Easter Holiday

April 16-23, 2014

Tikalon is on Easter holiday. The next article will be posted on Wednesday, April 23, 2014.

Although Christmas is more popular, especially among children, Easter is the theologically most important holiday in Christendom. As are most things in today's world, Easter has been secularized, and we'll see many more bunnies, chicks, and flowers than religious symbols. Easter is a movable feast; so, unlike Christmas, it occurs on different dates in different years. This year, Easter is on April 20, which is the birthday of three famous physicists and one likewise famous astronaut and engineer. (Photo by Zeisterre, via Wikimedia Commons.)

George Robert Stibitz (April 20, 1904 - January 31, 1995), a mathematical physicist working at Bell Laboratories, built a binary adder in his kitchen in November, 1937. This battery-powered circuit had just two light bulbs, two relays, and two switches constructed from bits of metal, but it was the first electromechanical computer circuit. This prototype led to the design and construction in 1939-1940 of an electromechanical computer capable of multiplication and division of complex numbers. That computer cost $20,000, which is more than $300,000 in today's money.[1-2]

An electric relay, not that different from the ones that George Stibitz used in his two-bit binary adder. In electronics circles, Sibitz's circuit is known as a "breadboard." (Photo by the author).

Kai Manne Börje Siegbahn (20 April 1918 - 20 July 2007) was a Swedish physicist who shared the 1981 Nobel Prize in Physics for his development of X-ray photoelectron spectroscopy (XPS).

Karl Alexander Müller (April 20, 1927 -) is a Swiss physicist who shared the 1987 Nobel Prize in Physics with Georg Bednorz for their discovery of high temperature superconductivity. Most critically, some high temperature superconductors operate at liquid nitrogen, rather than liquid helium, temperatures.

Levitation of a magnet above the high temperature superconductor, YBa2Cu3O7, at -196°C. Levitation is the consequence of the Meissner effect. (Photo by Julien Bobroff, Frederic Bouquet and Jeffrey Quilliam, Laboratory of Solid State Physics (Orsay, France), via Wikimedia Commons.)

Donald Roy Pettit (April 20, 1955 -) is a chemical engineer and NASA astronaut. Pettit had two tours of duty on the International Space Station, and he was a crew member of one Space Shuttle mission. Engineering, or perhaps coffee, is Pettit's passion, since he invented a zero-g coffee cup that can be used without a straw. The cup makes use of surface tension and capillarity to hold and deliver the liquid. As explained in his patent abstract,

"A beverage cup comprised by an open top and at least one channel defined by a corner with an acute angle so placed that the channel runs along the cup side from the cup bottom to the cup rim. In the absence of significant gravitational force as found in microgravity, weightless or weightlessness of spacecraft or the International Space Station, capillary forces between the beverage and the cup wall allow the beverage to creep along the channel and be in near proximity to the open cup rim. Lips placed at or near the channel at the rim can readily sip, drink, and consume the beverage without the need for a straw and without undue spillage for normal drinking motions including toasting. The channel conducts the beverage via capillary forces from the bottom of the cup to the rim until the beverage has been consumed."[3]

Fig.1 of US Patent No. 8,074,827, 'Beverage cup for drinking use in spacecraft or weightless environments,' by Donald Roy Pettit, Mark Milton Weislogel, Paul Concus and Robert Finn, Dec 13, 2011. (Via Google Patents.)[3]

References:

1. Georgi Dalakov, "Relay computers of George Stibitz," History of Computers, Computing and Internet Web Site.
2. Stibitz calculators at Bell Labs, Chapter Four of the History of Mechanized Thought, Haverford College Web Site.
3. Donald Roy Pettit, Mark Milton Weislogel, Paul Concus and Robert Finn, "Beverage cup for drinking use in spacecraft or weightless environments," US Patent No. 8,074,827, Dec 13, 2011.