A Timeline of Atomic Spectroscopy
Oct 01, 2006
By Volker Thomsen
Volume 21, Issue 10
Editado por paoleb:
1666: Isaac Newton (1642–1727) (Figure 1) shows that the white light from the sun could be dispersed into a continuous series of colors. He coined the word “spectrum.” His apparatus, an aperture to define a light beam, a lens, a prism, and a screen, was the first spectroscope. He suggested that light was composed of minute corpuscles (particles) moving at high speed.
1678: Dutch mathematician and physicist Christian Huygens (1629–1695) proposes the wave theory of light.
Figure 2: Alessandro Volta.
1776: Italian physicist Alessandro Volta (1745–1827) (Figure 2) uses his “perpetual electrophorus” device for producing static electric charges to spark various materials. He notes different colors with different materials. Eventually he is able to identify certain gases by the colors emitted when sparked.
1826: Scotsman William Henry Fox Talbot (1800–1877) observes that different salts produce colors when placed in a flame.
1861: The element thallium is discovered by Sir William Crookes (1832–1919) (Figure 4) using the method of spectral analysis.
1868: Swedish physicist Anders Jonas Ångström (1814–1874) (Figure 5) publishes a detailed study of the wavelengths of solar spectral lines, expressed in units of 10–10 meters. This unit is now known as the angstrom (Å). He is considered one of the fathers of modern spectroscopy.
1895: German physicist Wilhelm Conrad Röntgen (1845–1923) (Figure 9) discovers X-rays and experiments extensively to discern their properties. He is awarded the first Nobel Prize in physics for his discovery (1901).
1900: German physicist Max Planck (1858–1947) introduces the quantum concept. He is awarded the 1918 Nobel Prize in physics.
1905: Albert Einstein (1879–1955) explains the photoelectric effect, for which he was awarded the Nobel Prize in 1921. His theory explains that when a photon strikes the surface of some materials, an electron is ejected. This same year, he publishes his “Special Theory of Relativity.”
1913: Danish physicist Niels Bohr (1885–1962) (Figure 12) presents his theory of the atom, which explains the Rydberg formula of simple spectra. He receives the 1922 Nobel Prize in physics.
1923: Austrian physicist Lise Meitner 1878–1968) (Figure 16) discovers the radiationless transition now known the Auger effect (see 1925).
1925: German physicist Werner Heisenberg (1901–1976) (Figure 17) establishes matrix mechanics. He receives the Nobel Prize in 1932.
1926: German physicist Erwin Schrödinger (1887–1961) (Figure 18) develops wave mechanics and presents the equation that now bears his name. He is awarded the Nobel Prize in physics in 1933.
1926: Schrödinger shows that his wave mechanics and Heisenberg’s matrix mechanics are mathematically equivalent.
1927:Heisenberg develops his uncertainty principle, which explains the natural linewidth of spectral lines.