The confusion over the aluminum/aluminium spelling arose because of some uncharacteristic indecisiveness on Davy’s part. When he first isolated the element in 1808, he called it alumium. For some reason he thought better of that and changed it to aluminum four years later. Americans dutifully adopted the new term, but many British users disliked aluminum, pointing out that it disrupted the -ium pattern established by sodium, calcium, and strontium, so they added a vowel and syllable.
14
The principle led to the much later adoption of Avogadro’s number, a basic unit of measure in chemistry, which was named for Avogadro long after his death. It is ume of any other gas). Its value is placed at 6.0221367 x 1023, which is an enormously large number. Chemistry students have long amused themselves by computing just how large a number it is, so I can report that it is equivalent to the number of popcorn kernels needed to cover the United States to a depth of nine miles, or cupfuls of water in the Pacific Ocean, or soft drink cans that would, evenly stacked, cover the Earth to a depth of 200 miles. An equivalent number of American pennies would be enough to make every person on Earth a dollar trillionaire. It is a big number.
15
Specifically it is a measure of randomness or disorder in a system. Darrell Ebbing, in the textbook General Chemistry, very usefully suggests thinking of a deck of cards. A new pack fresh out of the box, arranged by suit and in sequence from ace to king, can be said to be in its ordered state. Shuffle the cards and you put them in a disordered state. Entropy is a way of measuring just how disordered that state is and of determining the likelihood of particular outcomes with further shuffles. Of course, if you wish to have any observations published in a respectable journal you will need also to understand additional concepts such as thermal nonuniformities, lattice distances, and stoichiometric relationships, but that’s the general idea.
16
Planck was often unlucky in life. His beloved first wife died early, in 1909, and the younger of his two sons was killed in the First World War. He also had twin daughters whom he adored. One died giving birth. The surviving twin went to look after the baby and fell in love with her sister’s husband. They married and two years later she died in childbirth. In 1944, when Planck was eighty-five, an Allied bomb fell on his house and he lost everything— papers, diaries, a lifetime of accumulations. The following year his surviving son was caught in a conspiracy to assassinate Hitler and executed.
17
Einstein was honored, somewhat vaguely, “for services to theoretical physics.” He had to wait sixteen years, till 1921, to receive the award—quite a long time, all things considered, but nothing at all compared with Frederick Reines, who detected the neutrino in 1957 but wasn’t honored with a Nobel until 1995, thirty-eight years later, or the German Ernst Ruska, who invented the electron microscope in 1932 and received his Nobel Prize in 1986, more than half a century after the fact. Since Nobel Prizes are never awarded posthumously, longevity can be as important a factor as ingenuity for prizewinners.
18
How c came to be the symbol for the speed of light is something of a mystery, but David Bodanis suggests it probably came from the Latin celeritas, meaning swiftness. The relevant volume of the Oxford English Dictionary, compiled a decade before Einstein’s theory, recognizes c as a symbol for many things, from carbon to cricket, but makes no mention of it as a symbol for light or swiftness.
19
Named for Johann Christian Doppler, an Austrian physicist, who first noticed the effect in 1842. Briefly, what happens is that as a moving object approaches a stationary one its sound waves become bunched up as they cram up against whatever device is receiving them (your ears, say), just as you would expect of anything that is being pushed from behind toward an immobile object. This bunching is perceived by the listener as a kind of pinched and elevated sound (the yee). As the sound source passes, the sound waves spread out and lengthen, causing the pitch to drop abruptly (the yummm).
20
The name comes from the same Cavendishes who produced Henry. This one was William Cavendish, seventh Duke of Devonshire, who was a gifted mathematician and steel baron in Victorian England. In 1870, he gave the university ?6,300 to build an experimental lab.
21
Geiger would also later become a loyal Nazi, unhesitatingly betraying Jewish colleagues, including many who had helped him.
22
There is a little uncertainty about the use of the word uncertainty in regard to Heisenberg’s principle. Michael Frayn, in an afterword to his play Copenhagen, notes that several words in German—Unsicherheit, Unscharfe, Unbestimmtheit— have been used by various translators, but that none quite equates to the English uncertainty. Frayn suggests that indeterminacy would be a better word for the principle and indeterminability would be better still.
