1905 in science

The year 1905 in science and technology involved some significant events, listed below.

Astronomy

* January 2 - Charles Dillon Perrine at Lick Observatory discovers Elara, one of Jupiter's natural satellites.
* The Dominion Observatory opens.
* Various astronomers discover the minor planets 554 Peraga through 583 Klotilde (see List of asteroids/501-600).
* The nova V604 Aquilae appears in the constellation Aquila.

Biology

*William Bateson coins the term "genetics" in a letter to Adam Sedgwick.
*Nettie Stevens and Edmund Beecher Wilson independently describe the XY sex-determination system.
*Stamen Grigorov identifies the bacterium "Lactobacillus bulgaricus", a major agent in the creation of yogurt.

Chemistry

*Carl von Linde obtains pure liquid oxygen and nitrogen by cooling air.
*The first commercial production of calcium nitrate as a fertilizer begins.

Mathematics

*Pierre Fatou defines the Mandelbrot set.
*Oswald Veblen proves the Jordan curve theorem.
*Martin Kutta describes the popular fourth-order Runge-Kutta method.
*James Cullen, S.J., begins the first studies of Cullen numbers.
*Emanuel Lasker proves the Lasker–Noether theorem for the special case of polynomial rings.

Paleontology

*The Saurian Expedition led by John C. Merriam recovers many specimens of ichthyosaur.
*"Tyrannosaurus rex" is described and named by Henry Fairfield Osborn.

Physics

* Albert Einstein publishes four papers. In particular, he formulates the theory of special relativity and states the law of mass-energy conservation: "E" = "mc"². He also explains the photoelectric effect by quantization and mathematically analyzes Brownian motion. Because of this, 1905 is said to be the miraculous year for physics, and its 100th anniversary (2005) has been declared the World Year of Physics.

Technology

* Pathé Frères colors black-and-white films by machine.
* Alfred Buchi files a patent for the turbocharger.
* Paul de Vivie invents a two-speed derailleur gear for bicycles.
* Pipe manufactures the first automobile with a hemi engine.
* Walter Griffiths invents a manually-powered domestic vacuum cleaner.

Awards

* Nobel Prizes
** Physics - Philipp Eduard Anton von Lenard
** Chemistry - Johann Friedrich Wilhelm Adolf von Baeyer
** Medicine - Robert Koch

Births

* February 1 - Emilio G. Segrè (d. 1989), physicist, Nobel laureate
* February 23 - Derrick Henry Lehmer (d. 1991), mathematician
* March 18 - Thomas Townsend Brown (d. 1985), physicist.
* March 27 - Elsie MacGill (d. 1980), aeronautical engineer, "Queen of the Hurricanes".
* April 13 - Bruno Rossi (d. 1993), physicist and astronomer
* April 18 - George H. Hitchings (d 1998), scientist, Nobel laureate in Medicine
* April 20 - Albrecht Unsöld (d. 1995), astronomer
* August 1 - Helen Sawyer Hogg (d. 1993), astronomer
* August 11 - Erwin Chargaff (d. 2002), biochemist.
* August 16 - Marian Rejewski (d. 1980), mathematician and cryptologist
* August 31 - Robert Bacher (d. 2004), nuclear physicist.
* September 3 - Carl David Anderson (d. 1991), physicist, Nobel laureate
* September 22 - Eugen Sänger (d. 1964), aerospace engineer
* September 24 - Severo Ochoa (d. 1993), biochemist, Nobel laureate
* September 30 - Nevill Francis Mott (d. 1996), physicist, Nobel laureate
* October 22 - Karl Guthe Jansky (d. 1950), physicist
* October 22 - Albert Whitford (d. 2002), astronomer
* October 23 - Felix Bloch (d. 1983), physicist, Nobel laureate
* December 7 - Gerard Kuiper (d. 1973), astronomer
* December 16 - Piet Hein (d. 1996), mathematician

Deaths

* January 4 - Paul Henry (b. 1848), astronomer
* January 14 - Ernst Abbe (b. 1840, physicist
* March 24 - Jules Verne (b. 1828), science fiction author
* April 14 - Otto Wilhelm von Struve (b. 1819), astronomer
* June 18 - Per Teodor Cleve (b. 1840), chemist
* October 6 - Ferdinand von Richthofen (b. 1833), geologist