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  • I started this course by saying that people have made knowledge about the natural world,

  • pretty much forever.

  • They've done this by carefully observing the world and then devising tests to find

  • out if their ideas are true.

  • Today, we refer to a specific series of stepscoming up with a hypothesis, testing it, and drawing

  • conclusionsas the scientific method.

  • But, historically speaking, there is no one scientific method.

  • There's more than one way to make knowledge.

  • Still, if you look at some of the great minds who helped shape today's concept of the

  • scientific method, a set of basic principles starts to emerge.

  • Like rationality.

  • Experimentation.

  • And ruthless self-examination.

  • For these ideas and a lot of other stuff, we have to thank three of the natural philosophers who

  • pioneered this abstractscientific method”: Galileo, Bacon, and Descartes.

  • [INTRO MUSIC PLAYS}

  • Galileo, Bacon, and Descartes are each so

  • fascinating that they could each have their own episode.

  • But one reason to talk about them together is that they lived at roughly the same time.

  • A lot changed in European natural philosophy between the mid-1500s and the mid-1600s, when

  • Newton started dropping his hits.

  • We'll get there later!

  • But first, Dr. Galileo Galilei was born in Pisa in 1564.

  • He considered becoming a priest, studied art, attended school for medicine, but then attended

  • a lecture on geometry, and went on to study math in secret, because his dad wanted him

  • to focus on medicine.

  • Much to his father's chagrin, I'm sure, Galileo became a professor of a bunch of math-related

  • stuff at University of Pisa, a lowly, poorly paid position.

  • In 1593, Galileo took a job as a ballistics consultant at the Arsenal of Venice, which

  • is a heck of a title to have on your C.V.

  • Then, starting in 1609, he built and refined telescopes, which eventually made him famous.

  • The very first telescope was invented by Dutch spectacle-maker Hans Lippershey in Holland

  • in 1608.

  • But Galileo's versions were much better.

  • And telescopes are a good example of how scientific instruments change the nature of scientific

  • practice.

  • We often design experiments around how we can use our instrumentsin the case of astronomy,

  • around what we can see through a telescope.

  • With his new telescopic success, Galileo quit his job at Pisa for a much better one at Padua,

  • and he also took on the role of Chief Mathematician and Philosopher of Florence.

  • I love this guy's resume!!!

  • As he continued to research the night sky, Galileo became convinced that Copernicus was

  • right: the earth is not the center of the universe.

  • He also looked into Kepler's ideas but wasn't convinced by them.

  • By 1611, Galileo's name had been brought up by the Inquisition.

  • And, of course, nobody expects that.

  • But it seems that his vocal support of Copernicanism was creating some friction in the Florentine

  • court.

  • Among many others, the Grand Duchess Christina, who was basically one of his patrons, said

  • she took issue with the idea of heliocentrism.

  • So in 1615, he wrote to a letter to explaining that the Bible and nature did not disagree:

  • One was God's word to the masses—a story about how to behave and why.

  • The other was God's workthe physical reality that He created.

  • So science, he said, was simply the uncovering of God's work.

  • Galileo was a man of faith!

  • Unfortunately for him, Church officials didn't like this explanation.

  • In 1616, the Church added Copernicus' text, De rev, to its official list of banned books.

  • The Inquisitors deemed heliocentrismfoolish and absurd in philosophy.”

  • This was bad news for Galileo: he was told not to uphold or defend Copernicanism.

  • (But he may have been able to teach a heliocentric astronomy as a thought experiment.

  • Historians aren't sure.)

  • But Galileo wasn't having any of it.

  • In 1623, Galileo published a pamphlet called the Assayer that basically said scientists

  • should be free to do their work.

  • Pope Urban VIII, Galileo's personal friend, was a fan.

  • He said that God could move the heavens in numberless ways, so the ultimate source of

  • truth would always be faith.

  • So sure, Galileo, you want to spend your nights staring at tiny dots of light?

  • Knock yourself out.

  • Urban even renamed Galileo's next book, Dialogue on the the Two Chief World Systems

  • of 1632.

  • All Urban asked was for his friend to treat different astronomical systems fairly.

  • But

  • Galileo picked a fight.

  • The Dialogue made a clear argument for Copernicanism, comparing it point by point with the AristotelianPtolemaic

  • system.

  • He brought new data to the battle: he described the phases of Venus, which appears to grow

  • larger and smaller like earth's moon.

  • This phasing did not fit with a geocentric model.

  • An even stronger argument came from the tides, whose movements seemed to prove that the earth

  • moves.

  • And the pope was not happy.

  • Urban felt that Galileo had not heard his warning.

  • All copies of the Dialogue were recalled.

  • And in 1632, Galileo was called to Rome to speak to the Inquisition.

  • His trial got under way in 1633, and in time, he was placed under house arrest for the rest

  • of his life.

  • Amazingly, Galileo didn't give up.

  • Humiliated, under arrest, he kept sciencing.

  • Beyond his contributions to astronomy, physics, and the scientific method, Galileo is a rockstar

  • thanks to his fearlessness.

  • Galileo's last text was also perhaps his most relevant to the idea of methods in science:

  • His Two New Sciences of 1638 was a mathematical treatise about how bodies fall through the

  • air, and how wooden beams break.

  • It was also a record of the process by which he discovered these physical laws.

  • He called for specific tests that would let experimenters confirm his laws with their

  • own senses.

  • This, in his words, was the mark of a “true scientist”: independent confirmation.

  • This is an awesome norm to try to live up to!

  • So, we shouldn't be surprised that a lifelong nerd like Galileo would have played a critical

  • role in developing better methods of doing science.

  • But Francis Bacon, born in London in 1561, is more of a historical surprise.

  • For one, he was cast out of public office for taking bribes.

  • Two, some people for some reason think he was Shakespeare.

  • And I mean, if you've ever read these two writersthere's a clear difference.

  • And most of Bacon's impact on science was posthumous.

  • We can basically boil it to down to a new approach to science, which was practical,

  • instrumental, and supported by the state.

  • Bacon wanted to create a whole replacement system of natural philosophythat meant

  • philosophy, mathematics, physics, biology, all wrapped up together.

  • He rejected the Aristotelian way of doing sciencearguing rationally using logic.

  • Instead, he believed that natural philosophers should help improve the wellbeing of humanity

  • through technological advances.

  • Bacon expressed this within a Christian framework, casting Aristotle's philosophy as a dereliction

  • of the Christian duty of charity toward others.

  • Improving wellbeing meant understanding and controlling the chaos of the natural.

  • Bacon described nature as female and passive, and humanity as male and active.

  • So, science was supposed to be a masculine activity: it allowed humans to exploit nature.

  • Now, this metaphor has not aged well at all, and not just because it was sexist and horrible.

  • We also now have plenty of examples of all the ways that humans simply can't control

  • nature.

  • And yet this metaphor is, sadly, still very much alive.

  • So.

  • What did Bacon's new system of natural philosophy look like up close?

  • Help us out, ThoughtBubble:

  • For Bacon, control over nature meant deriving useful artsor technē—like gunpowder,

  • silk, and the printing press, from basic knowledge.

  • And how were Baconians supposed to make useful knowledge?

  • They needed first-hand experiences.

  • This meant testing answers to important questions, without relying on the words of long-dead

  • Greek and Arabic philosophers.

  • For Bacon, science also required central planning and state support.

  • Natural philosophy should not be the domain of a few random nobles, he thought.

  • It should be a program, or system, that worked for the public good.

  • He outlined a vision of a utopian science bureaucracy in his book called New Atlantis,

  • published in 1626.

  • Bacon proposed creating a hub for intellectual work, a kind of super-university called Salomon's

  • House.

  • Here, the personnelall male, of coursewould be strictly segregated into specific roles.

  • Some would travel the world to gather facts.

  • Others would conduct experiments to generate new facts.

  • Yet others would extract potential facts from booksbut these proto-facts would have to

  • be tested experimentally.

  • Further up the hierarchy, others would analyze all of the different natural facts and experimental

  • outcomes and direct the next round of research.

  • And at the very top were the Interpreters of Naturethree men who would take all facts

  • and use them to produce axioms.

  • Working along with them weredowry menwho drew conclusions from these axioms to

  • yield specific practical benefits.

  • That, in a nutshell, is the scientific world according to Bacon.

  • Thanks Thought Bubble, Now, another thinker who advocated for a practical

  • science was René Descartes.

  • Born in central France in 1596, Descartes lived mostly in the Netherlands.

  • He's known as a founding figure in mathematics and modern philosophy.

  • So, that's not bad.

  • In math, he's known as the dude who bridged geometry and algebra.

  • We call the numbered X–Y axes the plane ofCartesiancoordinates.

  • You can map a lot of math with this system.

  • Now, Descartes knew what had happened to Galileo, and his publishers in France didn't want

  • to wind up on trial, too.

  • So Descartes stopped publication of his own Copernican book, Le monde or The World, in

  • 1633.

  • But he did come up with a whole new cosmology, based on Copernicus, that featured a chaotic,

  • rapidly moving ætherial fluid in which the planets and stars were suspendedinstead

  • of perfect crystalline spheres.

  • His Discourse on Method, published in 1637, was his major contribution to the history

  • of making knowledge.