Science and Magic Part I: Astrology

One of the earliest attempts by man to understand the universe and man’s place in it was the study of astrology.

Early History

Astrology is basically the study of the effects of the movements of the planets and the stars on human activities. The study of astrology dates back to the days of the Babylonians. Its principles were further developed by the Greeks and Romans and later in the middle ages by the Arabs. The Egyptians, Indians, Persians, and the Chinese all observed the planets and the stars in order to predict the course of present and future events whether they were personal, political, military or environmental (prediction of natural disasters).

One famous astrologer/ astronomer was Ptolemy (Claudius Ptolemaeus) who lived in the second century in Alexandria, Egypt. He codified the astrological tradition of the Babylonians and was responsible for coining such terms as “planets ascendant in a solar or lunar house” or the “Age of Aquarius.” He set out his astrological principles in his book “Tetrabiblos.” He thought that you could predict a person’s appearance and temperament by knowing the positions of the planets and the stars at the time of an individual’s birth. 

In Ptolemy’s time, there was no clear distinction between astrology and astronomy so that he also wrote about the motion of planets, the precession of the equinoxes, and atmospheric friction.  He named the stars, listed their brightness, argued that the Earth was a sphere, and set down rules for predicting eclipses. Ptolemy tried to understand why planets at times exhibit a strange wandering motion known as retrograde motion, which is the perception by an observer on Earth that a passing planet is moving backwards. This effect occurs when one planet “on the inner lane” or smaller orbit passes a slower moving planet with a larger orbit resulting in each planet “seeing” the other one as apparently moving backwards. Ptolemy’s idea of an Earth centered universe with all planets including the sun moving around it had been known for thousands of years before his time. He imagined that the planets orbiting the Earth were attached to transparent spheres via little wheels.  He built a mechanical device that demonstrated planetary motion (in fact Archimedes is reported to have built a similar device 400 years earlier). Ptolemy’s model was supported by the church for centuries and probably prevented the advance of astronomy for 1000 years.

Importance of Astrology in the 16^th century

During the 16^th century in Europe people felt powerless in a world full of famine, disease, and constant religious conflict. It is therefore of little wonder that many people sought explanations for what was happening around them in the certainty of the stars in the sky. Astrologers took advantage of people’s fears by preparing nativities (horoscopes), which predicted their future and told them what they should do.

Early “scientists” during the 16^th century postulated that the universe was comprised of 7 stars or planets that included the Sun, the Moon, Saturn, Jupiter, Mars, Venus and Mercury. These bodies constantly shifted their position in relation to the Earth against a backdrop of the stars forming the 12 signs of the zodiac. A horoscope was a map of the positions of these bodies in the heavens at some future point in time in order to predict what influence the heavens would have on any given occasion.

As strange as it may seem to us today, the doctrines of astrology at the beginning of the 16^th century in Europe was an essential part of the intellectual framework accepted by most educated people at the time. These doctrines taught that there were 4 elements earth, air, water, and fire that these were constantly combining and recombining dependent on the movements of the planets and the stars. It was believed that all physical change was comprised of the interaction of the physiological qualities of heat and cold, dryness and moisture. It was considered necessary to understand astrology in order to understand the physiology of medicine. The stars were also thought to affect plants and minerals (botany and metallurgy) as well as psychology and ethnography. Astrology pervaded all aspects of scientific thought.

Astrologers were very influential in medieval times and physicians also consulted horoscopes to know how best to treatment patients.

Paracelsus’s ideas were based on believing that god provided a remedy for every disease and that the stars influenced human behavior and destinies (astrology and alchemy were considered scientific pursuits in those days).

Types of Astrological Practice

In the 16^th and 17^th centuries, astrology or judicial astrology (since the term astrology was considered synonymous with astronomy in those days) was divided into 4 fields those of the general predictions, nativities, elections, and horary questions. General predictions took into account the movements of the heavens (including eclipses of the sun and moon) in order to forecast the weather, the state of crops, questions of mortality, epidemics, and those of politics and war. The nativities were maps of the sky at the time of a person’s birth that were created in order to predict a person’s prospects for the future. Elections were all about giving advice about choosing the right moment for the right actions by comparing a person’s horoscope with what was known about the future movements of the heavens, Horary questions,  the most controversial of the services offered by the astrologer, were based on the state of the heavens at the time of the “birth of the mind.” For instance if a person had a medical question he would provide the astrologer with a sample of urine and the astrologer’s answer would be his interpretation of the sky at the moment the urine was voided. However, every personal question could be answered as a horary question. (see Religion and the Decline of Magic by Keith Thomas. Penguin Books, London, 1971. pp 337-347)

Famous Practitioners of Astrology

Astrologers (those practicing astrology and preparing horoscopes) at first only consulted kings. Astrologers  were very influential in medieval times e.g. monarchs such as Elizabeth I had her own astrologer, John Dee. Other famous scientists were also astrologers including Tycho Brahe, Johannes Kepler and even Galileo Galilee.  Physicians also consulted horoscopes to know how best to treatment patients (e.g. William Harvey the discoverer of blood circulation). Other 17th century scientists who believed or practiced astrology included Edmund Gunter the mathematician, and Henry Oldenburg (a president of the Royal Society). Isaac Newton also had an interest in astrology as a young man and it might have been his interest in astrology that led him to astronomy

Up to the 18^th century the heavens and the universe were viewed as the perfect creation of god. However it became increasingly difficult to defend this idea due, for instance, to the discoveries of sunspots and that the surface of the moon was not smooth but riddled with craters by Galileo, and the observation by Tycho Brahe that comets traveled higher than the moon when passing over the Earth. This indicated that the universe was corrupt and changeable. Edmond Halley showed that the appearance of comets in 1531, 1607, and 1682 were all the same one and he correctly predicted that the next appearance would be in 1758.

Modern Attitudes and a Criticism of Astrology

Even today according to a Gallup poll held in 2005 based on telephone calls to around 1000 people, approximately 25% of Americans  believe that the position of the stars and planets can affect people’s lives. There are according to Carl Sagan, 10,000 astrologers in the US and approximately 3000 astronomers and in France more astrologers than Roman Catholic clergy (see the Demon Haunted World by Carl Sagan, Ballantine Books, NY 1996 pp 302-304). These numbers fly in the face of the fact there is no evidence that astrology works. Other facts call astrology into question e.g. the constellations of stars identified to be important in determining horoscopes have changed their positions over time (over 30 degrees). For instance, the original position of the constellation Aries in ancient Greece was pinpointed at its position at the spring equinox. However over the millennia since that time, the sign of Aries is no longer where it originally was. Astrologers however continue to calculate horoscopes based on the old position rather than allowing the position of Aries to move with the equinoxes.

In addition, the only planets that are considered by astrologers are those that can be seen with the naked eye. They do not take into account any newly discovered astronomical objects (e.g. near earth asteroids). Astronomers are inconsistent with the information they require to calculate the position of stars and planets at the time of a subjects birth e.g. the time at birth is taken into consideration but not the latitude and longitude of where a person was born (since this would also affect the observed position of the planets). It has been shown that different astrologers make different predictions when given the same data to start,that there is a lack of correlation of predictions for identical twins, and no correlation has been shown between horoscopes and psychological tests such as the Minnesota
Multiphasic Personality Inventory.

The popularity of astrology may have something to do with the selective bias of people who have horoscopes done i.e. that they tend to remember predictions that confirm what they want to believe and conveniently forget those predictions that are false. Perhaps one can consider belief in astrology as somewhere between religion and psychotherapy.

References:

• Science in Medieval Islam by Howard R. Turner. University of Texas Press, Austin1997. pp 108-111
• Cosmos by Carl Sagan. Random House, New York 1980. pp 48-51
• Religion and the Decline of Magic by Keith Thomas. Penguin Books, London, 1971. pp 337-347

Paracelsus the real Dr Faust?

Science in the middle east under Islam was very advanced compared to Europe. This applied to astronomy, geography, and mathematics, and medicine. The writings of the Roman physician Galen,  the ancient Greek physician Hippocrates, and the Greek pharmacist Dioscredis were translated into Arabic and were used as a major source of medical knowledge by Persian scholars such as al Razi and Ibn Sina (Avincenna) who both lived in 11th century Persia. These men’s writings were very influential until the 16^th and 17 centuries in Europe.

Based on these early writings passed down through the centuries, physicians in medieval England for instance were taught about the 4 humors (blood, phlegm, yellow bile and black bile) described by Galen. A diagnosis consisted for the most part of determining which of the humors was out of balance and trying to reestablish the normal balance by either bloodletting (by applying leeches or by venesection) or purging (using enemas), or inducing vomiting. These kinds of treatments often caused more harm than good.

One man living at this time, who opposed theses mindless practices of physicians, was Theophrastus Bombastus von Hohenheim (1493- 1541) more commonly known as Paracelsus. He is considered one of the fathers of the modern practice of medicine.

Paracelsus publicly broke with the past by burning the books of Galen and Avicenna and proclaiming that direct experience of patient’s symptoms was superior to following the writings of ancient authorities.

He was the first to consider looking closely at the symptoms of a patient to determine the cause of their disease instead of merely referring to the old texts of Galen and Avicenna. Paracelsus believed that the causes of diseases originated outside of the body. He thought that the causes of diseases came mainly from minerals and poisons originating in the stars.

His ideas were based on believing that god provided a remedy for every disease and that the stars influenced human behavior and destinies (astrology and alchemy were considered scientific pursuits in those days).  This insight of Paracelsus (although not correct) led future generations of doctors to search for causes of disease outside of the body leading eventually to the discovery of pathogens (e.g. bacteria and viruses) as causes of disease. He believed in the search for new treatments for diseases rather than relying on the old texts of Galen.

Paracelsus was an alchemist who studied the ancient texts of the Arabs (who learned from the Chinese). He called for the search by alchemists for metals and minerals to be used in the treatment of diseases in additional to the commonly used herbal medicines of the time. He observed the ailments of miners in Villach,  Switzerland and wrote a book (“On the Miners’ Sickness and Other Miner’s Diseases”), which was published 25 year after his death but was very influential for centuries afterward. The "miner's sickness" affected the lungs and induced ulcers due to miners breathing in the dust of the minerals in the mines and due to their having contact with poisons via  the skin.  He was able to distinguish between chronic and acute poisoning and noticed the differences between diseases caused by exposure to arsenic, antimony, or to alkalis (e.g. oxides of magnesium, potassium, or calcium). He accurately predicted the symptoms of mercury poisoning (shivering, gastrointestinal disorders, blackening of the teeth, putrefaction of the mouth) and developed a treatment for it. This consisted of creating openings in the body for the mercury to escape by applying corrosive plasters to the skin or by prescribing baths. This type of therapy is still used today. Paracelsus thought more of the folk medicine of the peasants than he did of the remedies prescribed by the established doctors of his time.

Alchemist in Paracelus’s day, believed boiling liquid substances released spirits and the technique of distillation was devised to capture the spirits as they arose from the boiling liquids.  They were convinced that these spirits were powerful especially after drinking them. Actually, alcoholic beverages are sometimes still referred to as spirits.

Paracelsus made progress in the field of chemistry but for the wrong reasons. He believed in the existence of vital spirits who inhabited the different organs of the body (he called them archaei). The vital spirits were spread by the arteries through the body, for example to the ventricles of the brain becoming the animal spirit, and passing through the nerves giving motion to the body. These archaei were little creatures who took human form and controlled the functioning of the stomach, liver and heart. For whatever reason, it was the intuitive and mythical approach of Parcelsus that advanced the study chemistry until its revolutionary development in the 18^th century. This made Paracelus the undisputed founder of modern chemistry.

He was the first to write about there being a miniature man in all sperm cells (the homunculus). This was before it was understood that chromosomes and genes in sperm combine and fertilize the egg cell eventually lead to the development of an embryo and a human being.

Parcelsus realized that the dose of a medicine made the difference between being able to treat a person’s disease successfully and poisoning him. He also believed that sometimes it was better to not do anything rather than to  resort to the invasive practices commonly used  by physicians.

He divided “drugs” into different categories according the disease that they were meant to treat rather than according to the tables of Galen who divided drugs according to the humors that they were meant to treat.

Paracelcus was immortalized by the playwright Christopher Marlowe (1564-1593 a contemporary of Shakespeare) in his play the “Tragical History of Doctor Faustus.” It tells the story of an alchemist who was willing to forgo salvation and live in hell in order to gain power over the mysteries of nature. Two centuries later, Goethe also wrote a poem about Doctor Faustus which makes reference to the life and opinions of Paracelsus as well as his opinions, alchemical symbolism, and the cabbala.

References

Paracelsus Magic into Science by Henry Pachter; Henry Schuman, New York. 1951 pp 14, 56

The Discoverers by Daniel J. Boorstin. Random House Inc, New York, Toronto. 1983. pp 338-344

Science in History by JD Bernal. C.A. Watts and Co. Ltd., London. 1965. pp 272-273

Religion and the Decline of Magic by Keith Thomas.   Penguin Books Ltd. London 1991. pp 271

A Lesser known contemporary of Tycho Brahe and Johannes Kepler 

It is generally thought that Jews  made no contribution to the advancement of the natural sciences during the middle ages and the Renaissance. The reason for this is that Jew's lives were precarious in those days due to rampant religious persecution and the general instability in Europe in those days.  Jews had no time for scientific pursuits because they had to struggle for survival or were constantly on the move.

One exception to this is David Gans a contemporary of Galileo and Kepler, who was a Talmud scholar historian, mathematician, astronomer and geographer.

He was born in Lippstadt, Germany in 1541 (died 1613). He was educated in Bonn and Frankfurt by famous talmudist teachers and attended the yeshiva in Cracow that was headed by Moses Isserles. Isserles encouraged Gans to study philosophy, mathematics, astronomy, geography, and history. He came to Prague in 1564 and was taught by two brothers Sinai ben Bezalel and Jehuda ben Bezalel also known as Rabbi Loew and as the Maharal of Prague (the legendary rabbi who was supposed to have conjured up the Golem). In the late 1560’s, Gans studied Euclidian geometry and mathematics in Nordheim. Because of the relatively peaceful and tolerant atmosphere enjoyed by the Jewish 
community in Prague at the end of the 16^th century and the beginning of the 17^th century, outstanding Jews were allowed to have contact with the Christian community. David Gans established contact with Tycho Brahe and his assistant Johann Müller as well as with Johannes Kepler.

In his book Nehmad ve-naim (“The Pleasant and the Dear” written in Hebrew), Gans reports that he participated in three different observations made in Tycho Brahe’s observatory in Benátky nad jizerou and that he had translated the Alphosine tables from Hebrew into German. The Alphosine tables were created in 1252 upon commission by Alphonso X of Castile in Toledo Spain. These were tables used to determine the positions of the sun, moon, and the planets relative to the fixed positions of stars. Interestingly Gans also knew of the work of Copernicus (concerning the heliocentric theory stating that the sun and not the earth was the center of the solar system). Gans however preferred the system of Ptolemy with an earth centered solar system (Ptolemy was educated by Jewish teachers in his day).

The Nehmad ve-naim is considered to be a unique book written by a Jewish Ashkenazi author of that time that summed up all existing knowledge by both Jewish and non-Jewish scholars on geometry, astronomy, and mathematical geography. It is interesting to note that the book was written during a time of relative conservatism among Central European Jews at that time. His book however remained neglected and was not printed until the 18the century.

David Gans is perhaps best known for his historical work "Zemach David" (the Wand of David) which consisted of a history of the Jews from biblical times till 1592 (considered by him as the sacred part), and a more general history of the world. Also interesting in this work is that it presents a summary of the humanities during the Renaissance from the point of view of a Jewish scholar.

It is a stroke of luck that we know about David Gans and his accomplishments making him an exception to the rule that Jews did not contribute to the advancement of knowledge in the natural sciences in the middle ages. I would suggest that he is at the tip of an ice berg of possibly many more unknown heroes in science.

Source:

RyBar Citibor. 1991 TV Spektrum in cooperation with Akropolis Publishers Jewish Prague (Notes on History and Culture, A Guidebook). pp 155-159

Religious views of Famous Scientists Continued

Carl Sagan (1934-1996)
Carl Sagan was a distinguished astronomer and a pulitzer prize winning popularizer of science. He presented and co-wrote the COSMOS television series that had been broadcast around the world in 60 countries.

Sagan was an outspoken critic of religion and a strong lobbyist for clear thinking. He believed that religion drew on primitive fears in the society and that ancient superstitions have been replaced by other superstitions in the modern world (e.g. UFOs and the paranormal).
In a Gifford lecture he presented at the University of Glasgow entitled “The God Hypothesis” (published in the Portable Atheist edited by Christopher Hitchens; Da Capo Press 2007) Sagan discussed the concept and the arguments for the existence of god.
Sagan goes through each of the arguments including the ontological argument, the argument from consciousness, and the argument from experience. He then one by one discounts these explanations as being unsatisfactory.

The cosmological argument basically asks what caused everything or how did the universe begin? One answer is that the universe was always there or god was always there. If god made the universe then who made god one might ask? The current thinking is that the universe arose when all matter compressed into an extremely small volume and that something like an explosion occurred (Big bang theory) around 15 billion years ago. This led to the expansion of all this condensed matter to form the known universe. The cooling and condensing of this matter led to the formation of galaxies, stars, planets, life, and living beings. There are also theories about what existed before that. For instance,the theory that the universe oscillates and there have been multiple occurrences of compressions and expansions over time and that these have always occurred and will continue to occur indefinitely. There are also theories that there are multiple universes existing simultaneously at any given time. Current evidence however sees the universe as expanding forever.
Sagan states that religious as opposed to scientific theories of the origins of the universe cannot be tested and answers will only come from continued research. We, he says, have to be patient, and live with ambiguities rather than accept religious theories. Experiments can be done that someday will allow us to know, whether there is enough matter in the universe that will stop its expansion (by “self-gravity”) leading eventually to contraction and the destruction of the universe as we know it, or whether there is not enough matter to cause this to happen and  the universe will continue to expand forever.

The argument from design states that all life and the world as we see it looks so perfect that it could only have been designed by a creator, someone smarter than us. This argument was completely refuted by Darwin who showed that given enough time (millennia) and random changes in individuals, that environmental pressures could confer selective advantages on individuals. These individuals would produce more offspring who would eventually replace those individuals who did not have these advantages. This was therefore a mechanism of change and could therefore explain that the world and life as we see it has evolved and was not perfectly created in its present form. In any case, there are many examples in nature that show that “god” made mistakes e.g. the backbone of humans is built for walking on two leg, ;the  mass extinction of the dinosaurs,  and the many examples of the destruction of galaxies in the universe which could mean that inhabited worlds in other solar systems were and continue to be routinely destroyed over the eons. Sagan says  "this does not sound as if god knows what he is doing."

The moral argument states because we are moral beings god must exist.
Sagan states that there are examples of altruistic behavior in the animal kingdom e.g. crocodiles who carry their eggs for enormous distances to protect their young. He argues that if crocodiles didn’t take care of their young, their species would most likely disappear. So what looks like ethical behavior in the animal kingdom is really behavior that enables the survival of species that have evolved by natural selection. Human beings, he argues, are aware of their surroundings and can see what is important and can therefore take steps to ensure their survival. He states that it is not clear whether you require the existence of god to explain “the limited but definite degree of moral and ethical behavior that is apparent in our species.”

The ontological argument for the existence of god, is as follows:
God is perfect, existence is an essential attribute of perfection. You can’t be perfect if you don’t exist, therefore God exists.
Sagan poses the questions what is meant by perfection and how do you know that god is perfect? He also asks why is existence a necessary prerequisite of perfection? Why for example is non-existence not an essential attribute of perfection? This is similar to Buddhism whose god is so great that he does not have to exist.

The argument from consciousness states that I think therefore god exists. In other words, you need god for consciousness to come into being. Sagan takes issue with the definition of consciousness citing examples from the animal kingdom such as the ability of earthworms to learn to find food in certain experiments or the phototactic response of microorganism. These behaviors are programmed genetically into the brains of these organisms. Finding food by an earthworm enables it to survive and therefore leave offspring. Sagan mentions that a view held by many neurobiologists is that consciousness is a function of the number a complexity of neuronal connections as well as the architecture of the brain. He states that human consciousness is seen with a brain that has approximately 10 to the 11th power neurons and 10 to the 14th power synapses. He then asks what would happen if humans would have brains of 10 to the 20th power or 10 to the 30th power synapses? Would such humans be as superior to humans with the normal number of neurons as would a human being currrntly is to an ant. There are he mentions alternatively explanations being tested using artificial intelligence.He questions whether the consciousness one observes in the animal kingdom as demonstrated by the gradient of behavior one sees going higher on the phylogenetic tree demonstrates the existence of god.

With regard to the argument from experience, Sagan mentions that although people in many cultures have reported having religious experiences that have changed their lives and led them to reforming their ways and doing good in the world, there are also examples where this has led to people doing the opposite. Can one trust such subjective experiences as providing proof for the existence of god? Sagan provides a parallel with the millions of reports of UFOs one can find since 1947, although there have been no known visitations to earth by any extraterrestrial beings. He also mentions that certain substances are known to produce hallucinogenic effects are used in some cultures (e.g. peyote culture in some Indian tribes) to bring about religious experiences and that, for instance, wine is consumed as a sacrament in western religions. So it seems that the use of such substances can bring on personal religious experiences rather than any natural theological evidence for the existence of god. This he implies discredits such arguments for the existence of god.

He sumarizes he views as follows. Arguments from the time of the early Greek philosophers (before Socrates) have stated that evil exists in the world and that god is benevolent, omnipotent, and omniscient. Can all of these statements be true Sagan asks? If god is omnipotent why does he allow some much suffering and pain in the world? Why can’t he arrange it so that there is no pain? If god is not benevolent or compassionate does it mean that he is too busy to know about the day to day problems of people? Could this be explained by the fact that there are 10 to the 11th power worlds in each galaxy and that there are several times 10 to the 11th power galaxies in the universe showing that god would have a lot of ground to cover to keep up with everyone's problems and answer all prayers? Apparently god could create the universe and life and occasionally intervene in historical events but he doesn’t have time to oversee and influence everything and can’t therefore also cannot know everything. Why, Sagan asks, is it even necessary for god to intervene in human affairs at all coming to tell humans what the should and shouldn’t do? Why didn’t god get it right in the first place? If you can create the universe and see all potential future consequences why not arrange things so that your desired end is achieved? If all views of god are clearly more competent then human views, then the status quo of the world speaks of the limitations of god and not omnicompetence.

Sagan also presents some rather interesting and provocative thoughts of how god, if he had wanted to, could have left evidence of his existence in ancient times in the holy texts. For instance Sagan asks, if god is all knowing and all powerful, why did he not leave clues in the holy writings dating back to 600 BC during the Jewish Diaspora in Babylon in the Old Testament to say, for instance, that “the Sun is a star”, or to say “don’t forget that there is a planet mars that is now red, dusty, and dry but that used to have rivers. He could have said don’t forget these things, trust me, it will become clear later. Or why didn’t god make any mention of the laws of motion, that an object will keep moving if there is no friction opposing this motion, or why is there no law saying “Thou shalt not travel faster than the speed of light?” Or why are there no equations perhaps written in hieroglyphics to describe electric or magnetic fields or stating prophetically that two strands Of DNA will provide the secret of life. Of course none of these examples would have made sense to the scribes in ancient times but they would have been dutifully copied by the ancients over and over again during the centuries. But these writings would have been reproduced as are some of the puzzling texts that we now have today in the bible. Sagan’s point is that only a divine being would have been able to foresee what scientific progress would be made in the centuries to come. No one would have been able to understand this information in ancient times and would have shown the prophetic power of a divine being. Sagan even asks jokingly why didn’t god carve out the Ten Commandments on the surface of the moon. He could have made it large enough (10 kilometers across) allowing it to be seen with modern telescopes by spacecraft visiting the moon. Any of these things would be possible for an all powerful and all knowing god. Sagan asks why god should be so clear in the writing in the bible and so obscure in the world?

Sagan cites a quote from Protagoras, a Greek philosopher predating Socrates in the 5th century B.C, who said: "About the gods I have no means of knowing either that they exist or that they do exist or what they are to look at. Many things prevent my knowing. Among others is the fact that they are never seen"

Christians Huygens Christian Huygens (1629 to 1695) was probably the greatest Dutch scientist of his time. He was primarily a mathematician and physicist but also made contributions to astronomy using his own designed telescopes), biology (through his discoveries using microscopes of his own making), and the construction of clocks. He was the son of Constantin Huygens a famous poet and influential statesman and diplomat under the Dutch Republic. He had two other brothers and sisters. Being from an aristocratic family he was educated in languages (including French and Latin) drawing, law, science, engineering, mathematics and music. He is known to have said “science is my religion” (see Cosmos by Sagan pg 143). The Huygens family had many distinguished guests visiting the including Descartes. Huygens also had contact with Spinoza although he did keep this relationship polite but distant (he loaned Spinoza books and Spinoza did work grinding lenses for Huygens). Huygens had contact with other great scientists of his time including Gottfried Leibnitz who visited Huygens to study mathematics with Huygens. Huygens was also a member of French Academy of Science as well as the Royal Society in its early days. He kept an active correspondence with the members of the Royal Society including Isaac Newton, and Robert Hooke. He was greatly admired within these scientific communities. In the field of astronomy Huygens was one of the first to discover the rings of Saturn. He invented the pendulum clock that he hoped could be used to accurately measure time on ships in the opens seas. At this time navigation at sea had a very high priority for trade as well as for military strategy. Note: The idea of longitude is based on the fact that the earth rotates on its axis once every 24 hours. This means that it moves a total of 360 degrees in 24 hours meaning that each hour is equivalent to 15 degrees of longitude. An idea that came from Galileo was to use the moons of Jupiter as a reference point to record the time at any given geographical point on the earth and thereby observe its position at the local time. The difference in the apparent position of the reference point at a specific time in the local area could be used to calculate the longitude compared with a 0 geographical position i.e. the prime meridian. Accurate navigation required the determination of longitude which was not yet known. Therefore governments greatly encouraged the development of such clocks since longitude at sea could be calculated if one knew the time difference between two different geographic positions using a fixed reference point (e.g. position of the sun). Despite Huygen’s efforts the first chronometer that could accurately measure time at sea was invented by a clockmaker John Harrison in 1760. He developed a wave theory to describe the nature of light. Huygens considered that light behaved as if it travelled in waves in a vacuum similar to waves on the ocean. This differed from Newton’s idea that light was composed of particles. Red light was made up of larger particles than blue light. Actually both turned out to be right. Einstein later showed that a particle theory of light could explain the photoelectric effect (that a light beam shinning on a metal surface could knock off electrons). Modern quantum mechanics considers both the light behaves if it is composed of particles and as if it is composed of waves. He made early progress in describing the moving bodies and their collisions but never published them. Centrifugal force and gravity Huygens through experimentation with measuring the motion of pendulums, discovered that they exhibited constant acceleration. Through this work he derived formulas describe this motion and came also to describe motion in terms of centrifugal force around 1647. He saw that centrifugal force and gravity were related (today called the equivalence of gravity and inertial mass). He estimated “g” (the constant for the force of gravity) at 9.8 m/sec2. These discoveries were made independent of Isaac Newton. Discoveries in Astronomy Huygens believed as did Copernicus that the Earth moves around the Sun. This was widely accepted even by ordinary people in Holland at that time. Huygens even mentioned that Copernicus was acknowledged by all astronomers accept those who “were a bit slow witted or under superstitions imposed by merely human authority” (see Cosmos by Sagan pg 145). Christian philosophers during the middle ages argued that the heavens circled the Earth once a day and that it was not infinite in extent and therefore the existence of an infinite number or even a large number of worlds was not possible. The discovery that the Earth and not the sky moving and profound implications with respect to how unique the Earth was considered and whether there was life on other planets. Copernicus thought that the entire universe was heliocentric and Johannes Kepler did not think that stars had planetary systems. Huygens believed in the existence of other inhabitable worlds in the universe. Before he died in 1690, he published a book entitled “The Celestial Worlds Discover’d: Conjectures Concernng the Inhabitants, Plants and Productions of the Worlds in the Planets. In this book Huygens even speculated as to how the inhabitants of these other worlds would look . Huygens maintained that science was his religion and that the planets in the universe must be inhabited otherwise God had created them for nothing.

<b>Robert Hooke Renaisance Man of 17th Century England Life One of the most interesting early founders of the British Royal Society was Robert Hooke (1635-1703). No reliable likeness of him exists so no one knows what he looked like. Hooke was known for his competitive nature, for the quickness of his ingenuity, and for his quarrels with other scientist about the priority of discoveries and inventions. He was a kind of Renaissance man of the 17th century and was considered one of the most accomplished experimentalists of his time in that he designed and built various scientific devices including microscopes, telescopes, pendulum clocks (balance-spring watches), and vacuum devices. His response to any scientific problem was to invent a piece of equipment to resolve it. In this way, he considered himself a kind of “scientific craftsman.” He also helped redesign St Paul’s Cathedral in London together with Christopher Wren and provided surveying assistance to the team rebuilding London after the “Great London Fire” of 1666. Royal Society Hooke was appointed Curator of Experiments for the Royal Society. His duties involved the demonstration of various experiments for the members often using devices of his own making in order to test the experiments of others. He was appointed by his boss at that time, Robert Boyle, who was then one of the most well-known scientists of his time. Boyle employed Hooke to design customized experimental equipment and to investigate any topic that Boyle was currently interested in. These experiments included creating vacuums using air pumps, an experiment on respiration on a live dog whose thorax was cut open to show the beating of its heart and whose lungs were inflated by Hooke using a bellows (he never repeated this experiment because of “the torture of the poor creature”). Inventions and patents He was one of the first to devise a regulator for a marine clock that worked using springs instead of gravity. It functioned by causing a balance wheel that was attached to a spring to oscillate back and forth around its own center of gravity thereby facilitating a regular periodic interval for the stopping and starting of the clock. This allowed the measurement of units of time. Hooke never patented this invention and had a dispute with Christian Huygens over who had priority. He did manage to build a watch and presented to the King. Hooke asserted in the inscription on the clock that it had been invented as far back as 1658. Although Hooke lacked mathematics he sought to persuade through practical experimentation and formalized recording of data. Hooke invented or improved barometers, thermometers, and wind gauges. He recorded London’s weather regularly. This and other discoveries made by Hooke were quite often written in code in order to protect the priority of his claims. This was common practice in Hooke’s time to write up observations in code and file them as patents until deciding when to make these public. Often additional work had to be done on these entries before these discoveries could be revealed to the public. The first portable clock that could be used at sea to measure longitude was not invented until 1714 by John Harrison who won a prize of 10,000 pound from the English government. Discoveries Hooke’s law A physical law is named after Hooke which states that “a spring when stretched resists with a force proportional to the extension of the spring” (see The Discoverers, by Daniel Boorstin, pg 52). Redspot of the planet Jupiter Hooke’s discoveries in astronomy include the massive “redspot of the planet Jupiter” which today is known to be a massive storm area “40,000 kilometers long and 10,000 kilometers wide” (see Cosmos by Carl Sagan pg 136). He also observed the rings of Saturn as did his contemporary Christian Huygens and Galileo before them both. The Micorgraphia Hooke had made many observations of microscopic life using his microscope which had a higher magnification than the one originally designed by Antoine Leuwenhoek. He observed for instance thin layers of cork and was able to see regular square-like honeycomb structures that he called “cells.” This was the first time this term was used to describe these regular structures that make up all living animal and plant tissue. Robert Hooke’s most famous work was the “Micorgraphia” published in 1665. In this book Hooke states that “The Science of Nature has been already too long made only a work of the Brain and the Fancy. It is now high time that it should return to the plainness and soundness of Observations on material and obvious things.”(see Isaac Newton by James Gleick pg 62). In this book Hooke provided a description of the microscope and its uses. He presented 57 handrawn and engraving illustrations of what he saw under his compound microscope including the eye of a fly, the shape of a bee’s stinger, the anatomy of a flee and a louse, structure of feathers and the structure of plantlike molds (there were also engravings that included a thyme seeds). The book also presented Hooke’s theories of light and color as well as his theories about respiration and combustion. Hooke in order to improve the quality of the images he saw under the microscope invented a device that he called a “scotoscope (or a condenser in modern terminology).” This consisted of a glass globe filled with brine that he positioned between the light source and the lens of the microscope. He also placed a convex lens between the light source and the globe to focus the light source. He found that he could improve the quality of the images by adjusting the relative positions of the lamp, globe, and lens. Hooke also speculated on the nature of light and color. “Light is born of motion” he claimed. He stated that all luminous bodies are in motion and that we see two main colors red and blue that are caused by their impression on the retina of the eye by an “oblique and confused pulse of light.” At this point red and blue “met and crossed each other” to produce “different kinds of greens.” Hooke and Newton According to Gleick, Hooke was an inspiration to Newton who was actually 7 years younger than Hooke. Newton never admitted this and throughout their lives Newton was goaded by Hooke. Newton saw Hooke as his nemesis and tormentor. Hooke also became Newton’s victim. One famous dispute Hooke had with Isaac Newton was after the publication of Newton’s landmark work the “Principia” (Mathematical Principles of Natural Philosophy). Hooke claimed that many of the ideas presented by Newton were plagiarized from communication he had had with Hooke a dozen years before. (An interesting aside involved a dispute between Hooke, Christopher Wren, and Edmond Halley that they addressed to Newton. The asked Newton what he thought would be the best curve or path of the planets that would describe their motion around the Sun assuming that their force of attraction to the Sun would decrease with the reciprocal of the square of their distance from the Sun. According to this story, Newton immediately answered that the path would be best described by an ellipse. Halley asked him how he knew that and Newton claimed that he had calculated it. However after some searching he could not find the proof but said that he would derive it again and send it to Halley. This turned out to take 3 years (1684 to 1687) and resulted in the “Principia” Newton’s most famous work). (See the Ascent of Man by Jacob Bronowski pg 233) Newton was so upset by Hooke’s claims of plagiarism that he deleted all reference to Hooke’s work and even threatened to give up publishing the “Principia.” Newton so resented Hooke that he refused to assume the presidency of the Royal Society until after Hooke’s death. It is not entirely clear whether Hooke’s claims were true or not. However, Newton did not merely speculate on the ideas he discussed (as Hooke apparently did), but he also presented mathematical proofs for his ideas. Hooke may have had early insights into the ideas presented by Newton but he had not done the experiments to prove his hypotheses. Hooke also argued against Newton’s theory of the physical nature of white light. Newton described that white light is not modified by passing through a prism but instead it is physically separated when passing through a prism and this brings forth the characteristic spectrum. Hooke did not agree with this and the dispute must have been so vehement that Newton refused to publish his book on optics until after Hooke died