Contact Evelyn Kinzel, 137 St. Albert Hall, mailbox 274 in Erskine Hall,


"The past is a foreign country; they do things differently there."  L.P.Hartley

History of Science SCI 348

Reading Assignments

in addition to Joy Hakim’s The Story of Science

before Class 2

How science is not done

Wishful thinking makes it so for Don Quixote.

If you don't know what a fulling mill is, look it up, for example, at

 Don Quixote by Miguel de Cervantes Saavedra, translated by John Ormsby, published in 1605, published on the Worldwide Web by Project Gutenberg,



It now began to rain a little, and Sancho was for going into the fulling mills, but Don Quixote had taken such an abhorrence to them on account of the late joke that he would not enter them on any account; so turning aside to right they came upon another road, different from that which they had taken the night before. Shortly afterwards Don Quixote perceived a man on horseback who wore on his head something that shone like gold, and the moment he saw him he turned to Sancho and said:

"I think, Sancho, there is no proverb that is not true, all being maxims drawn from experience itself, the mother of all the sciences, especially that one that says, 'Where one door shuts, another opens.' I say so because if last night fortune shut the door of the adventure we were looking for against us, cheating us with the fulling mills, it now opens wide another one for another better and more certain adventure, and if I do not contrive to enter it, it will be my own fault, and I cannot lay it to my ignorance of fulling mills, or the darkness of the night. I say this because, if I mistake not, there comes towards us one who wears on his head the helmet of Mambrino, concerning which I took the oath thou rememberest."

"Mind what you say, your worship, and still more what you do," said Sancho, "for I don't want any more fulling mills to finish off fulling and knocking our senses out."

"The devil take thee, man," said Don Quixote; "what has a helmet to do with fulling mills?"

"I don't know," replied Sancho, "but, faith, if I might speak as I used, perhaps I could give such reasons that your worship would see you were mistaken in what you say."

"How can I be mistaken in what I say, unbelieving traitor?" returned Don Quixote; "tell me, seest thou not yonder knight coming towards us on a dappled grey steed, who has upon his head a helmet of gold?"

"What I see and make out," answered Sancho, "is only a man on a grey ass like my own, who has something that shines on his head."

"Well, that is the helmet of Mambrino," said Don Quixote; "stand to one side and leave me alone with him; thou shalt see how, without saying a word, to save time, I shall bring this adventure to an issue and possess myself of the helmet I have so longed for."

"I will take care to stand aside," said Sancho; "but God grant, I say once more, that it may be marjoram and not fulling mills."

"I have told thee, brother, on no account to mention those fulling mills to me again," said Don Quixote, "or I vow--and I say no more-I'll full the soul out of you."

Sancho held his peace in dread lest his master should carry out the vow he had hurled like a bowl at him.

The fact of the matter as regards the helmet, steed, and knight that Don Quixote saw, was this. In that neighbourhood there were two villages, one of them so small that it had neither apothecary's shop nor barber, which the other that was close to it had, so the barber of the larger served the smaller, and in it there was a sick man who required to be bled and another man who wanted to be shaved, and on this errand the barber was going, carrying with him a brass basin; but as luck would have it, as he was on the way it began to rain, and not to spoil his hat, which probably was a new one, he put the basin on his head, and being clean it glittered at half a league's distance. He rode upon a grey ass, as Sancho said, and this was what made it seem to Don Quixote to be a dapple-grey steed and a knight and a golden helmet; for everything he saw he made to fall in with his crazy chivalry and ill-errant notions; and when he saw the poor knight draw near, without entering into any parley with him, at Rocinante's top speed he bore down upon him with the pike pointed low, fully determined to run him through and through, and as he reached him, without checking the fury of his charge, he cried to him:

"Defend thyself, miserable being, or yield me of thine own accord that which is so reasonably my due."

The barber, who without any expectation or apprehension of it saw this apparition coming down upon him, had no other way of saving himself from the stroke of the lance but to let himself fall off his ass; and no sooner had he touched the ground than he sprang up more nimbly than a deer and sped away across the plain faster than the wind.

He left the basin on the ground, with which Don Quixote contented himself, saying that the pagan had shown his discretion and imitated the beaver, which finding itself pressed by the hunters bites and cuts off with its teeth that for which, by its natural instinct, it knows it is pursued.

He told Sancho to pick up the helmet, and he taking it in his hands said:

"By God the basin is a good one, and worth a real of eight if it is worth a maravedis," and handed it to his master, who immediately put it on his head, turning it round, now this way, now that, in search of fitment, and not finding it he said, "Clearly the pagan to whose measure this famous head-piece was first forged must have had a very large head; but the worst of it is half of it is wanting."

When Sancho heard him call the basin a headpiece he was unable to restrain his laughter, but remembering his master's wrath he checked himself in the midst of it.

"What art thou laughing at, Sancho?" said Don Quixote.

"I am laughing," said he, "to think of the great head the pagan must have had who owned this helmet, for it looks exactly like a regular barber's basin."

"Dost thou know what I suspect, Sancho?" said Don Quixote; "that this wonderful piece of this enchanted helmet must by some strange accident have come into the hands of some one who was unable to recognise or realise its value, and who, not knowing what he did, and seeing it to be of the purest gold, must have melted down one half for the sake of what it might be worth, and of the other made this which is like a barber's basin as thou sayest; but be it as it may, to me who recognise it, its transformation makes no difference, for I will set it to rights at the first village where there is a blacksmith, and in such style that that helmet the god of smithies forged for the god of battles shall not surpass it or even come up to it; and in the meantime I will wear it as well as I can, for something is better than nothing; all the more as it will be quite enough to protect me from any chance blow of a stone."


Homer explains events as divine intervention.

Iliad, likely composed by Homer between 800 and 700 BCE,

Book 1

Sing, O goddess, the anger of Achilles son of Peleus, that brought countless ills upon the Achaeans. Many a brave soul did it send hurrying down to Hades, and many a hero did it yield a prey to dogs and vultures, for so were the counsels of Jove fulfilled from the day on which the son of Atreus, king of men, and great Achilles, first fell out with one another.

And which of the gods was it that set them on to quarrel? It was the son of Jove and Leto; for he was angry with the king and sent a pestilence upon the host to plague the people, because the son of Atreus had dishonoured Chryses his priest. Now Chryses had come to the ships of the Achaeans to free his daughter, and had brought with him a great ransom: moreover he bore in his hand the sceptre of Apollo wreathed with a suppliant's wreath, and he besought the Achaeans, but most of all the two sons of Atreus, who were their chiefs.

"Sons of Atreus," he cried, "and all other Achaeans, may the gods who dwell in Olympus grant you to sack the city of Priam, and to reach your homes in safety; but free my daughter, and accept a ransom for her, in reverence to Apollo, son of Jove."

On this the rest of the Achaeans with one voice were for respecting the priest and taking the ransom that he offered; but not so Agamemnon, who spoke fiercely to him and sent him roughly away. "Old man," said he, "let me not find you tarrying about our ships, nor yet coming hereafter. Your sceptre of the god and your wreath shall profit you nothing. I will not free her. She shall grow old in my house at Argos far from her own home, busying herself with her loom and visiting my couch; so go, and do not provoke me or it shall be the worse for you."

The old man feared him and obeyed. Not a word he spoke, but went by the shore of the sounding sea and prayed apart to King Apollo whom lovely Leto had borne. "Hear me," he cried, "O god of the silver bow, that protectest Chryse and holy Cilla and rulest Tenedos with thy might, hear me oh thou of Sminthe. If I have ever decked your temple with garlands, or burned your thigh-bones in fat of bulls or goats, grant my prayer, and let your arrows avenge these my tears upon the Danaans."

Thus did he pray, and Apollo heard his prayer. He came down furious from the summits of Olympus, with his bow and his quiver upon his shoulder, and the arrows rattled on his back with the rage that trembled within him. He sat himself down away from the ships with a face as dark as night, and his silver bow rang death as he shot his arrow in the midst of them. First he smote their mules and their hounds, but presently he aimed his shafts at the people themselves, and all day long the pyres of the dead were burning.

For nine whole days he shot his arrows among the people, but upon the tenth day Achilles called them in assembly—moved thereto by Juno, who saw the Achaeans in their death-throes and had compassion upon them. Then, when they were got together, he rose and spoke among them.

"Son of Atreus," said he, "I deem that we should now turn roving home if we would escape destruction, for we are being cut down by war and pestilence at once. Let us ask some priest or prophet, or some reader of dreams (for dreams, too, are of Jove) who can tell us why Phoebus Apollo is so angry, and say whether it is for some vow that we have broken, or hecatomb that we have not offered, and whether he will accept the savour of lambs and goats without blemish, so as to take away the plague from us."

With these words he sat down, and Calchas son of Thestor, wisest of augurs, who knew things past present and to come, rose to speak. He it was who had guided the Achaeans with their fleet to Ilius, through the prophesyings with which Phoebus Apollo had inspired him. With all sincerity and goodwill he addressed them thus:—

"Achilles, loved of heaven, you bid me tell you about the anger of King Apollo, I will therefore do so; but consider first and swear that you will stand by me heartily in word and deed, for I know that I shall offend one who rules the Argives with might, to whom all the Achaeans are in subjection. A plain man cannot stand against the anger of a king, who if he swallow his displeasure now, will yet nurse revenge till he has wreaked it. Consider, therefore, whether or no you will protect me."

And Achilles answered, "Fear not, but speak as it is borne in upon you from heaven, for by Apollo, Calchas, to whom you pray, and whose oracles you reveal to us, not a Danaan at our ships shall lay his hand upon you, while I yet live to look upon the face of the earth—no, not though you name Agamemnon himself, who is by far the foremost of the Achaeans."

Thereon the seer spoke boldly. "The god," he said, "is angry neither about vow nor hecatomb, but for his priest's sake, whom Agamemnon has dishonoured, in that he would not free his daughter nor take a ransom for her; therefore has he sent these evils upon us, and will yet send others. He will not deliver the Danaans from this pestilence till Agamemnon has restored the girl without fee or ransom to her father, and has sent a holy hecatomb to Chryse. Thus we may perhaps appease him."


How science and history are done nowadays

Herodotus (c484–c425 BCE) wrote of what he saw and what he was told and usually as a straightforward reporter. The Histories includes the Persian Wars, fought between Persia and Greece in the 500s and 400s BCE.  As the earliest known rationalist historian, Herodotus is called the father of history.

The Histories by Herodotus, 5th century BCE,

[8.97] Xerxes, when he saw the extent of his loss, began to be afraid lest the Greeks might be counselled by the Ionians, or without their advice might determine to sail straight to the Hellespont and break down the bridges there; in which case he would be blocked up in Europe, and run great risk of perishing. He therefore made up his mind to fly; but, as he wished to hide his purpose alike from the Greeks and from his own people, he set to work to carry a mound across the channel to Salamis, and at the same time began fastening a number of Phoenician merchant ships together, to serve at once for a bridge and a wall. He likewise made many warlike preparations, as if he were about to engage the Greeks once more at sea. Now, when these things were seen, all grew fully persuaded that the king was bent on remaining, and intended to push the war in good earnest. Mardonius, however, was in no respect deceived; for long acquaintance enabled him to read all the king's thoughts. Meanwhile, Xerxes, though engaged in this way, sent off a messenger to carry intelligence of his misfortune to Persia.

[8.98] Nothing mortal travels so fast as these Persian messengers. The entire plan is a Persian invention; and this is the method of it. Along the whole line of road there are men (they say) stationed with horses, in number equal to the number of days which the journey takes, allowing a man and horse to each day; and these men will not be hindered from accomplishing at their best speed the distance which they have to go, either by snow, or rain, or heat, or by the darkness of night. The first rider delivers his despatch to the second and the second passes it to the third; and so it is borne from hand to hand along the whole line, like the light in the torch-race, which the Greeks celebrate to Vulcan. The Persians give the riding post in this manner, the name of "Angarum."


before Class 3

Naming Rights

Where science is done

Of course, the United States has not always been the leader in science.  Before us it was Ionia (Greece) and Alexandria (North Africa) and Baghdad and western Europe and probably other places whose work we don't know much about.

© Neil deGrasse Tyson Naming Rights From Natural History magazine, February 2003

If you visit the gift shop at the Hayden Planetarium in New York City, youll find all manner of space-related paraphernalia for sale. Familiar things are thereplastic models of the Space Shuttle and the International Space Station, cosmic refrigerator magnets, Fisher space pens. But unusual things are there toodehydrated astronaut ice cream, astronomy Monopoly, Saturn-shaped salt-and-pepper shakers. And thats not to mention the weird things such as Hubble Telescope pencil erasers, Mars rock super-balls, and edible space worms. With hindsight, youd expect a place like the planetarium to stock such stuff. But something much deeper is going on. The gift shop bears silent witness to the iconography of a half-century of American scientific discovery.

            In the twentieth century, astronomers in the United States discovered galaxies, the expanding of the universe, the nature of supernovas, quasars, black holes, gamma ray bursts, the origin of the elements, the cosmic microwave background, and most of the known planets in orbit around solar systems other than our own. Although the Russians reached one or two places before us, we sent space probes to Mercury, Venus, Jupiter, Saturn, Uranus, and Neptune. American probes have also landed on Mars and on the asteroid Eros. American astronauts have walked on the Moon. And nowadays most Americans take all this for granted, which is practically a working definition of culture: something everyone does or knows about, but no longer actively notices.

            While shopping at the supermarket, most Americans arent surprised to find an entire aisle filled with sugar-loaded, ready-to-eat breakfast cereals. But foreigners notice this kind of thing immediately, just as traveling Americans immediately notice that supermarkets in Italy have vast selections of pasta, and that markets in China and Japan offer an astonishing variety of rice. The flip side of not noticing your own culture is one of the great pleasures of foreign travel: realizing what you hadnt noticed about your own country, and noticing what the people of other countries no longer realize about themselves.

            Snobby people from other countries like to make fun of the U.S. for its abbreviated history and its uncouth culture, particularly compared with the millennial legacies of Europe, Africa, and Asia. But five hundred years from now historians will surely see the twentieth century as the American centurythe one in which American discoveries in science and technology, rank high among the worlds list of treasured achievements.

            Obviously the U.S. has not always sat atop the ladder of science. And theres no guarantee or even likelihood that American preeminence will continue. As the capitals of science and technology move from one nation to another, rising in one era and falling in the next, each culture leaves its mark on the continual attempt of our species to understand the universe and our place in it. When historians write their accounts of such world events, the traces of a nations presence on center stage sit prominently in the timeline of civilization.

Many factors influence how and why a nation will make its mark at a particular time in history. Strong leadership matters. So does access to resources. But something else must be presentsomething less tangible, but with the power to drive an entire nation to focus its emotional, cultural, and intellectual capital on creating islands of excellence in the world. Those who live in such times often take for granted what they have created, on the blind assumption that things will continue forever as they are, leaving their achievements susceptible to abandonment by the very culture that created it.

            Beginning in the 700s and continuing for nearly 400 yearswhile Europes Christian zealots were disemboweling hereticsthe Abbasid caliphs created a thriving intellectual center of arts, sciences, and medicine for the Islamic world in the city of Baghdad. Muslim astronomers and mathematicians built observatories, designed advanced timekeeping tools, and developed new methods of mathematical analysis and computation. They preserved the extant works of science from ancient Greece and elsewhere and translated them into Arabic. They collaborated with Christian and Jewish scholars. And Baghdad became a center of enlightenment. Arabic was, for a time, the lingua franca of science.

            The influence of these early Islamic contributions to science remains to this day. For example, so widely distributed was the Arabic translation of Ptolemys magnum opus on the geocentric universe, (originally written in Greek in A.D. 150), that even today, in all translations, the work is known by its Arabic title Almagest, or The Greatest.

            The Iraqi mathematician and astronomer Muhammad ibn Musa al-Khwarizmi gave us the words algorithm, (from his name, al-Khwarizmi) and algebra (from the word al-jabr in the title of his book on algebraic calculation). And the worlds shared system of numerals0, 1, 2, 3, 4, 5, 6, 7, 8, 9though Hindi in origin, were neither common nor widespread until Muslim mathematicians exploited them. The Muslims, furthermore made full and innovative use of the zero, which did not exist among Roman numerals or in any established numeric system. Today, with legitimate reason, the ten symbols are internationally referred to as Arabic numerals.

Portable, ornately etched, brass astrolabes were also developed by Muslims, from ancient prototypes, and became as much works of art as tools of astronomy. An astrolabe projects the domed heavens onto a flat surface and, with layers of rotating and non-rotating dials, resembles the busy, ornate face of a grandfather clock. It enabled astronomers, as well as others, to measure the positions of the Moon and the stars on the sky, from which they could deduce the time a generally useful thing to do, especially when its time to pray. The astrolabe was so popular and influential as a terrestrial connection to the cosmos that, to this day, nearly two-thirds of the brightest stars in the night sky retain their Arabic names.

            The name typically translates into an anatomical part of the constellation being described. Famous ones on the list (along with their loose translations) include: Rigel (Al Rijl, foot) and Betelgeuse (Yad al Jauza, hand of the great one,”— in modern times drawn as the armpit), the two brightest stars in the constellation Orion; Altair (At-Tair, the flying one), the brightest star in the constellation Aquila, the eagle; and the variable star Algol (Al-Ghul, the ghoul), the second brightest star in the constellation Perseus, referring to the blinking eye of the bloody severed head of Medusa held aloft by Perseus. In the less-famous category are the two brightest stars of the constellation Libra, although identified with the scorpion in the heyday of the astrolabe: Zubenelgenubi (Az-Zuban al-Janubi, southern claw) and Zebueneschamali (Az-Zuban ash-Shamali, northern claw), the longest surviving star names in the sky.

            At no time since the eleventh century has the scientific influence of the Islamic world been equal to what it enjoyed the preceding four centuries. The late Pakistani physicist Abdus Salam, the first Muslim ever to win the Nobel Prize, lamented:

There is no question [that] of all civilizations on this planet, science is the weakest in the lands of Islam. The dangers of this weakness cannot be overemphasized since honorable survival of a society depends directly on strength in science and technology in the conditions of the present age.

Plenty of other nations have enjoyed periods of scientific fertility. Think of Great Britain, and the basis of Earths system of longitude. The prime meridian is the line that separates geographic east from west on the globe. Defined as zero degrees longitude, it bisects the base of a telescope at an observatory in Greenwich, a London borough on the south bank of the River Thames. The line doesnt pass through New York City. Or Moscow. Or Beijing. Greenwich was chosen in 1884 by an international consortium of longitude mavens who met in Washington D.C. for that very purpose.

By the late nineteenth century, astronomers at the Royal Greenwich Observatoryfounded in 1675 and based, of course, in Greenwichhad accumulated and catalogued a centurys worth of data on the exact positions of thousands of stars.  The Greenwich astronomers used a common, but specially designed telescope, constrained to move along the meridional arc that connects due north to due south through the observers zenith.  By not tracking the general east to west motion of the stars, they simply drift by as Earth rotates.  Formally known as a transit instrument, such a telescope allows you to mark the exact time a star crosses your field of view.  Why?  A stars longitude on the sky is the time on a sidereal clock the moment the star crosses your meridian. Today we calibrate our watches with atomic clocks, but back then there was no timepiece more reliable than the rotating Earth itself. And there was no better record of the rotating Earth than the stars that passed slowly overhead.  And nobody measured the positions of passing stars better than the astronomers at the Royal Greenwich Observatory.

            During the seventeenth century Great Britain had lost many ships at sea due to the challenges of navigation that result from not knowing your longitude with precision.  In an especially tragic disaster in 1707, the British fleet, under Vice Admiral Sir Clowdesley Shovell, ran aground into the Scilly Isles, west of Cornwall, losing four ships and two thousand men. Finally enough impetus for England to commissioned a Board of Longitude, which offered a fat cash award£20,000to the first person who could design an ocean-worthy chronometer. Such a timepiece was destined to be important in both military and commercial ventures. When synchronized with the time at Greenwich, such a chronometer could determine a ships longitude with great precision. Just subtract your local time (readily obtained from the observed position of the Sun or stars) from the chronometers time. The difference between the two is a direct measure of your longitude east or west of the prime meridian.

            In 1735 the Board of Longitudes challenge was met by a portable, palm-sized clock designed and built by an English mechanic, John Harrison. Declared to be as valuable to the navigator as a live person standing watch at a ships bow, Harrisons chronometer gave renewed meaning to the word watch.

            Because of Englands sustained support for achievements in astronomical and navigational measurements, the Royal Observatory at Greenwich landed the prime meridian. This decree fortuitously placed the international date line (180 degrees away from the prime meridian) in the middle of nowhere, on the other side of the globe in the Pacific Ocean. No country would be split into two days, leaving it beside itself on the calendar.

            From the 1890s until the 1930s the Brits also made stunning advances in physics. Atoms are mostly empty space, with a small, dense nucleus packed with positively charged protons and neutral neutrons. Together, they are surrounded by negatively charged electrons. These particles are the principal components of atoms themselves. We take this fundamental knowledge for granted, as though it had been known forever. But using clever tabletop experiments, as well as early versions of particle accelerators, it was J. J. Thompson who discovered the electron in 1897, Ernest Rutherford who discovered the proton in 1914, and James Chadwick discovered the neutron in 1932.

            Impressed it was all done in the same country? It all happened in the same building: the Cavendish Laboratory at the University of Cambridge. And it was data from these labs that forced a new generation of theorists to abandon classical concepts of physics in favor of the new branch of science known as quantum mechanics, a description of matter and energy that applies to nature on its smallest scales. To the worlds community of physicists, the original Cavendish Laboratories are hallowed ground.

If the English have forever left their mark on particles and on the spatial coordinates of the globe, our basic temporal coordinate systema solar-based calendaris the product of an investment of science within the Roman Catholic Church.  The incentive to do so was not driven by cosmic discovery itself but by the need to keep the date for Easter in the early spring.  So important was this need, that Pope Gregory XIII established the Vatican Observatory, staffing it with erudite Jesuit priests who tracked and measured the passage of time with unprecedented accuracy.  By decree, the date for Easter had been set to the first Sunday after the first full moon after the vernal equinox (preventing Holy Thursday, Good Friday and Easter Sunday from ever falling on a special day in somebody elses lunar-based calendar.)   That rule works as long as the first day of spring stays in March, where it belongs. But the Julian calendar of Julius Caesars Rome was sufficiently inaccurate that by the sixteenth century it had accumulated ten extra days, placing the first day of spring on April 1 instead of March 21. The four-year leap day, a principal feature of the Julian calendar, had slowly overcorrected the time, pushing Easter later and later in the year.

            In 1584, when all the studies and analyses were complete, Pope Gregory deleted the ten offending days from the Julian calendar:  the day after October 4 was declared to be October 15. The Church thenceforth made an adjustment: for every century year not evenly divisible by four-hundred, a leap day gets omitted that would otherwise have been counted, thus correcting for the overcorrecting leap day itself.

            This new Gregorian Calendar was further refined in the twentieth century to become even more precise, preserving the accuracy of your wall calendar for tens of thousands of years to come.  Nobody else had ever kept time with such precision. Enemy states of the Catholic Church (such as Protestant England, and its rebellious progeny, the American colonies) were slow to adopt the change, but eventually everyone in the civilized world, including cultures that traditionally relied on Moon-based calendars, adopted the Gregorian calendar as the standard for international business, commerce, and politics.

Ever since the birth of the Industrial Revolution the European contributions to science and technology have become so embedded in western culture that it may take a special effort to step outside and notice them at all. The Revolution was a breakthrough in our understanding of energy enabling engineers to dream up ways to convert it from one form to another.  In the end, the Revolution would serve to replace human power with machine power, drastically enhancing the productivity of nations and the subsequent distribution of wealth around the world.

The language of energy is rich with the names of those scientists who contributed to the effort.  James Watt, the Scottish engineer who perfected the steam engine in 1765, has the moniker best known outside the circles of engineering and science.  Either his last name or his monogram gets stamped on the top of practically every light bulb.  A bulbs wattage measures the rate it consumes energy, which correlates with its brightness.  Watt worked on steam engines while at the University of Glasgow, which was, at the time, one of the worlds most fertile centers for engineering innovation.

The English physicist Michael Faraday discovered electromagnetic induction in 1831, which enabled the first electric motor.  The farad, a measure of a devices capacity to store electric charge, probably doesnt do full justice to his contributions to science.

The German physicist Heinrich Hertz discovered electromagnetic waves in 1888, which enabled communication via radio; his name survives as the unit of frequency along with its metric derivatives kilohertz, megahertz, and gigahertz.

From the Italian physicist Alessandro Volta we have the volt, a unit of electric potential.  From the French physicist André-Marie Ampère, we have the unit of electric current known as the ampere, or amp for short.  From the British physicist James Prescott Joule, we have the joule, a unit of energy.  The list goes on and on.

With the exception of Benjamin Franklin and his tireless experiments with electricity, the U.S. as a nation watched this fertile chapter of human achievement from afar, preoccupied with gaining its independence from England and exploiting the economies of slave labor. Today the best we could do was pay homage in the original Star Trek television series:  Scotland is the country of origin of the industrial revolution, and of the Chief Engineer of the star ship Enterprise. His name? Scotty of course.

In the late eighteenth century the Industrial Revolution was in full swing, but so too was the French Revolution. The French used the occasion to shake up more than the royalty; they also introduced the metric system to standardize what was then a world of mismatched measuresconfounding science and commerce alike. Members of the French Academy of Sciences led the world in measures of the Earths shape and had proudly determined it to be an oblate spheroid.  Building on this knowledge, they defined the meter to be one ten-millionth the distance along the Earths surface from the North Pole to the equator, passing throughwhere else?Paris. This measure of length was standardized as the separation between two marks etched on a special bar of platinum alloyed with iridium.  The French devised many other decimal standards that (except for decimal time and decimal angles) was ultimately adopted by all the civilized nations of the world except the U.S., the west African nation of Liberia, and the politically unstable, tropical nation of Myanmar. The original artifacts of this metric effort are preserved at the International Bureau of Weights and Measures--located, of course, near Paris.

Beginning in the late1930s the U.S. became a nexus of activity in nuclear physics. Much of the intellectual capital grew out of the exodus of scientists from Nazi Germany.  But the financial capital came from Washington, in the race to beat Hitler to build an atomic bomb. The coordinated effort to produce the bomb, was known as the Manhattan Project, so named because much of the early research had been done in Manhattan, at Columbia Universitys Pupin Laboratories.

            The wartime investments had huge peacetime benefits for the community of nuclear physicists.  From the 1930s through the 1980s, American accelerators were the largest and most productive in the world. These race-tracks of physics are windows into the fundamental structure and behavior of matter  They create beams of subatomic particles, accelerate them to near the speed of light with a cleverly configured electric field, and smash them into other particles, busting them to smithereens. Sorting through the smithereens, physicists have found evidence for hoards of new particles and even new laws of physics.

            American nuclear physics labs are duly famous. Even people who are physics-challenged will recognize the top names: Los Alamos; Lawrence Livermore ; Brookhaven; Lawrence Berkeley, Fermi Labs; Oak Ridge. Physicists at these places discovered new particles, isolated new elements, informed a nascent theoretical model of particle physics, and collected Nobel Prizes for doing so.

            The American footprint in that era of physics is forever inscribed at the upper end of the periodic table.  Element number 95 is americium; number 97 is berkelium; number 98 is californium; number 103 is lawrencium, for Ernest O. Lawrence, the American physicist who invented the first particle accelerator; and number 106 is seaborgium, for Glenn T. Seaborg, the American physicist whose lab at the University of California, Berkeley, discovered ten new elements heavier than uranium.

Ever-larger accelerators reach ever higher energies, probing the fast receding boundary between what is known and unknown about the universe. The big bang theory of cosmology asserts that the universe was once a very small and very hot soup of energetic subatomic particles. With a superduper particle-smasher, physicists might be able to simulate the earliest moments of the cosmos. In the 1980s, when U.S. physicists proposed just such an accelerator (eventually dubbed the Superconducting Super Collider), Congress was ready to fund it. The U.S. Department of Energy was ready to oversee it. Plans were drawn up. Construction began. A circular tunnel fifty miles around (the size of Washington DCs beltway) was dug in Texas. Physicists were eager to peer across the next cosmic frontier. But in 1993, when cost overruns looked intractable, a fiscally frustrated Congress permanently withdrew funds for the $11 billion project. It probably never occurred to our elected representatives that by canceling the Super Collider they surrendered Americas primacy in experimental particle physics.

            If you want to see the next frontier, hop a plane to Europe, which seized the opportunity to build the worlds largest particle accelerator and stake a claim of its own on the landscape of cosmic knowledge. Known as the Large Hadron Collider, the accelerator will be run by the European Center for Particle Physics (better known by an acronym that no longer fits its name, CERN). Although some U.S. physicists are collaborators, America as a nation will watch the effort from afar, just as so many nations have done before.


before Class 4

Galileo's Sidereus Nuncius (Message of the Stars or The Starry Messenger), 1610, written in Italian (not Latin) and translated by Stillman Drake in Discoveries and Opinions of Galileo, Anchor Books, New York, 1957.

Title page in Italian and English                                                        

Galileo dedicated Sidereus Nuncius "to the Most Serene Cosimo II de' Medici Fourth Grand Duke of Tuscany", whom he had tutored in mathematics one summer.  Read this excerpt from the dedication for the information addressed in the square brackets and for its language in addressing a patron.

To the Most Serene

Cosimo II de’ Medici

Fourth Grand Duke of Tuscany

Surely a distinguished public service has been rendered by those who have protected from envy the noble achievements of men who have excelled in virtue, and have thus preserved from oblivion and neglect those names which deserve immortality.  In this way images sculptured in marble or cast in bronze have been handed down to posterity; to this we owe our statues, both pedestrian and equestrian; thus have we those columns and pyramids whose expense (as the poet says) reaches to the stars; finally, thus cities have been built to bear the names of men deemed worthy by posterity of commendation to all the ages.  For the nature of the human mind is such that unless it is stimulated by images of things acting upon it from without, all remembrance of them passes easily away.

Looking to things even more stable and enduring, others have entrusted the immortal fame of illustrious men not to marble and metal but to the custody of the Muses and to imperishable literary monuments.  But why dwell upon these things as though human wit were satisfied with earthly regions and had not dared advance beyond?  For, seeking further, and well understanding that all human monuments ultimately perish through the violence of the elements or by old age, ingenuity has in fact found still more incorruptible monuments over which voracious time and envious age have been unable to assert any rights.  Thus turning to the sky, man’s wit has inscribed on the familiar and everlasting orbs of most bright stars the names of those whose eminent and godlike deeds have caused them to be accounted worthy of eternity in the company of the stars.  And so the fame of Jupiter, of Mars, of Mercury, Hercules, and other heroes by whose names the stars are called, will not fade before the extinction of the stars themselves.

Yet this invention of human ingenuity, noble and admirable as it is, has for many centuries been out of style.  Primeval heroes are in possession of those bright abodes, and hold them in their own right.  In vain did the piety of Augustus attempt to elect Julius Caesar into their number, for when he tried to give the name of “Julian” to a star which appeared in his time (one of those bodies which the Greeks call “comets” and which the Romans likewise named for their hairy appearances), it vanished in a brief time and mocked his too ambitious wish.  But we are able, most serene Prince, to read Your Highness in the heavens far more accurately and auspiciously.  For scarce have the immortal graces of your spirit begun to shine on earth when in the heavens bright stars appear as tongues to tell and celebrate your exceeding virtues to all time.  Behold, then, four stars reserved to bear your famous name; bodies which belong not to the inconspicuous multitude of fixed stars, but to the bright ranks of the planets.  Variously moving about most noble Jupiter as children of his own, they complete their orbits with marvelous velocity – at the same time executing with one harmonious accord might revolutions every dozen years about the center of the universe; that is, the sun.  [This is the first published intimation by Galileo that he accepted the Copernican system.  Tycho had made Jupiter revolve about the sun, but considered the earth to be the center of the universe.  It was not until 1613, however, that Galileo unequivocally supported Copernicus in print.]

Indeed, the Maker of the stars himself has seemed by clear indications to direct that I assign to these new planets Your Highness’s famous name in preference to all others.  For just as these stars, like children worthy of their sire, never leave the side of Jupiter by any appreciable distance, so (as indeed who does not know?) clemency, kindness of heart, gentleness of manner, splendor of royal blood, nobility in public affairs, and excellency of authority and rule have all fixed their abode and habitation in Your Highness.  And who, I ask once more, does not know that all these virtues emanate from the benign star of Jupiter, next after God as the source of all things good?  Jupiter; Jupiter, I say, at the instant of your Highness’s birth, having already emerged from the turbid mists of the horizon and occupied the midst of the heavens, illuminating the eastern sky from his own royal house, looked out from that exalted throne upon your auspicious birth and poured forth all his splendor and majesty in order that your tender body and your mind (already adorned by God with the most noble ornaments) might imbibe with their first breath that universal influence and power.  But why should I employ mere plausible arguments, when I may prove my conclusion absolutely?  It pleased Almighty God that I should instruct Your Highness in mathematics, which I did four years ago at that time of year when it is customary to rest from the most exacting studies.  And since clearly it was mine by divine will to serve your Highness and thus to receive from near at hand the rays of your surpassing clemency and beneficence, what wonder is it that my heart is so inflamed as to think both day and night of little else than how I, who am indeed your subject not only by choice by birth and lineage, may become known to you as most grateful and most anxious for your glory?  And so, most serene Cosimo, having discovered under your patronage these stars unknown to every astronomer before me, I have with good right decided to designate them by the august name of your family.  And if I am first to have investigated them, who can justly blame me if I likewise name them, calling them the Medicean stars, in the hope that this name will bring as much honor to them as the names of other heroes have bestowed on other stars?  For, to say nothing of Your Highness’s most serene ancestors, whose everlasting glory is testified by the monuments of all history, your virtue alone, most worth Sire, can confer upon these stars an immortal name.  No one can doubt that you will fulfill those expectations, high though they are, which you have aroused by the auspicious beginning of your reign, and will not only meet but far surpass them.  Thus when you have conquered your equals you may still vie with yourself, and you and your greatness will become greater every day.

Accept then, most clement Prince, this gentle glory reserved by the stars for you.  May you long enjoy those blessings which are sent to you not so much from the stars as from God, their Maker and their Governor.

Your Highness’s most devoted servant,

Galileo Galilei

Padua, March 12, 1610

What follows is Galileo's night-to-night description of the four previously unknown moons of Jupiter.  The big idea is that if Jupiter has moons = Medicean stars (title page) = starlets = satellites in various places in the manuscript, it is something like the earth, which has a moon.  Therefore, since Jupiter moves, perhaps the earth moves.

We have now briefly recounted the observations made thus far with regard to the moon, the fixed stars, and the Milky Way.  There remains the matter which in my opinion deserves to be considered the most important of all – the disclosure of four PLANETS never seen from the creation of the world up to our own time, together with the occasion of my having discovered and studied them, their arrangements, and the observations made of their movements and alterations during the past two months.  I invite all astronomers to apply themselves to examine them and determine their periodic times, something which has so far been quite impossible to complete, owing to the shortness of the time.  Once more, however, warning is given that it will be necessary to have a very accurate telescope such as we have described at the beginning of this discourse.

On the seventh day of January in this present year 1610, at the first hour of night, when I was viewing the heavenly bodies with a telescope, Jupiter presented itself to me; and because I had prepared a very excellent instrument for myself, I perceived (as I had not before, on account of the weakness of my previous instrument) that beside the planet there were three starlets, small indeed, but very bright.  Though I believed them to be among the host of fixed stars, they aroused my curiosity somewhat by appearing to lie in an exact straight line parallel to the ecliptic, and by their being more splendid than others of their size.  Their arrangement with respect to Jupiter and each other was the following:

That is, there were two stars on the eastern side and one to the west.  The most easterly star and the western one appeared larger than the other.  I paid no attention to the distances between them and Jupiter, for at the outset I thought them to be fixed stars, as I have said.  [The reader should remember that the telescope was nightly revealing to Galileo hundreds of fixed stars never previously observed.  His unusual gifts for astronomical observation are illustrated by his having noticed and remembered these three merely by reason of their alignment, and recalling them so well that when by chance he happened to see them the following night he was certain that they had changed their positions.  No such plausible and candid account of the discovery was given by the rival astronomer Simon Mayr, who four years later claimed priority.]  But returning to the same investigation on January eighth – led by what, I do not know – I found a very different arrangement.  The three starlets were now all to the west of Jupiter, closer together, and at equal intervals from one another as shown in the following sketch:

At this time, though I did not yet turn my attention to the way the stars had come together, I began to concern myself with the question  how Jupiter could be east of all these stars when on the previous day it had been west of two of them.  I commenced to wonder whether Jupiter was not moving eastward at that time, contrary to the computations of the astronomers, and had got in front of them by that motion.  [Jupiter was at this time in “retrograde” motion; that is, the earth’s motion made the planet appear to be moving westward among the fixed stars.]  Hence it was with great interest that I awaited the next night.  But I was disappointed in my hopes, for the sky was then covered with clouds everywhere. 

On the tenth of January, however, the stars appeared in this position with respect to Jupiter:

that is, there were but two of them, both easterly, the third (as I supposed) being hidden behind Jupiter.  As at first, they were in the same straight line with Jupiter and were arranged precisely in the line of the zodiac.  Noticing this, and knowing that there was no way in which such alterations could be attributed to Jupiter’s motion, yet being certain that these were still the same stars I had observed (in fact no other was to be found along the line of the zodiac for a long way on either side of Jupiter), my perplexity was now transformed into amazement.  I was sure that the apparent changes belonged not to Jupiter but to the observed stars, and I resolved to pursue this investigation with greater care and attention. 

And thus, on the eleventh of January, I saw the following disposition:

There were two start, both to the east, the central one being three times as far from Jupiter as from the one farther east.  The latter star was nearly double the size of the former, whereas on the night before they had appeared approximately equal.

I had now decided beyond all question that there existed in the heavens three stars wandering about Jupiter as do Venus and Mercury about the sun, and this became plainer than daylight from observations on similar occasions which followed.  Nor were there just three such stars; four wanders complete their revolutions about Jupiter, and of their alterations as observed more precisely later on we shall give a description here.  Also I measured the distances between them by means of the telescope, using the method explained before.  Moreover I recorded the times of the observations, especially when more than one was made during the same night – for the revolutions of these planets are so speedily completed that it is usually possible to take even their hourly variations.

Thus on the twelfth of January at the first hour of night I saw the stars arranged in this way:

The most easterly star was larger than the western one, though both were easily visible and quite bright.  Each was about two minutes of arc distant from Jupiter.  The third star was invisible at first, but commenced to appear after two hours; it almost touched Jupiter on the east, and was quite small.  All were on the same straight line directed along the ecliptic.

On the thirteenth of January four stars were seen by me for the first time, in this situation relative to Jupiter:

Three were westerly and one was to the east; they formed a straight line except that the middle western star departed slightly toward the north. The eastern star was two minutes of arc away from Jupiter, and the intervals of the rest from one another and from Jupiter were about one minute.  All the stars appeared to be of the same magnitude, and though small were very bright, much brighter than fixed stars of the same size.  [Galileo’s day-by-day journal of observations continued in unbroken sequence until ten days before publication of the book, which he remained in Venice to supervise.  The observations omitted here contained nothing of a novel character.]

On the twenty-sixth of February, midway in the first hour of night, there were only two stars:

One was to the east, ten minutes from Jupiter; the other to the west, six minutes away.  The eastern one was somewhat smaller than the western.  But at the fifth hour three start were seen:

In addition to the two already noticed, a third was discovered to the west near Jupiter; it had at first been hidden behind Jupiter and was now one minute away.  The eastern one appeared farther away than before, being eleven minutes from Jupiter.  

This night for the first time I wanted to observe the progress of Jupiter and its accompanying planets along the line of the zodiac in relation to some fixed star, and such a star was seen to the east, eleven minutes distant from the easterly starlet and a little removed toward the south, in the following manner:                                                                                                                                                         

On the twenty-seventh of February, four minutes after the first hour, the stars appeared in this configuration:


The most easterly was ten minutes from Jupiter; the next, thirty seconds; the next to the west was two minutes thirty seconds from Jupiter, and the most westerly was one minute from that.  Those nearest Jupiter appeared very small, while the end ones were plainly visible, especially the westernmost.  They marked out an exactly straight line along the course of the ecliptic.  [ecliptic: the sun’s apparent path through the stars]  The progress of these planets toward the east is seen quite clearly by reference to the fixed star mentioned, since Jupiter ad its accompanying planets were closer to it, as may be seen in the figure above.  At the fifth hour, the eastern star closer to Jupiter was one minute away.

At the first hour on February twenty-eighty, two stars only were seen; one easterly, distant none minutes from Jupiter, and one to the west, two minutes away.  They were easily visible and on the same straight line.  The fixed star, perpendicular to this line, now fell under the eastern planet as in this figure:


At the fifth hour a third star, two minutes east of Jupiter, was seen in this position:

On the first of March, forty minutes after sunset, four stars all to the east were seen, of which the nearest to Jupiter was two minutes away, the nest was one minute from this, the third two seconds from that and brighter than any of the others; from this in turn the most easterly was four minutes distant, and it was smaller than the rest.  They marked out almost a straight line, but the third one counting from Jupiter was a little to the north.  The fixed star formed an equilateral triangle with Jupiter and the most easterly star, as in this figure:


On March second, half an hour after sunset, there were three planets, two to the east and one to the west, in this configuration:


The most easterly was seven minutes from Jupiter and thirty seconds from its neighbor; the western one was two minutes away from Jupiter.  The end stars were very bright and were larger than that in the middle, which appeared very small.  The most easterly star appeared a little elevated toward the north from the straight line through the other planets and Jupiter.  The fixed star previously mentioned was eight minutes from the western planet along the line drawn from it perpendicularly to the straight line through all the planets, as shown above. 

I have reported these relations of Jupiter and its companions with the fixed star so that anyone may comprehend that the progress of those planets, both in longitude and latitude, agrees exactly with the movements derived from planetary tables.

Such are the observations concerning the four Medicean planets recently first discovered by me, and although from these data their periods have not yet been reconstructed in numerical form,  it is legitimate at least to put in evidence some facts worthy of note.  Above all, since they sometimes follow and sometimes precede Jupiter by the same intervals, and they remain within very limited distances either to east or west of Jupiter, accompanying that planet in both its retrograde and direct movements in a constant manner, no one can doubt that they complete their revolutions about Jupiter and at the same time effect all together a twelve-year period about the center of the universe.  That they also revolve in unequal circles is manifestly deduced from the fact that at the greatest elongation [By this is meant the greatest angular separation from Jupiter attained by any of the satellites.] from Jupiter it is never possible to see two of these planets in conjunction, whereas in the vicinity of Jupiter they are found united two, three, and sometimes all four together.  It is also observed that the revolutions are swifter in those planets which describe smaller circles about Jupiter, since the stars closest to Jupiter are usually seen to the east when on the previous day they appeared to the west, and vice versa, while the planet which traces the largest orbit appears upon accurate observation of its returns to have a semimonthly period.

Here we have a fine and elegant argument for quieting the doubts of those who, while accepting with tranquil mind the revolutions of the planets about the sun in the Copernican system, are mightily disturbed to have the moon alone revolve about the earth and accompany it in an annual rotation about the sun.  Some have believed that this structure of the universe should be rejected as impossible.  But now we have not just one planet rotating about another while both run through a great orbit around the sun; our own eyes show us four stars which wander around Jupiter as does the  moon around the earth, while all together trace out a grand revolution about the sun in the space of twelve years.

And finally we should not omit the reason for which the Medicean stars appear sometimes to be twice as large as at other times, though their orbits about Jupiter are very restricted.  We certainly cannot seek the cause in terrestrial vapors, as Jupiter and its neighboring fixed stars are not seen to change size in the least while this increase and diminution are taking place.  It is quite unthinkable that the cause of variation should be their change of distance from the earth at perigee and apogee, since a small circular rotation could by no means produce this effect, and an oval motion (which in this case would have to be nearly straight) seem unthinkable and quite inconsistent with the appearances.  [The marked variation in brightness of the satellites which Galileo observed may be attributed mainly to markings upon their surfaces, though this was not determined until two centuries later.  The mention here of a possible oval shape of the orbits is the closest Galileo ever came to accepting Kepler’s great discovery of the previous year (1609).  Even here, however, he was probably not thinking of Kepler’s work but of an idea proposed by earlier astronomers for the moon and the planet Venus.]  But I shall gladly explain what occurs to me on this matter, offering it freely to the judgment and criticism of thoughtful men.  It is known that the interposition of terrestrial vapors makes the sun and moon appear large, while the fixed stars and planets are made to appear smaller.  Thus the two great luminaries are seen larger when close to the horizon, while the stars appear smaller and for the most part hardly visible.  Hence the stars appear very feeble by day and in twilight, though the moon does not, as we have said.  Now from what has been said above, and even more from what we shall say at greater length in our System, it follows that not only the earth but also the moon is surrounded by an envelope of vapors, and we may apply precisely the same judgment to the rest of the planets.  Hence it does not appear entirely impossible to assume that around Jupiter also there exists an envelope denser than the rest of the aether, about which the Medicean planets revolve as does the moon about the elemental sphere.  Through the interposition of this envelope they appear larger when they are in perigee b the removal, or at least the attenuation, of this envelope.

Time prevents my proceeding further, but the gentle reader may expect more soon.


before Class 5

In the century before Galileo's Starry Messenger, Agricola Latinized his name and wrote in Latin.  De Re Metallica (On Metals) is about the mining practices in Germany in the 1500s.  Published about a century after the development of the printing press, it is lavishly illustrated with woodcuts.  This excerpt is about how underground veins of metal are found; one famous mine is said to have been located by a horse.

De Re Metallica: Georgius Agricola [Georg Bauer] 1556, translated by Herbert and Lou [President and Mrs.] Hoover, available in the Ohio Dominican University library and online in Latin at

The miner, after he has selected out of many places one particular spot adapted by Nature for mining, bestows much labor and attention on the veins.  These have either been stripped bare of their covering by chance and thus lie exposed to our view, or lying deeply hidden and concealed they are found after close search; the latter is the more usual, the former more rarely happens, and both of these occurrences must be explained.  There is more than one force which can lay bare the veins unaided by the industry or toil of man; since either a torrent might strip off the surface, which happened in the case of the silver mines of Freiberg (concerning which I have written in Book I of my work “De Veteribus et Novis Metallis”) [Around 1170 AD, the people carting salt in wagons through Meissen (Saxony) into Bohemia noticed galena, PbS = lead sulfide, in which 1% of the lead may be substituted by silver, in the wheel tracks, which had been uncovered by torrents of water.  This lead ore, since it was similar to that of Goslar [well-known German silver mine], they put into their carts and carried to Goslar, for the same carriers were accustomed to carry lead from that city.  And since much more silver was smelted from this galena than from that of Goslar, certain miners betook themselves to that part of Meissen in which is now situated Freiberg]; or they may be exposed through the force of the wind, when it uproots and destroys the trees which have grown over the veins; or by the breaking away of the rocks; or by long-continued heavy rains tearing away the mountain; or by an earthquake; or by a lightning lash; or by a snowslide; or by the violence of the winds. …or by fire … or, as at Goslar, where an iron-shod horse, which was named Ramelus, pawed the earth and uncovered a hidden vein of lead [~936 AD].

But by skill we can also investigate hidden and concealed veins, by observing in the first place the bubbling waters of springs, which cannot be very far distant from the veins because the source of the water is from them; secondly, by examining the fragments of the veins which the torrents break off from the earth, for after a long time some of these fragments are again buried in the ground.  Fragments of this kind lying about o the ground, if they are rubbed smooth, are a long distance from the veins, because the torrent, which broke them from the vein, polished them while it rolled them a long distance; but if they are fixed in the ground, or if they are rough, they are nearer to the veins.  The soil also should be considered, for this is often the cause of veins being buried more or less deeply under the earth; in this case the fragments protrude more or less widely apart, and miners are wont to call the veins discovered in this manner “fragmenta”.

Further, we search for veins be observing the hoar-frosts, which whiten all herbage except that growing over the veins, because the veins emit a warm and dry exhalation which hinders the freeing of the moisture, for which reason such plants appear rather wet than whitened by the frost.  This may be observed in all cold places before the grass has grown to its full size, as in the months of April and May; or when the late crop of hay, which is called the cordum, is cut with scythes in the month of September.  Therefore in places where the grass has a dampness that is not congealed into frost, there is a vein beneath; also if the exhalation be excessively hot, the soil will produce only small and pale-colored plants.  Lastly, there are trees whose foliage in springtime has a bluish or leaden tint, the upper branches more especially being tinged with black or with and other unnatural color, the trunks cleft in two, and the branches black or discolored.  These phenomena are caused by the intensely hot and dry exhalations which do not spare even the roots, but scorching them, render the trees sickly; wherefore the wind will more frequently uproot trees of this kind than any others.  Verily the veins do emit this exhalation.  Therefore, in a place where there is a multitude of trees, if a long row of them at an unusual time lose their verdure and become black or discolored, and frequently fall by the violence of the wind, beneath this spot there is a vein.  Likewise along a course where a vein extends, there grows a certain herb or fungus which is absent from the adjacent space, or sometimes even from the neighborhood of the veins.  By these signs of Nature a vein can be discovered. 

There are many great contentions between miners concerning the forked twig, for some say that it is of the greatest use in discovering veins, and others deny it.  Some of those who manipulate and use the twig, first cut a fork from a hazel bush with a knife, for this bush they consider more efficacious than any other for revealing the veins, especially if the hazel bush grows above a vein.  Others use a different kind of twig for each metal, when they are seeking to discover the veins, for they employ hazel twigs for veins of silver; ash twigs for copper; pitch pine for lead and especially tin, and rods made of iron and steel for gold.  All alike grasp the forks of the twig with their hands, clenching their fists, it being necessary that the clenched fingers should be held toward the sky in order that the twig should be raised at that end where the two branches meet.  Then they wander hither and thither at random through mountainous regions.  It is said that the moment they place their feet on a vein the twig immediately turns and twists, and so by its action discloses the vein; when they move their feet again and go away from that spot the twig becomes once more immobile.

The truth is, they assert, the movement of the twig is caused by the power of the veins, and sometimes this is so great that the branches of trees growing near a vein are deflected toward it.  On the other hand, those who say that the twig is of no use to good and serious men, also deny that the motion is due to the power of the veins, because the twigs will not move for everybody, but only for those who employ incantations and craft.  Moreover, they deny the power of a vein to draw to itself the branches of trees, but they say that the warm and dry exhalations cause these contortions.  Those who advocate the  use of the twig make this reply to these objections: when one of the miners or some other person holds the twig in his hands, and it is not turned by the force of a vein, this is due to some peculiarity of the individual, which hinders and impedes the power of the vein, for since the power of the vein in turning and twisting the twig may not unlike that of a magnet attracting and drawing iron toward itself, this hidden quality of a man weakens and breaks the force, just the same as garlic weakens and overcomes the strength of a magnet.  For a magnet smeared with garlic juice cannot attract iron; nor does it attract the latter when rusty.  Further, concerning the handling of the twig, they warn us that we should not press the fingers together too lightly, nor clench them too firmly, for if the twig is held lightly they say that it will fall before the force of the vein can turn it; if however, it is grasped too firmly the force of the hands resists the force of the veins and counteracts it.  Therefore, they consider that five things are necessary to insure that the twig shall serve its purpose: of these the first is the size of the twig, for the force of the veins cannot turn too large a stick; secondly, there is the shape of the twig, which must be forked or the vein cannot turn it; thirdly, the power of the vein which has the nature to turn it; fourthly, the manipulation of the twig; fifthly, the absence of impending peculiarities.  These advocates of the twig sum up their conclusions as follows: if the rod does not move for everybody, it is due to unskilled manipulation or to the impeding peculiarities of the man which oppose and resist the force of the veins, as we said above, and those who search for veins by means of the twig need not necessarily make incantations, but it is sufficient that they handle it suitable and are devoid of impeding power; therefore, the twig may be of use to good and serious men in discovering veins.  With regard to deflection of branches of trees they say nothing and adhere to their opinion.

Since this matter remains in dispute and causes much dissention amongst miners, I consider it ought to be examined on its own merits.  The wizards, who also make use of rings, mirrors and crystals, seek for veins with a diving rod shaped like a fork; but its shape makes no difference in the matter, - it might be straight or of some other form – for it is not the form of the twig that matters, but the wizard’s incantations which it would not become me to repeat, neither do I wish to do so.  The Ancients, by means of the divining rod, not only procured those things necessary for a livelihood or for luxury, but they were also able to alter the forms of things by it; as when the magicians changed the rods of the Egyptians into serpents, as the writings of the Hebrews relate [Exodus 8:10-12]; and as in Homer, Minerva with a divining rod turned the aged Ulysses suddenly into t youth, and then restored him back again to old age; Circe also changed Ulysses’ companions into beasts, but afterward gave them back again their human form [Odyssey16:172 and 10:238]; moreover by his rod, which was called “Caduceus,” Mercury gave sleep to watchmen and awoke slumberers [Odyssey 24:1, etc.  The Caduceus of Hermes had also the power of turning things to gold, and it is interesting to note that in its oldest form, as the insignia of heralds and of ambassadors, it had two prongs.]  Therefore it seems that the divining rod passed to the mines from its impure origin with the magicians.  Then when good men shrank with horror from the incantations and rejected them, the twig was retained by the unsophisticated common miners, and in searching for new veins some traces of these ancient usages remain. 

But since truly the twigs of the miners do move, albeit they do not generally use incantations, some say this movement is caused by the power of the veins, others say that it depends on the manipulation, and still others think that the movement is due to both these causes.  But, in truth, all those objects which are endowed with the power of attraction do not twist things in circles, but attract them directly to themselves; for instance, the magnet does not turn the iron, but draws it directly to itself, and amber rubbed until it is warm does not bend straws about, but simply draws them to itself.  If the power of the veins were of a similar nature to that of the magnet and the amber, the twig would not so much twist as move once only, in a semi-circle, and be drawn directly to the vein, and unless the strength of the man who holds the twig were to resist and oppose the force of the vein, the twig would be brought to the ground; wherefore, since this is not the case, it must necessarily follow that the manipulation is the cause of the twig’s twisting motion.  It is a conspicuous fact that these cunning manipulators do not use a straight twig, but a forked one cut from a hazel bush, or from some other wood equally flexible, so that if it be held in the hands, as they are accustomed to hold it, it turns in a circle for any man wherever he stands.  Nor is it strange that the twig does not turn when held by the inexperienced, because they either grasp the forks of the twig too tightly or hold them too loosely.  Nevertheless, these things give rise to the faith among common miners that veins are discovered by the use of twigs, because whilst using these they do accidentally discover some; but it more often happens that they lose their labor, and although they might discover a vein, they become none the less exhausted in digging useless trenches than do the miners who prospect in an unfortunate locality.  Therefore a miner, since we think he ought to be a good and serious man, should not make use of an enchanted twig, because if he is prudent and skilled in the natural signs, he understands that a forked stick is of no use to him, for as I have said before, there are the natural indications of the veins which he can see for himself without the help of twigs.  So if Nature or chance should indicate a locality suitable for mining, the miner should dig his trenches there; if no vein appears he must dig numerous trenches until he discovers an outcrop of a vein.

A vena dilatata [fissure vein] is rarely discovered by men’s labor, but usually some force or other reveals it, or sometimes it is discovered by a shaft or a tunnel of a vena profunda [sheet deposit].


Note the clothing worn by 16th century German working men and women and by a patron at a shop.


A letter from Karl Scheele to Antoine Lavoisier

Of all the "airs" that provided the impetus for the chemical revolution at the end of the 18th Century, the most important was oxygen, which provided both the basis of Lavoisier's theory of acids and the means of "ultimate" analysis of organic substances by combustion.

Among Scheele's papers at the Center for History of Science at the Royal Swedish Academy of Sciences in Stockholm is the draft of a letter he sent to Lavoisier in 1774. In this letter Scheele, the apothecary in Uppsala, thanks Lavoisier for his book and tries to establish a collaboration for the study of oxygen with the well-equipped Lavoisier. Apparently Lavoisier never replied, even though Scheele had gone to the trouble to have a friend help him render the letter from German into French.

Scheele suggests that Lavoisier use the French Academy's 33-inch burning glass to focus the sun's rays on silver carbonate. Heating will generate carbon dioxide (fixed air) and silver oxide, which decomposes (at about 340°C) to silver metal and oxygen. If the fixed air in the collecting jar is removed by alkali, the oxygen could support respiration or the burning of a candle.

It is not known whether Lavoisier carried out this experiment, or why he did not reply to Scheele. Perhaps he was reluctant to share credit for this important discovery. Perhaps his protective wife intercepted the mail and never showed him the letter.  He later wrote that some months before Easter in 1775 he had prepared "a new kind of air entirely unknown at that time". It was surely not unknown to Scheele.

From the clarity of this first communication describing the preparation and properties of what Scheele referred to as "Feuerluft" (fire air) or "Vitriol air", it is clear that he should at least share with Lavoisier and Priestly in discovering oxygen. His laboratory notes show him preparing the gas by heating silver carbonate in 1771-72.

The letter and translation were online at but the link does not work in 2009.

Here is the letter in French and English.


I have received by way of Secretary Wargentin a book, which he says that you have had the goodness to give me (as a present). Although I do not have the honor of being known by you, I am taking the liberty of thanking you very humbly. I desire nothing with as much (passion) ardor as to be able to show you my gratitude.

For a long time I have wanted to be able to read an account of all the experiments that have been done in England, in France and in Germany on the many

[Wargentin was secretary of the Royal Swedish Academy of Sciences. On April 12, 1774, Lavoisier had sent him a copy of his recently published "Opuscules physiques et chimique" for the Academy with another copy to give to Scheele. Apparently Lavoisier never wrote directly to Scheele. Scheele never corresponded with Priestly, the third discoverer of oxygen.]






kinds of air. You have not only satisfied this wish, but by new experiments you have given scientists in the future the most beautiful opportunities to better examine fire and the calcination of metals.

During the past several years I have carried out experiments on several kinds of air, and I have also spent a good deal of time in discovering the singular properties of fire, but I have never been able to prepare ordinary air from fixed air : I have tried many times, following the opinion of M. Priestley, to produce an ordinary air from fixed air by a mixture of iron filings, sulfur, and water, but I have never succeeded because fixed air always united with the iron and made it soluble in the water. Perhaps you do not know a way to do this either.

Because I do not have






any large burning glass, I beg you to carry out an experiment (a trial) with yours in this way : Dissolve some silver in nitrous acid and precipitate it with alkaline tartrate, wash the precipitate, dry it, and reduce it with the burning glass in your machine, fig. 8, but because the air in this bell jar (this receiver) is such that animals die in it and a part of the fixed air separates from the silver in this operation, it is necessary to place a bit of quick lime in the water where one has put the bell, so that this fixed air joins more quickly with the lime. This is the way that I hope that you will see how much air is formed during this reduction, and whether a lighted candle can keep burning and animals live in this air it. By this experiment you will do me a great favor. I would be infinitely obliged if you would inform me of the result of this experiment. I have the honor of remaining with great esteem, Monsieur, your very humble servant.

Uppsala, the _ September, 1774.







The letter was recopied and sent on September 30. Sometime since 1890 it has disappeared from the papers of Lavoisier.


before Class 6

Benjamin Franklin (1706-1790) was a scientist as well as a statesman and public leader.  In one of his experiments, he was trying to kill a turkey with an electric shock, but something went wrong and Franklin himself got shocked.  Later Franklin said: "I meant to kill a turkey, and instead, I nearly killed a goose."

The excerpt is provided by the American Institute of Physics History Center, College Park, MD.  Note that although the language of 250 years ago gives us no problem, the printing uses a different form of the letter "s", depending on whether it is at the end of a word or otherwise.




before class 7

Theophrastus of Lesbos (370-286 BC)  Theophrastus was originally named Tyrtamos.  He was renamed Theophrastus for his god-like speech by Aristotle, his teacher and collaborator.  The book, De Causis Plantarum (The Causes of Plants), is about plant physiology.  This excerpt mentions spontaneous generation as well as generation from seed.  Theophrastus wrote in Greek on papyrus.  The oldest extant copy dates from the 1000s AD, also in Greek, and is in Vatican City.  The first known Latin translation is by Theodore of Gaza (an ancient city in the Gaza Strip, where the blinded Sampson pushed down the Philistine temple), completed in 1451 at the request of Pope Nicholas V.  The illuminated frontispiece and first page are from Theodore’s translation.  The English translation here is by Benedict Einarson and George K. K. Link, copyright 1976, and is available in the Ohio Dominican University library.

The point to remember from this excerpt is that Theophrastus and his contemporaries believed in spontaneous generation as well as generation of new plants from seeds.


Modern Evolutionary Studies - Dinosaur Disputes

In the social arena, controversies are fed by opinion and ideology.  Uncomfortable facts are routinely ignored.  Among scientists – ideally, at least – controversies must be grounded in facts.  But merely piling up facts doesn’t close a case.  It’s how the facts fit together that counts.  That’s the role of a theory: to make sense of disparate facts.

Theories excite scientists, because theories make predictions: new evidence, if it is relevant at all, should conform to the theory.  If it does not, the theory must be revised. 

Ever since the first discoveries of dinosaur bones, theories about the animals – how they lived and died, how their bodies functioned, why they grew so large and had such strange armament, how they were related to other animals – have occupied some of the best scientific minds.  Some of those theories have emerged as mainstream scientific thinking – most paleontologists espouse them more or less whole, though dissenting voices are usually around to highlight their imperfections.  Other theories, on topics that still lack decisive evidence, remain vigorously competitive. 

Excepted from Natural History, May 2005

What Good Was All the Headgear?

For Decoration                                                                                    by Mark B. Goodwin

Goodwin is a curator at the university of California museum of Paleontology in Berkeley.

After prospecting for several hours one hot, dusty afternoon in the summer of 1983, I noticed a round, cracked, softball-size, and honey-colored fossil emerging from the badlands around the Judith River Formation in Montana.  I was about to uncover the best pachycephalosaur (“thick-headed lizard”) skull yet found, buried in the bed of an ancient stream that had meandered across a broad coastal plain 78 million years age.

Pachycephalosaurs first gained notoriety when the science-fiction writer L. Sprague de Camp characterized them as “bonehead” dinosaurs with a fondness for using the “bulge” of “solid bone” on top of their brains to “butt each other with these heads in fighting over the females.”

In pachycephalosaurs, the bones at the top of the skull do indeed unite to form a conspicuous round (and quite solid) dome, surrounded by clusters of bony horns, nodes, and tubercles.  Some specimens even sport multiple pairs of horns, between four and six inches long.  Needless to say, all this headgear is prominently featured when charging pachycephalosaurs are portrayed.  But did these dinosaurs really butt heads?

My colleague John R. (“Jack”) Horner, of Montana State University – Bozman, and I tested the head-butting hypothesis on some thirty pachycephalosaur domes and skulls.  We examined micron-thin sections of bone from the insides of the skulls under the microscope, and imaged the skulls with high-resolution computer tomography.  Both juvenile and subadult pachycephalosaur domes turned out to be highly porous and filled with spaces for blood vessels, showing that the bone tissue was fast-growing and well nourished. 

For decades paleontologists had assumed that what they called “radiating structures” in the dome could resist compression, giving the animals a biomechanical advantage in head-butting.  Our microscopic examinations proved instead that the structures were transitory, a product of the growth of the dome.  Remarkably, they were absent in the skulls of adults – precisely the individuals that would have engaged in head-butting, such as the adaptations that occur in bighorn sheep. 

So if the elaborate cranial dome was not for head-butting, what was its function?  We think the “Bulge of solid bone” and accompanying cranial protuberances were chiefly ornamental.  They enabled individuals within a species to recognize each other and communicate, the way African antelope such as hartebeest, impala, and wildebeest do when they display their elaborate horns.  If the modern animals are good models, most encounters among head-butting dinosaurs would have been ritualized displays of intimidation, aggression, and submission.

Our microanalysis yielded another noteworthy discovery: collagen fibers that typically anchor tendon and ligaments to bone lay within and just below the surface of the dome.  The finding indicates that the skull had an external covering, most likely of hard keratin, similar to the bills of modern birds.  Many birds display brightly colored keratin on their heads to communicate with other members of their species.  The domed skulls of pachycephalosaurs may likewise have been vibrantly colored to indicate sexual maturity, attract a mate, or warn an adversary.


For Defense                                                      Catherine A. Forster and Andrew A. Farke

Forster is an associate professor in the department of anatomical sciences at Stony Brook University in New York.  Farke is a Ph.D. candidate in the same department. 

When fossil ceratopsians, or horned dinosaurs, were first discovered in the American West in the 1870s, the enormous spikes, horns, and neck shields that sprouted from the creatures’ humongous skulls instantly captivated the public and paleontologists alike.  Speculation about the purpose of these bizarre cranial appendages quickly followed.  Paleontologists suggested that the long horns were used defensively, to “impale the enemy.”  Even today this idea makes perfect intuitive sense.  Any animal fairly bristling with long, pointed horns and spikes simply looks ready to fend off any and all would-be predators.  More recently, paleontologists have suggested that other dinosaurs, notably the dome-headed pachycephalosaurs, also used their cranial appendages defensively. 

Pointy headgear certainly plays a role in the defensive strategies of many modern animals.  For example, the horned lizard Phynosoma mcalli apparently uses the horns on its head to deter the shrike, a bird fond of impaling lizards on thorns or barbed wire for later consumption.  Longer horns make a lizard less likely to end up as a shrike’s meal.  Much larger animals adopt a similar defensive strategy: some unfortunate visitors to Yellowstone National Park have experience the use of horns by bison firsthand.

But paleontologists early on recognized that defense may not have been the sole function of cranial “weaponry.” In 1907 J.B. Hatcher and colleagues charmingly informed their readers that “Triceratops was extremely deficient mentally” and likely quite docile, except during the breeding season, when “combats between rival males … must have been prompted and carried out by blind, unreasoning instinct.” 

The “mate competition” hypothesis is borne out by research showing that the cranial headgear of most modern animals evolved not only for defense against predators, but also for ritualized jousting or just plain “showing off” among members of their own species.  Male bighorn sheep with the largest horns, for instance, have the highest social rank and are more likely to mate.  Similar patterns hold for many horned or antlered mammals, including African antelope, deer, and pronghorn.  Among reptiles, the male Jackson’s chameleon (which looks like a miniature Triceratops with three horns and a bony frill, or ruff, over its neck), also engages in horn-to-horn combat with other males of its kind. 

Actual evidence of horn use in ceratopsians is circumstantial.  On some Triceratops fossils, both on the face and on the frill (the only plate extending back over its neck), there are healed puncture wounds as evidence of combat with members of the same species.  Other skulls show that ceratopsians underwent rapid evolutionary change and that, in particular, the size and shape of their horns and frills responded to shifting circumstances with great plasticity.  Those findings suggest that natural selection focused on diversifying the cranial appendages for use in relations with other members of the same species.  Beyond that, comparison to modern animals is all paleontologists have to go on to infer ceratopsian behavior.   

Ultimately, dinosaurs probably used their cranial appendages in whatever way they were needed.  The pattern is well demonstrated in deer: even though antlers function primarily for display and for combat with rivals, they can also be used with deadly efficiency against predators.  Triceratops likely used its horns to impress mates, shoo off rivals, or argue for territorial ownership.  But it’s hard to imagine that such deadly weaponry wasn’t aimed at a menacing Tyranosaurus when the need arose.  If you’ve got it, use it.


Darwin himself

The Origin of Species by Charles Darwin, first published in 1859, on the web at


Authors of the highest eminence seem to be fully satisfied with the view that each species has been independently created. To my mind it accords better with what we know of the laws impressed on matter by the Creator, that the production and extinction of the past and present inhabitants of the world should have been due to secondary causes, like those determining the birth and death of the individual. When I view all beings not as special creations, but as the lineal descendants of some few beings which lived long before the first bed of the Silurian system was deposited, they seem to me to become ennobled. Judging from the past, we may safely infer that not one living species will transmit its unaltered likeness to a distant futurity. And of the species now living very few will transmit progeny of any kind to a far distant futurity; for the manner in which all organic beings are grouped, shows that the greater number of species of each genus, and all the species of many genera, have left no descendants, but have become utterly extinct. We can so far take a prophetic glance into futurity as to foretell that it will be the common and widely-spread species, belonging to the larger and dominant groups, which will ultimately prevail and procreate new and dominant species. As all the living forms of life are the lineal descendants of those which lived long before the Silurian epoch, we may feel certain that the ordinary succession by generation has never once been broken, and that no cataclysm has desolated the whole world. Hence we may look with some confidence to a secure future of equally inappreciable length. And as natural selection works solely by and for the good of each being, all corporeal and mental endowments will tend to progress towards perfection.

It is interesting to contemplate an entangled bank, clothed with many plants of many kinds, with birds singing on the bushes, with various insects flitting about, and with worms crawling through the damp earth, and to reflect that these elaborately constructed forms, so different from each other, and dependent on each other in so complex a manner, have all been produced by laws acting around us. These laws, taken in the largest sense, being Growth with Reproduction; inheritance which is almost implied by reproduction; Variability from the indirect and direct action of the external conditions of life, and from use and disuse; a Ratio of Increase so high as to lead to a Struggle for Life, and as a consequence to Natural Selection, entailing Divergence of Character and the Extinction of less-improved forms. Thus, from the war of nature, from famine and death, the most exalted object which we are capable of conceiving, namely, the production of the higher animals, directly follows. There is grandeur in this view of life, with its several powers, having been originally breathed into a few forms or into one; and that, whilst this planet has gone cycling on according to the fixed law of gravity, from so simple a beginning endless forms most beautiful and most wonderful have been, and are being, evolved.


before Class 8

Emotional aspects of doing science

Nobel physicist Richard Feynman wrote hundreds of inspiring letters, often to strangers.

On science writing

Early in 1967, while both visiting the University of Chicago, James Watson gave Feynman a copy of the manuscript for the book that would later be published as The Double Helix. They had met when Watson visited Caltech to give lectures. This was Feynman's reaction.

To James Watson, February 10, 1967

Don't let anybody criticise that book who hasn't read it through to the end. Its apparent minor faults and petty gossipy incidents fall into place as deeply meaningful and vitally necessary to your work (the book — the literary work I mean) as one comes to the end. From the irregular trivia of ordinary life mixed with a bit of scientific doodling and failure, to the intense dramatic concentration as one closes in on the truth and the final elation (plus with gradually decreasing frequency, the sudden sharp pangs of doubt) — that is how science is done. I recognise my own experiences with discovery beautifully (and perhaps for the first time!) described as the book nears its close. There it is utterly accurate.

And the entire "novel" has a master plot and a deep unanswered human question at the end: is the sudden transformation of all the relevant scientific characters from petty people to great and selfless men because they see together a beautiful corner of nature unveiled and forget themselves in the presence of the wonder? Or is it because our writer suddenly sees all his characters in a new and generous light because he has achieved success and confidence in his work, and himself? Don't try to resolve it. Leave it that way. Publish with as little change as possible. The people who say "that is not how science is done" are wrong.

In the early parts you describe the impression by one nervous young man imputing motives (possibly entirely erroneous) on how the science is done by the men around him. But when you describe what went on in your head as the truth haltingly staggers upon you and passes on, finally fully recognised, you are describing how science is done. I know, for I have had the same beautiful and frightening experience.

On teaching

A high school teacher in Venezuela sought help on a student's question: when a man lowers a weight from overhead to the ground, the law of conservation on energy says the weight must do work on his muscles. But experience says this can't happen. "The issue became a debate," Garcia wrote, "taking us nowhere; my class lost its prestige."

To Armando Garcia J, December 11, 1985

There is no harm in doubt and scepticism, for it is through these that new discoveries are made. The doubts can, and therefore must, be tested and resolved by experiment. It is true that energy is a scalar quantity, like temperature, that has no direction. But measured from some arbitrary level it can be either plus or minus — surely the changes have a sign. In lifting a weight the weight's energy is increased (and the rest of the world's decreased) and in lowering it, the signs are reversed.


I judge from your letter that in Venezuela you are teased badly if you are a professor and say you don't know or are not sure. I am glad that I am not so teased because I am sure of nothing, and find myself having to say "I don't know" very often. After all, I was born not knowing and have only had a little time to change that here and there. It is fun to find things you thought you knew, and then to discover you didn't really understand it after all.


Finally, Albert Einstein (1879-1955)

Archives of the Universe: edited and with introductions by Marcia Batusiak, Pantheon Books, New York, 2004.

After struggling for a decade on a theory of gravitation, Einstein was able to explain a small displacement in Mercury's orbit:

"I was beside myself with ecstasy for days."


Greek alphabet with transliterations


How the ancient Greeks measured the distances to the moon and the sun

Note on astronomy and the great pyramid of Khofu

A solution to the Bakshali Manuscript problem

Chinese proof of the Pythagorean Theorem