Yearly Archives: 2017

Neptune — December 12 is the birthday of James Challis. Challis was an English astronomer who is best known for not discovering the planet Neptune. English mathematician John Couch Adams computed an orbit for an unknown planet that should exist to cause the peculiar orbit of the planet Uranus. Adams passed his […]

Today In Science History – December 12 – James Challis ...

This entry was posted on December 7, 2017 by Todd Helmenstine (updated on April 29, 2026)

Annie Jump Cannon — December 11 is the birthday of Annie Jump Cannon. Cannon was an American astronomer who developed the star classification system in use today. Astronomy students learn the system using the mnemonic “Oh! Be A Fine Girl — Kiss Me!” The system ranks stars by their temperature, color and spectrum lines […]

Today In Science History – December 11 – Annie Jump ...

This entry was posted on December 6, 2017 by Todd Helmenstine (updated on July 11, 2026)

yuansu zhouqi biao — Have you ever wondered if the names of elements are the same in other languages? Different languages have different words for the same thing, why should the elements be any different? This table is a list of the elements in Chinese and English arranged by atomic number. The last column […]

List of Elements in Chinese

This entry was posted on December 3, 2017 by Todd Helmenstine (updated on May 16, 2021)

yuansu zhouqi biao — Have you ever needed a Chinese periodic table? This Yuánsù zhōuqí biǎo will give you just what you need. This color periodic table contains all 118 element’s atomic numbers, symbols, names in Chinese, and atomic masses. The colors show the different element groups. It is optimized to print on a […]

Yuánsù zhouqí biao – Chinese Periodic Table of the Elements

This entry was posted on December 3, 2017 by Todd Helmenstine (updated on May 16, 2021)

What Is Density Definition — Get the definition of density in science and the equation to calculate it from mass and volume.

Density Definition in Science

This entry was posted on December 2, 2017 by Anne Helmenstine (updated on April 12, 2026)

Alfred Nobel (1833 - 1896) — December 10 marks the passing of Alfred Nobel. Nobel was a Swedish chemist and entrepreneur who invented the explosive known as dynamite. He was attempting to create a method to make nitroglycerin safer to use and handle. The success of dynamite and his patents made him a wealthy man. On […]

Today In Science History – December 10 – Alfred Nobel

This entry was posted on November 30, 2017 by Todd Helmenstine (updated on January 24, 2024)

Fritz Haber — December 9 is Fritz Haber’s birthday. Haber was a German chemist who discovered a process to create ammonia from atmospheric gases. The Haber-Bosch process is a reaction that fixes nitrogen to form ammonia (NH3) from nitrogen gas (N2) and hydrogen gas (H2) under pressure over an iron catalyst. Haber discovered […]

Today In Science History – December 9 – Fritz Haber ...

This entry was posted on November 30, 2017 by Todd Helmenstine (updated on April 26, 2025)

Jan Ingenhousz (1730 - 1799) — December 8 is Jan Ingenhousz’s birthday. Ingenhousz was a Dutch scientist who made the first step to understanding plant respiration or photosynthesis. English chemist Joseph Priestly had recently demonstrated that plants give off oxygen. Ingenhousz expanded this research by noting that plants not only give off oxygen but absorb carbon […]

Today In Science History – December 8 – Jan Ingenhousz ...

This entry was posted on November 30, 2017 by Todd Helmenstine (updated on November 18, 2025)

December 7 marks the passing of Walter Noddack. Noddack was a German chemist who searched for two elements missing from Mendeleev’s periodic table. The two blank placeholder elements appeared underneath manganese called eka-manganese and dvi-manganese. (eka means 1 and dvi means 2 in Sanskrit). Together with Ida Tacke (who would […]

Today In Science History – December 7 – Walter Noddack

This entry was posted on November 29, 2017 by Todd Helmenstine (updated on July 30, 2025)