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| .p101 [[ | ]] | .p101 [[ https://en.wikipedia.org/wiki/Kibble_balance | Kibble balance ]] new definition of Kilogram based on Planck's constant measured with Josephson effect and [[ https://en.wikipedia.org/wiki/Quantum_Hall_effect | Quantum Hall effect ]] |
http://wiki.keithl.com/SevenMeasures
The Seven Measures of the World
Piero Martin 2021/2023 CedarMill 530.18 Martin
fusion researcher at University of Padova
Translated from Italian by Gregory Conti
p008 stere cubic meter of cut firewood
- p008 meter defined as 1e-7 of distance from North Pole to Equator through Paris
p009 1960 Oct 15 Hamburg: John/Paul/George/Ringo record Gershwin's Summertime Pete Best?
p009 Original Système international d'unités was meter, second, kilogram, ampere, Kelvin, candela; mole added in 1971
- p011 Redefined 2018 Nov 16 by fundamental physical constants
p016 1946 May 3 Einstein attends Lincoln University graduation, "first college degree for an African American student"
er, no, Alexander Lucius Twilight 1823 from Middlebury College in Vermont
p021 Roman passus 1.48 meters 4.854 feet, left+right step, hence 29 inches per step
p026 International Bureau of Weights and Measures in Sèvres? (or Saint-Cloud?) near Paris
p028 Heinrich Hertz 1893? Maxwell electromagnetic waves "will have any practical application"
p039 "c" either constant or celeritas (velocity)
p049 Luxor Obelisk traded for mechanical clock in 1830
p051 Galileo timing cathedral lamp swing, isochronism of the pendulum
p052 Galileo draws first pendulum clock?
- his son Vincenzo makes prototype? citation needed
p052 Christiaan Huygens first functional prototype 1656
p054 Beethoven may have misread his metronome, too-fast tempo on symphony scores compared to modern interpretations
p055 Quartz wristwatch 32768 Hz crystal, accurate to 15 seconds per month ? ... my digital watch is better than 5 seconds in six months
p057 Cesium 133 clocks 9,192,631,770 Hz. Book error, says "per minute"
p058 NIST Clock accuracy one second in 3e8 years, 1e-16
p060 Picasso sketch: "it didn't take eight seconds to make this drawing, it took eighty years"
p069 Atomic clock in Fréjus Road Tunnel altitude 1200m ran faster than in Turin 200m
- p069 special relativity slows GPS clocks by 7μs per day ... no faster, orbiting about 94% out of the gravity well minus 3% for orbital velocity. 7 microseconds or two kilometers per day
p074 Laura Fermi Jewish, so Enrico and wife left Italy in 1938
p074 Eugene Fubini ditto, followed Fermis to US
p076 Fritz Haber also Jewish, developed Zyklon-B, died in Switzerland 1934
p077 Erwin Planck hanged 1945 Jan 23 for Operation Valkyrie Hitler assassination attempt 19444
p079 Talent 26? Kg ... if silver, a month's salary for trireme crew of 200
p081 carat was weight of 200 mg carob seed
- p081 kilogram / liter of water redefined from 0℃ to maximum density 4℃, more stable
p082 1875 International Prototype Kilogram gained 50 micrograms in 100 years
- p085 1919 eclipse test of relativity, wild New York Times headline reported from London by NYT golf correspondent
p085 anecdote: Eddington told 3 people understood relativity; he wondered who the third was.
p085 Feynman: many people understand relativity, nobody understands quantum mechanics
p090 Svante Arrhenius Worlds in the Making 1908 future ages better climate
p095 Cumaean Sibyl
- "You will go, you will return, never in war you will perish" OR
- "You will go, you will return never, in war you will perish"
p101 Kibble balance new definition of Kilogram based on Planck's constant measured with Josephson effect and Quantum Hall effect