia. He was also nominated several times for the Nobel Prize in Chemistry, but was not chosen for the award due to Svante Arrhenius, who discouraged his selection due to Mendeleev's critiques on Arrhenius's work.

The End

Before he died, Mendeleev received the Copley Medal from the Royal Society of London. He also was elected as a member of the Royal Swedish Academy of Science. Mendeleev died in 1907 at the age of 72 in Saint Petersburg due to influenza. Mendeleev has been honored by having both a crater on the moon and an element named after him. Mendeleev is on our list because he developed a table that is known world wide and can be found in almost every university and high school science classroom. Also, anyone with a moon crater named after them is pretty awesome.