Historic Appendix – Timeline of Interest

The latest installment for my book….

Historic Appendix

This list of scientific advances since 1800 is meant to give more insight into how recently in human history we developed the foundations for understanding quantum mechanics. A few historic references are thrown in for perspective.

For more detail, I heartily recommend Dr. Asimov’s “Chronology of Science & Discovery”, Harper-Collins 1994, the source from which most of this was selected.

 

1800   Electric batteries (single use). IR light.

1801   UV light. Young discovered that light waves give interference patterns.

1803   Atomic theory.

1804   Steam Locomotives (commercialized later, in 1825).

1807   Fourier Transform mathematics, and the concept of wave basis sets.

1808   Polarized light.

1811   Avagadro’s hypothesis – that all gases have the same N for a given PVT.

1812   The universe was hypothesized to be a giant machine with no free will.

1814   Spectral lines were first observed.

1815   Napoleon lost at Waterloo, a major champion of science in warfare.

First paved road. Prout’s hypothesis that Hydrogen is the fundamental atom.

1817   Chlorophyll discovered. (Biology’s way of trapping photons).

1818   Fresnel realizes light is a transverse wave, rather than a compression wave.

Berzelius puts together the first atomic weight table.

1819   Steamships cross the open ocean.

1820   First linkage between electricity and magnetism.

1821   Faraday uses magnets to move wires differently depending on electrical current.

1823   Electromagnetic theory.

1824   Earth-Sun distance estimates only 2.6% off.

1827   Ohm’s law. Brownian motion observed.

1831   Electric generators, motors. North pole visited.

1838   Distance of stars determined by parallax.

1840   Thermo-chemistry measurements show heat evolution is independent of route.

1842   Doppler effect described.

1843   Work and heat determined to be the same thing – energy.

1844   Telegraph.

1845   Spiral nebulae observed.

1847   Conservation of energy.

1848   Absolute Zero. spectral line shifts.

1849   Speed of light on Earth first measured.

1850   Second Law of Thermodynamics – entropy always increases

1852   Joule-Thompson cooling of expanding gases. Valence theory of electrons (shells).

1855   Lines of electromagnetic force described.

1856   Bessemer process for making steel launches the new industrial era.

1858   Electricity in a “vacuum” opens a new era.

1859   Storage batteries. Spectral lines of the elements. Maxwell’s Kinetic Theory of gases

1860   Internal Combustion engine. Molecular structure.

1861   American Civil War begins.

1862   Pasteur describes germs. Sun is recognized to be mostly hydrogen.

1865   Maxwell’s equations linking electric and magnetic fields with light waves.

Avagadro’s Number first estimated based on kinetic theory of gases.

This is the first time atom mass had been determined.

1866   Nova composition. Earth recognized as having an iron core.

1869   Periodic Table of the Elements.

1876   Telephone. Chemical Thermodynamics. Cathode rays.

1879   Electric Lights.

1881   Michelson invents the Interferometer.

1882   Michelson measures speed of light more accurately than ever before.

1883   Tesla invents AC current. (It is not widely adopted for 10 more years.)

1884   Boltzmann Law relates heat and temperature via statistical mechanics.

1887   Infamous Michelson-Morely experiment, regarding the ether wind concept.

Rubber Tires. Photoelectric effect (light shining on metal allows current to flow).

1888   Radio Waves (first antennas to detect them were not for another 7 years)

1889   Motion Pictures.

1891   Term “electron” invented, with the fundamental quantum of charge.

Gravitational and inertial mass are found to be the same.

1892   Fitzgerald contraction (postulate that distance decreases with speed).

1893   Ford’s first automobile.

1895   X-rays. Cathode ray has negative charge.

Lorentz contraction (postulate that mass increases with speed).

1896   Radiation from Uranium is determined NOT to be light waves.

1897   Cathode rays are electrons, and can be bent by an electric field.

Charge/mass ratios measured, electron is 1/1837 the mass of a proton.

Curie begins work on alpha and beta rays.

1899   Ford’s car company founded.

1900   Quanta. Mass of moving electron said to increase, but could argue force is weaker.

1901   Heat energy is derived from radium. Marconi broadcasts radio from a balloon.

1902   Radioactive Series. Photoelectric effect is determined to be electron ejection

1903   Powered flight – the Wright brothers at Kitty Hawk, NC.

1905   Einstein’s Miracle Year. Publications (all in one year) on:

Special Relativity (does not cover accelerated frames of reference)

The Photo-electric Effect (the basis of his Nobel prize, not this other “stuff”)

Brownian motion explanation.

Mass – Energy conversion.

1906   Alpha particles are seen to be helium-4 nuclei. Third Law of Thermodynamics.

1907   Concept of space-time continuum, and time as a fourth dimension.

1908   Perrin experimentally shows Einstein was right about Brownian Motion, thus measuring the size of atoms and temporarily putting to bed the question of particles vs. waves. (Yes, planes & autos came before atoms were accepted as fact).

Geiger Counter invented.

Ford puts together the assembly line for the model T.

1910   Neon lights.

1911   Rutherford scattering suggests a positively charged nuclear core of atoms.

Millikan measures size of electric charge. Super-conductivity observed.

1912   Cephid variable stars understood, velocity of distant Nebulas thus “measured”.

1913   Isotopes. Bohr postulates atoms have orbits. Stark changes spectra with magnets.

1914   Main Sequence of stars defined.

1914   World War I begins.

1915   Eliptical electron orbits are proposed.

1916   General Relatively improved to include accelerated frames of reference

Black Holes are postulated.

Lewis dot structure first used to predict molecular structures.

1917   Expanding Universe extrapolated from a fudge factor Einstein had to include in general relativity, and later came to regret.

1918   Size of galaxies determined.

1919   Mass spectroscopy and isotopes seen.

First inconclusive experiments about bending light with gravity.

1923   Compton effect (x-rays kicking electrons taken as proof that light is a particle).

DeBroglie suggests “wave-particle” duality.

1925   Pauli Exclusion Principle leads to “spin” quantum number.

1926   Schrodinger describes “wave packets” (my grandparents were adults then!)

1927   Heisenberg points out position and momentum are inter-related and can’t both be pinned down at the same time for a wave packet. This “uncertainty principle” has been turned into so, so much psycho-gobbledy-gook over the years.

Planck’s constant. Electron wave defraction.

LeMaitre postulates Universal creation from a cosmic egg.

1929   Hubble red shift noted.

1930   Dirac speculates about antimatter, with reversed charges.

Babbage’s partially electronic computer.

1931   Neutrons are postulated (the year my parents were born!).

“Resonance” theories used to explain stability of aromatic molecules.

1932   Nucleus is neutrons mixed with protons. Positron observed.

1933   About the third time in history, “Dark Matter” was invoked to explain odd data.

This is the first time that the original observations were in fact correct, however.

Zwicky would definitely not be the last to invoke this fudge factor.

1934   Neutron bombardment, artificial isotopes made. Supernovas and neutrons stars.

1935   Unstable U-235 isotope isolated, “strong interaction” deduced in nucleus.

1936   Neutron absorption

1937   Muons, odd particles from outer space.

1939   World War II officially begins with the Nazi invasion of Poland.

Nuclear Fission and chain reactions.

1940   UF₆ used to extract valuable U-235 from U-238 (1 part in 140).

1942   Atomic reactions observed.

1945   Fission Bomb (A-bomb).

1946   Eniac, the first 100% electronic computer. Nuclear Magnetic Resonance invented.

1947   Pion discussed as an accounting “exchange particle”. Carbon-14 dating.

Chuck Yeager flies 740 mph in level flight, faster than sound. First ever sonic boom.

1948   Transistor Radios. Big Bang Theory proposed. (Come on, this was thought up by guys who thought a device with a single p-n-p junction in it was way cool…..!)

“Nuclear Shells” theory uses magic numbers to explain nuclear stability.

1952   Fusion Bomb (H-bomb).

1953   Maser (microwave laser) invented.

1954   Fission reactors. PV cells.

1955   Antiproton. Colliding galaxies observed.

1956   Neutrino detected.

1959   Solar Wind.

1960   Laser invented in May (month & year I was born!).

Energy of a photon seen to increase due to gravity, “proving” general relativity.

1961   Quark Theory.

1964   Background microwaves in space gave boost to Big Bang theory.

1967   Pulsars.

1970   Discussion of Black Hole evaporation.

1971   First claim of observing a Black Hole.

1976   String Theory proposed.

1977   Inflationary Universe proposed.

1979   Gluons proposed to make quarks stick together and behave as they ought to.

1989   Pons & Fleischmann announces “Cold Fusion” in solid state, setting off a circus.

1990   Hubble Space Telescope Launched.