The 1900s Science and Technology: Chronology

1900:      Thomas Alva Edison invents the nickel-based alkaline storage battery.

1900:      German scientists invent the modern pendulum seismograph to detect earthquakes.

1900:      Sigmund Freud's On the Interpretation of Dreams is published.

1900:     July 2 The first Zeppelin dirigible is flown in Germany.

1900:     December 14 Max Planck, a German physicist, announces the basis of quantum theory: Light rays are emitted in discrete amounts called quanta.

1901:      General Electric establishes the first corporate research laboratory.

1901:      Andrew Carnegie announces his intention to donate $10 million to promote scientific research.

1901:      Brothers Orville and Wilbur Wright begin glider flights to study the aerodynamics of flight.

1901:      Hugo de Vries, a Dutch biologist, publishes his theory of genetic mutation.

1901:     December 12 Guglielmo Marconi receives the first transatlantic radio transmission.

1902:      The lawn mower and vacuum cleaner are invented in England.

1902:      Arthur Korn, a German inventor, develops the photofacsimile machine, which transmits photographs by telegraph.

1902:      Ivan Pavlov, a Russian physiologist and psychologist, discovers conditioned reflexes.

1902:      Richard Zsigmondy, a German chemist, invents the ultramicroscope.

1902:      British physicists Ernest Rutherford and Frederick Soddy explain radioactivity as the disintegration of atomic structures.

1903:      Reginald Fessenden discovers the electrolytic radio detector, a machine capable of receiving the human voice.

1903:      The safety razor is invented

1903:      Edison perfects a technique for producing master record molds, called electroplating.

1903:      Bertrand Russell, an English philosopher, publishes The Principles of Mathematics, which attempts to reduce pure mathematics to a limited number of concepts.

1903:     December 17 The Wright brothers successfully take flight at Kitty Hawk, North Carolina.

1904:      The Panama Canal construction project begins.

1904:      John Fleming invents the diode vacuum tube, which converts an alternating electric current into a one-way signal.

1904:      Charles Perrine discovers the sixth moon of Jupiter.

1904:      Phonograph records replace Edison's wax cylinders in sound recording.

1904:      The United States Engineering Society is founded.

1905:      Albert Einstein publishes several important papers on the theory of relativity, Brownian motion, and the photoelectric effect.

1905:      German physicist Philipp Lenard is awarded the Nobel Prize in physics for his discovery of cathode rays.

1905:      The German Navy launches the first U-boat submarine.

1905:      Ernest Starling, an English physiologist, coins the term "hormone" to identify chemical messengers produced by the endocrine glands.

1906:      Thaddeus Cahill invents telharmonium, a type of telephonic organ.

1906:      The Nobel Prize in physics is awarded to scientist J.J. Thomson for his discovery of the electron.

1906:     December 24 The first radio broadcast originates from Brant Rock, Massachusetts.

1906:     December 31 Lee De Forest invents the triode vacuum tube, which made possible the transmission of human voice, music, and other broadcast signals via wireless telephony.

1907:      The first helicopter flight takes place in France.

1907:      Albert Michelson becomes the first American Nobel laureate when he wins the Nobel Prize in physics for measuring the speed of light.

1908:      The electric razor is invented.

1908:      George Ellery Hale discovers magnetic fields in sunspots.

1908:      The Ford Motor Company introduces the Model T, or "Tin Lizzie," the most popular of the early automobiles.

1908:      Dutch physicist Heike Kamerlingh Onnes produces liquid helium.

1908:      The Holt Company introduces the first tractor with moving treads.

1908:     December 21 Wilbur Wright flies seventy-seven miles in two hours and twenty minutes, winning the Michelin Cup in France.

1909:      The terms gene, genotype, and phenotype are introduced by biologist Wilhelm Johannsen.

1909:     April 6 U.S. Navy commander Robert Peary reaches the North Pole.

1909:     September Psychoanalyst Sigmund Freud makes his only visit to the United States, to lecture at Clark University in Worcester, Massachusetts.

1909:     November 24 Celebrations in England and the United States mark the fiftieth anniversary of the publication of Charles Darwin's On the Origins of Species and the centennial of Darwin's birth.