The Audacity of Exploration

by Shane L. Larson

We are perhaps the most audacious species to ever inhabit the Earth. Our audacity is not defined by our weird physical features (as perhaps defines our cousin the duck-billed platypus), nor defined by our strange physical geometry (as perhaps defines our cousins the octopuses), nor defined by abbreviated or extenuated oddities in our life cycles (as perhaps defines our cousins the mayflies or cicadas respectively).

Humans have been on Earth a long time. Doing what humans do.

Humans have been on Earth a long time. Doing what humans do.

The existence of modern humans as a distinct biological species on planet Earth goes back around 200,000 years. At the time modern humans appear in the fossil record, we were just as smart and as strong as we are now, but we hadn’t become a society yet. The oldest known artifacts of human manufacture are roughly 100,000 years old (shell jewelry), and the oldest bit of recorded history goes back only 5500 years, to the time of the ancient Sumerians and the Early Dynastic era of Egypt.  Humans have been on Earth a long time, just existing. Living off the land much as the other plants and animals do. For most of that time, we’ve been aware of the sky over our heads. We’ve stared at the Moon and stars and wondered what they are. But the idea of visiting those otherplaces in the Cosmos was the purview of madmen and addle-minded fools.

But all that changed in 1957 when we started shooting rockets into outer space. Soaring aloft on harnessed tongues of fire redefined what was crazy and what was possible. Voyages to other worlds was suddenly within our grasp, if only we could build a machine to take us there.  And we did.

The principle requirement for flying to the sky, beyond having the audacious impulse to do so?

BELGIUM TRIAL DUTROUXPerseverance. Throwing machines into space is hard. To build a machine capable of sailing the void requires solving a lot of problems. One at a time. The race is long, but in the end, the product of your imagination and sweat stands realized on the launch pad. Girded in vaporous fumes and draped with umbilicals and support arms, it awaits those last few moments.

Three… Two… One

Ignition!

The great machine lifts off, straining to reach the shallows of the sea of space, ready to embark on a long journey for which it was uniquely designed. Power, fuel, sensors, computers, and memorized instructions — all accustomed to a journey far from the tradewinds of Earth, sailing in the vastness between the worlds.

Yesterday we witnessed a milestone in one of these epic voyages, when the European Space Agency probe Rosetta dropped its lander Philae to descend onto the surface of the Comet 67P/Churyumov–Gerasimenko. Philae had been carried by Rosetta for ten years across the void from Earth, like a parent carrying a sleeping child.  Ten long years, all alone in the night.

The ultimate goal of this long sojourn to a tumbling hulk of rock and ice? To understand the nature of comets — what are they made of, what is their internal structure, how are they assembled and put together, and how do they hold up?  These are all questions about the comet, to be sure, but they are the cloth draped over the true quest: we want to know about water. One of the ideas about the water on Earth is that it came from comets, the left-over detritus from the formation of the solar system. Water is the central player in the development and sustainability of life on Earth. The quest to understand this comet is part of the much larger quest to understand where we came from.

The Philae lander dropped 10km from the mothership, Rosetta.

The Philae lander dropped 10km from the mothership, Rosetta.

Philae, after a 7 hour drop from 10 kilometers above the comet, soft-landed on the surface. For the first time in human history, we landed on the surface of a comet. And you and I were alive to see it.  We know now that it wasn’t the end of the adventure. Philae BOUNCED off the surface, at a mere 38 cm/s, but it bounced and didn’t come back down for nearly two hours.  But come down it did, pulled by the weak, inexorable draw of gravity. It bounced a second time, remaining airborne for 7 minutes. Now, it is at rest, somewhere on the foreboding surface of 67P/Churyumov–Gerasimenko. We’re talking with Philae, but still trying to understand where it is and what its status is.

Grandeur, one of the principal commodities from the exploration of beautiful places.

Grandeur, one of the principal commodities from the exploration of beautiful places.

Exploration is about discovering beauty, in experiencing the grandeur of places unknown. There are few places that show us the stark and desolate beauty we are now seeing from the surface of 67P/Churyumov–Gerasimenko — it is a barren and altogether alien landscape that you and I are witnessing for the first time. But exploration is also about seeing ourselves and our own home and our intense problems anew. If you are not moved by the great achievement of your fellow humans, if you can’t see what the big deal is with a rock in space, know that this mission is still for you and in some way is still about the things here on Earth that you do care about.

There are some who are not moved by such a great endeavour. That’s fine; some of us are not impressed by poetry, or fine French cooking, or NASCAR, or the designated hitter rule in baseball. But that does not diminish the accomplishment — we should all revel in what our fellow citizens have overcome and accomplished. They demonstrated the perseverance to solve one of the most complicated problems you can imagine — throwing a robot into space, having it survive for 10 years, and then landing a probe on the completely unknown, unseen, and hostile surface of another place. That should impress on you that these scientists and engineers are experts at solving hard problems. Someday you are going to rely on them to build a pacemaker that will survive inside your body for the remaining decades of your life. Someday they are going to build the autonomous car that can drive you to work. Someday they are going to repair the aging bridge in your town before it collapses under the burden of morning traffic.

There are some who question whether we needed to spend a billion Euros to voyage into space. That’s fine; it is right to question what we do with the pool of money that we as a society grudgingly set aside for great endeavours like this. But don’t let the idea of waste fool you; all of that money was spent here on Earth, not on Comet 67P/Churyumov–Gerasimenko. It paid for a miner to extract titanium ore from the ground; it paid for an electrician to wire the power harness that kept Philae alive for 10 years; it paid for a machinist to make a precision mounting bracket on a rocket engine; it paid a truck driver to transport the liquid oxygen to the launch facility in French Guiana; it paid for an engineer to design efficient solar cells that (in this case) can work for 10 years in the vacuum of space; it paid for a student intern who learned to program guidance computers in a basement in Germany, but is now going to use that knowledge in medical school to program micro-precision surgical robots. And a hundred thousand other parts and people.

The first image in human history returned from the surface of a comet, via our emissary, Philae.

The first image in human history returned from the surface of a comet, via our emissary, Philae.

We sent Rosetta and Philae into the darkness to be our eyes, to brave the dangers on the surface of an unknown rock 600 million kilometers from home.  Why did we do it?

Not just because we can. Not just because we want to know the unknown. Not just  because we are exploring.

We did it to remind ourselves — to prove to ourselves — that the problems we encounter can be solved. Nothing is unsolvable. We can do anything with enough imagination, dedication, and work.

We can land on the surface of a comet.  That’s Deep Blue hero stuff. That is the audacity of our species.

Stories from a Race Called Humans

by Shane L. Larson

On a forgotten autumn day long ago, I sat amidst hundreds of strangers in the far-away ballroom of a convention center in Oregon. I was younger than I am now, younger than most of those who were sitting around me. Yet somehow, I had been chosen. I had been waiting. I had rolled that singular moment of time around in my head, over and over again. Out of all the hundreds of hands in the air, mine was chosen, and I stood to ask a question.

My palms were sweaty, my heart raced. I took the microphone, and thankfully didn’t drop it. In those days, I had yet to ever speak in front of more than a small group of my friends in class, but here I was, and damnit I was going to ask my question!  Five hundred pairs of eyes stared right at me, and from the stage, the cool gaze of our guest, encouraging and expectant. I’m sure I squeaked; I must have squeaked. But out came my question: “What is the responsibility of science fiction to bring plausible visions of the future to us?

shatnerThe person I had directed my inquiry to was William Shatner, who had been regaling the crowd of Trekkers with tales of life in the Big Chair, and answering questions about how to properly act out a Star Trek Fight Scene, whether he really thought Kirk should have let the Gorn survive, and whether Spock ever just burst out laughing on set.  And then I stood up to ask my question.

What is the responsibility of science fiction to bring plausible visions of the future to us?

For all the ribbing that Shatner takes for being Shatner, I think he responded in a way that might surprise many people. He smiled, he didn’t laugh. He looked me straight in the eye and told me this: “Science fiction is like all art — it is a medium for telling stories about our humanity. Visions of the future are just stories about us.”  It was a brilliant and thoughtful answer, and I’ve always remembered it.

Now, many years later, I practice science.  I still watch a lot of Star Trek, and I absorb a lot of science fiction, and every time I reach the end of a novel or movie, I know Bill was right — the best stories are the ones that use the future as a backdrop to tell human stories.

lear

Larry Yando as the titular character in the Chicago Shakespeare Theatre’s 2014 production of King Lear.

That’s a very interesting thought when I drape it across the tapestry of art, literature, and theatre. All forms of art are explorations of what it means to be human, attempts to understand on a very deep level who we are. Just this past weekend, sitting in the darkened theatre of the Chicago Shakespeare Theatre, I was bludgeoned by that simple fact once again watching King Lear. Though the story is set long ago, and though the language is not all together our own, we sat there enraptured. The tale is full of intrigue and betrayal, but at the core is the King. Watching the play reflected the dark pools of shadowed eyes, you could see an audience tearfully and painfully aware that the tragedy unfolding from the King’s descent into madness was an all too relevant tale for those of us who have suffered the loss of elderly friends and relatives to the ravages of age.  Our humanity was laid out, naked and bare on the stage, in a tale written more than 400 years ago. The core message is as relevant and pertinent today as it was when the Bard penned it those long centuries ago.

The exploration of the nature of the human spirit has long been the purview of all forms of art, especially performance. The whole point in acting out stories is to tell stories about people.  Even when the characters aren’t people, they still talk and act like people, anthropomorphized by their actions, their thoughts, and their words in the tapestry of story on the stage or screen.  And so I suppose it should not have surprised me that Shatner did not think of tales from the far future any differently — the stories are still stories about us. They still are stories about our triumphs, our tragedies, our frailties, and our fallacies.

But that younger version of myself carried a particular conceit — I wasn’t clear about it then, but I still harbor it today: I fundamentally believe that art and science have exactly the same purpose — to discover the stories of who we are, and what our place in the Cosmos is. The truth of this is hidden in every science book and every textbook you have ever picked up and thumbed through.  How?  Very seldom is science explained without the context, the wrapper, of the human story around it.

Newton witnessed the falling of an apple when visiting his mother's farm, inspiring him to think about gravity. It almost certain is apocryphal that it hit him on the head! But art gives the story a certain reality!

Newton witnessed the falling of an apple when visiting his mother’s farm, inspiring him to think about gravity. It is almost certainly apocryphal that it hit him on the head! But art gives the story a certain reality!

When we are first taught about the Universal Law of Gravitation, very seldom are you simply told the equation that relates mass and distance to gravitational force. Instead, we cast our minds back to a late summer day in the 17th Century. On a warm evening after dinner, Isaac Newton was sitting in his mother’s garden, on her farm in Lincolnshire and was witness to an ordinary event: an apple falling to the ground. A simple, ordinary event, part of a tree’s ever-repeating cycle of reproduction. But witnessing the event sparked a thought in Newton’s mind that ultimately blossomed into the first modern Law of Nature. The tale inspires a deep sense of awe in us. How many everyday events have we witnessed, but never taken the time to heed? How many secrets of Nature have passed us by, because we never connected the dots the Cosmos so patiently lays out before us?

Marie Curie in her laboratory.

Marie Curie in her laboratory.

When we first learn about the discovery of radioactivity, very seldom are we only told the mass of polonium and the half-life of uranium.  Instead, we relive the discovery of radioactive decay alongside Marie Curie, who unaware of the dangers of radiation, handled samples with her bare hands and carried test tubes full of the stuff around in her pockets. We know that she developed the first mobile x-ray units, used in World War I, a brilliant realization of mobile medical technology at the dawn of our modern age. But we also know that Curie perished from aplastic anemia, brought on by radiation exposure. Today, her notebooks and her belongings are still radioactive and unsafe to be around for long periods of time. Curie’s death is a tragic tale of how the road to discovery is fraught with unknown dangers. While we mourn her loss we celebrate also the wonder that our species has such brilliant minds as Marie Skłodowska-Curie, the only person ever to win TWO Nobel Prizes in different sciences (Chemistry and Physics)

Alexander Fleming in his lab.

Alexander Fleming in his lab.

When we learn about antibiotics, seldom do we begin in the lab with petri dishes full of agar. Instead, we are taught the value of serendipity through the tale of Alexander Fleming. In late September of 1928 he returned to the laboratory to find that he had accidentally left a bacterial culture plate uncovered and it had developed a mold growth. You can imagine a visceral emotional reaction — anger! Another days-long experiment ruined! By sheer carelessness! It happens to all of us every day when we burn a carefully prepared dinner, or break a favorite coffee mug, or accidentally drop a smartphone down an elevator shaft. But through the haze of aggravation, Fleming noticed something subtle and peculiar — there were no bacterial growths in the small halo around the mold. The mold, known as Penicillium rubens, could stop a bacteria in its tracks. That single moment of clarity launched the development of antibiotics, so crucial in modern medical care. What world would we inhabit today, if Fleming had thrown that petri dish away in disgust, without a second glance? Surely a tragedy of world-girdling proportions.

All of these stories illustrate a subtle but singular truth about our species: we are different from all the other lifeforms on our planet.  Not in sciencey ways — we have the same biochemical machinery as sunflowers, opossums and earthworms — but in less tangible abstract ways.  What separates us from all the other plants and animals is the way we respond to the neurological signals from our brains. Our brains are wired to do two interesting things: they imagine and they create. The truth is we don’t fully understand how our brains do these things, or why there is an apparent biological imperative to do either. But the result of those combined traits is an insatiable curiosity to know and understand ourselves and the world around us, and an uncontrollable urge to express what we discover.

Sometimes those expressions burst out of us in moments of creation that lead to lightbulbs, intermittent windshield wipers, kidney dialysis machines, and iPads. Sometimes those same expressions burst out of us in moments of creation that lead to Jean van Eyck’s Arnolfini Portrait, or Auguste Rodin’s The Kiss, or Steve Martin’s “Picasso at the Lapine Agile,” or Ridley Scott’s desolate future in “Blade Runner.”

(Top L) Jean van Eyck's Arnolfini Portrait; (Top R) Rodin's The Kiss; (Bottom) The urban dystopia of the future in Ridley Scott's Blade Runner.

(Top L) Jean van Eyck’s Arnolfini Portrait; (Top R) Rodin’s The Kiss; (Bottom) The urban dystopia of the future in Ridley Scott’s Blade Runner.

Art is like science. Imagination expressed through long hours of practice, many instances of trial and error, and moments of elation that punctuate the long drudgery of trying to create something new.  Science is like art. Trying to understand the world by constantly bringing some new creative approach to the lab bench in an attempt to do something no one else has ever done before.

Both science and art are acts of creation with one express goal: to tell our stories. Both require deep reservoirs of creativity. Both require vast amounts of imagination. Both require great risks to be taken. But in the end, the scientist/artist creates something new that changes who we are and how we fit into the world. And wrapped all around them are all-together human tales of the struggles encountered along the road to discovery.

It is not entirely the way we are taught to think about scientists and artists. Isaac Asimov famously noted this in his 1983 book Roving Mind: “How often people speak of art and science as though they were two entirely different things, with no interconnection. An artist is emotional, they think, and uses only his intuition; he sees all at once and has no need of reason. A scientist is cold, they think, and uses only his reason; he argues carefully step by step, and needs no imagination. That is all wrong. The true artist is quite rational as well as imaginative and knows what he is doing; if he does not, his art suffers. The true scientist is quite imaginative as well as rational, and sometimes leaps to solutions where reason can follow only slowly; if he does not, his science suffers.” An interesting thought to ruminate on the next time you are preparing DNA samples or soldering stained glass mosaics.

I have to go now. The crew of the Enterprise have some moments of humanity to show me. See you in an hour.

Equality in the Market of Ideas

by Shane L. Larson

Science is a beautiful and inspiring endeavour that has many facets. It satiates a deep and abiding curiosity about the world around us. It expands the boundaries of knowledge. It resolves powerful mysteries about the machinery of the Cosmos. It provides solutions to daunting problems, both abstract and concrete. It teaches us about cause and effect, about predicting the future from the past and the now. It inspires us to think deeply about our place in the Cosmos, and our role in the future of our small planet.

All of these things that science can do are uplifting, and in the end serve to condition our brains to accept the most important feature of science: that science can help us improve the human condition. Medical imaging allows us to diagnose and prepare treatments for conditions that killed our ancestors. Modern vaccines have almost wiped out diseases like smallpox and polio. Clean drinking water is available to millions of people around the planet. Disaster relief supplies can be flown around the world in less than a day, to any locale on the planet. Massive dikes and levee systems can protect cities from seasonal flooding, and bank water for future agricultural use. There are millions of examples of how science touches our lives, every single day.

Science directed at the human condition. (Top L) Non-invasive medical imaging. (Top C) Iron lungs keeping victims alive during a 1952 polio outbreak. (Top R) Clean water supplies. (Lower L) Dikes and levees to manage water. (Lower R) Transportation technology connects the world, especially in times of need.

Science directed at the human condition. (Top L) Non-invasive medical imaging. (Top C) Iron lungs keeping victims alive during a 1952 polio outbreak. (Top R) Clean water supplies. (Lower L) Dikes and levees to manage water. (Lower R) Transportation technology connects the world, especially in times of need.

Perhaps one of the most recognized ways that science has improved our lives is through the connectivity of the modern world. We live in an age where the world is inter-connected in exquisite and instantaneous ways. Technology has democratized the collection and distribution of information. The internet, the great marvel of the modern age, changed information from a commodity into a pervasive entity that many of us take for granted, in the same way we take electricity and air for granted. Digital communications technology allows us to be instantly in contact with colleagues, family and friends on opposite ends of the planet, and it puts every bit of human knowledge instantly at the fingertips of everyone who has a link to the pulsing network of information exchange that now girdles the Earth.

But the global information network has an unappreciated shadowy side, namely that everyone can post/blog/tweet anytime they want, and can post/blog/tweet anything they want. Gone are the days when produced newspaper and television and radio were the only sources of information. Not everything you see now has been carefully thought out, researched, or vetted. Much of the information we receive today is spat out in the moment, as events are happening, and colored by whatever emotionally charged state we find ourselves in at the moment we post/blog/tweet.  Additionally, information gets compressed into easily digestible soundbites (something that is not always easy to do with difficult concepts!).

The currency of the day is not expertise in a particular area of human knowledge. No, that idea would preclude the central tenet of the information age: the web is an egalitarian medium, where every voice has an equal chance to garner attention. The currency of the day is influence — the number of followers you have, who listen to what you have to say and repeat it to those who listen to them.  And therein lies the hidden seed sown with the idea of equal access to information. In this web of the information age, any opinion is and can be expressed.

This simple fact has one enormous consequence on the world: ideas from the fringe (sometimes dangerous ideas, if dangerous ideas do exist) gain traction in our society.

If you have a lot of social influence in the electronic sphere of information that cradles our society, then it is easy for you to promote ideas that support your agendas and ideals. The global network allows you to connect with like-minded people in a way that was never possible before, and those connections will help amplify your agenda. Soon, your ideas have been repeated so often and seen by so many people, that it gains status as a “fact.”

There is no stronger lobby in this respect than the growing anti-science movement. Science created the web, and as it turns out, is falling victim to it as well. Every day, the long slow gains our species has made against the darkness, the triumphs that have been excruciatingly won from Nature, are roundly challenged in the wild frontiers of the information age. Climate change denialism; anti-vaccination propaganda; moon-landing hoaxers. It is at best, misunderstood ideological differences that could easily be resolved over beers and pizza. It is at worst, willful ignorance being promoted to prop up other ideological, economic, and social agendas. But it is enabled — powered — by the notion that every idea has equal validity and deserves equal voice in the electronic medium of our time.

IsaacAsimov[1]This willful promotion of ignorance is nothing new. It has always been a weapon used by those with their own agendas to sow discord among the masses. Isaac Asimov famously noted this in a 1980 essay for Newsweek (21 Jan 1980), that is an almost eerily prescient assessment of the world today. He wrote, “There is a cult of ignorance in the United States, and there has always been. The strain of anti-intellectualism has been a constant thread winding its way through our political and cultural life, nurtured by the false notion that democracy means that ‘my ignorance is just as good as your knowledge.’ 

At the heart of Asimov’s point is the meaning of the all important commodity of science: knowledge. As scientists, we must accept any ideas as valid points for consideration — science is founded on the equality of ideas. All points of view are deserving of investigation and consideration. However with that open and egalitarian philosophy about ideas comes the hammer of science: scrutiny. There are no aspects of an idea that are off-limits for investigation; no implications are left unconsidered, no question is left unasked, there are no weak spots in ideas that are left unpoked and unprodded. The analysis of all ideas in science is ruthless and unforgiving — as much as possible, it is dispassionate and detached. Sometimes the outcome of our investigations are uncomfortable, but as scientists we must accept that fact courageously and move forward, no matter what the implications might be. In this sense, not all ideas are created equal. Notions about the world that fail to explain or predict what we see going on around us must be abandoned and discarded.

Knowledge is nothing more than our current best understanding of the world, based on everything we see around us. Science is the tool we continually use to cast self-doubt on our knowledge, to ask “Is this right? Are we still sure it is right? Have I seen anything that convinces me this is wrong?”  If we see something new, that conflicts with what we previously believed, then we update our beliefs — we update our knowledge.  Science is not politics — flip-flopping is a required part of the game.

This idea makes people uncomfortable and nervous. If knowledge can evolve, how can we believe anything? The problem with this perception is that most of us have been raised to put knowledge on the highest pedestal of importance. In reality, however, there are two pillars in science: knowledge and data. And they are NOT on equal footing.

Data is what we see around us, observations of the world. Data is immutable; it can be added to, but never changed. By and large, there are not huge shifts in scientific thinking because for the most part we’ve been observing the world for 40,000 generations, and Nature seems pretty well behaved. Gravity on the Earth doesn’t suddenly start pulling upward instead of downward. Cups of coffee don’t sit on your kitchen counter and start spontaneously heating up. Squirrels don’t suddenly develop fangs capable of delivering venom more deadly than a cobra’s. The preponderance of millennia of observations assure us none of these crazy things will happen. But if they did, we would have to explain them!

Knowledge is how we explain the world.  “Knowledge” is malleable, constantly evolving to reflect new data. It seldom changes dramatically, because of the preponderance of data that exists. Any knew observation of the world has little, if any chance, of invalidating the millions and millions of things we’ve seen before. If we see something new — a new particle in Nature, a new kind of cloud, or evidence of water on Mars — we update our knowledge in such a way as fully explain everything that we knew before, but explain the new data as well.

signEqualityYou and I do this every day.  For instance, consider color. You think you know what you mean when you say “green” and when you say “yellow.” So what color is this sign? If you had never seen this sign before, you probably wouldn’t have a name for it. Now go show it to several of your friends, and ask them what color it is — you’ll probably get several different answers. In the end, you have to update your “knowledge” (your list of colors) to accommodate your observations of the world (whacky colored signs). The data (a new colored sign) was more important than your previous knowledge (a limited number of colors).

There are many examples of this kind of “updating” of knowledge that have occurred in the course of history. The transition from Newtonian gravity to general relativity, which is now used in every GPS device on Earth. The mathematical development of quantum mechanics and its subsequent experimental validation, ultimately leading to the development of diodes and transistors in the computer you are reading this blog post on. The discovery of Mendelian inheritance in genetics, and its use in the cross-breeding of agricultural crops to develop foodstocks that are high-yield and resistant to disease and drought. Knowledge evolves, and the consequence of that evolution is the improvement of the human condition.

In the end, the epic battle of our age is a struggle to explain and communicate ideas as subtle and conflated as “data” and “knowledge” because they are central to the scientific underpinning of our modern world. They are notions that every scientist has to be comfortable with. But in the parliament of the the global information network, not everyone has the same background and training and vocabulary as your garden variety scientist — it makes communication difficult at best, and it makes understanding even harder. But the effort must be made, lest we condemn our society and planet to an uncertain, if not bleak, future. The efforts must be ongoing, relentless, understanding, and compassionate. Beliefs about the world are dearly held, and difficult to let go of. It is easy to ignore or dismiss ideas that are difficult to understand. It is uncomfortable to feel confused, it is disconcerting to not know who to trust or what to believe.

sagan01Carl Sagan, ever a great humanist, commented on those arrayed against science in his 1995 book, The Demon Haunted World, writing, “In the way that skepticism is sometimes applied to issues of public concern, there is a tendency to belittle, to condescend, to ignore the fact that, deluded or not, supporters of superstition and pseudoscience are human beings with real feelings, who, like the skeptics, are trying to figure out how the world works and what our role in it might be. Their motives are in many cases consonant with science. If their culture has not given them all the tools they need to pursue this great quest, let us temper our criticism with kindness. None of us comes fully equipped.”

None of us comes fully equipped.

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This post was written as part of Blog Action Day 2014, whose theme this year was #inequality. #bad2014

Science Folk Tales

by Shane L. Larson

The Cosmos is a stunning and beautiful place that inspires unabashed awe in many of us. The story of understanding the Cosmos and what makes it tick is what science is all about. But there is an extra dimension to these tales of discovery, and that dimension is the personal stories of the scientists who have wrested utterly amazing secrets from Nature.

Every discovery ever made has a human story at its core. (L to R) Galileo, Henrietta Swan Leavitt, Louis Slotin, and Emmy Noether.

Every discovery ever made has a human story at its core. (L to R) Galileo, Henrietta Swan Leavitt, Louis Slotin, and Emmy Noether.

The human stories wrapped around science stories touch each one of us on a deep level because we can identify with the uniquely human response to difficulties, to friendships and collaborations, to confusion, to success and elation, and sometimes to tragedy. Can you imagine Galileo’s astonishment when he saw craters on the Moon through his little telescope, something no one had ever seen before? Can you feel the elation Henrietta Swan Leavitt must have felt when she discovered she could measure the distance to the stars? We can sympathize with the colleagues of physicists Henry Daghlian and Louis Slotin, both of whom died from radiation exposure in accidents at Los Alamos during the Manhattan Project. We are horrified by the unexpected death of Emmy Noether, one of the greatest mathematical physicists of the early 20th Century, who died suddenly from complications after an operation.

The stories of the scientists at the heart of discovery remind us that science is an all together human endeavour; we are the only species, so far as we know, to systematically explore and understand the Cosmos. We are one of the few species that use an understanding of the Cosmos to improve our lives. Mixed in with the biographies and well documented histories of science, there is also a bit of folklore — funny tales and anecdotes that capture the endeavour in small vignettes. I think sometimes we tell these bits of folklore, whether they are true or not, because they often capture some of the ephemeral emotions that we all feel when faced with the Big Questions in the Cosmos. One of my favorite examples of this kind of folklore has to do with the realm of the atoms, quantum mechanics, and Albert Einstein.

The emission spectrum of hydrogen has a few bright lines, as well as many faint lines.

The emission spectrum of hydrogen has a few bright lines, as well as many faint lines.

In the early part of the 20th Century, physicists were trying to understand the discrete colors of light emitted and absorbed by hydrogen atoms. All atoms have a unique and discrete spectrum of light they emit — a spectral fingerprint that identifies precisely what kinds of atoms you are working with. Hydrogen, being the simplest of atoms, was the focus of everyone’s attention, in the hopes it would be the easiest to understand. There was an empirical formula for the hydrogen spectrum — a simple formula that was worked out from observations — but no one knew why the formula worked. It just did!

bohr

The first clue as to what was going on came from Danish physicist, Neils Bohr, who proposed something we now call “the Bohr Model of the Atom” in 1913; it is just the classic picture of an atom that we are all taught in grade school.  Bohr’s colleague, Ernst Rutherford had shown in 1911 that the atom was comprised of two parts — a small, hard center called “the nucleus” and an outer cloud where the electrons resided.  Bohr discovered that if the electrons are required to reside on orbits — circles of specific size — he could predict exactly the spectrum of colors emitted by hydrogen. The Bohr Model was one of the early discoveries that helped drive the emerging branch of physics called “quantum mechanics,” which was concerned primarily with how the world behaves on the smallest scales imaginable.

The classic "Bohr-Rutherford atom" with a small central nucleus being orbited by electrons on fixed orbits.

The classic “Bohr-Rutherford atom” with a small central nucleus being orbited by electrons on fixed orbits.

One of the interesting features of the Bohr-Rutherford atom is that it is mostly empty space. The nucleus is only about a femto-meter across.  That’s one-billionth-millionth of a meter, 0.000 000 000 000 001 meters. By contrast, the electron cloud is about a million times larger, about a tenth of a nano-meter across. That’s only 0.000 000 000 1 meters. That means the atom is mostly empty space. Now think about that for a minute. That sounds crazy, because if atoms are mostly empty space, then you are mostly empty space, and so is everything else!

That notion certainly doesn’t jive with your everyday experiences. When you fall off your mountain bike, you most certainly collide with the ground and stop! If you and the ground were both mostly empty space, shouldn’t you just pass right through each other? It would be a lot less painful! It turns out that electrons dislike being around one another — they are “electrically repulsive.” The reason you and the ground bounce off of one another is because the electrons in the ground repulse the electrons in you. But if the electrons are on little orbits, wouldn’t they still usually miss each other? As it turns out, the little orbits picture isn’t the right picture to carry around in your head; the sub-atomic world is much stranger than that.

The Bohr-Rutherford model of the atom was one of the central starting points in the development of quantum mechanics, the branch of study concerned with understanding the interactions and dynamics of particles on the scales of atoms. Over the course of two decades following Bohr’s model, all the major tenets of quantum mechanics were discovered. The cacophony of quantum effects that were amassed and tested in this time were triumphant revelations about the world of small things, but they all smacked of absurdity because they almost always clash with the direct sensory reality of what goes on in the macroscopic world.

The shape and direction of electron orbitals found in atoms.

The shape and direction of electron orbitals found in atoms.

One of those discoveries was that the position of tiny particles, like the electron, were not so easy to nail down. In fact, the electron was known to inhabit areas around the nucleus of an atom that we now call “orbitals” — extended regions of space where we are “most likely to find the electron” if we go looking for it.  The reality of “position” was suddenly replaced by the idea of probability and statistics. There was no definitive answer anymore to the question of “where is the electron?”  A new mathematical entity was discovered to describe this idea, called a “wavefunction.”

So what’s going on? We said Bohr’s model completely and accurately described the spectrum of hydrogen by imagining the electron was a little ball going around a fixed orbit. How can that be right, AND this electron probability cloud be right? Insights into the physical world often capture precisely the correct physics, but the picture we carry around in our head or the words we use to describe what has been captured in the mathematics are incomplete. This is the case of the Bohr atom. Bohr’s mathematics was correct, and explained the behaviour of the hydrogen atom, but the picture of an electron going around on a little orbit was not the correct picture, because it didn’t capture one important aspect of the physics, namely why only certain orbits were allowed. The reason was a discovery of one of Bohr’s contemporaries, and points the way to wave mechanics.

Louis_de_Broglie10Louis Victor deBroglie proposed in his 1924 PhD thesis that all matter behaves like waves, including electrons. This idea is known as “wave-particle duality.” The idea was so radical, his graduate committee didn’t know what to make of it. They passed the work on to Einstein, who supported it whole-heartedly, and deBroglie was awarded his PhD. Five years later, deBroglie was awarded the Nobel Prize in Physics for his discovery. How did this connect the Bohr atom to wave mechanics? deBroglie suggested that if the electron were a wave, the only Bohr orbits that were allowed were those which perfectly fit an electron wave around it. Thus the electron was not a particle located somewhere around the orbit, rather it was the entire wave that covered the entire orbit.

How deBroglie explained Bohr's restriction of orbits. (L) If an electron wave does not fit on an orbit perfectly, the orbit is now allowed. (R) The only orbits are the ones where the wave fits perfectly.

How deBroglie explained Bohr’s restriction of orbits. (L) If an electron wave does not fit on an orbit perfectly, the orbit is not allowed. (R) The only orbits are the ones where the wave fits perfectly.

The reality of the wavefunction idea was born out in experiments time and time again, forcing physicists to accept that the microscopic world was truly different than the world of Big Things like ping pong balls, Yugos, hedgehogs and popsicles. But there are certain implications of accepting the wavefunction idea that are even weirder than not knowing where the electron is. One of those things is quantum tunneling.

Imagine I have a pet electron, trapped in an aquarium. Where is the electron?

Imagine I have a pet electron, trapped in an aquarium. Where is the electron?

Imagine I caught an electron and am keeping it as a pet in an aquarium in my living room. According to quantum mechanics, if I go looking for my electron, I am most likely to find it in the aquarium. But the wavefunction extends oustside the aquarium, and that means there is a teeny-tiny probability that the electron will be found OUTSIDE the aquarium. If I do find it there (sneaky little quantum jailbreaker), we say that the electron “tunneled” through the barrier of the aquarium wall.

This really happens. If it didn’t, you wouldn’t be reading this blog post, because modern microchips work on the premise that electrons can tunnel their way through barriers; this is one of the operational principles behind transistors and diodes, which make up a significant fraction of the guts of your computer.

I don't know if Einstein had giant clown shoes, but he was well known to own and use some fuzzy slippers.

I don’t know if Einstein had giant clown shoes, but he was well known to own and use some fuzzy slippers.

And this brings me back to our starting point: folklore. There is a story that Einstein was so uncomfortable with this idea of tunneling, that he took to wearing gigantic shoes around his house (I imagine them to be kind of like giant clown shoes), in order to inhibit his feet from tunneling through the floor while he was walking around! Now, this story about Einstein is almost certainly false; Einstein was perfectly aware of the fact that quantum effects are not important on the scales of the macroscopic, and he was certainly capable of computing the probability of his feet tunneling through his floor!

But we tell this tale tale anyhow, not because it is funny, but because quantum mechanics IS disconcerting! Quantum tunneling makes NO SENSE, especially if you are used to thinking about hacky-sacks, pomegranates, and freight trains. We use this story to tell ourselves that Einstein was uncomfortable with this idea, thus reassuring us that it is okay for us to be uncomfortable too.

And it is okay to be uncomfortable. Discomfiture over cherished ideas being challenged and overturned is the bread and butter of science. This is how our knowledge grows, and how our understanding of the Cosmos evolves to be more complete. We abandon old beliefs, no matter how cherished, if we find them to be unworkable in the face of new data and new knowledge.

A Pale Blue Glow

by Shane L. Larson

One of the great things about being a scientist is I’m exposed to amazing and awesome things. Every. Single. Day. Sometimes I am astonished by Nature itself, and other days I am amazed by our ingenuity and abilities as we come of age in the Cosmos. Today was one of those days.

The first picture of the Moon and Earth together in space, taken by Voyager 1.

The first picture of the Moon and Earth together in space, taken by Voyager 1.

This story has its origins long ago. On 5 September 1977 we hucked a 722 kg spacecraft into the sky, named Voyager 1. That was the last time any of us ever saw Voyager 1 with our own eyes. But Voyager has been on a 37-year journey to act as our eyes in the Solar System. On 18 September 1977, barely 13 days after launch, when it was 7.25 million miles from Earth, Voyager sent home the first picture ever of the Earth and Moon together in space. It went on to Jupiter, where it took pictures of clouds and storms that look for all the world like the finest paintings on Earth, and discovered the first active volcanoes beyond the Earth on the enigmatic moon Io. At Saturn, it returned the first high-resolution images of an exquisite ring system, and showed us a shattered Death Star like Moon known as Mimas, dominated by an enormous crater named Herschel. But for all the wondrous pictures, we never saw Voyager. Like your Mom taking pictures of your childhood, we have never once seen the photographer chronicling our growth.

Just a sample of the kinds of discoveries made by Voyager 1. (TopL) Exquisite cloud structure on Jupiter. (TopR) Active volcanism on Jupiter's moon, Io. (BottomL) Tremendous structure in Saturn's rings. (BottomR) Saturn's moon, Mimas.

Just a sample of the kinds of discoveries made by Voyager 1. (TopL) Exquisite cloud structure on Jupiter. (TopR) Active volcanism on Jupiter’s moon, Io. (BottomL) Tremendous structure in Saturn’s rings. (BottomR) Saturn’s moon, Mimas.

But today, I saw something that made me smile. Since it began its long outbound journey, we’ve been talking with Voyager 1 on a radio. In all, it only transmits about 20 watts of power, something typical of a larger compact-fluorescent-lightbulb. The total power received on Earth from Voyager is about a ten-billionth of a millionth of a watt. In one second, we receive less than a trillionth the energy a single snowflake delivers to your shoulder as you’re walking to work.

VLBI image of Voyager 1, diligently beaming its signal back to Earth.

VLBI image of Voyager 1, diligently beaming its signal back to Earth.

But take a look at the picture above, released by NASA last fall. See that pale blue dot right there? That is Voyager 1, seen through the eyes of the Very Long Baseline Interferometer, an array of linked radio telescopes that stretches from one side of the Earth to the other. It sees the sky in radio light. Normally it looks at quasars and distant nebulae, but this image is of Voyager 1, shining its radio back at Earth. This is the first radio signal of human origin ever to be received from outside the solar system. It is also the first picture of Voyager 1 taken since its launch. It’s a bit like seeing your friend in the dark, waving their cellphone at you from a distant mountaintop.  But it’s there, and we can see it — the pale radio beacon of Voyager 1, drifting alone in the immense dark between the stars.

Long after it runs out of power, Voyager 1 will continue to drift alone through the galaxy.

Long after it runs out of power, Voyager 1 will continue to drift alone through the galaxy.

What will happen to Voyager 1? It will continue to talk to us for a little while longer. It is powered by a small nuclear power plant, gleaning energy from the decay of plutonium. But that energy supply is dwindling, and sometime around the mid 2020’s, just more than a decade from now, Voyager 1 will fall silent. The pale blue glow will disappear forever; there will be no more pictures of our loyal emissary. Voyager 1 will continue onward however, bound for the depths of the galaxy, a dead hulk built by a race of curious lifeforms that call themselves “humans.”

But now this has me thinking. All of our knowledge of the outer solar system has been gleaned with telescopes, and with robotic emissaries.  None of the sights you have seen in pictures has ever been witnessed directly by human eyes. Not the dual-tone colors of Saturn’s enigmatic moon Iapetus; not the spider-web of canyons in Mercury’s Caloris Basin; not the misty depths of the Valles Marineris on Mars. Instead, Casinni has been twirling through the Saturn system for almost a decade, and has returned the highest resolution images of Iapetus we’ve ever seen.  Mercury MESSENGER, only the second spacecraft ever to visit Mercury, finally arrived in 2011 and sent high resolution images of the Spider Crater back to Earth. And Mars? Well, Mars has its own fleet of orbiting satellites and ranging rovers to investigate its mysteries.

(L) Saturn's moon Iapetus has a light and a dark side. (C) The Spider Crater on the floor of Mercury's Caloris Basin. (R) Fog in the Valles Marineris on Mars.

(L) Saturn’s moon Iapetus has a light and a dark side. (C) The Spider Crater on the floor of Mercury’s Caloris Basin. (R) Fog in the Valles Marineris on Mars.

What happens to all our tiny robots, sent out into the Cosmos all on their own? We’ve been tossing them into space almost non-stop since the start of the Space Age — what happens to all of them?

Only 5 will ever travel beyond the solar system. Pioneers 10 and 11 are both bound for interstellar space, now quiet and dead after their power supplies failed in 2003 and 1995. Voyager 1 and 2, having completed their Grand Tour of the outer solar system, are also outbound; we expect to lose contact with them within the next 10 to 20 years. And lastly, there is New Horizons, bound for Pluto and the Kuiper Belt beyond. It is by far the youngest of this august group of explorers. It was designed to have power for 20-25 years, but it has already spent the last eight-and-a-half years just getting to Pluto — it should last another 15 years or so.

Spacecraft that are going to escape from the solar system. (L) Pioneer (C) Voyager (R) New Horizons

Spacecraft that are going to escape from the solar system. (L) Pioneer (C) Voyager (R) New Horizons

(T) When Spirit got stuck on Mars, NASA engineers recreated the situation on Earth, trying to figure out how to free the rover. (C) Artist's imaging of what Galileo looked like as it burned up in the Jovian atmosphere. (B) The LCROSS mission before impact.

(T) When Spirit got stuck on Mars, NASA engineers recreated the situation on Earth, trying to figure out how to free the rover. (C) Artist’s imaging of what Galileo looked like as it burned up in the Jovian atmosphere. (B) The LCROSS mission before impact.

Many of our robots, like the Voyagers and Pioneers, will just die. This famously happened to the Spirit rover on Mars. It trundled around the Martian surface for 2269 days (perhaps, some say, trying to earn a trip back home) before we lost contact with it. Spirit had become stuck in a Martian sand dune and was unable to free itself. Stuck on flat ground, unable to tilt itself toward the Sun to keep warm in the cold Martian winter, we last spoke with Spirit on 22 March 2010.

The Galileo mission, which spent more than seven-and-a-half years exploring the Jovian system, was crashed into Jupiter, to prevent it from tumbling out of control when its power failed, possibly contaminating a moon like Europa, where we can imagine extraterrestrial life may exist. On 21 September 2003, it was plowed into Jupiter. We couldn’t see it take the final plunge, but we listened to it faithfully radioing us everything it could for the last few hours before its end.

Sometimes, we crash our spacecraft on purpose, for science! One of the most spectacular examples of the was LCROSS, the Lunar Crater Observation and Sensing Satellite. The goal of this mission was to look for water ice in the perpetually shadowed craters on the surface of the Moon; water on the Moon would have important implications for the sustainability of lunar colonies. LCROSS had two pieces — it’s Centaur rocket stage, and the Shepherding Spacecraft that carried the science instruments. On 9 Oct 2009, the Centaur rocket impacted the Moon at a speed of about 9000 kilometers per hour; the Shepherding Spacecraft flew through the cloud of debris and radioed the composition back to Earth. This exquisitely timed dance was a planned suicidal flight for the Shepherding Spacecraft; its unavoidable fate was to impact on the Moon about 6 minutes after the Centaur stage. The result? There is water, frozen in the lunar soil.

But the saddest fate to me, is that of Mercury MESSENGER. MESSENGER was the first spacecraft to visit Mercury since Mariner 10 flew by three times in 1974. Despite three passes, Mariner 10 only mapped out about 45% of the surface; until MESSENGER’s arrival in 2011, we had no idea what more than half of Mercury looked like.  It took MESSENGER 7 years to get to Mercury. It has been there for about three-and-a-half years at this point, and we are looking ahead to the end. Over time, the closest point of MESSENGER’s orbit has been getting lower and lower, affording us the opportunity to understand Mercury’s gravitational field and to map and  probe the surface of Mercury with exquisite resolution. But lowering the orbit, to get a closer view of the planet, is a one way ticket, eventually leading to MESSENGER’s impact on the surface of Mercury.

Mercury MESSENGER

Mercury MESSENGER

The end will come sometime in March of 2015, on the far side of Mercury from our view.  MESSENGER will die alone, cut-off from us by distance and astronomical happenstance. In the words of MESSENGER PI, Sean Solomon, “This will happen in darkness, out of view of the Earth. A lonely spacecraft will meet its fate.”

This emotional attachment and personification of machines seems disingenuine to some people; spacecraft aren’t people, they are collections of wires and circuits and nuts and bolts — they don’t have souls to become attached to.  I dunno. I think they do have souls. They are the embodiment of every one who ever imagined them, worked on them, or stared at the data and pictures they returned. These little robots, in a way, are us. They are our dreams. Dreams of adventure, of knowledge, of a better tomorrow, of understanding who and what we are in a Cosmos that is vast and daunting.

And so today I smiled at the pale blue picture of our long departed friend, Voyager 1. And on the day it falls silent, I’ll shed a tear and drink a drink to its remarkable voyage, a voyage it made for you and me.

A Thin Rain of Black Holes

by Shane L. Larson

As a scientist, I am used to being humbled by Nature. Consider how difficult it is for us to replicate physical situations that the Universe creates and maintains almost effortlessly. For instance, in the central African nation of Gabon, in the hills near the eastern border, there are vast deposits of Uranium ore in an area known as Oklo. Analysis of the Oklo ore has shown that it has been processed via nuclear fission roughly 2 billion years ago. All on it’s own, Nature created and ran a nuclear reactor.

The Oklo natural reactors are found in exposed ore deposits in central Africa. Note the person for scale!

The Oklo natural reactors are found in exposed ore deposits in central Africa. Note the person for scale!

Human beings didn’t even know of the existence of nuclear fission until 1938 when Otto Hahn and Fritz Strassman first detected it in the laboratory; it wasn’t understood until the following year when Lise Meitner explained what was going on! It would take a further 4 years and a huge team of scientists and engineers, supervised by Enrico Fermi, to create the first nuclear fission reactor under the football field at the University of Chicago. On 2 December 1942, “Chicago-Pile 1” became active, finally replicating what the Universe had figured out 2 billion years before.

(L) Strassman, Meitner and Hahn in 1956, at the dedication of the Max Planck Institute. (R) The Hahn-Meitner-Strassman experimental setup that first detected nuclear fission. Note it fits on a tabletop!

(L) Strassman, Meitner and Hahn in 1956, at the dedication of the Max Planck Institute. (R) The Hahn-Meitner-Strassman experimental setup that first detected nuclear fission. Note it fits on a tabletop!

Today, our experimental efforts in science have continued to grow, continued to allow us to peer into Nature’s great mysteries. One of the most prominent efforts is the construction of the Large Hadron Collider (LHC) outside of Geneva, on the border of France and Switzerland.  All told, more than 10,000 scientists and engineers from 100 countries contributed to the design, construction, and operation of the LHC.  It is the most powerful particle-collider in the world, smashing together hadrons (particles that are made up of quarks, bound together by the strong force).

An aerial view of the area around Geneva, with the location of the LHC indicated; the tunnel is 27 kilometers in circumference. Center left is Lake Geneva, the background are the Swiss Alps.

An aerial view of the area around Geneva, with the location of the LHC indicated; the tunnel is 27 kilometers in circumference. Center left is Lake Geneva, the background are the Swiss Alps.

The LHC is an enormous machine. The ring is 27 kilometers in circumference, and the major experiments that watch the collisions of sub-atomic particles are bigger than buildings — gigantic, complex machines designed to watch what Nature does on the tiniest scales, which we have only begun to understand over the past 100 years.

The ATLAS experiment, along the beamline of the LHC. It is difficult to comprehend exactly how huge these experiments are, but note the person in front of the experiment, lower center!

The ATLAS experiment, along the beamline of the LHC. It is difficult to comprehend exactly how huge these experiments are, but note the person in front of the experiment, lower center!

The collision energies in the LHC are so high that the protons we smash together break apart into their constituent bits: quarks, gluons, and a lot of energy. At its highest energies — as physicists say, “14 TeV” or “14 Tera-electron-Volts” — the protons we are smashing together will only be travelling about 2.7 meters per second slower than light. What does that mean? Imagine a race to the Moon, between a laser beam and a proton ejected from the LHC. The laser beam would reach the Moon in 1.282 217 0463 seconds, but the protons would only be 11.3 meters behind, arriving at 1.282 217 0578 seconds after the race started. They are moving incredibly fast, which is why they blast themselves to smithereens when they collide.

The post collision mess is a hot writhing, seething mass of energy and fundamental particles that we think is very similar to the conditions just after the Big Bang. At some point in our planning for the LHC, and as we were imagining this hot burst of quark-gluon plasma, someone asked a very interesting question.  Aren’t the collisions strong enough that all of the energy could concentrate mass and energy down to a microscopic point, creating a microscopic black hole? After all, that’s what we expect to happen after the Big Bang — we call them “primordial black holes.”

And then what you’re saying sinks in. We can MAKE black holes? What could happen? Could they sink to the core of the Earth and slowly consume the Earth? If that happened, is there anything we could do about it? This is an idea that has been explored in science fiction before, notably by my astrophysics colleague, J. Craig Wheeler, in his 1986 novel, The Krone Experiment. But what about the case of the Large Hadron Collider? Should we be worried?

There are two very simple reasons why the answer should be “No.”  First and foremost, the protons are travelling at enormous speeds, 99.999 999 1% the speed of light, and the post collision detritus will be travelling at similarly high speeds, propelled by the enormous release of energy in the collision.  Anything travelling at 11.2 kilometers per second or faster can escape the gravitational pull of the Earth.  How fast is 11.2 kilometers per second compared to lightspeed?  That is 0.0037% the speed of light. Any microscopic black holes created by the LHC will easily be travelling so fast that the Earth’s gravity could not possibly keep them stuck here.

Second is this: Nature is far better at making particle accelerators than we are. The LHC energies are paltry compared to the energetic particles that the Cosmos is bombarding the Earth with every single minute of every single day.

The Earth is constantly under the drizzle of a thin cosmic rain (that turn of phrase is the title of an excellent book by Michael Friedlander) of particles from outer space, called “cosmic rays.” These particles come from all over — the vast majority are from the Sun, but others come from highly magnetized stars, or from supernovae, or from shock fronts in vast clouds of interstellar gas and plasma, or from active galactic nuclei, or from black holes. They are constantly bombarding the planet in vast numbers; we like to tell people that TWO cosmic rays go right through your head, every second. :-)

Cosmic rays constantly bombard the Earth. Very often they collide with particles in the Earth's atmosphere, creating MORE particles (just like collisions in the LHC) when then shower down to Earth.

Cosmic rays constantly bombard the Earth. Very often they collide with particles in the Earth’s atmosphere, creating MORE particles (just like collisions in the LHC) when then shower down to Earth.

Like the particles in the LHC, every cosmic ray that hits the earth has an energy, sometimes a very large energy. Imagine grabbing some masking tape and marking out a square on the floor next to you, 1 meter by 1 meter. About 1 time per hour, every hour, a cosmic ray with the same energy as an LHC collision passes through your square.  And not just for your square — for EVERY 1 meter by 1 meter square you could make on the surface of the Earth! In the 15 minutes it takes you to read this article, roughly 10 such events will happen right in your living room. In one year, across the surface of the entire Earth, there are about 4 billion billion such events (4 x 1018).

When astronomers talk about cosmic rays, they often think about something called FLUX -- how many particles go through a known area in a known time. The cosmic ray flux at LHC energies is about 1 particle in a square meter (the blue square in this image) every hour.

When astronomers talk about cosmic rays, they often think about something called FLUX — how many particles go through a known area in a known time. The cosmic ray flux at LHC energies is about 1 particle in a square meter (the blue square in this image) every hour.

But that’s not the whole story either. Because at higher energy, it should be easier to make black holes, right? If I smash harder, I can compress more, and get into that black hole state much more easily. Imagine making a square 1 kilometer by 1 kilometer.  About 1 time every year, a cosmic ray particle will hit that square with an energy that has 1 MILLION times the energy of the LHC. That means every square kilometer on Earth (0.4 square miles) will get hit about 1x per year by a particle that has about 1 MILLION times the energy of the LHC. Over the entire surface of the Earth then, there are about 500 million events every year that have 1 million times the energy of the LHC.

And this has been going on for the entire 4.5 billion year history of the solar system!

Because of this, most scientists aren’t worried by the idea that the LHC could make black holes or transform the quantum state of the Universe, because Nature is already doing its best to do the same thing, and doing it at energies we could only imagine in our wildest experimental dreams.

I’m not worried about the LHC making microscopic black holes. You should not be worried about the LHC making microscopic black holes. Because there is probably already a thin rain of them showering over us every moment of every day. Thanks, Universe!

——————————–

This post is based on a short “Expert Show” talk I gave at the iO Improv Theatre in Chicago; I talked for about 10 minutes about the LHC and black holes, and then the improv troop took over. :-)

Stand in the Shadow of the Moon

By Shane L. Larson

Imagine a late August morning on the Oregon seashore. Around 10 AM the morning breezes whip your hair around your face. You can hear the crying call of gulls over the relentless crash of waves on the packed sand of the beach. Rocky hills and cliffs rise up to the north and south, giving way to green forests that race eastward toward the seaside town of Lincoln Beach, Oregon.  The water is cold here — the currents flow south along the Oregon coast after skirting the shores of Alaska far to the north; you’re thankful for the warm Sun on your back, drying you off after a brave leap into the chilly water.

Photograph of the 1919 eclipse captured by Sir Arthur Stanley Eddington on an expedition to test general relativity. With the face of the Sun occulted, the outer corona is visible to the naked eye.

Photograph of the 1919 eclipse captured by Sir Arthur Stanley Eddington on an expedition to test general relativity. With the face of the Sun occulted, the outer corona is visible to the naked eye.

But the warm respite provided by the Sun on this morning is soon interrupted, because to the west, beyond the distant horizon, a vast darkness is racing across the Pacific toward you. Around 10:15am, you will experience the darkness  yourself — it will race inland across the Pacific coast, and for 1 minute and 58 seconds, the Sun will vanish, its once brilliant disk replaced by an inky black orb surrounded by ghostly streamers, silently dancing in the sky where moments before you had seen blue skies and that seemingly eternal friend that has warmed and comforted you since childhood. The skies will darken as if night had fallen, the temperature will noticeably drop, and nighttime birds and insects will suddenly become active.  You will be experiencing one of the great spectacles of Nature: a total solar eclipse. But your two minutes of darkness will pass quicker than you can imagine, and the Sun will suddenly appear, as the darkness that you once stood in races eastward toward inland North America.

You will be able to experience this, almost exactly as I’ve described it, on 21 August 2017, when a total solar eclipse crosses the United States from Oregon to South Carolina. It will be the first total solar eclipse visible in the United States since 1979. This is your chance to see what I’ve described, with one notable exception: you will probably be surrounded by thousands of others who have traveled to the centerline to witness this spectacle and stand in the darkness. Never-the-less, it is well worth the experience, and I suggest you start making travel plans now!

What is a total solar eclipse? A total solar eclipse happens when the Moon passes between the Earth and the Sun. When that happens, along a thin path on the Earth, you can see the Sun completely covered by the Moon. For a couple of minutes along the eclipse line, day becomes night — the bright face of the Sun is hidden, making a halo of blazing streamers known as the corona.

A total solar eclipse occurs when the Moon passes between the Earth and Sun. The Moon's shadow races across the surface of the Earth, blotting out the Sun for those who stand under the racing shadow. [Illustration by S. Larson]

A total solar eclipse occurs when the Moon passes between the Earth and Sun. The Moon’s shadow races across the surface of the Earth, blotting out the Sun for those who stand under the racing shadow. [Illustration by S. Larson]

Because the Earth is spinning and the Moon is moving in its orbit, the shadow is moving along, just like your shadow does when you are moving. The combined motion of the Moon in its orbit with the spin of the Earth means the shadow will rocket across the North American continent at 1200 miles per hour. From the moment total shadow first occurs on the Oregon coast (10:15:58am MDT) to the last moment of total darkness on the South Carolina coast (2:49:01pm EDT), only 1 hour 33 minutes and 3 seconds will have elapsed. After that, the event will be all over for those of us rooted to the land.

Track of the 21 Aug 2017 total solar eclipse across North America. The red line is the centerline; anyone standing between the blue lines at the right time will witness the entire Sun being hidden by the Moon.

Track of the 21 Aug 2017 total solar eclipse across North America. The red line is the centerline; anyone standing between the blue lines at the right time will witness the entire Sun being hidden by the Moon. Map from NASA’s eclipse page.

Can you imagine what it was like, hundreds or thousands of years ago, before we had blogs and newspapers and radios to tell us all of upcoming astronomical marvels? The astronomical know-how to predict (and explain!) eclipses has been around for sometime, understood in the Middle Ages by priests and astrologers and in more recent eras by scientists and astronomers. But there was no way (or reason?) to tell anyone what was going to occur. If you and I were peasants in medieval times, we should have been dumbstruck with terror to witness the Sun being eclipsed, yet today we know it is a great marvel and wonder to behold.

The fact that we have such beautiful eclipses on Earth is a matter of complete, cosmic happenstance. It just so happens that the Moon and the Sun appear to be about the same size in the sky, so the Moon can almost perfectly cover the Sun. But this will not always be the case. At some point in the distant future, there will be one last, perfect total solar eclipse, and then none ever again.  There will come a day when there are no more eclipses on planet Earth.

The reason is that the Earth and the Moon are locked together in an inexorable gravitational dance. These two worlds have been locked together almost since the beginning of the solar system. You can see evidence of their sensuous cosmic tango every day. The relatively large size of both bodies, and their proximity, means that each has a profound effect on the other, largely through tides.

Most of us are familiar with the notion of ocean tides — the daily rise and fall of the seas on the Earth’s coasts. These cycles of high and low tides are caused by the effect of the Moon’s gravity on the Earth. The Moon’s gravity pulls on the parts of the oceans that are closest to it, causing a “rise” in the sea, a “tidal bulge” that points toward the Moon. There is a second bulge, on the far side of the Earth, caused by the fact that the strength of the Moon’s gravity grows weaker the farther you are from the Moon. The oceans on the far side of the Earth from the Moon get “left behind” as the Earth and near side oceans are pulled more strongly toward the Moon.

(A) The Moon's gravity raises ocean tides on the Earth. (B) The rotation of the Earth pulls the tides out of alignment with the Moon. (C) The Moon tries to pull the tides back into a line, slowing the rotation of the Earth.

(A) The Moon’s gravity raises ocean tides on the Earth. (B) The rotation of the Earth pulls the tides out of alignment with the Moon. (C) The Moon tries to pull the tides back into a line, slowing the rotation of the Earth.

The Earth is constantly rotating, so the interaction of the Earth’s crust with the bulged oceans drags the bulge in the direction the Earth spins, so the bulges don’t point directly at the Moon, rather they point in a direction off to one side of the Moon.

The gravity of the Moon is still pulling on the bulges, so the Moon tries to pull the bulges back in line. Since the Earth is simultaneously trying to move the bulge ahead, the net effect of this gravitational tug-o-war is to slow the spin of the Earth down, ever so slowly (between 15 and 25 millionths of a second every year).

Despite this diminutive change in the Earth’s spin speed, it represents a substantial amount of energy. Where does all that energy go? The only place it can — into the Moon’s orbit. When you dump energy into an orbit, the orbit gets larger. In the case of the Moon, it is getting farther and farther from the Earth every year, at a rate of about 22 mm/yr.

As the Moon gets farther from the Earth, it appears smaller in our sky. Eventually, it will be so small in the sky that it will not be able to cover the Sun, and we will see no more total solar eclipses. At the current rate of 22 mm/yr, the last solar eclipse will happen in about 733,200,000 years.

An annular solar eclipse happens when the Moon is too far away, so it does not appear big enough to cover the entire Sun. [Illustration by S. Larson]

An annular solar eclipse happens when the Moon is too far away, so it does not appear big enough to cover the entire Sun. [Illustration by S. Larson]

Filtered image of the annular eclipse on 20 May 2012 as seen from Cedar City, Utah. [Image by S. Larson]

Filtered image of the annular eclipse on 20 May 2012 as seen from Cedar City, Utah. [Image by S. Larson]

While those days are in the very far future, we sometimes get a hint for what they will be like, because the Moon’s orbit is not perfectly circular, so sometimes it is a bit too far away to completely cover the Sun, and we see an “annular eclipse.”  When this happens, the entire Sun is not covered, and the daylight does not fade. To the unaided eye, the Sun appears much like the Sun always does, but through a filtered telescope you can see that The Moon has clearly occulted the Sun — 733 million years in the future, that is all our descendants will ever see.

But that is not your fate — you live in a time when you CAN witness the spectacle of the eclipsed Sun, and you should.  Take a look at NASA’s eclipse page, and start planning where you might go.  But be quick; before too long, hotels are going to start filling up. Look at that — another one just got sucked up in Casper, Wyoming. :-)

PS: If you for some reason miss this one, you’ll only have another 7 years to wait. There will be another North American solar eclipse on 8 April 2024, running from Texas to Maine. It may not be as easy to get to for most people, but it will be worth the effort. My advice: see the eclipse in 2017, because after your first eclipse you immediately ask, “When is the next one?! :-)  Here is NASA’s page for the April 2024 eclipse.