13 Evolution of High-Mass Stars

13 Evolution of High-Mass Stars

13.1 High-mass stars follow their own path

13.2 High-mass stars go out with a bang

13.2.1 Introduction

13.2.2 The final days in the life of a massive star

13.2.3 The core collapses and the star explodes

Young, Monica, “The star that wouldn’t die,” Sky and Telescope (135, 2, February 2018, p. 12

13.3 Supernovae change the galaxy

13.3.1 Introduction

Melott, Adrian L. “How supernovae have affected life,” Astronomy, 46, 4, April 2018, pp. 44-49. The article focuses on the effect of supernovae characterized by the explosion of stars, on the life on planet Earth. Topics discussed include the implication of the blue light generated by supernovae on the depletion of the Earth’s ozone, the impact of the cosmic waves consists of atomic nuclei and protons on human life, and the effect of the rays on increasing the Earth’s flux of muons on the ground.

13.3.2 The energetic and chemical legacy of supernovae

13.3.3 Neutron stars and pulsars

13.3.4 The Crab Nebula: Remains of a stellar cataclysm

13.4Einstein moved beyond Newtonian physics

13.4.1 The speed of light in a vacuum

13.4.2 Time dilation

13.4.3 The implications of relativity

13.5 Gravity is a distortion of spacetime

13.5.1 Free fall and free float

13.5.2 Spacetime as a rubber sheet

13.5.3 The observable consequences of general relativity

Betz, Eric, Robert Naeye, and Jake Parks. “The first observation of a gravitational wave source,” Astronomy, 46, 2, February 2018, p. 10

Carlisle, Camille M. “LIGO sees its smallest black hole binary yet,” Sky and Telescope, 135, 2, February 2018, p. 11

Govert Schilling, “When neutron stars collide,” Sky & Telescope (135, 2, pp. 32-39)

13.6 Black holes are a natural limit

13.6.1 Overview

13.6.2 Properties of black holes

13.6.3 “Seeing” black holes

Monica Young, “Decoding a black hole jet,” Sky and Telescope, 135, 2, February 2018, p. 13


Why Study Astronomy

That’s Astronomy, Too[1]

A student needing science credits to graduate flips through the catalog. He considers biology for a moment, but that sounds squishy. Chemistry sounds smelly. Geology sounds. . . well, how much fun could rocks be? He doesn’t even glance at physics.

That leaves astronomy. “Stars? I can do stars. Sign me up?”

The irony is that astronomy is physics, chemistry, geology, biology, and most other kinds of science you can think of. Throw in some history, politics, math, computer science, engineering, and philosophy for good measure. Astronomy is an any-port-in-a storm science. Astronomers don’t get to put a star in a laboratory where we can poke it and prod it under controlled conditions. We have to work with what nature gives us. Astronomy requires its devotees to be clever and to draw on absolutely everything that we know.

Humankind’s historical conception of the universe was built on two pillars. The first was that Earth is the center of all things. The second was the belief that the heavens are other. From Hindus and Buddhists in the East to the Greeks in the West, our ancestors spoke of the four classical elements: earth, air, fire, and water. But there was a heavenly fifth element as well, described by Aristotle as unchanging and incorruptible. To this day we call the perfect example “quintessential,’ literally “made of the fifth element.”

It is perhaps ironic that grasping the reality of the universe meant standing those traditional beliefs on their heads. We aren’t the center. We are residents of an ordinary planet, orbiting an ordinary star in the disk of an ordinary spiral galaxy. And rather than other, the heavens are the same. The “principle” that terrestrial physics applies throughout the universe is actually a testable scientific theory. It is corroborated every time we observe familiar features in the spectrum of a distant galaxy or use computer models to build a virtual star with properties that match the real thing. The universal applicability of physical law is so ingrained today that we forget what a radical and world-changing idea it was.

That brings us back to that first day of class when, wearing a puckish smile, I would disavow students of the notion that by taking astronomy they had avoided all the hard stuff.

Physics is everywhere in astronomy. From the interaction of electromagnetic radiation with matter to the theories of space time that describe the fabric of the universe, they don’t call it astrophysics for nothing! Likewise, interplanetary dust, molecular clouds, and the oxidation that gives Mars its red color are chemistry. Thoughts about extraterrestrial life are guided by what we know of terrestrial biology and evolution.

Comparative planetology is the cornerstone of modern planetary science. Starting with the geology, atmospheric physics, and chemistry of Earth, we look at other worlds and study how they are similar and how they are different. Comparative planetology is a two-way street. What we have learned from our sister worlds, along with the tools developed to explore them, has revolutionized the way we think about our own planet.

You can’t talk meaningfully about astronomy without grappling with historical, social, and philosophical currents like those present at the birth of the Renaissance. We revere Copernicus, Galileo, Newton, and others because their discoveries about the heavens changed the course of civilization.

Astronomy benefits from technology, but it also has driven innovation from the dawn of time. Imagine the new technologies needed to build Stonehenge! Physics was invented in large part to explain planetary motions. More recently you might know that Riccardo Giacconi won the 2002 Nobel Prize in Physics “for pioneering contributions to astrophysics, which have led to the discovery of cosmic x-ray sources.” You might not know that x-ray astronomers are responsible for the technologies that form the heart of x-ray machines at airport security checkpoints and the CT scans that remade medicine.

Astronomy is mind-bendingly cool, but it’s not comfort able. It demands that we change how we think about everything. To claim to know things about the distant universe, we have to carefully consider what knowledge is in the first place. We have to be willing to put even our most cherished notions on the chopping block. And we have to broaden our perspective. When Apollo 8 astronauts took the famous photo of Earth rising above the lunar horizon, it marked the first time human eyes saw our seemingly limitless and inexhaustible world as it truly is: a small, beautiful, fragile oasis adrift in space.

Astronomy is the study of the cosmos. If you run across something that is not part of the cosmos, be sure and let me know!

From time to time someone will ask me why an astronomer would spend so much time thinking about philosophy, history, evolution, climate science, cognition, and on down the list. I always give the same reply.

“Because that’s astronomy too.”

[1] Jeff Hester, “That’s Astronomy, Too,” Astronomy (44, 3, March 2016, p 14). Jeff Hester is a keynote speaker, coach, and astrophysicist. Follow his thoughts at http://jeff-hester.com .

The Hermeneutics of Bunk

The Hermeneutics[1] of Bunk[2]

How a physicist gave postmodernism a black eye.

For anyone who pays attention to popular accounts of physics and cosmology, quantum gravity is a thing. How could it not be? Quantum gravity is the place where the two pillars of modern physics—quantum mechanics and relativity—collide head-on at the very instant of the Big Bang. The two theories, each triumphant in its own realm, just don’t play well together. If you are looking for fundamental challenges to our ideas about the universe, quantum gravity isn’t a bad place to start.

A bit over two decades ago, quantum gravity also proved to be the perfect honey trap for a bunch of academics with a taste for nonsense and an envious bone to pick with science.

In 1994, NYU physicist Alan Sokal ran across a book by biologist Paul Gross and mathematician Norman Levitt. In Higher Superstition: The Academic Left and Its Quarrels with Science[3], Gross and Levitt raised an alarm about those in the new field of “cultural studies” who were declaring that scientific knowledge, and at some level reality itself, is nothing but a social construct. Unsure whether he should take Gross and Levitt at face value, Sokal went to the library and dove into the literature that they were criticizing. When he came up for air, he was much more familiar with the postmodernist critique of science. He was also appalled at the depth of its ignorance about the subject.

Most scientists respond to such nonsense with a muttered, “good grief,” but Sokal felt compelled to do more. He decided to give postmodernists a first-hand demonstration of the destructive testing of ideas that tie science to a reality that cuts across all cultural divides.

Sokal had a hypothesis: Those applying postmodernism to science couldn’t tell the difference between sense and nonsense if you rubbed their noses in it. He predicted that the cultural science studies crowd would publish just about anything, so long as it sounded good and supported their ideological agenda. To test that prediction, Sokal wrote a heavily footnoted and deliciously absurd 39-page parody entitled, “Transgressing The Boundaries. Toward A Transformative Hermeneutics of Quantum Gravity.”[4]

The paper is worth reading just for a belly laugh. It promises “emancipatory mathematics” at the foundation of “a future post-modern and liberatory science.” “Physical ‘reality’,” it declares, “is at bottom a social and linguistic concept.” He embraces the notion, seriously proposed by some, that logic itself is invalidated by “contamination of the social” When he showed it to friends, Sokal says, “the scientists would figure out quickly that either it was a parody or I had gone off my rocker.”

Sokal submitted his paper to a trendy journal called Social Text. Understanding the importance of ego, he freely and glowingly cited work by several of the journal’s editors. For their part, the folks at Social Text were thrilled to receive Sokal’s manuscript. Here at last was a physicist who was “on their side!” After minor revisions, the paper was accepted and scheduled to appear in an upcoming special “Science Wars” edition.

The bait had been taken, but the trap had yet to be sprung. That came with a piece by Sokal in Lingua Franca[5] that appeared just after Social Text hit the stands, exposing “Transgressing the Boundaries” as the hoax it was.

Parody sometimes succeeds where reasoned discourse fails. Sokal’s little joke burst free of the ivory tower on May 18, 1996, when The New York Times ran a front-page article entitled, “Postmodern Gravity Deconstructed, Slyly.[6]” The Sokal Hoax became a hot topic of conversation around the world!

Reactions to Sokal’s article were, shall we say, mixed. The editors of Social Text were not amused, to put it mildly, and they decried Sokal’s unethical behavior. One insisted that the original paper was not a hoax at all, but that fearing reprisal from the scientific hegemony, Sokal had “folded his intellectual resolve.” It was lost on them that had they showed the paper to anyone who knew anything about science or mathematics, the hoax would have been spotted instantly.

As most scientists did: When I heard about it, I busted a gut!

I still laugh, but the Sakai Hoax carries a serious message. In addition to diluting intellectual rigor, the postmodern assault on science undermines the very notion of truth and robs scientists and scholars of their ability to speak truth to power. As conservative columnist George Will correctly observed, “the epistemology that Sokal attacked precludes serious discussion of knowable realities.” Today, from climate change denial, to the anti-vaccine movement, to the nonsensical notion of “alternative facts,” that blade is wielded on both sides of the political aisle.

Sokal gets the last word. Quoting from his 1996 Lingua Franca article, “Anyone who believes that the laws of physics are mere social conventions is invited to try transgressing those conventions from the windows of my apartment. (I live on the 21st floor.)”

[1] Hermeneutics: the branch of knowledge that deals with interpretation.

[2] See Jeff Hester, “The Hermeneutics of Bunk: How a physicist gave postmodernism a black eye,” in Astronomy (45, 7, July 2017. p. 14). Jeff Hester is a keynote speaker, coach, and astrophysicist. Follow his thoughts at Jeff-hester.com.

[3] See Paul R. Gross (1998) and Norman Levitt. Higher Superstition: The Academic Left And Its Quarrels With Science, Baltimore, MD: Johns Hopkins University Press [LCCN: 98106819]

[4] Sokal, Alan D. “Transgressing the Boundaries: Toward a Transformative Hermeneutics of Quantum Gravity,” Social Text (46/47, Spring-Summer, 1996, pp. 217-252)

[5] Sokal, Alan, “A Physicist Experiments with Cultural Studies,” Lingua Franca (6, July-August 1996, pp. 54-67).

[6] Janny Scott, “Postmodern Gravity Deconstructed, Slyly,” New York Times (May 18, 1996). Accessed at http://www.nytimes.com/1996/05/18/nyregion/postmodern-gravity-deconstructed-slyly.html.

Cosmic Surprises Keep Blowing Our Minds

Cosmic Surprises Keep Blowing Our Minds[1]

Some areas of science advance in increments. We see slow evolutionary improvements in aeronautical engineering and medical discoveries. But astronomy is different. Here, the universe often leaps out and goes boo! Although we are far from it, let’s use April Fool’s Day as our excuse to review the top 20 pranks” the cosmos has sprung on us.

Start with Galileo. Since no one had pointed a telescope at the sky before, he was bound to get surprises. Nobody had foreseen lunar craters or moons going around other planets like Jupiter, as he observed. But when he looked at Saturn, he entered the Twilight Zone. On Earth, there’s no example of a ball surrounded by unattached rings. This was beyond human experience. No wonder it took two centuries for anyone to deduce that they’re neither solid nor gaseous, but made of separate moonlets. So our first April Fool’s prank? Saturn’s glorious rings.

Fast forward to 1781. That’s when William Herschel first peered at a bizarre green ball. No one had discovered any planets beyond the five bright ones since prehistory. No great thinker, no holy book, no philosopher had done more than idly speculate about more planets out there in our Solar System. Herschel’s spotting of Uranus was the most unexpected and amazing discovery all time.

Surprise No. 3 stays with Herschel. Nineteen years after finding Uranus, he discovered the first-ever invisible light. Light we cannot see?

It astonished the world. The bulk of the Sun’s emissions are invisible “calorific rays.” Late that century, people started calling it infrared.

We have to credit Albert Einstein with several mind-blowers. First, that space and time both shrink or grow depending on the observer’s conditions. This means the universe does not have a fixed size. And a million years elapse in one place while a single second is experienced by someone else—at the same time. Did anyone see that coming? Do most people grasp this even today? As if that wasn’t enough mind twisting, he showed that solid objects and energy are two faces of the same entity.

Jump ahead to 1920. That’s when Arthur Eddington figured out what makes the stars shine. Imagine: a new type of “burning.” An alchemic change of one element to another. This nuclear fusion process is so efficient that each second the Sun emits the energy of 96 billion 1-megaton H-bombs. Sure, physicists knew the Sun couldn’t create light and heat by burning in the usual way. But this?

A few years later, Edwin Hubble announced that all those spiral nebulae were separate “island universes.” Granted, this had been suspected by half of all astronomers for decades. It was not a sudden April Fool’s. Still, bam, the universe officially became unspeakably larger than it was before. That’s gotta count as a boo! event.

Then the quantum gang rode into town. Their revelations were astonishing. Empty space seethes with energy. A bit of matter can know what another is doing and react instantaneously across the universe as if no space exists between them. An observer’s presence influences the experiment.

In 1930 came the prediction for a new tiny entity, the neutrino. It’s the universe’s most common particle. Five trillion zoom through your tongue every second. The 1936 discovery of the subatomic muon was equally unexpected. It famously made Nobel Prize winner Isidor Rabi say, “Who ordered that?”

The 1967 discovery of the first neutron star revealed—a sun smaller than Hawaii, whose material is so dense that each speck equals a cruise ship crushed down to the size of the tip of a ballpoint pen. And that was a double whammy because it was also the first pulsar. Did any genius foresee that some stars could spin hundreds of times a second?

The surprises haven’t let up. A microwave background energy filling all space? A solid Pluto-size ball in the middle of our planet, spinning faster than the rest of Earth? And what about the enormous hexagon at Saturn’s north pole? Or the fact that cosmic “rays” are overwhelmingly protons?

1998 brought astronomers another stunner. When the universe was half its present age, all its galaxy clusters simultaneously started moving faster. It’s as if stupendous rocket engines fired simultaneously everywhere in the cosmos. We don’t know anything about this antigravity force—but we now call it dark energy.

Then in 2010, the Fermi gamma ray telescope found two ultra high-energy spheres, each 25,000 light-years across, occupying half of our southern sky. The entities meet tangentially at our galaxy’s core like an hourglass. They’re violent and utterly baffling.

We’re out of room, but the universe never is. For the cosmos—and we who explore it—it’s always April Fool’s.

[1] Derived from an article by Bob Berman, “April Fool’s!” in Astronomy (44, 6, April 2016, p. 10)

Human History and Distant Orbits

Human History and Distant Orbits[1]

Human history has always been linked to the influence of distant orbits.

Every astronomer has had the annoying experience of being introduced as an “astrologer”. Students often ask for permission to take one of my “astrology” courses. We then have to explain that astronomy is the study of the universe beyond Earth, while astrology is the belief that this universe controls our lives. There’s no good reason to hold that the position of the planets at your birth decided your personality or life path. But it is true that planetary motions have strongly influenced human history and nature.

For several million years, climate changes in Africa repeatedly shaped our evolution. In large part, these climate swings were forced by a complex series of rhythmic oscillations in Earth’s orbit and spin—oscillations that stem largely from the perturbing gravitational influence of Jupiter, Saturn, and the Moon.

Several evolutionary breakthroughs came about during such periods of extreme, modified climate. Upright posture, which freed up our inventive hands; a rapid increase in brain size; and the use of fire, allowing a meat diet that spurred further increase in brain size—scientists have linked all these to episodes of rapid climate alteration. These great leaps forward transformed us from just another species to one with the abilities that enabled the science and technology through which we’ve uncovered our own natural history.

Later we left Africa and peopled the world, our path set by climate-driven changes in sea level such as the one that opened up the Bering Strait land bridge to North America. Seven thousand years ago a phase of stable sea level coincided with the first large coastal settlements and the rise of complex societies. The origin of many sophisticated technologies and the symbolic language to pass them down also seem to have arisen in response to climate-caused survival threats.

Now in a twist, some of our technology threatens the climate we depend on to survive. Astrology will not save us, but astronomy might. By widening our scope of knowledge and improving our modeling capabilities, planetary exploration is crucial for understanding climate and responding effectively to our current challenges.

Our exploration of the Solar System owes its own path to fortuitous planetary positions. Every 175 years the outer planets arrange themselves perfectly for a “grand tour” mission that can ricochet from one gas giant to the next. One such rare alignment came in the 1970s, when we’d just barely developed the necessary technology to launch the pair of Voyager spacecraft. Another important lineup occurred soon after astronomers discovered Pluto’s moon Charon in 1978 (no doubt causing astrologers to redo their charts).

It’s lucky we found Charon when we did. Just two years later, the plane of its orbit lined up precisely with Earth to create a 5-year-long season of Pluto-Charon eclipses. This won’t happen again for more than a century. More importantly, these events and subsequent studies, along with the puzzling nature of Neptune’s moon Triton, seen in Voyager’s final pass in 1989, helped motivate those who agitated for a dedicated Pluto mission, culminating in last year’s historic flyby.

Maybe a species that has colonized its home world would have emerged on Earth even if the Solar System didn’t work the way it does. Once here, maybe we were bound to explore our neighboring worlds. But route and timing were dictated from above. The planets have indeed always ruled us.

[1] See David Grinspoon, “Thank Our Lucky Planets,” Sky and Telescope (132, 5, November 2016), p. 16. David Grinspoon is an astrobiologist and senior scientist at the Planetary Science Institute. His book, Grinspoon, David Harry (2016). Earth in Human Hands: Shaping Our Planet’s Future. New York, NY: Grand Central Publishing. [LOC: 2016025817] is worth a read. Follow him on Twitter at @ DrFunkySpoon.

Starmus Festival IV

Starmus Festival IV: Life And The Universe

The Starmus International Festival was held this year, June 18–23, 2017, in Trondheim, Norway. Starmus is an international gathering focused on celebrating astronomy, space exploration, music, art, and allied sciences such as biology and chemistry. It was founded by Garik Israelian, an astronomer at the Institute for Astrophysics in Tenerife, Canary Islands, Spain. The Festival has featured Buzz Aldrin, Neil Armstrong, Richard Dawkins, Stephen Hawking, Alexei Leonov, Jim Lovell, Brian May (English musiciaN), Jill Tarter, Kip Thorne, and Rick Wakeman among others. This year Brian Eno gave the keynote speach opening the Festival.


In 2007 Brian May, founding guitarist of the rock band Queen, completed his PhD dissertation, which was left unfinished in 1974 when Queen began to achieve significant success. May’s work focused on zodiacal dust in the Solar System. He had studied at Tenerife earlier through Imperial College in London, and resumed work there more than 30 years later. In 2007, his new advisor was Garik Israelian, and the two struck up a friendship, Israelian also being a musician. This led to the founding of the Starmus Festival—the name paying homage to stars and music—and the stage was set for the first Festival, which would occur four years later.


The festival has occurred in 2011, 2014 and 2016 in Tenerife, Spain. The fourth Starmus festival was held in Trondheim, Norway from June 18 to 23, 2017, under the title “Life And The Universe”.

The festival is described as an event where “the greatest minds in space exploration, astronomy, cosmology, and planetary science get together for a week of incredible talks, sharing of information, and appreciation of the knowledge we have of space and the universe.” This year there were enough brains and Brians to fill the multiverse

Brians Cox, Eno and May joined Stephen Hawking and Richard Dawkins in Tenerife to celebrate the synergy between astronomy and music, while astronaut Chris Hadfield, interviewed below, talked of our innate instinct to explore

In Starmus IV, gathered around the giant pool of the Mediterranean Palace hotel in Tenerife, hundreds of people focused on a familiar star. As pounding bass-filled music booms out of the PA, a great mass of the young, the middle-aged and the old are all glazed with submission as they appear to seek the meaning of the universe in the transformative process of ultraviolet radiation.

A few yards away in a darkened auditorium beneath a strange mock pinkish pyramid the Starmus festival was under way. Dedicated to celebrating a synthesis between astronomy and music that is of a more transcendent kind than that practiced around the Mediterranean Palace pool, it has drawn hundreds of people focused on very different but no less familiar stars: Brian Cox, Richard Dawkins, Brian May and, the greatest scientific supernova of them all, Stephen Hawking.

These, along with 11 Nobel laureates, were some of the leading speakers at the third Starmus festival at the Pirámide de Arona, an island of vaulting intellectual aspiration surrounded by tourist hotels with armies of sunbathers fastened to their poolside loungers as if by superglue.

Starmus is an unusual affair, but not necessarily for its setting. It’s not a typical science conference for academics at which new papers are presented. Nor is it a typical public talk designed to popularize established academic theories. Instead it’s a sort of hybrid—at once specialist and popularizing, openly public, and yet sufficiently off-circuit to feel discreetly private. It also seeks to bridge the separate worlds of science and the arts or, more specifically, music and cosmology.

The original idea was to do a concert at La Palma observatory, which features the world’s largest optical and infrared telescope. A disarming 53-year-old with a scattershot charm, Israelian had been working at NASA “trying to get acoustic sound waves in stellar atmospheres” and wondered if musicians might be able to use his collection. He approached Jean-Michel Jarre, who was keen on the idea, only for the concert to be cancelled when the Canary Islands government withdrew funding.

Undeterred, Israelian decided to commemorate the 50th anniversary of Yuri Gagarin’s first space flight with a festival in 2011. That was the first Starmus. In one sense it was a tremendous success because the keynote speaker was Neil Armstrong, the first man to walk on the moon and someone whose public appearances were so rare as to raise suspicion of their authenticity.

“When we announced Neil Armstrong was coming,” Israelian recalls, “we completely lost our credibility because no one believed he was going to be there. People said we were crazy. It was the worst thing we could do. And then he came!”

Armstrong’s fellow crew member Buzz Aldrin was also there, as well as Jim Lovell, commander of the ill-fated Apollo 13 who was played by Tom Hanks in the eponymous film. In addition there was the progressive electronic band Tangerine Dream.

However, in financial terms it was a disaster. Admission was free for most visitors, there was no sponsorship, and Israelian and his co-producers were left to pick up a hefty bill. But that didn’t stop them holding a second Starmus, again on Tenerife. This time Stephen Hawking came. He was a massive draw, but once again the festival lost money. Israelian talks darkly of broken promises by the Canary Islands government and the disappointing lack of sponsorship.

They say that one definition of madness is to keep doing the same thing and to expect different results. If so, then Israelian is mad in the best tradition of mad professors, because he came back for a third time with a cast list that was starrier than ever.

Not until you’ve seen Brian Cox at a gathering of science buffs can you appreciate how much the awe-filled physicist and TV personality is adored by his public. To walk alongside him though the Pirámide de Arona is to be submerged by a sea of autograph hunters and selfie-takers. Unlike Dawkins, who looks as if he can’t wait to get to the green room, Cox seems to relish the attention. What did he think of his first Starmus?

“It’s brilliant,” he says, tucking into an ice-cream. “There’s a lot of time to talk to the speakers. And you don’t normally get people like Brian Eno, Brian May and Hans Zimmer in the same room as Stephen Hawking and Joe Stiglitz.”

Starmus IV featured a lecture by Brian Eno. Eno’s discussed the intimate relationship between science and art, one the legendary music producer and former Roxy Music synthesizer player characterized as “science discovers and art digests”.

“He’s right,” says Cox. “If you look at the history of astronomy, these ideas of finding our place in the universe have had a massive social impact. The obvious one is the relegation of the Earth from the centre of it. That battle to define whether or not we’re special was one of the defining battles of the 17th century onward. Our physical demotion is now widely accepted, but what of the emotional impact if you start talking as Brian Greene and Martin Rees [two other speakers] did about the multiverse. What does it mean if there are an infinite number of these pocket universes? If that’s the case, we’re not geographically significant. We’re not even lucky. We’re just inevitable. Does that matter?”

Good question, but I’m not sure that I’ve fully mastered the concept of an infinite number of pocket universes, so I silently nod with as much sagacity as I can muster.

“The fact that we’re in an insignificant physical speck in a possibly infinite universe,” he continues, “is as easy or difficult to accept as that we are a very tiny temporal speck in a possibly infinite time span. We know how to deal with that, with death and a finite life time. There is an interesting parallel to be drawn. But it’s a conversation that won’t be had by physicists. It’s a conversation that’s best had in art, philosophy, literature and theology. That’s where the meaning of the things we discover about the universe is teased out.”

Israelian was asked if the lack of diversity was an issue for him. “No, no. I don’t think about such things,” he said, irritated by the question. “I invited many female scientists and they couldn’t come. I’ve got limited time—I cannot keep inviting people to get 50%. That’s not my problem.”

The round table debate turned out to be quite dull, with everyone speaking in optimistic platitudes or pessimistic generalities. It’s not a forum for deep expertise but strong opinion and it turns out that in a group debate the sum is less than its parts.

The debate is streamed live on the internet and also into the auditorium beneath the pyramid in Tenerife, which is about half full. The crowd at Starmus is much younger on average than the speakers and, in terms of gender at least, much more representative of the outside world.

A 40-year-old physics student, Raquel Rodriguez, was interviewed. If you were looking for a stereotype of an astro-nerd, then Rodriguez is not where you’d start. She looks like Sharon Stone in Basic Instinct and said her favorite area of discussion is “dark matter and quantum physics”.

Then there’s a 32-year-old Norwegian nurse called Guro Nygård. Her brother brought her for the week as a birthday present. She’s fascinated by astronomy, she says, though this is the first time she’s been to such an event. Her personal highlight from the week was seeing Hawking. “He’s unbelievable,” she says. “His personal history is truly amazing.”

Both women noticed the imbalance between men and women but both believed the key thing was to get the best people and that gender, in the short term, was a secondary issue.

Thirty-six-year-old Sam Alexandroni was talking to a neuroscientist, a brain surgeon and a rocket sci-entist. He used to be a journalist at the New Statesman, he said, but now he’s writing a novel. “My teachers did a miserable job at school of communicating the wonder of science. Having discovered it later in life, events like this are brilliant for communicating ideas,” he says. As for combining the sciences and the arts, Alexandroni is all for it, though he says he’s “yet to experience the synergy” at Starmus.

Starmus IV highlighted moonwalkers and women scientists.

Nature of Scientific Reasoning

The Nature of Scientific Reasoning[1]

Jacob Bronowski (1908–1974), a Polish-born intellectual, was trained as a mathematician but eventually studied and wrote on the sciences, technology, poetry, the relation between creativity in the arts and the sciences, and man’s attempts to control nature throughout history. A mathematician, a literary critic, a playwright, a scientist, and an acclaimed Renaissance man, Bronowski earned an M.A. degree at Jesus College, Cambridge, England, in 1930, and a Ph.D. in 1933. His extremely wide-ranging career includes lecturing at University College in England; serving as wartime researcher for the British Ministry of Home Security during World War II, when he studied the effects of the atomic bomb; and working at multiple posts at the Salk Institute for Biological Studies in San Diego and posts at Oxford University, Massachusetts Institute of Technology, the University of Rochester, Oregon State University, Yale University, Columbia University, and the National Gallery of Art; and serving as head of projects for the United Nations Educational, Scientific, and Cultural Organization (UNESCO).

Bronowski also worked as a British Broadcasting Corporation (BBC) commentator on atomic energy and other scientific and cultural subjects.

Bronowski came to the United States in 1964. He wrote that, after 1932, he realized it was not enough to work at a desk, was more important and what was defending human decency. It was then that Bronowski turned his attention to studying connections between art and science. Among his writings are: The Poet’s Defence (1939; retitled and reprinted, 1966); a study of William Blake (1943; retitled and reprinted, 1965); Science and Human Values (1965; rev. ed., 1972), his most acclaimed work; and The Ascent of Man (1973), essays based on a BBC television series, his most popular work. Bronowski believed that the progress of science could best be understood by recognizing the interdependence of the sciences, arts, literature, and philosophy. He emphasized the universality of human nature and the need to control violence in modern society.

The Nature of Scientific Reasoning[2]

Jacob Bronowski

What is the insight in which the scientist tries to see into nature? Can it indeed be called either imaginative or creative? To the literary man the question may seem merely silly. He has been taught that science is a large collection of facts; and if this is true, then the only seeing which scientists need to do is, he supposes, seeing the facts. He pictures them, the colorless professionals of science, going off to work in the morning into the universe in a neutral, unexposed state. They then expose themselves like a photographic plate. And then in the darkroom or laboratory they develop the image, so that suddenly and startlingly it appears, printed in capital letters, as a new formula for atomic energy.

Men who have read Balzac and Zola are not deceived by the claims of these writers that they do no more than record the facts. The readers of Christopher Isherwood do not take him literally when he writes “I am a camera.” Yet the same readers solemnly carry with them from their schooldays this foolish picture of the scientist fixing by some mechanical process the facts of nature. I have had of all people a historian tell me that science is a collection of facts, and his voice had not even the ironic rasp of one filing cabinet reproving another.

It seems impossible that this historian had ever studied the beginnings of a scientific discovery. The Scientific Revolution can be held to begin in the year 1543 when there was brought to Copernicus, perhaps on his deathbed, the first printed copy of the book he had finished about a dozen years earlier. The thesis of this book is that Earth moves around the Sun. When did Copernicus go out and record this fact with his camera? What appearance in nature prompted his outrageous guess? And in what odd sense is this guess to be called a neutral record of fact?

Less than a hundred years after Copernicus, Kepler published (between 1609 and 1619) the three laws which describe the paths of the planets. The work of Newton and with it most of our mechanics spring from these laws. They have a solid, matter-of-fact sound. For example, Kepler says that if one squares the year of a planet, one gets a number which is proportional to the cube of its average distance from the Sun. Does anyone think that such a law is found by taking enough readings and then squaring and cubing everything in sight? If he does, then, as a scientist, he is doomed to a wasted life; he has as little prospect of making a scientific discovery as an electronic brain has.

It was not this way that Copernicus and Kepler thought, or that scientists think today. Copernicus found that the orbits of the planets would look simpler if they were looked at from the Sun and not from Earth. But he did not in the first place find this by routine calculation. His first step was a leap of imagination—to lift himself from Earth, and put himself wildly, speculatively into the Sun. “Earth conceives from the Sun,” he wrote; and “the Sun rules the family of stars.” We catch in his mind an image, the gesture of the virile man standing in the Sun, with arms out-stretched, overlooking the planets. Perhaps Copernicus took the picture from the drawings of the youth with outstretched arms which the Renaissance teachers put into their books on the proportions of the body. Perhaps he had seen Leonardo’s drawings of his loved pupil Salai. I do not know. To me, the gesture of Copernicus, the shining youth looking outward from the Sun, is still vivid in a drawing which William Blake in 1780 based on all these: the drawing which is usually called Glad Day.

Kepler’s mind, we know, was filled with just such fanciful analogies; and we know that they were. Kepler wanted to relate the speeds of the planets to the musical intervals. He tried to fit the five regular solids into their orbits. None of these likenesses worked, and they have been forgotten; yet they have been and they remain the stepping stones of every creative mind. Kepler felt for his laws by way of metaphors, he searched mystically for likenesses with what he knew in every strange corner of nature. And when among these guesses he hit upon his laws, he did not think of their numbers as the balancing of a cosmic bank account, but as a revelation of the unity in all nature. To us, the analogies by which Kepler listened for the movement of the planets in the music of the spheres are farfetched. Yet are they more so than the wild leap by which Rutherford and Bohr in our own century found a model for the atom in, of all places, the planetary system?

No scientific theory is a collection of facts. It will not even do to call a theory true or false in the simple sense in which every fact is either so or not so. The Epicureans held that matter is made of atoms 2000 years ago and we are now tempted to say that their theory was true. But if we do so we confuse their notion of matter with our own. John Dalton in 1808 first saw the structure of matter as we do today, and what he took from the ancients was not their theory but something richer, their image: the atom. Much of what was in Dalton’s mind was as vague as the Greek notion, and quite as mistaken. But he suddenly gave life to the new facts of chemistry and the ancient theory together, by fusing them to give what neither had: a coherent picture of how matter is linked and built up from different kinds of atoms. The act of fusion is the creative act.

All science is the search for unity in hidden likenesses. The search may be on a grand scale, as in the modern theories which try to link the fields of gravitation and electromagnetism. But we do not need to be browbeaten by the scale of science. There are discoveries to be made by snatching a small likeness from the air too, if it is bold enough. In 1935 the Japanese physicist Hideki Yukawa wrote a paper which can still give heart to a young scientist. He took as his starting point the known fact that waves of light can sometimes behave as if they were separate pellets. From this he reasoned that the forces which hold the nucleus of an atom together might sometimes also be observed as if they were solid pellets. A schoolboy can see how thin Yukawa’s analogy is, and his teacher would be severe with it. Yet Yukawa without a blush calculated the mass of the pellet he expected to see, and waited. He was right; his meson was found, and a range of other mesons, neither the existence nor the nature of which had been suspected before. The likeness had borne fruit.

The scientist looks for order in the appearances of nature by exploring such like- nesses. For order does not display itself of itself; if it can be said to be there at all, it is not there for the mere looking. There is no way of pointing a finger or camera at it; order must be discovered and, in a deep sense, it must be created. What we see, as we see it, is mere disorder.

This point has been put trenchantly in a fable by Karl Popper. Suppose that someone wishes to give his whole life to science. Suppose that he therefore sat down, pencil in hand, and for the next twenty, thirty, forty years recorded in notebook after notebook everything that he could observe. He may be supposed to leave out nothing: today’s humidity, the racing results, the level of cosmic radiation and the stock-market prices and the look of Mars, all would be there. He would have compiled the most careful record of nature that has ever been made; and, dying in the calm certainty of a life well spent, he would of course leave his notebooks to the Royal Society. Would the Royal Society thank him for the treasure of a lifetime of observation? It would not. The Royal Society would treat his notebooks exactly as the English bishops have treated Joanna Southcott’s box. It would refuse to open them at all, because it would know without looking that the notebooks contain only a jumble of disorderly and meaningless items.

Science finds order and meaning in our experience, and sets about this in quite a different way. It sets about it as Newton did in the story which he himself told in his old age, and of which the schoolbooks give only a caricature. In the year 1665, when Newton was 22, the plague broke out in southern England, and the University of Cambridge was closed. Newton therefore spent the next 18 months at home, removed from traditional learning, at a time when he was impatient for knowledge and, in his own phrase, “I was in the prime of my age for invention.” In this eager, boyish mood, sitting one day in the garden of his widowed mother, he saw an apple fall. So far the books have the story right; we think we even know the kind of apple; tradition has it that it was a Flower of Kent. But now they miss the crux of the story. For what struck the young Newton at the sight was not the thought that the apple must be drawn to Earth by gravity; that conception was older than Newton. What struck him was the conjecture that the same force of gravity, which reaches to the top of the tree, might go on reaching out beyond Earth and its air, endlessly into space. Gravity might reach the moon: this was Newton’s new thought; and it might be gravity which holds the Moon in her orbit. There and then he calculated what force from Earth (falling off as the square of the distance) would hold the Moon, and compared it with the known force of gravity at tree height. The forces agreed; Newton says laconically, “I found them answer pretty nearly.” Yet they agreed only nearly: the likeness and the approximation go together, for no likeness is exact. In Newton’s science modern sciences is full grown.

It grows from a comparison. It has seized a likeness between two unlike appear- ances; for the apple in the summer garden and the grave moon overhead are surely as unlike in their movements as two things can be. Newton traced in them two expres- sions of a single concept, gravitation: and the concept (and the unity) are in that sense his free creation. The progress of science is the discovery at each step of a new order which gives unity to what had long seemed unlike.

Questions for Discussion

  1. What is scientific reasoning? How does it differ from other kinds of reasoning?
  2. Where does the erroneous image of scientists as merely reporting facts come from?
  3. If science is not “a collection of facts” (Paragraph 2), what is it? Why can science not be just a collection of facts? What is a “fact”?
  4. How do new scientific theories develop? How are old ideas transformed into new ones?
  5. What is the purpose of science?
  6. Why can good science never be purely objective? Why will pure objectivity not work? In what way should scientists be subjective?
  7. Bronowski says in Paragraph 8, “All science is the search for unity in hidden likenesses.” What examples does he include to illustrate that statement? What does that statement mean?

Questions for Reflection and Writing

  1. Describe the process by which scientists think. Consider Copernicus and Kepler: What were their processes? How does their way of thinking still describe how scientists think today?
  2. Define a type of reasoning, besides scientific, with which you are familiar. Examples might include artistic reasoning, intuitive reasoning, and historical reasoning. Describe the thinking process, providing examples from your experience, and explain how this process works.
  3. Look up Leonardo da Vinci’s drawing of the proportions of the body and William Blake’s Glad Day, mentioned in Paragraph 5. Write an essay in which you explain how these drawings illustrate scientific thought. Other artworks on scientific topics could also be used in your essay.

[1] From http://www.public.iastate.edu/~bccorey/105%20Folder/The%20Nature%20of%20Sci.pdf.

[2] Copyright © 1956 by Jacob Bronowski. Copyright renewed 1984 by Rita Bronowski.