Tag Archives: Scientific Method

November 21, 1953 (a Saturday)

At the Piltdown site.

On this date, the 40-year-long hoax of the Piltdown Man ended when the British Museum revealed that it was a “perfectly executed and carefully prepared fraud.” The Piltdown forgery was conceived, planned and executed sometime between 1907 and 1911. The faux hominid skull was constructed from the remains of a recent human cranium, later shown to have been thickened by disease during the subject’s lifetime (thus giving the primitive look); half the lower jaw of an orangutan from which telltale parts had been removed and whose teeth had been filed to resemble worn human teeth; and a doctored canine tooth, probably from the same lower jaw. In all, 37 pieces of carefully selected bone and stone were involved, each altered and stained.

October 19, 1932 (a Wednesday)

Depression-era U.S. poster advocating early syphilis treatment. Although treatments were available, participants in the study did not receive them.

On this date, Dr. Raymond A. Vonderlehr arrived in Montgomery, Alabama, following a rainy drive from Washington, DC. After meeting Dr. Oliver C. Wenger, both men drove down to Tuskegee, checking into the only hotel for whites in town – the Carr Hotel. Here they intended to spread the word to Macon County’s black population that a new syphilis control demonstration was about to begin. In actuality, this was the beginning of what was to become the notorious Tuskegee Syphilis Study, a non-therapeutic, observational study of the effects of untreated sexually-transmitted syphilis in poor, rural black men who thought they were receiving free health care from the U.S. government.

Investigators enrolled in the study a total of 600 impoverished, African-American sharecroppers from Macon County, Alabama; 399 who had previously contracted syphilis before the study began, and 201 without the disease. For participating in the study, the men were given free medical care, meals, and free burial insurance. They were never told they had syphilis, nor were they ever treated for it. According to the Centers for Disease Control, the men were told they were being treated for “bad blood,” a local term used to describe several illnesses, including syphilis, anemia and fatigue.

The 40-year study was controversial for reasons related to ethical standards, primarily because researchers knowingly failed to treat patients appropriately after the 1940s validation of penicillin as an effective cure for the disease they were studying. Choices available to the doctors involved in the study might have included treating all syphilitic subjects and closing the study, or splitting off a control group for testing with penicillin. Instead, the Tuskegee scientists continued the study without treating any participants and withholding penicillin and information about it from the patients. In addition, scientists prevented participants from accessing syphilis treatment programs available to others in the area. The study continued under numerous U.S. Public Health Service supervisors until 1972, when a leak to the press by Peter Buxtun, a PHS venereal disease investigator, eventually resulted in its termination.

The Tuskegee Syphilis Study has been called “arguably the most infamous biomedical research study in U.S. history.”


  • James H. Jones. Bad Blood (Simon & Schuster, 1992) pp. 113-114.

October 9, 1676

Anton Van Leeuwenhoek

In 1673 Regnier de Graaf, a brilliant young physician in Delft, Holland, wrote a letter of introduction about Anton Van Leeuwenhoek to Henry Oldenburg, Secretary of the Royal Society in London. De Graaf said that Leeuwenhoek had devised microscopes that were far superior to any then known.  Accompanying De Graaf’s letter was the first letter to the Royal Society written by Leeuwenhoek, which dealt with observations on the structure of mold, as well as the structure of the bee and the louse.  Leeuwenhoek’s letter was published in Philosophical Transactions of the Society, and Oldenburg wrote to the author requesting further communications. Over the next fifty years, Leeuwenhoek wrote more than three hundred letters to the Royal Society.

On today’s date, Anton Van Leeuwenhoek wrote his most famous letter to the Royal Society, communicating the results of a series of experiments on water infused with pepper. Leeuwenhoek began by examining some snow-water that he had kept sealed for three years. He noted no creatures. He then added some peppercorns to the solution in what might have been an attempt to discover “the cause of the hotness or power whereby pepper affects the tongue.” Three weeks later, on 24 April 1676, Leeuwenhoek discovered the sudden appearance of a tremendous number of “very little animals.” Judging by his calculations of their number and size, historians have surmised that Leeuwenhoek had become the first person to see bacteria. Leeuwenhoek wrote:

The 31th of May, I perceived in the same water more of those Animals, as also some that were somewhat bigger. And I imagine, that [ten hundred thousand] of these little Creatures do not equal an ordinary grain of Sand in bigness: And comparing them with a Cheese-mite (which may be seen to move with the naked eye) I make the proportion of one of these small Water-creatures to a Cheese-mite, to be like that of a Bee to a Horse: For, the circumference of one of these little Animals in water, is not so big as the thickness of a hair in a Cheese-mite.

Previously, the existence of single-celled organisms was entirely unknown. Thus, even with his established reputation with the Royal Society as a reliable observer, his observations of microscopic life were initially met with skepticism. Eventually, in the face of Van Leeuwenhoek’s insistence, the Royal Society arranged to send an English vicar as well as a team of respected jurists and doctors to Delft to determine whether it was in fact Van Leeuwenhoek’s ability to observe and reason clearly, or perhaps the Royal Society’s theories of life itself that might require reform.

Finally, in 1680, Van Leeuwenhoek’s observations were fully vindicated by the Society. Although he neither lectured nor wrote formal scientific papers, he was recognized as an original scientist and was admitted as a Fellow to the Royal Society. Given contemporary medical theories, it did not occur to Leeuwenhoek that what he saw with his microscope was in any way connected to disease, but his observations laid a foundation on which further investigations were born.


  • Letter to H. Oldenburg, 9 Oct 1676. In The Collected Letters of Antoni van Leeuwenhoek (1957), Vol. 2, 75.

September 20, 1952 (a Saturday)

The Hershey-Chase Experiments.

On this date, geneticists Alfred Hershey and Martha Chase published the findings of their so-called blender experiments, which concluded that DNA (DeoxyriboNucleic Acid) is where life’s hereditary data is found.

Prior to these experiments, so named because they were conducted using a regular kitchen blender, it was generally thought that proteins — not DNA — were the genetic stuff of life.

Their experiments used the T2 bacteriophage, which, like other viruses, is just a crystal of DNA and protein. It can reproduce when inside a bacterium such as Escherichia coli, or E. coli for short. When the new T2 viruses are ready to leave the host E. coli cell (and go infect others), they burst the E. coli cell open, killing it (hence the name “bacteriophage”).

Hershey and Chase were seeking an answer to the question, “Is it the viral DNA or viral protein coat (capsid) that is the viral genetic code material which gets injected into the E. coli?” Using the kitchen blender, Hershey and Chase separated the protein coating from the DNA of T2 bacteriophage. Injecting the DNA into the bacterial cell, they found that it was the nucleic acid itself, and not the protein, that caused the transmission of hereditary information.

The Hershey–Chase experiment, its predecessors, such as the Avery-MacLeod-McCarty experiment, and successors served to unequivocally establish that hereditary information was carried by DNA.

Alfred Hershey was awarded the Nobel Prize in Physiology or Medicine in 1969. He shared the prize with two American scientists, Max Delbrück and Salvador Luria, for “discoveries concerning the replication mechanism and the genetic structure of viruses” but Chase, who served as Hershey’s lab assistant during his experiments and whose name appears on the paper, was snubbed.


  • Hershey, A and Chase, M (1952). “Independent functions of viral protein and nucleic acid in growth of bacteriophage,” J Gen Physiol 36 (1): 39–56.

August 17, 1771 (a Saturday)

Alone in a sealed jar, a mouse would die from exhaled CO2. But as scientist Joseph Priestley observed in 1771, adding a mint plant allows the mouse to thrive. In this proof of photosynthesis, the mint absorbed CO2, retained carbon for growth, and released oxygen. Two centuries later humans tried—and failed—to survive in a sealed environment in Arizona's Biosphere 2.

On this date, Joseph Priestley began an experiment in which he discovered photosynthesis, although he did not give it that name. He described his experiment in 1772 in a paper entitled “Observations on Different Kinds of Air”:

…I flatter myself that I have accidentally hit upon a method of restoring air which has been injured by the burning of candles, and that I have discovered at least one of the restoratives which nature employs for this purpose. It is vegetation. In what manner this process in nature operates, to produce so remarkable an effect, I do not pretend to have discovered; but a number of facts declare in favour of this hypothesis…

One might have imagined that, since common air is necessary to vegetable, as well as to animal life, both plants and animal had affected it in the same manner, and I own that I had that expectation, when I first put a sprig of mint into a glass-jar, standing inverted in a vessel of water; but when it had continued growing there for some months, I found that the air would neither extinguish a candle, nor was it at all inconvenient to a mouse, which I put into it.

…Accordingly, on the 17th of August 1771, I put a sprig of mint into a quantity of air, in which a wax candle had burned out, and found that, on the 27th of the same month, another candle burned perfectly well in it. This experiment I repeated, without least variation in the event, not less than eight or ten times in the remainder of the summer.

Priestley’s experiment also demonstrated the key processes of the natural carbon cycle. Although Priestley could not name the gases responsible, the fire and respiration used up oxygen and gave off carbon dioxide. The mint reversed both processes. Photosynthesis took up the carbon dioxide, converted it into plant tissue, and gave off oxygen as a by-product.

Priestley’s experiment thus has ecological implications for today, since the world is just a bigger jar. Tens of billions of tons of carbon a year pass between land and the atmosphere: given off by living things as they breathe and decay and taken up by green plants, which produce oxygen. A similar traffic in carbon, between marine plants and animals, takes place within the waters of the ocean. And nearly a hundred billion tons of carbon diffuse back and forth between ocean and atmosphere.

1917 image of Athbasca Glacier, Jasper National Park, Canada, courtesy National Archives of Canada, from the Wheeler Survey; 2005 image by Gary Braasch. Receding glaciers are visible evidence of global warming.

Compared with these vast natural exchanges, the few billion tons of carbon that humans contribute to the atmosphere each year seem paltry. Yet like a finger on a balance, our steady contributions are throwing the natural cycle out of whack. The coal, oil, and natural gas that drive the industrial world’s economy all contain carbon inhaled by plants hundreds of millions of years ago — carbon that now is returning to the atmosphere through smokestacks and exhaust pipes, joining emissions from forests burned to clear land in poorer countries. The atmosphere’s carbon dioxide level has risen by some 30 percent since Priestley’s time. It may now be higher than it has been in at least 20 million years.

Carbon dioxide is foremost in an array of gases from human activity that increase the atmosphere’s ability to trap heat, resulting in ongoing global warming.


  • Allen, J.F. and W. Martin, “Evolutionary biology: Out of thin air,” Nature 445: 610-612 (8 February 2007)
  • Appenzeller, Tim, “The case of the missing carbon”, National Geographic Magazine (Feb 2004) , vol 205, number 2, p 88.

July 24, 1984 (a Tuesday)

Scales of Justice

On this date, the body of nine-year-old Dawn Venice Hamilton was found in a wooded area of Rosedale, Maryland, near her home. The young girl had been raped and beaten to death with a rock.

After witnesses saw a suspicious man in the area of the murder scene, a police sketch was publicized on television and in newspapers. Two weeks later, an anonymous caller identified Kirk Bloodsworth, a 23-year-old ex-Marine, as the man in the sketch. Bloodsworth, who had been in Baltimore (which is close to Rosedale) at the time of Hamilton’s murder, later returned to his home in Cambridge and told friends that he had done something that would “harm his marriage”.

Prosecutors, with little evidence other than this, accused Bloodsworth of murder. During his trial, the defense presented several witnesses who said that they were with Bloodsworth at the time of the murder, but the state had presented five witnesses who testified that they had seen Bloodsworth with the victim. The jury convicted Bloodsworth in March of 1985 for the brutal killing and sexual assault of the nine year old girl and sent him to death row.

On appeal, Bloodsworth won a new trial, on the ground that the prosecution had withheld evidence indicating that another suspect might have been the killer. A few weeks before the second trial, evidence of yet another suspect was made available to Bloodsworth’s counsel, who chose not to pursue the lead. This time, he was convicted and sentenced to two life terms, to run consecutively.

For the next seven years, Bloodsworth maintained his innocence while in prison. In the meantime, forensic DNA testing had come of age. On Dawn Hamilton’s underwear, police had observed a spot of semen, smaller than a dime, and science had finally progressed to the point where this small amount of physical evidence could be tested. Bloodworth’s attorney, Bob Morin, with support from the Innocence Project, a nonprofit legal clinic formed to promote the use of DNA analysis to exonerate innocent prisoners, persuaded prosecutors in 1992 to compare Bloodsworth’s DNA with the DNA of dried sperm found on the victim. The DNA testing, performed by Forensic Science Associates, a private California laboratory, excluded Bloodsworth.

After the FBI’s crime lab confirmed this test, prosecutors in Baltimore County had no choice but to release Bloodsworth (but pointedly refused to apologize). On 28 June 1993, nine years after first going to jail, Kirk Bloodsworth was released. He was officially pardoned in December 1993. He had spent over eight years in prison, two of those years facing execution.

PCR DNA tests, Bloodsworth case, 1993 (Forensic Science Associates)

In 2003, after much prodding from Bloodsworth and Innocence Project lawyers, Maryland authorities finally searched their DNA database for a “cold hit” match of the evidence in the Dawn Hamilton case. The search turned up Kimberley Shay Ruffner, a convicted rapist who Bloodsworth had known in prison, who was then tried and found guilty of the 1984 murder.

Bloodsworth thus became the first person to be exonerated from death row through postconviction DNA testing. This led to the Justice for All Act of 2004, which included the Innocence Protection Act of 2004 as Title IV, legislation that, among other things, grants any federal inmate the right to petition a federal court for DNA testing to support a claim of innocence. Title IV also established the Kirk Bloodsworth Post-Conviction DNA Testing Grant Program to award grants to States to help defray the costs of post-conviction DNA testing. By August 2004, a total of 144 prisoners, some on death row, had been exonerated by DNA testing.

Most Americans know that there is at least a danger that innocent people will be executed. Yet according to a recent Angus Reid Public Opinion poll (4 Oct 2011), 81% of Americans still support the death penalty for convicted murderers. Many believe that we can ensure that the innocent are never executed if we take further measures — provide competent defense counsel, improve police methods, and so on. But as the Bloodsworth case underlines, this faith in the perfectibility of capital punishment is misplaced. The system can be improved, but it cannot be perfected.

Today, Bloodsworth is an activist for criminal justice reform and a public speaker. Over 30 state and regional innocence projects are at work.

July 17, 1203 C.E.

On this date, Constantinople, the capital of the Byzantine Empire, was captured by armies from Western Europe during the fourth crusade. The ancient name of Constantinople was Byzantium (Greek: Byzantion), from which the Byzantine Empire’s name was derived. The name had been changed by Roman emperor Constantine I, who had moved the capital of the Roman empire here on May 11, 330 C.E. Constantine wanted to name the city Nova Roma (New Rome), but this name never caught on. Today, the city is known as Istanbul and is the cultural and financial center of Turkey.

Prior to the fall of Constantinople, Western scholars had had access to Latin translations of the writings of Aristotle, the ancient Greek philosopher who lived from 384 to 322 B.C.E. These translations were based on texts in Arabic, which in turn were based on translations in Syriac from the original Greek. This was because the West, unlike the East (such as Syria), had never preserved Aristotle’s original writings. The structure of the Arab language is quite different from Greek and Latin (which are fairly similar to each other), so there was unavoidable paraphrasing in the passage from the original Greek to Arabic, and then again in the translation from Arabic to Latin. In effect, the first exposure to the full extent of Aristotle’s writings by Western scholars came in the form of Latin paraphrases of Arab paraphrases of (and commentaries on) Syriac paraphrases of second-hand copies of the original Greek texts. Not surprisingly, the resulting Latin renderings were somewhat unreliable.

However, as a result of the fall of Constantinople, Western scholars gained access to Greek texts that were much closer to Aristotle’s original writings. Around 1265, the Flemish Dominican William of Moerbeke (1215-1286) and other scholars translated these Greek texts into Latin, which can almost be done word-for-word, given the structural similarity between the two languages. Later, Thomas Aquinas undertook to integrate and reconcile the Aristotelian principles of reason and rational thought with Christian theology, resulting in his monumental Summa teologica. Thus fused with Christian doctrine into a philosophical system known as Scholasticism, Aristotelian philosophy became the official philosophy of the Roman Catholic Church. The view of Aristotle as the indisputable epitome of reason dates from this time.

The ruins of Aristotle's school have been found only 2 kilometers away from the contemporary Naoussa, at the district of Isvoria in Athens, Greece.

Aristotle was called Ille Philosophus (The Philosopher), or “the master of them that know,” and many accepted every word of his writings — or at least every word that did not contradict the Bible — as eternal truth. Consequently, some scientific discoveries in the Middle Ages and Renaissance were criticized simply because they were not found in Aristotle. It is one of the ironies of the history of science that Aristotle’s writings, which in many cases were based on extraordinary first-hand observation, were actually used to impede observational science — a development that Aristotle, no doubt, never intended.

June 29, 1935 (a Saturday)

On this date, Wendell Meredith Stanley announced the isolation of tobacco mosaic virus (TMV) as a crystalline molecule in the journal Science. For this feat, he later was a co-recipient of the Nobel Prize in Chemistry for 1946.

Stanley’s work had great significance for the ongoing debate about the scientific distinction between life and non-life. In 1937 Barclay Moon Newman noted that, “It has astonished the scientific world that a single molecule can be the causative organism of a disease. How can a crystal be made up of living molecules?” Stanley said in his Nobel Prize Lecture on 12 December 1946:

Reproduction, mutation and metabolic activity have long been regarded as unique and special properties of living organisms. When viruses were found to possess the ability to reproduce and to mutate, there was a definite tendency to regard them as very small living organisms, despite the fact that the question of metabolic activity remained unanswered. Because of their small size they could not be seen by means of the ordinary light microscope. Although. this fact puzzled some investigators, it was pushed aside and for over thirty years interest in virus research was centered about the discovery of new viruses and on studies of the pathological manifestations of viruses.

Then, around 1930, Elford… demonstrated that different viruses possessed different and characteristic sizes, and that some viruses
were as large as about 300 mμ, whereas others were as small as 10 mμ… The fact that, with respect to size, the viruses overlapped with the organisms of the biologist at one extreme and with the molecules of the chemist at the other extreme only served to heighten the mystery regarding the nature of viruses. Then too, it became obvious that a sharp line dividing living from non-living things could not be drawn and this fact served to add fuel for discussion of the age-old question of “What is life?”.


Needless to say, for a time there was great skepticism that the crystalline material could be tobacco mosaic, due chiefly to the old idea that viruses were living organisms… As a whole, the results indicated that the crystalline material was, in fact, tobacco mosaic virus.


Stanley did not realize the importance of the nucleic acid component of TMV. Viruses today are recognized to be literally “parasitic” chemicals, segments of DNA or RNA wrapped in a protein coat. They can reproduce within cells, often with disastrous results to the host organism, but they cannot reproduce on their own, which is why they are not considered alive by biologists. Earlier ideas that viruses represent a kind of halfway point between life and non-life have largely been abandoned. Instead, viruses are now viewed as detached fragments of the genomes of organisms due to the high degree of similarity found among some viral and eukaryotic genes.

Stanley co-authored the book Viruses and the Nature of Life (1961).


  • Angela N. H. Creager. The Life of a Virus: Tobacco Mosaic Virus as an Experimental Model, 1930-1965 (Chicago, IL: University of Chicago Press, 2002) p. 47.
  • Wendell Stanley, “Isolation of a crystalline protein possessing the properties of tobacco-mosaic virus” Science, vol. 81, issue 2113: 644-645 (1935).
  • Wendell Stanley and Evans G. Valens. Viruses and the Nature of Life (New York: Dutton, 1961).

June 23, 1934 (a Saturday)

Police photographs of William Bayly taken in January 1934

On this date, William Alfred Bayly was convicted of murder in New Zealand despite the fact that the body of one of his victims was never found. Most of the evidence against Bayly consisted of trace amounts of human hair, bone, and tissue, representing a marked advance in the field of forensics.

I mention this historic event in jurisprudence to counter a fallacy that is often argued in what might seem to be an unrelated field – namely, evolutionary biology. Religious fundamentalists and creationists often argue that evolution can’t be true because no human being was around to see, for example, fish evolve into amphibians. If an eyewitness is necessary to “prove” evolution, how can someone be convicted of murder if not only is there no eyewitness, but even no corpse?!

This is how:

Sam and Christobel Lakey disappeared from their farm in Ruawaro, New Zealand, in October 1933, along with their rifles. Christobel’s body turned up on 16 October 1933 in a pond on the farm with terrible bruising to her face and head, and investigators then discovered fresh bloodstains in both an old buggy and a barn, leading them to believe that Sam had been shot and transported somewhere else.

One of the first suspects was William Bayly, who owned a farm adjacent to the Lakey’s and who was known to have had frequent arguments over fences and access roads with the Lakeys. Years earlier, he had been suspected of killing his cousin, but was released due to insufficient evidence. Suggesting to police that Sam Lakey had probably fled after killing his wife, Bayly soon dropped out of sight himself.

Meanwhile, detectives found the missing rifles buried in a swamp on Lakey’s property. Following up on a report that there had been thick smoke coming from a shed on Bayly’s property on the day that the Lakeys disappeared, investigators found pieces of hair and bones, ash, and shotgun lead in a large oil drum inside the shed. It appeared that Bayly had cremated Sam Lakey’s body in this drum.

Tests of the hair and bone fragments from the drum in the shed proved that they were human in origin. Bayly was found guilty and hanged in Auckland prison at 8 am on 20 July 1934.

Even today, juries are reluctant to return murder convictions without the presence of a corpse. That a New Zealand jury was willing to take this unprecedented step so many years ago speaks volumes about the quality and quantity of forensic evidence made available by the prosecution.


June 6, 1822 (a Thursday)

Alexis St. Martin with his wife in his later years.

Alexis St. Martin with his wife in his later years.

On this date, Alexis St. Martin was working at a fur-trading post in Mackinac Island in Lake Huron when he was accidentally shot with a gun at close range. The charge of the gunshot blew a fist-sized hole through his side and into his stomach. The following account from Gurdon S. Hubbard is the only eyewitness description of the incident.

This St. Martin was at the time one of the American Fur Company’s engages, who, with quite a number of others, was in the store. One of the party was holding a shotgun (not a musket) which was accidentally discharged, the whole charge entered St. Martins body. The muzzle was not over three feet from him — I think not over two. The wadding entered, was well as pieces of his clothing; his shirt took fire; he fell, as we supposed, dead.

William Beaumont, a US Army surgeon stationed at a nearby army post, treated the wound. Although St. Martin was a healthy 28-year-old [1], he was not expected to recover due to the severity of his wound. Nevertheless, he did so under Beaumont’s care, and when the wound healed itself, the edge of the hole in the stomach had attached itself to the edge of the hole in the skin, creating a permanent gastric fistula. The strong stomach acid essentially disinfected the wound from the inside out, making it safe to not sew it up.

The trading post where St. Martin was shot still stands today in Michigan.

The trading post where St. Martin was shot still stands today in Michigan.

Beaumont recognized the wonderful opportunity he had in St. Martin to investigate the mysterious process of digestion. For centuries, the stomach was thought to produce heat that somehow cooked foods. Alternatively, the stomach was imagined to be like a mill, a fermenting vat, or a stew pan. Beaumont performed two kinds of experiments on the digestive processes from 1825 to 1833. First, he observed the fluids discharged by the stomach when different foods were eaten (in vivo). Second, he extracted samples of the stomach’s content and put them into glass tubes to determine the time required for “external” digestion (in vitro).

Expressing his dislike for his role, St. Martin periodically disappeared. In 1832, to secure his experimental subject, Beaumont signed St. Martin to a 1-year contract. Per the contract, St. Martin was to “obey, suffer and comply with all reasonable and proper orders or experiments” for $150 and room, board, and clothing. In 1833, St. Martin went home to Canada, never to return to Beaumont’s care. The difference in social status and wealth makes Beaumont’s use of St. Martin ethically questionable.

Beaumont published the first results of his experiments on St. Martin in the Philadelphia Medical Recorder for January 1825, and full details in 1838 as Experiments and Observations on the Gastric Juice, and the Physiology of Digestion. He ended his treatise with a list of fifty-one inferences based on his 238 separate experiments. Although working away from the centers of medicine, Beaumont used findings from Spallanzini, Carminiti, Viridet, Vauquelin, Tiedemann and Gmelin, Leuret and Lassaigne, Montegre, and Prout. Even with their information, he still obeyed the scientific method, basing all his inferences on direct experimentation.

Beaumont proved once and for all that digestion in the stomach was chemical — a product (mostly) of the gastric juice itself which Beaumont surmised, correctly, was composed largely of hydrochloric acid. Beaumont’s important experiments quickly reached an international audience. In the United States, Dunglison’s 1844 second edition of Human Health included a 3-page appendix of Beaumont’s “…time required for the stomachal digestion of different alimentary substances,” and Cutter’s popular Anatomy and Physiology Designed for Academies and Families (1848) included Beaumont’s results for the mean times for digesting foods. In France, Claude Bernard cited Beaumont’s work in his 1865 Introduction to the Study of Experimental Medicine.

Beaumont’s accomplishment is even more remarkable because the United States, unlike England, France, and Germany, provided no research facilities for experimental medicine. Beaumont, a “backwoods physiologist,” inspired future studies of gastric emptying, intestinal absorption, electrolyte balance, rehydration, and nutritional supplementation with so-called sports drinks.

[1] For some reason, St. Martin’s age at the time was given by Beaumont as 18 years, and the error was not corrected until the Canadian Physiological Society marked his grave in 1962. Often referring to his patient as a “lad,” the doctor was actually just nine years his senior. It is possible that Alexis for some reason falsified his age throughout his dealings with Beaumont, or even that someone else stated the age and the wounded man was never actually asked. On the other hand, others think that it was not an error. “I doubt that Beaumont, who showed himself to be a notoriously accurate observer, would not have noticed the difference between a youth of 18 and a grown man of 28,” said Sylvio Leblond, MD. “I do not believe that Alexis had any reason to state that he was ten years younger than his correct age, and I feel certain that the thought would never have occurred to him…It is reasonable to conclude, then, that he was…18 or 19 in 1822.”


June 5, 469 B.C.E.

The Death of Socrates

Today is the estimated date of birth of the Greek philosopher Socrates. He is best known outside philosophy for being condemned to death by an Athenian people’s court and choosing to die by drinking hemlock. He had been charged with impiety and with corrupting Athenian youth through his teachings and had been given the opportunity to go into exile. However, he chose to die as sentenced because he believed he would otherwise dishonor the agreement he had willingly made to abide by the laws of Athens.

Perhaps his most important contribution to Western thought is his dialogical method of inquiry, known as the Socratic Method or method of elenchos, which he largely applied to the examination of key moral concepts such as the Good and Justice, concepts used constantly without any real definition. It was first described by Plato in the Socratic Dialogues. For this, Socrates is customarily regarded as the father of political philosophy and ethics or moral philosophy, and as a fountainhead of all the main themes in Western philosophy in general.

In this method, a series of questions are posed to help a person or group to determine their underlying beliefs and the extent of their knowledge. The Socratic method is a negative method of hypothesis elimination, in that better hypotheses are found by steadily identifying and eliminating those which lead to contradictions. It was designed to force one to examine his own beliefs and the validity of such beliefs.

My Favorite Quote (recorded by Plato in The Apology):

The unexamined life is not worth living for a human being.

May 25, 1769

Jan Ingen-Housz

On this date, the Dutch physician and scientist Jan Ingen-Housz was elected to the Royal Society of London. He is best known today for showing that light is essential to photosynthesis and thus having discovered photosynthesis. He also discovered that plants, like animals, have cellular respiration.

In the summer of 1771, Joseph Priestley had carried out experiments with air and jars, noting that a closed jar would eventually kill a mouse and extinguish a candle, but vegetation (he used mint) would allow the mouse to live and the candle to burn. Although he did not have the official names of the “types” of air he was observing, Priestly had discovered that mice and candles need something (oxygen), and plants are capable of using other things in the air (carbon dioxide) to produce that something. In short, plants restore to the air whatever breathing animals and burning candles remove.  However, Priestly and others were unable to reproducibly demonstrate oxygen production by plants because they were unaware of the requirement for light in photosynthesis.

Probably motivated by Priestley’s publications on the subject, Ingen-Housz obtained a short leave of absence in 1779 from his post in Vienna, Austria in order to do research in England on plants during the summer months. He performed more than 500 experiments trying to determine why plants restore bad air and described the results in his exceptional book entitled Experiments Upon Vegetables, Discovering Their Great Power of Purifying the Common Air in the Sunshine and of Injuring it in the Shade and at Night, published in October 1779.

Underwater plants producing bubbles of oxygen.

In some of his experiments, Ingen-Housz placed plants underwater in a transparent container.  He found they gave off bubbles of gas only when placed in sunlight and that the bubbles gradually ceased when the plants were placed in darkness. He determined that it is not because of the warmth of the sun, and it is not the sun acting on its own, but the light of the sun reacting with the green parts (stalks and leaves) of the plants.

Once he realized a gas was being produced in the presence of light, Ingen-Housz collected it and conducted a series of tests to determine its identity. He eventually discovered that a smoldering candle would relight when it was exposed to the unknown gas. This showed that it was oxygen (known at that time as ‘dephlogisticated’ or ‘vital’ air).

In another experiment, Ingen-Housz put a plant and a candle into a transparent closed space. He allowed the system to stand in sunlight for two or three days. This assured that the air inside was pure enough to support a candle flame. But he did not light the candle. Then, he covered the closed space with a black cloth and let it remain covered for several days. When he tried to light the candle it would not light. Ingen-Housz concluded that somehow the plant must have acted in darkness like an animal. It must have breathed, fouling the air. Ingen-Housz quickly printed his book in London, allowing him to take along copies when he returned to Vienna.

The biochemistry of photosynthesis.

So why is Priestley until today a well-known name in the history of science, while Ingen-Housz is virtually unknown , except for a few historians of chemistry and botany? Ingen-Housz was a humble person, not interested in fame, pomp, or circumstance. Low-key and introverted, enjoying friendships, shying away from stardom, he stood in contrast to some of his fellow researchers of that time. For example, Priestley admitted in private that Ingen-Housz indeed had been the first to describe the beneficial power of plants in a letter to Giovanni Fabroni from 1779:

I have just read and am much pleased with Dr. Ingenhousz’ work. The things of most value that he hit upon and I missed are that leaves without the rest of the plants will produce pure air and that the difference between day and night is so considerable.

Priestley promised Ingen-Housz that he would rectify the situation in a later publication. But the attribution never appeared in print; Ingen-Housz was not even mentioned by Priestley. In the meantime, Priestley repeatedly claimed in public to have observed and published before Ingen-Housz and kept repeating this until 1800. In fact, never did Priestley give an accurate reference to Ingen-Housz’ work, never did Ingen-Housz’ name appear in the index of Priestey’s works. On the other hand, Ingen-Housz systematically referred to Priestley, with much respect.  Ingen-Housz refrained from disputing the claims of his rival colleagues, but they continued as they did, obfuscating Ingen-Housz’ rightful place in science as the discoverer of photosynthesis in the eyes of the historians and the public.


May 21, 427 B.C.E.

Delphi Platon statue.

Today is thought to be the date of birth of the Greek philosopher Plato, student of Socrates and teacher of Aristotle. Together the three formed the basis of Western philosophy. Nevertheless, when one compares Plato with some of the other philosophers who are often ranked with him — Aristotle, Aquinas, and Kant, for example — he can be recognized to be far more exploratory, incompletely systematic, elusive, and playful than they. That, along with his gifts as a writer and as a creator of vivid character and dramatic setting, is one of the reasons why he is often thought to be the ideal author from whom one should receive one’s introduction to philosophy.

Plato was born with the name Aristocles. He was surnamed Plato because of his exceptionally well-developed broad shoulders. He founded the Academy in Athens, Greece, which is considered to have been the prototype of the modern university. Many of his writings focused on justice, virtue and politics, although he also had great interest in rhetoric, art, and literature. Plato himself did not contribute substantial works directly to science and mathematics, but his stress on mathematics and philosophy, and his insistence on defining terms rather than trusting intuition, influenced many later thinkers. Furthermore, his ideas on education and what constituted knowledge inspired his followers to explore the world in new ways.

In Plato’s dialogue entitled Theaetetus, Socrates considers a number of definitions as to what knowledge is, the last being that knowledge is true belief that has been “given an account of” — meaning explained or supported in some way. According to this definition, in order to know that a given proposition is true, one must not only believe the relevant true proposition, but one must also have a good reason for doing so. In other words, no one would gain knowledge just by believing something that happened to be true. For example, an ill person with no medical training, but a generally optimistic attitude, might believe that he/she will recover from his/her illness quickly. Nevertheless, even if this belief turned out to be true, the patient would not have known that he/she would get well since his/her belief lacked justification. This is the most widely accepted definition of knowledge that has persisted to the modern day.

Interestingly, Plato, through his famous Symposium, has given his name to the love that dare not speaks its name, even though Platonic love has come to mean lately a kind of sexless friendship. That Platonic love before Freud was clearly Gay love is evident in Patience, Gilbert and Sullivan’s devastating satire on the aesthetic movement, in which the effeminate poet Bunthorne sings about “an attachment a la Plato for a bashful young potato and not too French, French bean!”

Noteworthy Quote:

Every heart sings a song, incomplete, until another heart whispers back. Those who wish to sing always find a song. At the touch of a lover, everyone becomes a poet.

May 20, 1747 (a Saturday)

James Lind

James Lind wrote in his A Treatise of the Scurvy (published in 1753):

On the 20th of May, 1747, I took twelve patients in the scurvy on board the Salisbury at sea. Their cases were as similar as I could have them.

Thus began Lind’s description of his classic therapeutic experiment on sailors with the scurvy in which various, then proposed remedies, were tested as antiscorbutics. His report continued:

[The subjects] lay together in one place…in the fore-hold; and had one common diet, viz. water-gruel sweetened with sugar in the morning; fresh mutton-broth often times for dinner;…and for supper, barley and raisins, rice and currants, sago and wine, or the like. Two of these were ordered each a quart of cider a-day. Two others took twenty-five [drops] of elixir vitriol three times a-day, upon an empty stomach…Two others took two spoonfuls of vinegar three times a-day, upon an empty stomach;…Two of the worst patients…were put under a course of sea-water. Of this they drank half a pint every day…Two others had each two oranges and one lemon given them every day. These they eat with greediness, at different times, upon an empty stomach. They continued but six days under this course, having consumed the quantity that could be spared. The two remaining patients, took the bigness of a nutmeg three times a-day, of an electuary recommended by an hospital-surgeon, made of garlic, mustard-seed, [horse-radish], balsam of Peru, and gum myrrh…

The consequence was, that the most sudden and visible good effects were perceived from the use of the oranges and lemons; one of those who had taken them, being at the end of six days fit for duty… The other was the best recovered of any in his condition; and being now deemed pretty well, was appointed nurse to the rest of the sick.

Cider, Lind reported, had the next best effect. There was no remarkable alteration of the course of the disease in any of the other patients at the end of the two weeks’ tests. Although he does not mention them in the quotation above, Lind had a control group — all the other patients on board of his ship. These patients did not get anything that might cure their disease — all they got was a pain-killing paste (“lenitive electuary”), a laxative (cremor tartar), and/or a cough syrup (“pectoral”). It is clear that these products can have an effect on the symptoms (pain, constipation) but will not cure the disease. Thus, Lind’s experiment provided clear evidence of the curative value of oranges and lemons and was also the first example of a controlled clinical trial using human subjects.

April 28, 1975 (a Monday)

On this date, Peter Gwynne, at the time the science editor of Newsweek, pulled together some interviews from scientists and wrote a nine-paragraph story, entitled “The Cooling World“, about how the planet was getting cooler. Ever since, Gwynne’s “global cooling” story – and a similar Time Magazine piece – have been brandished gleefully by those who say it shows global warming is not happening, or at least that scientists – and often journalists – don’t know what they are talking about.

Fox News loves to cite it. So does Rush Limbaugh. Sen. James Inhofe, R-Okla., has quoted the story on the Senate floor. That one article in 1975 was so brilliant, that it has managed to disprove over 33,000 scientifically researched papers written since.

His piece has been used by Forbes as evidence of what the magazine called “The Fiction of Climate Science.” It has been set to music on a YouTube video. It has popped up in a slew of finger-wagging blogs and websites dedicated to climate denial.

But, revisionist lore aside, it was hardly a cover story. It was a one-page article on page 64. It was, Gwynne concedes, written with a bit of hyperbole that sometimes marked the magazine’s prose: “There are ominous signs the earth’s weather patterns have begun to change dramatically…” the piece begins, and warns of a possible “dramatic decline in food production.”

Although the story observed – accurately – that there had been a gradual decrease in global average temperatures from about 1940, by about 1980 it was clear that Earth’s average temperature was headed upward.

Even today, “there is some degree of uncertainty about natural variability,” acknowledged Mark McCaffrey, programs and policy director of the National Center for Science Education based in Oakland, California. “If it weren’t for the fact that humans had become a force of nature, we would be slipping back into an ice age, according to orbital cycles.”

But earth’s glacial rhythms are “being overridden by human activities, especially burning fossil fuels,” McCaffrey noted. The stories about global cooling “are convenient for people to trot out and wave around,” he said, but they miss the point:

What’s clear is we are a force of nature. Human activity – the burning of fossil fuels and land change – is having a massive influence. We are in the midst of this giant geoengineering experiment.

April 10, 1901 (a Wednesday)

On this date, Duncan MacDougall, MD, performed his first experiment to test a hypothesis, to wit, “If personal continuity after the event of death is a fact, if the psychic functions continue to exist as a separate individuality after the death of brain and body, then it must exist as a substantial material entity.” This implies that this entity should have mass, so MacDougall asked himself, “Why not weigh on accurate scales a man at the very moment of death?”

The following is an extract of a letter written by Dr. MacDougall to a Richard Hodgson, MD and dated 10 November 1901, describing MacDougall’s first experiment. The letter was published in May 1907, along with a report of his subsequent experiments, in the Journal of the American Society for Psychical Research:


Interestingly, in a commentary published with the report, the editor of the Journal wrote that he “does not share the hopes which many entertain regarding the possibility of ‘weighing a soul,’ but this does not preclude his [MacDougall’s] recognition of the value of experiment, whatever its outcome. The main point is to have a definite conclusion established, whether it be negative or affirmative.”

According to The New York Times, MacDougall was a “reputable physician” and “at the head of a Research Society which for six years has been experimenting in this field.”


April 1, 1578

William Harvey

On this date, the English physician and scientist William Harvey was born. He is credited with being the first in the Western world to describe correctly and in exact detail the systemic circulation and properties of blood being pumped around the body by the heart. Harvey published his discovery in a treatise entitled Exercitatio Anatomica de Motu Cordis et Sanguinis in Animalibus (On the Motion of the Heart and Blood in Animals) in 1628. Brief, well argued, and clearly written, De Motu Cordis is very probably the one and only great classic of Western science written before 1800 that is still widely read today. His discovery was dramatically confirmed later in the seventeenth century by microscopist Marcello Malpighi’s discovery of capillaries.

Functional knowledge of the heart and the circulation had remained almost at a standstill ever since the time of the Greco-Roman physician Galen – 1,400 years earlier. With Harvey, life began to receive mechanistic explanation. The essential idea of mechanistic explanation is that “natural” events have “natural” causes and can be explained by cause-and-effect relationships that do not involve special action of supernatural agency. This is fundamental to modern science.

Title page of *De Motu Cordis*

Just as important was Harvey’s methodology. De Motu Cordis quickly became understood as a rejection of traditional methods. It was viewed as challenging the traditional system of deductive reasoning via syllogisms, instead advocating experimentation and sensory experience. The empirical methodology observable in Harvey’s work is now the acknowledged scientific method and has been universally adopted across all science and medicine.

Harvey clearly understood the implications of his work, for he wrote at the opening of Chapter VIII (“Of the abundance of blood passing through the heart out of the veins into the arteries, and of the circular motion of the blood”), in which he demolishes the core of the Galenic model:

Thus far I have spoken of the passage of the blood from the veins into the arteries….But what remains to be said upon the quantity and source of the blood which thus passes, is of a character so novel and unheard-of that I not only fear injury to myself from the envy of a few, but I tremble lest I have mankind at large for my enemies, so much has wont and custom become second nature. Doctrine once sown strikes deep its root, and respect for antiquity influences all men. Still, the die is cast, and my trust is in my love of truth and the candor of cultivated minds.

He also left a message in De Motu Cordis that is as true today as it was 500 years ago:

True philosophers, who are only eager for truth and knowledge, never regard themselves as already so thoroughly informed, [so that they do not] welcome information from whomsoever and from wheresoever it may come; nor are they so narrow-minded as to imagine any of the arts or sciences transmitted to us by the ancients, in such a state of forwardness or completeness that nothing is left for the ingenuity or industry of others. On the contrary, very many maintain that all we know is still infinitely less than all that remains unknown. [Nor] do philosophers pin their faith to others’ precepts in such [ways] as they lose their liberty, and cease to give credence to the conclusions of their proper senses. Neither do they swear such fealty to their mistress Antiquity, that they openly, and in sight of all, deny and desert their friend, Truth. [emphasis added]

In Exercitationes de Generatione Animalium (On the Generation of Animals) in 1651, Harvey was extremely skeptical of spontaneous generation and proposed that every living animal originally comes from an egg, introducing the oft-quoted phrase “ex ova omnia” (all [life] from eggs). [However, Harvey did not completely reject spontaneous generation.] His experiments with chick embryos supported the theory of epigenesis, which states that organisms develop from substances in the egg that differentiate during embryonic development.  This was in conflict with the now-descredited preformationist view that perfect miniature versions of offspring exist in the gametes and grow during development.  [Please note that the term ‘epigenesis’ carries different meanings. Here, it used used in the older sense, as a theory of animal and plant development. In more modern times, it refers to mechanisms by which gene regulation over generations is controlled by elements other than DNA.]


  • Schultz, S.G., “William Harvey and the circulation of the blood: The birth of a scientific revolution and modern physiology,” News in Physiological Sciences 17: 175-180 (Oct 2002).

March 31, 1596 (a Sunday)

René Descartes

On this date, the French mathematician, anatomist, physiologist, and philosopher René Descartes was born in La Haye in the region of Touraine, France. He is often regarded as the first modern thinker to provide a philosophical framework for the natural sciences as these began to develop. In his Discourse on the Method of Rightly Conducting One’s Reason and Of Seeking Truth in the Sciences (1637) he attempts to arrive at a fundamental set of principles that one can know as true without any doubt.

Descartes is also known for the mind/body dualism he first articulated in his De homine (Treatise on Man), which he completed in Holland about 1633, on the eve of the condemnation of Galileo. When his friend and frequent correspondent, Marin Mersenne, wrote to him of Galileo’s fate at the hands of the Inquisition, Descartes became concerned for his own safety and refused to have De homine printed. Consequently, the first edition of this work was not published until 12 years after the author’s death.

Figure 1 from Descartes’ De homine (1664), depicting the human heart.

According to Descartes’ principle of dualism, the body works like a machine, has the material properties of extension and motion, and follows the laws of physics. The mind (or soul), on the other hand, is described as a nonmaterial thinking entity that lacks extension and motion, and does not follow the laws of physics. Descartes argued that only humans have minds, and that the mind interacts with the body at the pineal gland. [He chose the pineal gland because it appeared to him to be the only organ in the brain that was not bilaterally duplicated and because he believed, erroneously, that it was uniquely human.] In De homine, he wrote:

I suppose the body to be nothing but a statue or machine made of earth, which God forms with the explicit intention of making it as much as possible like us…

William Harvey’s recent discovery that the heart acts as a pump to circulate the blood had supplied additional arguments in favor of Descartes’ mechanical theory – in fact, Descartes probably did much to popularize the discovery. The Cartesian dualism set the agenda for philosophical discussion of the mind/body problem for many years after Descartes’ death.

March 20, 1904 (a Sunday)

The root of all superstition is that men observe when a thing hits, but not when it misses.

— Francis Bacon (1561-1626), English lawyer and philosopher

Zen stones

On this day, the American psychologist, author, inventor, social philosopher, and poet B(urrhus) F(rederic) Skinner was born. He developed the theory of operant conditioning — the idea that behavior is determined by its consequences, be they reinforcements or punishments, which make it more or less likely that the behavior will occur again. His principles are still incorporated within treatments of phobias, addictive behaviors, and in the enhancement of classroom performance (as well as in computer-based self-instruction).

B.F. Skinner and quote.

Skinner believed that the only scientific approach to psychology was one that studied behaviors, not internal (subjective) mental processes. He denied the existence of a mind as a thing separate from the body, but he did not deny the existence of thoughts, which he regarded simply as private behaviors to be analyzed according to the same principle as publicly observed behaviors. To further improve the objective scientific value of observed behaviors, he invented the “Skinner box”, or operant conditioning chamber. It was a small, soundproof enclosure in which an animal could be isolated from all distractions and outside influences, responding only to the controlled conditions within the box, and is still used today.

Skinner’s analysis of human behavior culminated in his work Verbal Behavior (1957). He was a prolific author who published 21 books and 180 articles. In a June, 2002 survey, B.F. Skinner was listed as the most influential psychologist of the 20th century (Review of General Psychology, June, 2002, pp. 139-152). He was named “Humanist of the Year” in 1972 by the American Humanist Association.

One of Skinner’s most interesting and famous experiments, a classic in psychology, examined the formation of “superstition” in one of his favorite experimental animals, the pigeon. Skinner placed a series of hungry pigeons in a cage attached to an automatic mechanism that delivered food to the pigeon “at regular intervals with no reference whatsoever to the bird’s behavior.” He discovered that the pigeons associated the delivery of the food with whatever chance actions they had been performing as it was delivered (accidental reinforcement), and that they subsequently continued to perform these same actions:

One bird was conditioned to turn counter-clockwise about the cage, making two or three turns between reinforcements. Another repeatedly thrust its head into one of the upper corners of the cage. A third developed a ‘tossing’ response, as if placing its head beneath an invisible bar and lifting it repeatedly. Two birds developed a pendulum motion of the head and body, in which the head was extended forward and swung from right to left with a sharp movement followed by a somewhat slower return.

Skinner suggested that the pigeons behaved as if they were influencing the automatic mechanism with their “rituals” and that this experiment shed light on human behavior:

The experiment might be said to demonstrate a sort of superstition. The bird behaves as if there were a causal relation between its behavior and the presentation of food, although such a relation is lacking. There are many analogies in human behavior. Rituals for changing one’s fortune at cards are good examples. A few accidental connections between a ritual and favorable consequences suffice to set up and maintain the behavior in spite of many unreinforced instances. The bowler who has released a ball down the alley but continues to behave as if she were controlling it by twisting and turning her arm and shoulder is another case in point. These behaviors have, of course, no real effect upon one’s luck or upon a ball half way down an alley, just as in the present case the food would appear as often if the pigeon did nothing — or, more strictly speaking, did something else.

It is easy to see other human parallels of this type of behavior. A person playing a slot machine may alter the way he puts money in the machine and the way he pulls the handle if he thinks that doing these things a certain way will bring him luck. Independent of these behaviors the machine will occasionally pay off (reinforcement). Such a situation allows the person to develop a superstitious behavior, such as not looking at the machine while he pulls the handle. Observation of a gambling casino will reveal a large number of people displaying their superstitious behaviors at the slot machines. Each person’s superstition may be unique to him, as each of Skinner’s pigeons had a unique superstition.

Human superstitions are quite abundant. A college student in an elevator may keep pushing the button of his floor as if this would cause the elevator to move faster. A card player may pick up his cards one at a time as if to improve the hand he was dealt. A businessman may wear a “special” tie when going to an important meeting.

Many ancient beliefs involve superstition. For example, the rain dance: once when someone was doing the so-called rain dance, it started to rain. This person thought that perhaps their dance affected nature. After this rain dance was reinforced intermittently on a frequent enough schedule it became established as a superstitious behavior.

However, the pigeons’ behaviors were later reinterpreted as behaviors that improve foraging efficacy (analogous to salivation in Pavlov’s dogs), which suggests that the pigeons’ behavior does not correspond to Skinner’s intended meaning of superstition.  Nevertheless, Skinner’s early account is notable in two respects. First, it recognized the possibility of superstition occurring outside the human realm. Second, and linked to this, Skinner emphasized the behavioral aspect of superstition: “The bird behaves as if there were a causal relation between its behavior and the presentation of food, although such a relation is lacking.”  That is, he focused on there being an incorrect response to a stimulus (behavioral outcome), rather than the conscious abstract representation of cause and effect (psychological relationship), with which human superstitions are often associated.

There other differences between human superstitions based on psychological relationship and animal superstitions based on behavioral outcome:

  • First, humans, as opposed to animals, often spend considerable time justifying why they are not reinforced each time they do their superstitious behavior. (“I have some questions about that so- called virgin we sacrificed to the volcano god.” “I lost the golf match today because my lucky hat doesn’t seem to work two days in a row.”)
  • Second, humans spend more time than animals trying to convince others to adopt their superstitious behaviors. Children often carry on many of the superstitions of their parents.
  • Finally, as Herrnstein (1966) points out, “Human superstition, unlike that of animals, arises in a social context.” The acquired superstitions in humans are not as arbitrary as those of animals. Rather they are molded by the person’s culture. Thus, although it is possible to develop a superstition about Wednesday the 11th, it is more probable in our culture to be superstitious about Friday the 13th.

It has only been with the advent of the scientific method that people have been able to distinguish between that which is superstitious and that which has a scientific basis.


  • B.F. Skinner. “‘Superstition’ in the Pigeon,” Journal of Experimental Psychology 38: 168-172 (1948).
  • Kevin R. Foster and Hanna Kokko.
    The evolution of superstitious and superstition-like behaviour,”
    Proc R Soc B 276 (1654): 31-37 (January 2009). DOI: 10.1098/rspb.2008.0981
  • R.J. Herrnstein. “Superstition: A corollary of the principles of operant conditioning,” in W. K. Honig (ed.), Operant Behavior: Areas of Research and Application. (New York: Appleton-Century-Crofts, 1966) pp. 33-51.

February 19, 1626 (a Thursday)

Francesco Redi

On this date, the Italian physician and poet Francesco Redi was born.

Spontaneous generation (abiogenesis), a long-held theory that life springs up from non-living or decaying organic matter, was based on observations of rotting food seemingly producing living organisms. Francesco Redi, a respected philosopher at the court of the Medici Grand Duke in Tuscany, was the first scientist to question the idea of spontaneous generation. By setting up a simple experiment in which decaying meat was placed in three jars, one uncovered, one sealed, and one covered by mesh, allowing air to circulate, he demonstrated that only the open jar which flies could access produced maggots. Thus, decaying meat does not spontaneously produce maggots. Partially due to the simplicity of Redi’s experiment (anyone could reproduce it), people began to doubt spontaneous generation.

It is important to note that what Redi and others demonstrated is that life does not currently spontaneously arise in complex form from nonlife in nature; they did not demonstrate the impossibility of life arising in simple form from nonlife by way of a long and propitious series of chemical steps/selections under conditions that do not exist on Earth today. In particular, they did not show that life cannot arise once, and then evolve. Neither Pasteur, who put to rest the notion of spontaneous generation for microorganisms, nor any other post-Darwin researcher in this field denied the age of planet Earth or the fact of evolution.

January 24, 1850 (a Thursday)

Hermann Ebbinghaus

On this date, the German psychologist Hermann Ebbinghaus was born.

The scientific study of memory started with the work of Hermann Ebbinghaus, published in 1885 in the book Memory: A Contribution to Experimental Psychology. He was a careful, cautious researcher who followed simple but logical procedures.

Ebbinghaus devised a set of items to be committed to memory that would have no previous associations, the so-called nonsense syllables. These each consist of two consonants separated by a vowel (C-V-C) that does not spell anything in one’s language — in English, BAF would be an example. Ebbinghaus constructed 2,300 of these items and then proceeded to memorize them in lists of about 20. He learned each list of these syllables until he had reached a pre-established criterion (perfect recall), and then recorded how many he was able to retain after specific time intervals. He also noted how many trials were necessary for relearning after the syllables had been forgotten. His first set of trials took place over the course of one year (1879-1880) and he replicated the experiments three years later.

The curved brown and dotted lines represent forgetting curves; the green line represents the learning curve. Relearning at periodic intervals produces forgetting curves that are progressively flatter.

Ebbinghaus made several findings that are still relevant and supported to this day. First, arguably his most famous finding, the forgetting curve. The forgetting curve refers to the exponential curve that describes how fast we tend to forget information after we have learned it. The sharpest decline is in the first twenty minutes, then in the first hour, and then the curve evens off after about one day.

The learning curve, which was described by Ebbinghaus, refers to the curve that describes how fast we relearn information. The sharpest increase occurs after the first relearning (“repetition”), and gradually evens out, meaning that less and less new information is retained with each successive relearning. Like the forgetting curve, the learning curve is also exponential.

The Ebbinghaus Illusion. Note that the orange circles appear of different sizes, even though equal.

Interestingly, Ebbinghaus is also credited with discovering an optical illusion now known after its discoverer — the Ebbinghaus illusion, which is an illusion of relative size perception. In the best-known version of this illusion, two circles of identical size are placed near to each other and one is surrounded by large circles while the other is surrounded by small circles; the first central circle then appears smaller than the second central circle. This illusion is now used extensively in research in cognitive psychology, to find out more about the various perception pathways in our brain.


  • Plucker, J. A. (Ed.). (2003). “Human intelligence: Historical influences, current controversies, teaching resources”. Retrieved 24 Jan 2012 from http://www.indiana.edu/~intell

January 22, 1561 (Julian calendar/old style: a Wednesday)

Francis Bacon

Francis Bacon, an English lawyer, statesman, essayist, historian, intellectual reformer, philosopher, and champion of modern science, was born on this date in London. His works established and popularized an inductive methodology for scientific inquiry, often called the Baconian method or simply, the scientific method. His demand for a planned procedure of investigating all things natural marked a new turn in the rhetorical and theoretical framework for science, much of which still surrounds conceptions of proper methodology today.  Francis Bacon influenced all of science, once proclaiming, “I have taken all knowledge to be my province.”

Bacon’s works include his Essays, as well as the Colours of Good and Evil and the Meditationes Sacrae, all published in 1597. His famous aphorism, “knowledge is power” (scientia potentia est), is found in the Meditations.  He also wrote In felicem memoriam Elizabethae, a eulogy for the Queen written in 1609.  The principal work of Francis Bacon is Instauratio magna scientiarum (The Great Restoration of Learning), which was intended to embrace the entire field of knowables, both theoretical and practical. But of this vast work he finished only the first and second parts: De degnitate et augmentis scientiarum (Of the Proficience and Advancement of Learning, published 1605), and Novum organum scientiarum (New Organ of Learning, published 1620).  Bacon left only notes for what was to have been the other parts of his monumental work.  Interestingly, in the Novum organum he cites three world-changing inventions:

Printing, gunpowder and the compass: These three have changed the whole face and state of things throughout the world; the first in literature, the second in warfare, the third in navigation; whence have followed innumerable changes, in so much that no empire, no sect, no star seems to have exerted greater power and influence in human affairs than these mechanical discoveries.

Bacon is also one of the few homosexual writers from periods as distant as the Renaissance for whom there is contemporary testimony about his sexuality. On 17 April 1593, Bacon’s mother wrote to his brother Anthony (also gay) castigating Bacon for keeping “that bloody Percy . . . as a coach companion and bed companion”, as well as others including Jones, Markes, Enney “and his Welchmen one after another.” “Bed companion” need not have implied eroticism since the nonsexual same-sex sharing of beds was common in the period, but “coach companion” would have been recognized as a sexual reference and thus defines “bed companion” here as one, too. Coaches were one of the few places in those times that provided privacy for a sexual liaison, and “coach” language was commonly used in the Renaissance to signify a sexual connection. In any case, Lady Ann’s major distress was not that her son was gay, but that it violated decorum for a nobleman to allow a servant to sleep in the master bedroom; she felt that a lower-ranking bedroom would have been more appropriate.

John Aubrey in his Brief Lives (composed 1665-1690) says quite bluntly that Bacon “was a pederast” and had “ganimeds and favourites” (“pederast” in Renaissance diction meant generally “homosexual” rather than specifically a lover of minors, as indicated by “E. K.”‘s use of it when discussing the Colin-Hobbinol peer-relationship in Spenser’s 1579 The Shepherd’s Calendar; “ganimed” of course derives from the mythical prince abducted by Zeus to be his cup-bearer and bed-warmer.) The Puritan moralist Sir Simonds D’Ewes (Bacon’s fellow Member of Parliament) in his Autobiography and Correspondence discusses Bacon’s love for his Welsh serving-men, in particular a “very effeminate-faced youth” whom he calls “his catamite and bed-fellow” (“catamite” is a corruption of “Ganymede”). The diary entry for 3 May 1621 — the date of Bacon’s censure by Parliament — reveals the full extent of Bacon’s homosexuality, and is worth quoting extensively if only because it has been suppressed in the only printed edition of the D’Ewes’s autobiography (not published until 1845), and has been studiously ignored by most of Bacon’s modern biographers:

. . . the favour he had with the beloved Marquis of Buckingham emboldened him, as I learned in discourse from a gentleman of his bedchamber, who told me he was sure his lord should never fall as long as the said Marquis continued in favour. His most abominable and darling sinne I should rather burie in silence, than mencion it, were it not a most admirable instance, how men are enslaved by wickedness, & held captive by the devill. For wheeras presentlie upon his censure at this time his ambition was moderated, his pride humbled, and the meanes of his former injustice and corruption removed; yet would he not relinquish the practice of his most horrible & secret sinne of sodomie, keeping still one Godrick, a verie effeminate faced youth, to bee his catamite and bedfellow, although hee had discharged the most of his other household sevants: which was the moore to bee admired, because men generallie after his fall begann to discourse of that his unnaturall crime, which hee had practiced manie yeares, deserting the bedd of his Ladie, which hee accounted, as the Italians and the Turkes doe, a poore & meane pleasure in respect of the other; & it was thought by some, that hee should have been tried at the barre of justice for it, & have satisfied the law most severe against that horrible villanie with the price of his bloud; which caused some bold and forward man to write these verses following in a whole sheete of paper, & to cast it down in some part of Yorkehouse in the strand, wheere Viscount St. Alban yet lay:

Within this sty a *hogg doth ly,
That must be hang’d for Sodomy.

(*alluding both to his sirname of Bacon, & to that swinish abominable sinne.)

But hee never came to anye publicke triall for this crime; nor did ever, that I could heare, forbeare his old custome of making his servants his bedfellowes, soe to avoid the scandall was raised of him, though hee lived many yeares after his fall in his lodgings in Grayes Inne in Holbourne, in great want & penurie.

Sir Francis Bacon’s relationships — like those of his King — closely followed the pattern of patron/favourite. More specifically, he had a preference for young Welsh serving-men. The roll of attendants for Bacon’s household in 1618 lists a total of 75 attendants, of whom some 25 were gentlemen waiters. There was Francis Edney, who, upon Bacon’s death in 1626, received “£200 and my rich gown”; young Thomas Meautys, who was to become Bacon’s secretary-in-chief; a Mr Bushell, “gent. usher,” who came to the household in 1608 as a lad of fifteen, and who remained until Bacon’s death; Edward Sherburn, groom of the chamber; and, above all, young Tobie Matthew, who was left only a ring to the value of £30, but who had become Sir Tobie through Bacon’s efforts, and who was well able to care for himself.

Tobie, widely acclaimed for his charm and good looks, had appeared in a play at Gray’s Inn in 1595, and he quickly became Bacon’s most particular friend, intelligencer and confidant. Tobie had previously served as a spy on the Continent, where he had met and been befriended by Buckingham. A contemporary observed that Tobie, while lodging with Bacon at York House, had “grown very gay or rather gaudy in his attire, and noted for certain night walks to the Spanish Ambassador.” Tobie was the inspiration for one of Bacon’s most famous essays, “Of Friendship.”

Although Bacon married, he did so late (at the age of 45), and his marriage produced no children.

Bacon’s biographers often find all this evidence “inconclusive.” This is simply because they cannot accept the notion that a person can be brilliant, virtuous, healthy, and gay at the same time. Historians regularly hide what they cannot deny, and suppress evidence of the homosexuality of historical figures. Happily, Bacon’s most recent biographers Liesa Jardine and Alan Stewart in Hostage to Fortune: The Troubled Life of Francis Bacon (1999) make no attempt to deny the evidence, and even add to it.

Suggested reading:

January 9, 1998 (a Friday)


The story of how Dark Energy was discovered is a classic case of nature confounding expectations.

Ever since astronomers had accepted the idea of the Big Bang, they had been out hunting for its subsequent cosmic deceleration.

The idea was simple.

While the Big Bang blows space apart (it literally stretches all points of space-time away from each other), the gravitational pull of matter should, over time, slow down that initial burst of cosmic expansion. Two research groups, one at Berkeley and the other at Harvard, were racing to find the magnitude of deceleration in the universe. It was a critical project since the rate of cosmic braking is directly related to the total density of mass (and energy) in the universe.

Things didn’t go quite as planned. As data was gathered and analyzed, both the Harvard and Berkeley groups were stunned to find no evidence for deceleration. Instead, according to observations, the expansion of the universe was speeding up — it was accelerating. After exhaustively checking and rechecking their data, both groups bit the bullet and announced their results on this date (9 January 1998) at a meeting of the American Astronomical Society in New York City.

“All the indications from our observations of supernovas spanning a large range of distances are that we live in a universe that will expand forever,” said the leader of one team, Dr. Saul Perlmutter of Lawrence Berkeley National Laboratory in California. “Apparently there isn’t enough mass in the universe for its gravity to slow the expansion, which started with the Big Bang, to a halt.”

Dr. Peter Garnavich of the Harvard-Smithsonian Center for Astrophysics in Cambridge, Mass., a leader of the other team, said the low deceleration of the expansion rate means that the universe is much older, about 15 billion years old, than had been calculated by some astronomers, whose estimates had ranged as low as 8 billion years. If the universe was not expanding at a faster rate earlier, then it has taken longer for it to reach its present size.

In an independent study of the expansion rates of 14 distant radio galaxies, Dr. Ruth A. Daly, a Princeton University astronomer, said “our results are basically almost identical” to those of the Berkeley and Harvard-Smithsonian supernova observations. “We are 95 percent confident that the universe is going to expand forever,” Dr. Daly said.

Remarking on the close agreement of the different studies, Dr. Neta A. Bahcall, a Princeton astrophysicist, said this reinforced confidence that the conclusions are correct, or else everyone has overlooked some hidden flaw.

Where does Dark Energy appear in all this? As Newton showed 400 years earlier, accelerations need forces. And, as the physicists of the eighteenth and nineteenth centuries demonstrated, forces need energy. The discovery of cosmic acceleration meant that space was being forced apart and must, therefore, be pervaded by a new form of energy acting as “anti-gravity.” While Newtonian gravity only produces attractions, Einstein’s more complete description of gravity — as the shape of space-time — demonstrated that repulsion and gravity could go hand-in-hand.

The discovery of cosmic acceleration and Dark Energy upended cosmology almost overnight. In spite of the community’s incredulity, further studies, including studies of cosmic geometry, gave new support (multiple lines of evidence) for the reality of Dark Energy. Like it or not, this unanticipated form of anti-gravity was now a powerful actor on cosmology’s stage.

“Like it or not” is the key phrase. The history of science is stacked high with ideas and discoveries nobody was expecting, or even wanted. From the discovery of the muon (“who ordered that?” asked physicist I.I. Rabi) to climate change (the ultimate inconvenient truth), we don’t get to dictate to nature how it should behave. The greatest and strangest beauty of science is, in fact, this constant reminder of just how wrong we can be.


December 31, 1514 (Julian calendar/old style: a Sunday)

Andreas Vesalius

On this date at 5:45 AM, the physician and anatomist Andreas Vesalius was born in Brussels, Belgium (at that time part of the Holy Roman Empire). Vesalius sought to understand the mechanisms of the natural world through careful observation, no longer relying on texts by ancient authorities. He is often referred to as the founder of modern human anatomy.

Vesalius studied in Louvain and Paris before earning a doctorate in medicine at the University of Padua in 1537. Appointed there as a lecturer in surgery at the age of twenty-three, he quickly consolidated his reputation as both a teacher and an anatomist.

Perhaps his most famous accomplishment was the publication in 1543 of De humani corporis fabrica libri septem (Seven Books on the Construction of the Human Body), or simply the Fabrica, a text that contained the first accurate illustrations of internal human anatomy. His book overthrew many of the previously uncontested doctrines of the second-century anatomist Galen, and caused a storm of criticism from other anatomists. It was revolutionary, as he was among the first to perform thorough cadaver dissections himself. He showed that Galen’s anatomy was merely an attempt to apply animal structure to the human body, and was not based on any direct knowledge of human anatomy. In the preface of the Fabrica, dated August 1, 1542, Vesalius wrote:

Title page of the Fabrica.

To this man they have all so entrusted their faith that no doctor has been found who believes he has ever discovered even the slightest error in all the anatomical volumes of Galen, much less that such a discovery is possible: even though (notwithstanding that Galen often corrects himself, that more than once after learning better he points out in some books a careless error he has made in others, and that he often contradicts himself) – even though it is just now known to us from the reborn art of dissection, from the careful reading of Galen’s books, and from the welcome restoration of many portions thereof, that he himself never dissected a human body, but in fact was deceived by his monkeys (granted a couple of dried-up human cadavers came his way) and often wrongly disputed ancient doctors who had trained themselves in human dissections. In fact, you will find many things in Galen which he misunderstood even in monkeys, not to mention the most astonishing fact that among the many and infinite differences between the organs of the human body and the monkey Galen noticed only those in the fingers and the flexion of the knee; he would no doubt have missed these as well, had they not been obvious to him without dissecting a human.

Vesalius’s discovery of the important differences between species also helped usher in the science of comparative anatomy, in which researchers studied animals to find their similarities and differences. In the process, they gradually began to recognize humans as being one species among many, with a few unique traits but many others shared in common with other animals. Some 300 years after Vesalius first shook off the blind obedience to Galen, Darwin used that vast stock of anatomical knowledge to build his theory of evolution.

December 27, 1822 (a Friday)

Louis Pasteur

On this date, the chemist and microbiologist Louis Pasteur was born in Dole in the Jura region of France.

From the time of the ancient Romans, through the Middle Ages, and until the late nineteenth century, it was generally accepted that some life forms arose spontaneously from nonliving matter. Such “spontaneous generation” appeared to occur primarily in decaying matter. For example, a seventeenth century recipe for the spontaneous production of mice required placing sweaty underwear and husks of wheat in an open-mouthed jar, then waiting for about 21 days, during which time it was alleged that the sweat from the underwear would penetrate the husks of wheat, changing them into mice. Likewise, the spontaneous generation hypothesis was proposed by scientists to explain the origin of the “animalcules” observed by Antoni van Leeuwenhoek in his magnifying lenses and had received wide acceptance all over Europe. Although such a concept may seem laughable today, it was consistent with the other widely held cultural and religious beliefs of the time.

It wasn’t until Louis Pasteur that this fallacy was finally disproved. In 1859, the French Academy of Science offered the Alhumbert Prize of 2500 francs to whoever could shed “new light on the question of so-called spontaneous generation”. Young Pasteur’s award winning experiment was a clever variation of earlier experiments performed by John Needham (1713-1781) and Lazzaro Spallanzani (1729-1799). Pasteur filled a long necked flask with meat broth. He then heated the glass neck and bent it into an “S” shape. Air could reach the broth, but gravity acted to trap airborne microorganisms in the curve of the neck. He then boiled the broth. After a time, no microorganisms had formed in the broth. When the flask was tipped so that the broth reached the microorganisms trapped in the neck, the broth quickly became cloudy with microscopic life.

Pasteur filled a flask with medium, heated it to kill all life, and then drew out the neck of the flask into a long S. This prevented microorganisms in the air from entering the flask, yet allowed air to flow freely. If the swan neck was broken, microbes could enter the flask and grow.

Thus, Pasteur disproved spontaneous generation. Furthermore, Pasteur proved that some microorganisms are airborne. “There is no known circumstance in which it can be confirmed that microscopic beings came into the world without germs, without parents similar to themselves,” he concluded in 1864. His experiment also supported germ theory. Germ theory states that specific microscopic organisms are the cause of specific diseases. While Pasteur was not the first to propose germ theory (Girolamo Fracastoro, Agostino Bassi, Friedrich Henle and others had suggested it earlier), he developed it and conducted other experiments that clearly indicated its correctness, thereby managing to convince most of Europe it was true.

Despite what creationists and proponents of “intelligent design” may insist, Pasteur’s research on spontaneous generation did not demonstrate the impossibility of life arising in simple form from nonliving matter under conditions vastly different from those today and by means of a long and propitious series of chemical steps/selections. In particular, he did not show that life cannot arise once, and then evolve. Neither Pasteur, nor any other post-Darwin researcher in this field, denied the age of Earth or the fact of evolution. What Louis Pasteur and the others who denied spontaneous generation did demonstrate is that life does not currently spontaneously (i.e., within a matter of weeks) arise in complex form from nonlife in nature.

Memorable Quote:

One does not ask of one who suffers: What is your country and what is your religion? One merely says: You suffer, this is enough for me: you belong to me and I shall help you.

— quoted in Louis Pasteur, Free Lance of Science (1950) by René Jules Dubos, p. 85