Flux Capacitor Day

posted Wednesday, 5 November 2014

The premise of the 1985 film Back to the Future is that time travel (in a direction other than into the future) is possible. In the movie, the mad scientist character Dr. Emmett Brown (Christopher Lloyd) tells the story of how he invented the "flux capacitor" on this day in 1955.

Dr. Emmett Brown with a diagram of the flux capacitor

That was the day I invented time travel. I remember it vividly. I was standing on the edge of my toilet hanging a clock, the porcelain was wet, I slipped, hit my head on the edge of the sink, and when I came to I had revelation. A vision. A picture in my head. A picture of this. This is what makes time travel possible. The flux capacitor.

A capacitor is an electronic device for storing separated electric charges. Capacitors are used in power supplies (to reduce fluctuations in DC voltages), condenser microphones, MEMS accelerometers (like those found in game controllers or car airbag triggers), and random access computer memory (RAM).

The word flux has many meanings, but in physics flux is the "rate of flow" of some quantity through an area. The thing "flowing" could be a fluid (like air or water), some form of energy (like heat, light, or radio waves), or a field (gravitational, electric, or magnetic). In the case of fields, however, the idea of "flow" is more poetic than literal.

The phrase "flux capacitor" is an example of a portmanteau — two different ideas joined together. Portmanteau is itself a portmanteau of the French words portez (to carry) and manteau (coat). Portmanteau makes sense as a word since it refers to a bag or case used to carry clothing — what I would call luggage. In contrast, "flux capacitor" is nonsense. It’s an example of science fiction technobabble. If you say it with enough conviction it almost sounds real, but that doesn’t make it so.

November 5, 1950 Flux Capacitor

Ivy Mike: First thermonuclear weapon test (1952)

posted Friday, 31 October 2014

Date: 1 November 1952 (7:15 AM New Zealand Standard Time)
Code name: Ivy Mike
Type: two-stage fusion
Yield: 10.4 million tons of TNT
Location: Enewetak Atoll, Marshall Islands (Note the obvious deep hole in the lagoon where the island of Elugelab used to be.)

Tsar Bomba: Most powerful nuclear weapon test (1961)

posted Thursday, 30 October 2014

Date: 30 October 1961
Code name: Tsar Bomba (Царь бомба)
Type: air drop, two-stage fusion
Yield: 50 megatons of TNT
Location: Novaya Zemlya, Russia

New York City Subway opened to riders (1904)

posted Monday, 27 October 2014

New York City Subway opened to riders (1904)

Nedelin Disaster (1960)

posted Friday, 24 October 2014

The Nedelin Distaster occurred on this day in 1960 at the Baikonur Cosmodrome in Kazakhstan. A two-stage R-16 ICBM prototype exploded on the launch pad killing over 100 engineers, technicians, and military personnel including the commander of the program Mitrofan Nedelin. The second stage of the rocket accidentally fired, which caused the first stage below it to explode. The disaster occurred during preflight operations as the rocket was being worked on and while dignitaries milled about on the launch pad.

Mole Day

posted Thursday, 23 October 2014

Mole Day commemorates the international unit for amount of material. A mole is like a dozen. It’s a name for a number of things. One mole of anything consists of 6.02 × 1023 of those things. The mole was chosen so that the mass of a mole of something in grams is the same value as the mass of one of those things in atomic mass units. One mole of water consists of 6.02 × 1023 water molecules and weighs approximately 18 g since one water molecule weighs …

 H2  +  O 
 2(1 proton)  +  1(8 protons + 8 neutrons) 
 2 atomic mass units  +  16 atomic mass units 
 18 atomic mass units 

The number 6.02 × 1023 is known as Avogadro’s constant in honor of the Italian chemist Lorenzo Romano Amedeo Carlo Avogadro (1776–1856) who conceived of this scheme for quantifying amounts of material in 1811. He never calculated the constant himself (probably because he used up all the space in his lab log writing his incredibly long name). That was first done by the Austrian chemist Johann Josef Loschmidt (1821–1895) in 1865.

Avogadro’s constant is a number that’s so large it’s difficult to comprehend. The only things that anyone would ever measure in moles would be tiny — atoms or molecules. When applied to everyday objects, the results are ridiculous.

Mole Day was started by a group of chemistry teachers in the 1980s as a way to raise awareness about chemistry. The Mole Day website is run by a US tax-exempt organization registered in the State of Wisconsin called the National Mole Day Foundation, Inc. IRS records published at indicate assets in excess of $30,000! I’ve been to their website. I’ve worked on several websites. The Mole Day website is no $30,000 website. The page layouts look locked in mid ’90s html and their jokes are so bad they make the notoriously lame jokes of scientists, mathematicians, and engineers seem uproariously funny in comparison.

  1. What is Avogadro’s favorite kind of music?
  2. Rock ‘N’ Mole

    Simply horrible.

    The best joke on Mole Day is the choice of the day itself. Mole Day begins every year at 6:02 AM on October 23. If one uses the American style of writing dates with the month preceding the day, that’s 6:02 10/23. There is no equivalent to Mole Day in Europe where the tradition is to write the day before the month. There is no 10th day in the 23rd month since there is no 23rd month in Europe or anywhere else in the universe as we currently know it. Mole Day ends at 6:02 PM on the same day, which is another witticism that wouldn’t work in Europe where 6:02 PM would be written 18:02.

    I feel sorry for the Europeans missing out on this great event. There is a serious deficiency in nerd-related holidays outside the US. Even Pi Day (3/14) doesn’t work for them. Of course, we can all enjoy Powers of Ten Day (10/10), which was two weeks ago (or fifty weeks away). The only other days I know of with international numerical significance are the Square Root Days (4/4/16, 5/5/25, 6/6/36, etc.).

    Physicists have it a lot easier than the mathematicians and chemists. We have Newton’s birthday (December 25th) which always seems to be filled with lots of celebration.

    Trans-Siberian Railroad completed (1916)

    posted Saturday, 18 October 2014

    Train service between St. Petersburg (then known as Petrograd) in the west and Vladivostok in the east began on this day in 1916 (October 18 in the Gregorian calendar, October 5 in the old Julian calendar). It is still the longest continuous rail line in the world.

    Source: University of South Florida

    596: First Chinese nuclear weapon test (1964)

    posted Thursday, 16 October 2014

    Date: 16 October 1964 (3:00 PM China Standard Time)
    Code name: 596
    Type: plutonium fission
    Yield: 22 thousand tons of TNT
    Location: Lop Nur, Xin JIang, China

    Chuck Yaeger breaks the sound barrier (1947)

    posted Tuesday, 14 October 2014

    On October 14, 1947, in the rocket powered Bell X-1, Capt. Charles E. Yeager flew faster than sound for the first time.

    Source: NASA

    Columbus and crew see America for the first time (1492)

    posted Sunday, 12 October 2014

    Crossing the Atlantic Ocean took 40 days. Sailor Rodrigo de Triana, who was stationed in the crow’s nest for the night watch, was the first member of Columbus’ crew to sight what is now known as the Bahamas. Columbus explored the Caribbean for 3 months before heading for the Azores.