The year 1907 in science and technology involved some significant events, listed below.
Mathematics
Paul Koebe conjectures the result of the Koebe quarter theorem.
Physics
The Ehrenfest model of diffusion is proposed by Tatiana and Paul Ehrenfest to explain the second law of thermodynamics. Albert Einstein introduces the principle of equivalence of gravitation and inertia and uses it to predict the gravitational redshift.
Chemistry
June 6 – Persil laundry detergent is first marketed by Henkel of Düsseldorf, Germany, the first to combine a bleaching agent (sodium perborate) with a base washing agent (sodium silicate) commercially. Emil Fischer artificially synthesizes peptide amino acid chains and thereby shows that amino acids in proteins are connected by amino group-acid group bonds. Hermann Staudinger prepares the first synthetic β-lactam. Georges Urbain discovers Lutetium (from Lutetia, the ancient name of Paris).
Geology
January 14 – 1907 Kingston earthquake: Earthquake in Kingston, Jamaica. c. March 28 – Volcanic eruption of Ksudach in the Kamchatka Peninsula. Bertram Boltwood proposes that the amount of lead in uranium and thorium ores might be used to determine the Earth's age and crudely dates some rocks to have ages between 410–2200 million years. The Moine Thrust Belt in Scotland is identified by Ben Peach and John Horne, one of the first to be discovered. The rare phosphate mineral tarbuttite is first discovered at Broken Hill, Barotziland-North-Western Rhodesia. Ludovic Mrazek describes and names diapirs.
Medicine
Paul Ehrlich develops a chemotherapeutic cure for sleeping sickness. George Soper identifies "Typhoid Mary" Mallon as an asymptomatic carrier of typhoid in New York. Dengue fever becomes the second disease shown to be caused by a virus. Indiana, in the United States, becomes the world's first legislature to place laws permitting compulsory sterilization for eugenic purposes on the statute book.
Paleontology
October 21 – Jaw of Homo heidelbergensis (Mauer 1) found.
Astronomy
Alfred Russel Wallace publishes the book Is Mars Habitable?, a refutation of Percival Lowell's theory of mars canals, and the first work in the emerging field of astrobiology
Psychology
Ivan Pavlov demonstrates conditioned responses with salivating dogs. Vladimir Bekhterev begins publication of Objective Psychology.
Technology
August 10 – Peking to Paris motor race concludes after 2 months, won by Prince Scipione Borghese driving a 7-litre 35/45 hp Itala. August 29 – The partially completed Quebec Bridge collapses. October 17 – Guglielmo Marconi initiates commercial transatlantic radio communications between his high power longwave wireless telegraphy stations in Clifden, Ireland, and Glace Bay, Nova Scotia. Lee de Forest invents the triode thermionic amplifier, starting the development of electronics as a practical technology. Furuholmen Lighthouse in Sweden is the world's first to be equipped with AGA's Dalén light incorporating Gustaf Dalén's invention of the sun valve which turns the beacon's accumulator gas supply on and off using daylight, and for which Dalén will be awarded the Nobel Prize in Physics in 1912. Ole Evinrude invents the first practical outboard motor, in the United States. Rudge-Whitworth of Coventry (England) produce the first detachable wire wheel for automobiles. The Autochrome Lumière is the first color photography process marketed. James Murray Spangler invents the first Hoover vacuum cleaner in the United States. Samuel Simon patents a screenprinting process in the United Kingdom.
Zoology
Carl Hagenbeck opens the Tierpark Hagenbeck in Stellingen, near Hamburg, Germany, the first zoo to use open moated enclosures, rather than barred cages, to better approximate animals' natural environments. December 28 – Last confirmed sighting of a Huia in New Zealand.