The Triumph of Science over science

February the 17^th, 2017 marks the 417^th anniversary of the death of Giordano Bruno. I know that many of my ardent readers are still trying to get over that.

Giordano Bruno's rather angelic looking Senior picture

Aristotle taught that the Earth is the center of the Universe. His proclamation cemented this idea into Western thought for almost 2,000 years. This is just one of the many examples of things that Aristotle said that mere observation would readily demonstrate to be just flat out wrong. Aristotle did lower-case science by decree. His attitude was that if reality disagrees with what he says, then reality is wrong.

Giordano Bruno challenged the idea of geocentricity (Earth being the center of all things) by proclaiming the heretical notion that the Earth travels around the Sun, rather than the other way around. He also proclaimed that the stars are just Suns like our own, but are just really darn far away. And (get this) Bruno said that those distant suns might have planets of their own, complete with living beings.

His challenge to conventional thought didn’t go over so well. He was burned at the stake by the Inquisition in 1600.

My attempts at marketing BBQ sauce have not proven successful

If Pew or Gallup were to do a poll asking people about Bruno, I’m gonna take a wild guess that most people would identify him as a pro wrestling promoter. Even if one were to restrict the poll to the scientifical and intellectual cream of the crop (which is to say, those people who regularly read my blog posts) I am gonna take another wild guess that a pretty small percentage would recognize the name Giordano Bruno. Yes, even the seven of you dear readers who have read more than one of my blogposts might say “who?”

But I should add that Bruno does have a crater on the Moon named after him. Kind of a small consolation what with his untimely death and all. I doubt if I ever get that honor. But if I do, I promise to look surprised.

Giordano Bruno, the lunar pimple

Some historians of science see Bruno as a martyr to the cause of Science. Perhaps he was killed for refusing to recant his beliefs about the universe?  But, perhaps not. I didn’t mention that he said quite a few nasty things about religion. More pointedly, he questioned some of the core beliefs of Christianity. The tamest of these was that the Bible is all about morals and stuff like that, and shouldn’t be treated like a textbook on astronomy. I’m not gonna get into all the other stuff that rankled the leaders of the church. Suffice it to say that his pontifications on religion were likely enough for the Inquisitors to get out their book of matches.

I think that explanation for his martyrdom is quite likely, but I’m going to make a different argument about why I don’t think Bruno was a martyr for Science. I argue that what he did wasn't Science. Bruno had some brilliant hypotheses that were way ahead of his time, but he didn’t do a lot of testing of those hypotheses. Testing of hypotheses is at the crux of Science. 

Copernicus

Bruno was not the first person to talk about the Earth revolving around the Sun. Aristarchus of Samos proposed this in 270 BC. An astronomer from India by the name of Aryabhata claimed this around 400 AD. The first person in “modern” times to make such a claim was Nicholas of Cusa in the early 1400’s. This time period was the start of the Renaissance, when people started questioning the dogma that Aristotle had left us with. (Note the forming of a theme here concerning Artistotle.)

Show of hands… Who remembers Aristarchus or Aryvhata? Anyone? Who remembers sending out Nicholas-of-Cusa-Day cards? He was the guy who updated the Alfonsine astronomical tables? Yeah, I didn’t think you remembered him either.

This is not one of the Alfonsine Tables

How about another Nick… Nicolaus Copernicus? Ahhh… now I am seeing some name recognition. I think a lot of people who paid attention in Science class will at least vaguely remember the name. Something to do with the Solar System and planets and stuff? Yup. That’s the guy. A few people reading this may actually remember some self-proclaimed math guy who blogged about Copernicus.

Copernicus was a true Scientist, with a capital S. Aristotle and Giordano Bruno and Nicholas of Cusa? They were all scientists of the lower case variety. They were pontificators. They had an interest in Science, and pontificated about it. They had great intuition. With the exception of Aristotle, their intuition often proved correct. (Yet another subtle jab at Aristotle.)

But they weren’t capital S Scientists in that they didn’t follow the scientific method. They got the first part of the method: observe some junk and hypothesize about an explanation. Then they went forth and pontificated on their hypotheses. That might be lower case s science, but it’s not upper case S Science.

Copernicus took it to the next step. He also pondered on the possibility of a Solar System with the Sun at the center, but he went out and found data. In this case, it was largely data about the positions of the planets that was consolidated a zillion years ago by Ptolemy. Copernicus demonstrated in his posthumous book (On the Revolutions of the Heavenly Spheres, 1543) that “the Earth and the Planets travel around the Sun, and the Moon travels around the Earth” provided a simple explanation that fit the data.

This was how Science is supposed to work. It's all about data and hypothesis testing. When observations contradict a theory, the theory doesn't get all defensive and call the data a loser. The theory is rejected. And when a hypothesis arises that is simpler but provides as good of an explanation of the data, the older hypothesis is moved to the side. 

By the way, Copernicus also has his own crater on the Moon and one on Mars. Two heavenly spots for vacation homes.

Copernicus' summer home is the large complex in the center of the crater

As a side note… I have a big pile of files on my computer that contain books that I almost finished writing, one of which is a history of science. In order to find what I had previously written about Copernicus, I used a program to search my computer that is ironically named Copernic. True story. Good program, by the way.

A few more Scientists

It can also be said that Ptolemy (around 200 AD) did some Science. He started with a hypothesis, Aristotle’s geocentric universe, collected a lot of data, and found a mathematical explanation of the data. This is the way Science is supposed to work.

But much to the detriment of Western thought, Ptolemy went through gyrations (quite literally Spirographic gyrations) to describe the various motions in terms of Aristotle’s geocentric universe. He built an overly complicated model based on the assumption that Aristotle's tweets about the Universe were infallible, but I would still argue that Ptolemy was doing capital S Science, what with all the hypothesis testing and real data stuff.

Ptolemy's explanation of the course of the planets 

(I want to point something out here, just to make sure I haven’t been too subtle. Aristotle is the bad guy in this blog post. I also heard that he has small hands.)

Galileo also did capital S Science. You will likely remember Galileo for doing a bunch of stuff with pendulums and rolling balls down inclines. You might also remember that bit about when his press agent told everyone that he leaned over and dropped some balls onto a tower of pizzas. Don't always believe press agents! But I want to point out some Science of his that did not get as much press.

Galileo had heard of Copernicus’ work. He was taken by the idea of a heliocentric solar system. When he came upon the first telescope in 1609, he anxiously built one, and pointed it to the skies to look for evidence. He used the telescope to observe many things that the Roman Catholic church did not want to hear: the moon has craters (and was not perfect), the Sun had spots (and was not perfect), the planet Venus has phases (so it must rotate around the Sun), and Jupiter has bodies revolving around it (rather than all bodies revolving around the Earth). These ideas all went against the accepted doctrine of the time.

This was capital S Science, where observational data trumps hypotheses.

All great Scientists have beards. I have a beard. Draw your own false syllogisms.

And by golly, did the whole Inquisition crowd get ticked off when Galileo published Dialogue Concerning the Two Chief World Systems! Galileo wasn’t invited to a barbecue like Bruno was, but he was put under permanent house arrest. I am happy to report that the Catholic church quickly reversed this. It took them a mere 325 years to pardon Galileo.

Ironically, this guy who discovered the craters on the Moon -- Galileo -- doesn’t have a single crater named after him. All the rest of his gang got one. The injustice! All he got was "a large, dark surface feature" on Ganymede, one of Jupiter's moons. If ever there was an example of Stigler's law of eponymy, Galileo's craters are it.

Johannes Kepler is another guy who did capital S Science. He looked at data on the positions of Mars and deduced that the orbit of Mars around the Sun is elliptical. He also developed some laws regarding the speed that planets move around the Sun. Data and theory going hand-in-hand. Capital S Science.

Does Kepler have a lunar crater to call his own? Ya, you betcha. And the obligatory second one on Mars, and then gobs of other stuff in outer space.

Kepler has a whole lotta astronomical stuff named after him!

How about Isaac Newton? No question about it, he did some capital S Science, in a large and bolded font. Newton took Kepler’s laws and had the Greatest Synthesis of All Science – he determined that Kepler’s laws were a consequence of the inverse square law of gravity, and vice versa. In other words, a simple rule about the relationship between distance and gravity replaced Ptolemy's Spirograph set as an explanation of how the celestial bodies move. And he invented calculus just to figger that out! Data begets a simple theory to explain a whole lotta stuff. Science don’t get no better’n that.

Newton got a crater on the Moon, and also one on Mars, just like Copernicus and Kepler. It's a shame though, that he didn't get a few asteroids and exo-planets. Newton doesn't even have is very own disambiguation page on Wikipedia like Kepler.

The triumph

This story has a happy ending. In the end, Science has triumphed over some smarty-pants guy who spouted off about a lot of bogus stuff that he just made up. Granted, it wasn't so happy along the way for some of the courageous people who challenged alternative facts with gosh darn real facts. But in the end, we wound up with Science that truly explains how the world really is. And there are no craters (that I know of) that are named after Aristotle.

Let us hope that we have the wisdom to let facts and data guide our course in the future.

The apple doesn’t fall far from the Newton

Isaac Newton was sitting in his garden, contemplating nature, when an apple fell on his head. The entire notion of gravity came to him in an instant. He immediately saw how it all must fit together.

Did this really happen?

The story of Newton’s apple is a wonderful story of a sudden flash of insight, that “Eureka!” moment. But I am going to argue here that this is not exactly what happened. Here is what we know for sure.

What Newton had to say

Newton was getting on in years, in his early 80's. He was reminiscing about when he was a young man, and told friends that seeing an apple fall got him to pondering on the idea that whatever drew the apple to the Earth most likely had some effect on the moon as well. From this pondering came his theory of gravity.

There are enough independent accounts of Newton’s reminiscence that we can be sure that Newton actually said this in his old age. Voltaire wrote that he heard it from Newton’s niece, Catherine Barton Conduitt. The husband of Newton’s niece, John Conduitt, also committed this story to paper. An independent account came from William Stukeley. He wrote a biography of Newton in which he recounted that Newton himself had told him this story while they walked in the garden.

Henry Pemberton, a mathematician and a friend of Newton’s, also published a biography of Newton. In this biography he said that Newton was meditating in the garden when the idea occurred to him that the moon must be subjected to the same force that drew a falling body to the Earth.

Thus, it is quite likely that Newton told this little anecdote about how he came to discover gravity in a garden when he was 23.  

    

Was he hit on the head?

It is unlikely that the apple actually hit Newton on the head. None of the first-hand and second-hand accounts – people who heard the story from Newton, or from a second party – mentioned this. The embellishment was apparently the creation of Isaac D'Israeli, who was born about 40 years after Newton’s death.

A dashing gentleman

Among other things, D’Israeli wrote a book of essays called Curiosities of Literature, which contained anecdotes about a number of historical figures. D’Israeli started an essay in this book by saying that “Accident has frequently occasioned the most eminent geniuses to display their powers.” 

Isaac Newton and the alleged story of the cranial collision merited one paragraph in this D'Iraeli's book. The preceding paragraph tells of how a fellow by the name of Corneille was saved from a drab lifetime of lawyer-hood by the act of writing poetry for his mistress. The paragraph following Newton’s story tells how Ignatius Loyola founded the Jesuit Society as a result of his reading while he was convalescing from a battle wound.

D’Israeli’s book sounds pretty much like Star Magazine to me.

The modern day version of D’Israeli’s book

Was the whole apple story a fabrication?

The falling of the apple was to have occurred when Newton was 23. It is somewhat strange that Newton never mentioned the anecdote until he was 83. Then again, maybe not? It may be that he never felt it was important, or it may have been a fabrication?

Then again, it might be that Newton provided this anecdote as a way to lend credence to his claim that he discovered the law of gravity.  

  

Did Newton invent discover gravity?

I distinctly remember learning in third grade that Newton invented gravity. Recently I did a thorough patent search and could not find any evidence of him getting credited for this invention. My own research suggests that gravity was invented sometime around one million years ago, since at that time there were certain objects not yet brought under its control.

Two objects not subject to the force of gravity 1,002,012 years ago

But, did Newton discover gravity?  This was not exactly what Newton has been given credit for. Aristotle had written about gravity, and had his own explanation of why it exists[1]. Galileo, who lived before Newton, also had a few things to say about gravity[2].

It would be a little closer to the truth to say that Newton discovered the inverse square law of gravity – that the gravitational force between two objects is inversely proportional to the square of the distance between them.

The inverse square law as applied to light

That statement is not nearly as fun as “Newton discovered gravity”. It is shrouded in arcane mathematical verbiage. I think it puts Newton’s accomplishments just a bit out of the reach of most third grader’s, no matter how thirsty they are for knowledge. But more importantly, that silly inverse square law bit hides a lot of the historical context. There were a number of brilliant insights buried in this law:

First insight – Gravity is not limited to making objects fall to the Earth. This is a completely non-intuitive concept. Gravitational effects between two objects are just not needed when explaining our day-to-day lives, except perhaps to explain why Julia Roberts was ever attracted to Lyle Lovett. I can think of no other explanation for that attraction[3].

Do the laws of physics explain this strange attraction?

Second insight – Gravity applies to objects out in space, like the moon, the Sun, the planets, and to stars other than Julia Roberts and Lyle Lovett.

Third insight – (This is the big one.)  Kepler’s laws, which describe the elliptical paths that planets take, can be explained by an inverse square law of gravity[4].

Newton gives this account of his discovery:

In the same year I began to think of gravity extending to the orb of the Moon and (having found out how to estimate the force with which globe revolving within a sphere presses the surface of a sphere) from Kepler's rule of the periodical times of the Planets being in sesquialternate proportion to their distances from the centres of their Orbs, I deduced that the forces which keep the Planets in their Orbs must reciprocally as the squares of their distances from the centres about which they revolve: and thereby compared the force requisite to keep the Moon in her Orb with the force of gravity at the surface of the Earth, and found them answer pretty nearly.

This is quite a mouthful for one sentence. Newton could have been a great patent writer, if he decided to turn his hand to that occupation[5]. Maybe if he had, he would have filed a patent for the invention of gravity.

Priority of Hooke

But this was Newton’s account, which doesn’t quite square with other facts about the discovery of the inverse square law.

Newton said his ruminations and discovery of the inverse square law date back to a period from 1665 to 1666, when Newton was 23. But, historical evidence contradicts this. In particular, there were a series of letters between Robert Hooke and Newton starting in 1679 that show that Newton had not yet put all the pieces together. In fact, Hooke may have had a better grasp at that time.

Robert Hooke, another dashing man

In the first letter between them, Hooke asserted without proof, that the elliptical motion of the planets around the Sun was the result of a force pulling them toward the Sun. In the ensuing letters, Hooke stated that an inverse square law of gravity would lead to an elliptical orbit.

Newton replied in one letter that an object falling to the center of the Earth, if unobstructed, would follow a spiral. Later he asserted that with a constant force of gravity the object would follow a clover leaf path. Clearly, he was not thinking about an inverse square law and ellipses at this time.

In 1684, Hooke told Edmund Halley that he (I mean Hooke) had developed a proof that an inverse square law of gravitational attraction between celestial objects would lead to elliptical orbits. He never produced the proof.

Edmund Halley (left), not to be confused with Alex Haley, author of Roots (right)

This idea intrigued Halley. Learned men of his time (sadly) did not have lofty discussion topics like Romney’s tax returns and Obama’s birth certificate. The men[6] in his circles were unfortunately limited to mundane topics like Copernicus’ revolutionary idea that the Earth was not the center of the universe about which the Sun and all that stuff revolved[7]. And the exciting idea of Kepler that Ptolemy’s ridiculously complicated mathematical model of the orbits of the planets could be explained by three simple laws[8].

Halley sought out Newton, and posed the question to him. In (Doctor) Halley’s words:

Sr Isaac replied immediately that it would be an Ellipsis, the Doctor struck with joy and amasement asked him how he knew it, why, said he I have calculated it, whereupon Dr Halley asked him for his calculation without any farther delay, Sr Isaac looked among his papers but could not find it, but he promised him to renew it, and then to send it him.

Newton was not immediately able to provide the proof, but shortly after produced a nine page demonstration. At Halley’s urging[9], this was fleshed out and was eventually published as Philosophiae Naturalis Principia Mathematica[10]. This was the first proof that an inverse square law of gravity implied elliptical orbits.

The acrimonious battle with Hooke over priority ensued, but that will be the topic of another blog.

My conclusions from this historical lesson

The bit about Newton being hit by an apple in the garden is clearly a fabrication. Newton did indeed discover the “law of gravity”, which is to say, he is the first to provide a proof that the inverse square law of gravity explained the paths of the planets. It is not likely, however, that he developed the full idea back when he was 23 sitting in a garden, pondering a falling apple.     

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[1] This is fascinating history that will be left to a future blog.

[2] Remember the guy who dropped the balls from the Leaning Tower of Pisa? Well, it probably wasn’t Galileo, but it will be another fascinating future blog.

[3] In a previous blog, “Flies walk on the ceiling”, I suggested that a hypothetical Flysaac Newton might have discovered the laws of surface tension instead of gravity.

[4] This sounds like yet another topic for a future blog.

[5] I introduce this as silliness, but patents did exist in England back to the year 1449, when King Henry IV granted a patent for the making of stained glass.

[6] Sadly, these were mostly men. That sounds like another blog topic.

[7] Grist for a future blog?

[8] Another blog? I sure hope I live long enough to write all the blogs that I have half-written in my head.

[9] Although Newton was a prolific writer, he was extremely reluctant o publish, partly due to the mockery he received from his first publication on the nature of light.

[10] It is a shame that Newton did not have the benefit of Google blogs to publish.