Looking Back 108 Years…

by Shane L. Larson

Today would have been Carl Sagan’s 82th birthday. It is an auspicious year, because after a 108 year drought, the Chicago Cubs have won a World Series title. The Cubs win reminded me of Sagan because his son, Nick, had told a story once of introducing his dad to computer baseball based on statistics, whereby you could pit famous teams in history against one another. Sagan apparently said to Nick, “Never show me this again; I like it too much.”

Today, Carl Sagan would have been 82 years old.

Today, Carl Sagan would have been 82 years old.

It is an instantly recognizable feeling to those of us who do science — a nearly uncontrollable urge to ask, “What if…” and then construct an experiment to answer that question. When faced with the prospect of being able to pit two great teams from baseball history against each other, the little science muse in the back of your mind begins to ask, who would win? What if I changed up the pitchers? Does the batting order matter? What if they played at home instead of away?

This incessant wondering is the genesis of all the knowledge that our species has accumulated and labeled “science.”  And so, to commemorate Sagan’s birthday, and the Cubs win this season, I’d like to look back at what we knew of the world the last time the Cubs won the World Series, 108 years ago, a time well within the possible span of a human life.  The year is 1908…

The title page of Einstein's PhD Thesis.

The title page of Einstein’s PhD Thesis.

In 1908, a young physicist named Albert Einstein, 3 years out from his college degree and after a multi-year stint working as a clerk in the Swiss Patent Office, got his first job as a professor, at the University of Bern. This era was a time in the history of physics where scientists were trying to understand the fundamental structure of matter. Einstein’s PhD thesis was titled, “A New Determination of Molecular Dimensions.” Despite the fact that he could not find a job as a faculty member in the years after he graduated, Einstein worked dutifully at the Patent Office, and did physics “in his spare time.” During 1905, he wrote a handful of transformative papers that would change physics forever. Like his PhD work, some of those were about the invisible structure of matter on the tiniest scales. One explained an interaction between light and matter known as the “photoelectric effect,” which would be the work for which he would win the Nobel Prize in 1921. Physicists had for sometime known that some materials, when you shone a light on them, generated electric current. Einstein was the first person to be able to explain the effect by treating light as if it were little baseballs (Go, Cubs! Go!) that were colliding with electrons and knocking them off of the material. Today we use that technology for devices like infrared remote controls to turn your TV on and off!  By the time Einstein became a professor, he was thinking about new and different things that had caught his attention, sorting out some new ideas about gravity that would, after an additional seven years of work become known as General Relativity.

(Top) Marie Curie in her laboratory. (Bottom) Curie's business card from the Sorbonne. [Image: Musee Curie]

(Top) Marie Curie in her laboratory. (Bottom) Curie’s business card from the Sorbonne. [Image: Musee Curie]

Other physicists were hard at work exploring other aspects of the properties of matter. In 1908, already having earned her first Nobel Prize (in 1903), Marie Curie became the first female professor ever at the Sorbonne in Paris. Her 1903 Nobel Prize in physics was for her work in the characterization of radioactive materials. She and her collaborators were not only trying to understand the nature of radiation and the properties of radioactive materials, but were discovering many of them for the first time. Today, we look at a periodic table of the elements and there are no gaps, but in 1908 there were. Curie and her colleagues discovered radium and polonium. They also discovered that some previously known elements, like thorium, were radioactive and we hadn’t known it. Before this pioneering work, the world knew nothing of radioactivity. At this time, the dangers of radiation were unknown. Curie for years exposed herself to radiation from samples in her laboratory; today, many of her notebooks are still too radioactive to be handled safely without protective equipment. In 1934, Curie died of aplastic anemia, a blood disease brought on by radiation exposure whereby your body cannot make mature blood cells.

We think a great deal of Curie’s exposure to radiation came not just from carrying radioactive samples around in her pockets (something that today we know is a bad idea), but also exposure from a new technology that she was a proponent of: medical x-rays. During World War I she developed, built, and fielded mobile x-ray units to be used by medical professionals in field hospitals. These units became known as petites Curies (“Little Curies”).

Orville Wright (R) and Lt. Thomas Selfridge (L) in the Wright Flyer, just before take off at Fort Myer. [Image: Wright Brothers Aeroplane Co]

Orville Wright (R) and Lt. Thomas Selfridge (L) in the Wright Flyer, just before take off at Fort Myer. [Image: Wright Brothers Aeroplane Co]

There were other technological advances being introduced to the world in 1908.  That year, the world was still becoming acquainted with the notion of flying machines. The Wright Brothers had successfully demonstrated a powered flying machine at Kitty Hawk in 1903, but in May of 1908, for the first time ever, a passenger was carried aloft when Charlie Furnas flew with Wilbur Wright over the Kill Devil Hills in North Carolina. Just as with Curie, the Wrights were in unexplored territory, learning about the art and science of flying for the first time. Dangers and unexpected events abounded — the Wright Flyer experienced a crash late in 1908 after a propellor broke during a demonstration for the military at Fort Myer. Orville Wright was seriously injured, but his passenger, Lieutenant Thomas Selfridge, sustained a serious skull injury and died 3 hours after the crash: the first person to perish in the crash of a self-powered aircraft.

(L) The 60-inch Telescope at Mount Wilson. (R) A young Harlow Shapley. [Images: Mt. Wilson Observatory]

(L) The 60-inch Telescope at Mount Wilson. (R) A young Harlow Shapley. [Images: Mt. Wilson Observatory]

On the opposite coast of the United States, also in 1908, the largest telescope in the world was completed on Mount Wilson, outside of Los Angeles: the 60-inch Reflector, built by George Ellery Hale. The 60-inch was built in an era when astronomers had discovered that building bigger and bigger telescopes enabled them to see deeper into the Cosmos in an effort to understand the size and shape of the Universe and our place within it. One of the biggest discoveries made with the 60-inch was still ten years away — astronomer Harlow Shapley would use the great machine to measure the distances to globular clusters near the Milky Way and discover that the Sun did not lie at the center of the galaxy(see Shapley’s paper here); today we know the Sun orbits the Milky Way some 25,000 light yeas away from the center.

The nature of the Milky Way was still, at that time, a matter of intense debate among astronomers. Some thought the Milky Way was the entire Universe. Others argued that some of the fuzzy nebulae that could be seen with telescopes were in fact “island universes” — distant galaxies not unlike the Milky Way itself.  The problem was there was no good way to measure distances. But 1908 saw a breakthrough that would give astronomers the ability to measure vast distances across the Cosmos when astronomer Henrietta Swan Leavitt published her observation that there was a pattern in how some stars changed their brightness. These were the first Cepheid variables, and by 1912 Leavitt had shown how to measure the distance to them by simply observing how bright they appeared in a telescope. A decade and a half later, in 1924, Edwin Hubble would use Leavitt’s discovery to measure the distance to the Andromeda Nebula (M31), clearly demonstrating that the Universe was far larger than astronomers had ever imagined and that the Milky Way was not, in fact, the only galaxy in the Cosmos. By the end of the 1920’s, Hubble and Milton Humason would use Leavitt’s discovery to demonstrate the expansion of the Universe, the first hint of what is today known as Big Bang Cosmology.

(L) Leavitt at her desk in the Harvard College Observatory. (R) The Magellanic Clouds, which Leavitt's initial work was based on, framed between telescopes at the Parnal Observatory in Chile. [Images: Wikimedia Commons]

(L) Leavitt at her desk in the Harvard College Observatory. (R) The Magellanic Clouds, which Leavitt’s initial work was based on, framed between telescopes at the Parnal Observatory in Chile. [Images: Wikimedia Commons]

Today, it is 108 years later. When I reflect on these items of historical note, I am struck by two things. First, it is almost stupefying how quickly our understanding of the workings of the world has evolved. It really wasn’t that long ago — barely more than the common span of a human life — that we didn’t know how to fly and we didn’t know that the Cosmos was ginormous beyond imagining. The pace of discovery continues to this day, dizzying and almost impossible to keep up with. The second thing that is amazing to me is how quickly we disperse and integrate new discoveries into the collective memory of our society. Flying is no longer a novelty; it is almost as common and going out and getting in a car. Large reflecting telescopes capable of making scientific measurements are in the hands of ordinary citizens like you and me, gathering starlight every night in backyards around the world. Most people know that the Milky Way is not the only galaxy in the Cosmos, and that radioactive materials should not be carried around in your pocket.

It is a testament to our ability to collect and disperse knowledge to all the far flung corners of our planet and civilization. In a world faced by daunting challenges, in a society in a tumultuous struggle to rise above its own darker tendencies, it is a great encouragement to me that the fruits of our knowledge and intellect are so readily shared and accessible. When the challenges facing the world seem to me too daunting to overcome, I often retreat to listen to Carl’s sonorous and poetic view of our history and destiny (perhaps most remarkably captured in his musings on the Pale Blue Dot). He was well aware of the problems we faced, but always seems to me to promote a never ending optimism that we have the power to save ourselves– through the gentle and courageous application of intellect tempered with compassion.  It seems today to be a good message.

Happy Birthday, Carl.

And Go Cubs, Go.

cubswinwrigley

#AdlerWall 06: #XPLORESTEM

by Shane L. Larson

All too often, we think of STEM as some kind of activity related to education — it is, after all, an acronym formed from “possible fields of study” in school: Science, Technology, Education, Mathematics.

But this is a great failure of imagination on our part. STEM is bigger than simply education, or careers. STEM is bigger than K-12 kids or young adults navigating college.

xplorestem

This week’s #AdlerWall segment is a hashtag that reads simply: #XPLORESTEM. While your high school guidance counselor may have used this notion to encourage you to think about certain majors in college, I’m going to use it as an aperture to an elegant truth: you do #XPLORESTEM every day, you just might not recognize it.

STEM, quite simply, is a way of life. One that we are all immersed in everyday, and one that we all appreciate and enjoy whether we realize it or not. But more importantly, STEM is something we practice every day without realizing it. It is something we were all once fantastic at (and very likely still are), but we’ve forgotten. We’ve listened to all those people who watch us through our lives say “you don’t think very clearly”, “you’re not good at math”, “science isn’t for you.” We’ve melded those soundbites with the seeds of doubt that talk to us in the quiet alone hours before the day dawns; we’ve sown and watered those seeds with inferiority gleaned from watching people around us who are seemingly unbaffled by IRS tax codes, computer operating systems, or the irrational math required to order pizza for teenagers.

I’m here to tell you it is time to burn that field of weeds you have sown.

I’m a theoretical physicist. I spend my days being baffled by really frickin’ hard stuff in astrophysics. I spend a lot of time teaching students and people just like you. I like to think I know what I’m talking about when I talk about STEM. So trust me when I say this:

We are all explorers. We are all scientists. We are all problem solvers. We are all critical thinkers. We just don’t know it.

You may think you are bad at math, you may think you are bad at science, you may think that scientific thinking is baffling, but that’s just the weeds talking. You think like a scientist every day; you practice the art of critical thinking (“scientific reasoning”) every day. You’ve just been trained to believe a lie that says you haven’t. Let’s take a walk, you and I, through some everyday things you encounter and think about in your life.

Like many of you, I’m related to a quilter. Which means I have a LOT of quilted stuff around my house. Here are some awesome examples.

Some excellent examples of quilt patterns. Quilts by Peggy Beauvais.

Some excellent examples of quilt patterns. Quilts by Peggy Beauvais.

Quilting is an artistic and crafty endeavour, to be sure, but there are well defined mathematical principles at work here, related to a topic we call “tiling” (which not surprisingly is similar to another household activity called “tiling” that is related to shower stalls and backsplashes in your kitchen). Tiling is the process of covering a space completely, without gaps. When the space is covered by the same shape over and over again, we call that “periodic tiling” or “regular tiling.”  Good examples include the gridded tread on your shoes, or a regular grid of floor tiles.

Zentangles are a a modern meditative artform that is built around completely filling a space with irregular tiles. [Zentangles by Shane L. Larson]

Zentangles are a a modern meditative artform that is built around completely filling a space with irregular tiles. [Zentangles by Shane L. Larson]

Tiling has given way to spectacular art. Part of the current trend toward meditative art has people engaged in coloring large patterns such as mandalas that symmetrically tile large spaces, or drawing Zentangles that cover a small space with a number of different patterns. Famous artists have made spectacular works of tiling, such as the colored tiling work of Marlow Moss and Piet Mondrian. MC Escher was especially well known for his talent with tessellations.

Tiling also appears in Nature — you can see it in the structure of the cells on a leaf, and in the “granulation” caused by convection on the surface of the Sun, and in the hexagonal lattice in the honeycomb of a beehive.

Two examples of tiling in Nature. (L) Granulation on the surface of the Sun [Image by NASA] (R) Honeycomb by bees [Image from Wikimedia Commons]

Two examples of tiling in Nature. (L) Granulation on the surface of the Sun [Image by NASA] (R) Honeycomb by bees [Image from Wikimedia Commons]

As I wander around my house I encounter another activity that my father taught me when I was young: woodworking. My dad mostly makes furniture (I have several pieces that I quite like that came from him and my childhood), but the form this most often takes for me is in building telescopes. At its most basic level, a lot of woodworking is about taking two pieces of wood and putting them together to make something, like a piece of art or a telescope or a piece of furniture. However, once you name a woodworking piece “chair” or “footstool” then there are some deeper requirements, namely “it should not collapse if I stand on top of it and do an arabesque!”

(L) My daughter doing ballet on a footstool my father made. There is a great deal of engineering that has to go into the woodworking of the footstool to make this possible. (R) One of my daughter’s creations from when she was perhaps 4 years old, and I was first teaching her about woodworking. There is no engineering requirement here beyond “it must stay together.” (Neither she nor I remember what this was supposed to be; it says "volcano" on it.) [Images by Shane L. Larson]

(L) My daughter doing ballet on a footstool my father made. There is a great deal of engineering that has to go into the woodworking of the footstool to make this possible. (R) One of my daughter’s creations from when she was perhaps 4 years old, and I was first teaching her about woodworking. There is no engineering requirement here beyond “it must stay together.” (Neither she nor I remember what this was supposed to be; it says “volcano” on it.) [Images by Shane L. Larson]

The Willis Tower in Chicago was enabled by a new thought in structural engineering -- tubular construction. [Image by Shane L. Larson]

The Willis Tower in Chicago was enabled by a new thought in structural engineering — tubular construction. [Image by Shane L. Larson]

This is the heart of structural engineering. I don’t do any serious design and planning when I make a footstool; I do it more or less by trial and error and appellation to past experience (“I better put a brace here, or it will be wobbly.”). The fundamental principles, however, are the same ones that go into bridge design, or keep the Willis Tower upright. Engineers and architects, to be sure, plan their buildings ahead of time. They do calculations and build models to make sure the beams are the right sizes and the braces are in the right places. But the beginning of any building or bridge or train tunnel is the same place every footstool or backyard tree fort starts — a sketch on the back of a Five Guys napkin with a little guesswork and a bit of previous experience.

I would be remiss, if I closed this oeuvre to life and STEM without mentioning the most obvious example of science hiding in your life: cooking.  Cooking is a bunch of thermodynamics and a helluva lot of chemistry.  We could spend weeks — months! — writing every day about the chemistry that goes into cooking. So let’s just focus on one small bit of culinary wonder: crisping and browning.

Imagine something simple, a little comfort food from childhood: grilled cheese sandwiches. Mmmmm. It starts with some simple bread, a few slices of cheddar nestled between, and a searing griddle. As soon as the bread hits the griddle, it sizzles and sings as heat seeps into the sandwich, beginning the slow melt of the cheese. The process of melting is a bit of thermodynamics, which describes how energy can change the state, the physical properties of matter. The outside of the bread (and probably some bits of cheese that have oozed out on the griddle) are browning under the heat. This is the beginning of pyrolysis, the conversion of organic material into charred material (like “charcoal”). But before the complete conversion of your sandwich into an inedible charcoal briquette, it attains a crispy golden brown state, crunchy and delicious. What happened there? The browning process and flavor change of food during the early stages of cooking (before burning) is called the Maillard process. It is a chemical process where amino acids (the building blocks of organic molecules in living things) and sugars (long chain molecules that are broken up by organisms to make energy) work together and combine into something new. The idea of the browning process was first described by French physician Louis-Camille Maillard in 1912, but the chemical reactions were not worked out until 1953 by John Edward Hodge, an African-American chemist working for the Department of Agriculture in Illinois.

The secret of my lasagne, is the sauce. [Image by Shane L. Larson]

The secret of my lasagne is the sauce. [Image by Shane L. Larson]

Of course, cooking is often as much an art as science. The exact blending of flavors to make something new from common ingredients is unique to every chef. My lasagne is probably quite different than your lasagne. We might both enjoy each other’s lasagne, trade some secrets and ideas, and then experiment to see if we want to tweak our individual recipes. Sometimes we decide the experiment was a success, and sometimes not.  It all depends if the result of the experiment tastes good or not!

Here’s a bit of cooking chemistry from my childhood. Do you know what doesn’t taste good? Tang mixed with hot chocolate. I know it sounds like it should be okay, but trust me. Barf.

Of course, it isn’t all over with the cooking. You and I can cook with guidance from a cookbook — that’s chemistry in the kitchen. But once you eat what we cooked, your body takes over. Without any input from your brain, your body fires up a process called “anerobic glycolosis” — how to take food molecules and quickly make energy out of them. YOU are a walking chemistry experiment, every hour of every day.

So what’s the point in #XPLORESTEM? While on the one hand the impetus is often to encourage the young generation of students to think about careers in STEM fields, because we largely associate such fields with the success of the economy, with progress and brighter tomorrows, and general competitiveness on the world stage, I think about it the way we’ve been talking about it here: the ideas and use of STEM are not just careers and equations and laboratories. The ideas and use of STEM are fundamental principles that we often use unconsciously and in our everyday lives and hobbies. I can’t go build a building bigger than the Willis Tower because I can make footstools. I can’t predict solar storms because I can make a pretty kitchen tile pattern. I can’t make a new durable metal alloy for joint replacements because I know how to mix up a great vinaigrette.

But I can understand and use the same basic ideas as the scientists and engineers who do those bigger things. I can appreciate that what we know about the Cosmos is not an unfathomable mystery, because it is rooted in action and activity you and I do every day.

Your kid may decide they really want to be a marine biologist or a mathematician or a computer engineer. You may decide to go back to school (now that your kids are out of college) and study astronomy, or physical chemistry, or geology.

When any of those things happen, don’t throw up your hands! Don’t make a face like you’ve eaten a bug and declare “I hated science!” I’m sure you did, but that’s because we didn’t tell you the truth — you’re a scientist every day, and you #XPLORESTEM every day. I know you do, because I do it too.

See you out in the world! I’ll be the guy at the chili competition, quite certain that my newest experiment is totally going to win the cook-off.🙂

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This post is part of an ongoing series about the #AdlerWall. I encourage you to follow along with the activities, and post your adventures, questions and discoveries on social media using the hashtag #AdlerWall.  Links to the entire series are here at the first post of the #AdlerWall Series.

#AdlerWall 05: Share Interesting Observations, Ask Questions

by Shane L. Larson

Apparently this creature eats quarters.

Apparently this creature eats quarters.

My wife and I just bought a new couch and when we flipped the old one over to carry it downstairs, a quarter fell out. When I was in high school, arcades were the rage and a quarter was a ticket to a nice half-hour playing Xenophobe or Blasteroids. These days, it goes in my pocket and gets spent on parking. Despite the sad evolution of my life into adulthood, the appearance of the quarter sparked an interesting thought: I don’t remember dropping a quarter in my couch, and probably no one else would either, so that must mean almost everyone’s couch likely has a loose quarter in it! That observation, sparked an interesting question: how much money in quarters is hidden in couches?

(L) How I used to spend quarters. (R) How I spend quarters now. If the place on the left still existed, I could feed the the thing on the right with my phone and put those quarters to good use! :-)

(L) How I used to spend quarters. (R) How I spend quarters now. If the place on the left still existed, I could feed the the thing on the right with my phone and put those quarters to good use!🙂

Because you and I live in the future, information is at our fingertips. I pulled my phone out of my pocket and was quickly at the US Census site, which told me there are approximately 116,000,000 households in the United States (this page is where I landed). So if they all have a couch, and each couch has a quarter in it, that amounts to:

$0.25 * 116,000,000 = $29,000,000

There are 29 MILLION dollars in quarters hiding in couches! This observation has sparked some interesting discussions with friends that are wide ranging and varied: is there really only 1 quarter per couch? How much money disappears from circulation every year? Is there some way we could collect all that money? What could we do with $29 million?

This little exercise is something known as a “Fermi Problem,” — taking something you know (my couch has a quarter in it) and figuring out the implications based on other things you know (the number of households in the United States). Scientists use the method all the time to understand what the Universe is all about, particularly in astronomy where we don’t know much. But the interesting bit about the quarter question is not the number, it is the discussions that ensue afterward.

Just a few observations I have made and shared with friends, found on my smartphone. You most likely have a similar set!

Just a few observations I have made and shared with friends, found on my smartphone. You most likely have a similar set!

You make observations of the world around you all the time, and share those observations on social media or over coffee with friends. I know you do, because I see jillions of people everyday taking pictures of flower bushes and posting them to social media, asking friends over coffee if they noticed they way the clouds were streaked over the city that day, speculating on why the traffic was heavy or light today, or simply enjoying the spectacle of the brilliant turquoise color of the lake on a sunny day. You see the world around you and record it and talk about it, every single day.

adlerwall_questionsobservations

Given our social connectedness in modern life, this week’s exhortations from the #AdlerWall are ones that might not seem totally incongruous: “Share Interesting Observations” and “Ask Questions.” We are all good at this to some varying degree, but kids are masters. Children ask incessant questions of their parents:

“How do airplanes fly?”

“Where do frogs go in the winter?”

“Why do we say ‘bark’ to mean the sound dogs make and the skin of a tree?” 

They also share interesting observations:

“Look how you can make a loud sound by squishing your hand in your armpit!”

“If I hit my spoon right here, it flips oatmeal WAY over there!”

“The shadows from this tree look like an octopus!”

But sadly, somewhere along the pathway to adulthood, many of us lose that unbridled enthusiasm we had as children for exploring the world around us, and declaring our discoveries to the world. Sure, I’ve wondered how many gummy bears I can fit in my mouth and figured out the answer (37) — who hasn’t? It’s not that we don’t know how to ask questions and share our observations.  It has just become the societal norm to squelch the unbridled enthusiasm.

Yes, that’s right: squelch, not kill. Because in the quiet moments, we all give into the most basic impulse to ask a question, to look at the world around us and see what is going on. You might not always post a picture of the weather radar during a torrential thunderstorm, but you still made a screen capture. You have stayed up too late at night because you went to Wikipedia to find out about The Great Platte River Archway and two hours later found yourself still on your tablet, having randomly navigated through clicks until you were reading about the Toledo War. You’ve almost certainly been hanging out with your friends, when someone has asked some esoteric question about the difference between fountain pens and calligraphy pens, igniting a debate that was only resolved by asking Google or Wikipedia.

img_7696For most of us, making interesting observations and asking questions of our friends and the internet are diversions to everyday life, something we do for the sheer enjoyment of learning. But lurking just below the surface of those questions and observations is always a myriad of important ideas and applications, some of which we understand and some of which we may not. Irrespective, it points a simple and inescapable fact: we are all close to being scientists, simply by doing what we do — asking questions and making observations.

Let me illustrate with a curious observation I just made the other day. I have a vertical glass shower door; the glass is maybe 10 mm thick. If you put your eye right up against the edge of the door, and look into the glass (not through the glass), you a mesmerizing collection of reflections inside the glass door!

The view inside a glass door, looking edge on into the glass.

The view inside a glass door, looking edge on into the glass.

I’m sure I could work out the physics of the all the reflections as to why it happens (and could probably subject some future students to the analysis of that problem), but instead I’ll just share that observation with you. The next time you walk through a glass door, take a moment and peer in through the edge, looking longways into the glass — you’ll be treated to the same awesome spectacle I discovered. Maybe you’ll show it to a friend, or you’ll sketch it in your pocket notebook, or you’ll create a new glass sculpture inspired by the sight.  Irrespective, I’ve shared my observation with you, and hopefully shown you something you haven’t see before!  You should share what you see too.

So what does that have to do with anything? Peering into the glass of your shower door produces a spectacle that is fun and pleasing to behold, like a piece of symmetric art or a kaleidoscope. But the basic physics, called internal reflection, led to many, many modern applications, not the least of which are fiber optics, and the heart of most high-speed communications networks that are likely streaming internet and movies into your home right now. Binoculars have a pair of prisms that use internal reflection to gather the images of distant objects and route them through the binoculars to make a correct, right-side up image at your eye. Internal reflection of light in a raindrop takes the light from the Sun behind you, and directs it back at you to make a rainbow. And perhaps last, but not least, internal reflection is the basic physical principle behind infinity mirrors (IMHO, one of the coolest pieces of home decor you can have — your spouse may or may not disagree…).

Everyday examples of internal reflection. (Top L) Binoculars. (Top R) Rainbow creation by raindrops. (Bottom) Light propagating through a fiber. [All images from Wikimedia Commons]

Everyday examples of internal reflection. (Top L) Binoculars. (Top R) Rainbow creation by raindrops. (Bottom) Light propagating through a fiber. [All images from Wikimedia Commons]

All of this is connected, in a simple way, to the little pane of glass on my shower door. The world is a strange and wondrous place, full of moments of giddy discovery if you take the time to notice.🙂

So I’ll see you out in the world — I’m the guy blocking the entrance to the coffee shop as I try to snap a picture looking longways into their glass door.🙂

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This post is part of an ongoing series about the #AdlerWall. I encourage you to follow along with the activities, and post your adventures, questions and discoveries on social media using the hashtag #AdlerWall.  Links to the entire series are here at the first post of the #AdlerWall Series.

The Cosmic Classroom on Boxing Day

by Shane L. Larson

The seas of the Cosmos are vast and deep. From our vantage point here on the shores of Earth, we have seen much that is beautiful, awe-inspiring, frightening, humbling, confusing, and enigmatic. The simple truth of astronomy is that it is a spectator sport. The only thing we can do, is watch the skies and wait for the next Big Thing to happen. We collect events, like bottle-caps or flowers, and add them to our collection. Each new addition is a mystery, a new piece of a puzzle that takes shape ever-so-slowly over time.

On 14 September 2015, the LIGO-Virgo collaboration announced that they had detected the first gravitational waves ever, and that those waves had been created by a pair of merging black holes far across the Cosmos.

Today, we have some more news: LIGO has detected the second gravitational wave event ever, and those waves were also created by a pair of merging black holes far across the Cosmos. But as is often the case with astronomy, we know what we’ve observed, but we still don’t know what it means.

The name of the event is GW151226 (the date of the event), but within the collaboration, we call it “The Boxing Day Event.” On 26 December 2015 (Boxing Day in Europe), the two LIGO detectors responded to the faint ripple of gravitational energy washing across the Earth, the signature of two black holes merging to form a new larger black hole.

LIGO detected the black holes merging at 3:53 UTC in the morning on Boxing Day (it was late in the evening on Christmas Day in the United States, 9:53pm Central Standard Time). The event happened 440 Megaparsecs away — almost 1.4 billion lightyears! As with GW150914 before it, this titanic merger of black holes happened long, long ago, in a galaxy far, far away. It happened before multi-cellular life had ever arisen on Earth, and for a billion years that information has been sailing through the void, until it washed across our shores.

Learning to do astronomy: We can’t do experiments in astronomy, not the way we all learned to do them in middle schoolExperiment. Observe. Fail. Learn. Repeat.

The timeline of LIGO's first Observing run (called O1). The first detection (GW150914) and the second detection (GW151226) are marked. There was also a candidate that looked like a gravitational wave, but was not strong enough for astronomers to confidently say a detection was made.

The timeline of LIGO’s first Observing run (called O1). The first detection (GW150914) and the second detection (GW151226) are marked. There was also a candidate that looked like a gravitational wave, but was not strong enough for astronomers to confidently say a detection was made. [Image: LIGO Collaboration]

In astronomy, all we can do is observe, and hope that when we see something interesting happen, it happens again. Or something similar happens again, so we can start trying to make connections. Since the first LIGO detection, we have been patiently waiting for more detections. It could have been anything: merging neutron stars, a gamma-ray burst with an associated gravitational wave signal, a supernova explosion in the Milky Way, or perhaps other pair of black holes similar to GW150914.  As it turns out, it was the merger of black holes, but somewhat different than the one we observed before. Excellent! A chance to learn something new about the Cosmos!

When you look at the pile of gravitational wave events we’ve seen before (it’s a very small pile — there is only one event there, GW150914), we do the most obvious thing you can imagine: we start to compare them.

sll_blackHoleSummary

Strictly in terms numbers, you see that the Boxing Day black holes are less massive than the GW150914 black holes, by a substantial amount. This tells astronomers something very important: black holes can and do come in a variety of masses. That certainly did not have to be the case; there are many instances in the Cosmos where almost every example of an object is similar to every other object. People are all roughly the same height; grains of sand are almost all roughly the same size; yellow-green stars like the Sun (“Type G2” in astronomer speak) are all roughly the same mass. Though we did not expect it to be true, it could have been the case that all black holes were about the same mass; LIGO is happy to report that black holes come in many different masses.

But this, in and of itself, inspires new questions and new mysteries. The question for astronomers now is where do black holes of different sizes come from? The Boxing Day black holes are “normal size” — we think we understand how black holes in this mass range are made in supernovae explosions. The GW150914 black holes are a much grander mystery — they are larger (by a factor of 2 or 3) than any black holes that we expect to form from stars today. We have some interesting ideas about where they may come from, but those ideas can only be tested with more gravitational wave observations.

Comparison of the size of black holes observed by LIGO, as well as other candidates detected with conventional telescopes. (L) The physical size of the black holes overlaid on a map of the eastern United States. (R) The same image showing the masses on the vertical axis, and the black holes that combined to make larger black holes. [Image: LIGO Collaboration]

Comparison of the size of black holes observed by LIGO, as well as other candidates detected with conventional telescopes. (L) The physical size of the black holes overlaid on a map of the eastern United States. (R) The same image showing the masses on the vertical axis, and the black holes that combined to make larger black holes. [Image: LIGO Collaboration]

Gravitational wave astronomy: Every observation is different, because every source is different. Every set of waves is a unique fingerprint that encodes the physical properties of the objects that made the waves: their masses, how fast they are spinning, what kind of object they are,  how physically big they are, the distance to them, and so on. It’s like looking at the pictures in your high school yearbook — every picture is the same size, and is what we all call a “picture,” but each one uniquely identifies you or your friends. It encodes the color of your hair and eyes, whether you were smiling and wearing braces, the sweater you wore on picture day, and so on.

A typical visualization of a black hole binary. They emit no light, so there are no pictures! [Image: SXS Collaboration]

A typical visualization of a black hole binary. They emit no light, so there are no pictures! [Image: SXS Collaboration]

When we look at our data, we don’t usually show pictures. LIGO is not a telescope, so it does not generate images like we are used to seeing from the Hubble Space Telescope. Most “pictures” you see are simulations or realizations of the data. Instead, we show our data as graphs and plots that represent our data in ways that tell astronomers what LIGO is measuring and how that relates to quantities in physics we understand, like orbit size or energy.

A stereo equalizer display.

A stereo equalizer display.

One common picture we use is something called a “spectragram” — you may have encountered something like a spectragram on a stereo. The equalizers on your stereo tell you how loud the music in terms of whether it is more treble sounding or bass sounding.  In LIGO, we look at our data by looking a spectragram and how it changes over time.  The fact that the Boxing Day black holes and GW150914 are different is immediately obvious when comparing their spectragrams — the fine details of the shape and duration is different in the two cases, but they have the same basic swoopy shape to them. Think about your high school yearbook: the pictures are all kind of the same, but different in the details.

The comparison of spectragrams from GW150914 (top) and the Boxing Day event (bottom). The blue swoop is the gravitational wave signal as it evolves in time (early in the event on the left, and the final merger in the tall swoop on the right). [Images: LIGO Collaboration]

The comparison of spectragrams from GW150914 (top) and the Boxing Day event (bottom). The blue swoop is the gravitational wave signal as it evolves in time (early in the event on the left, and the final merger in the tall swoop on the right). [Images: LIGO Collaboration]

The difference in the gravitational waves LIGO detected is even more obvious if you look at the waveforms themselves. Imagine you are standing on the beach watching waves roll in and crash on the sand. In between waves, the water is calm and relatively low, but at the moment the wave is washing ashore, the height of the water increases subtantially; if you happen to be standing in the wave as it washes by, you might not be able to stand up because the energy carried by the wave is enough to knock you over. In a very similar way, the waveforms illustrate the strength of the gravitational waves as they wash past the Earth. The size of the “up and down” in the waveforms we plot tells us how strong the waves are.  If you compare the Boxing Day black hole waveforms with the GW150914 waveforms, you see they both have a lot of up and down (a measure of strength — they were strong enough for LIGO to detect!), but their overall shape and duration is different.

Comparison of the "waveforms" for GW150914 (top) and the Boxing Day black holes (bottom). The signals are considerably different, and longer in the case of the Boxing Day event. [Images: LIGO Collaboration]

Comparison of the “waveforms” for GW150914 (top) and the Boxing Day black holes (bottom). The signals are considerably different, and longer in the case of the Boxing Day event. [Images: LIGO Collaboration]

Gravitational wave astronomers at LIGO are most excited about the long chain of up-and-downs in the Boxing Day waveforms. This is a part of the black hole evolution we call the insprial — the long, slow time where the orbit is shrinking, the black holes drawing inexorably closer, creeping toward their ultimate fate: the coalesence into a new, single, spinning black hole. The longer the inspiral is visible to LIGO, the longer we can study the black holes with gravitational waves. Once they merge to form a new black hole, they very quickly become quiet, much like a bell fading into silence after being struck by a hammer. The inspiral, and the merger, are the only chance we have to take the measure of these tremendous astrophysical entities.

What now? LIGO has now made two detections of gravitational waves, both during our first observing run (what we call “O1”). In mid-January 2016, we turned LIGO off and have spent the ensuing months combing over the machine and addressing all the problems and difficulties we encountered in O1. In late summer 2016, we’ll start up for “O2.” We’ll turn up the lasers a little bit, and LIGO will be able to see a bit farther into the Cosmos. If our first stint as gravitational wave astronomers is any indication, we will likely see something new; we don’t know, all we can do is observe.  After a few months, we’ll shut down again, tune things up, think hard about how we are working with the machine, and in 2017 expect to come back online with everything at full design specifications.  We are like toddlers, learning to walk. We’ve taken our first few steps, and have discovered there is a tremendous world just waiting to be explored. We’re learning to keep our balance and do things right, but in the not too distant future will be confident and excited in our new found ability to observe and discover a Cosmos that up to now, has been completely hidden from us.  Carpe infinitum!


Many of my colleagues in the LIGO Virgo Collaboration have also written excellent blog posts about the Boxing Day event, and the work we do to make gravitational wave astronomy a reality. You should visit their blogs!

Why you SHOULD respond to student requests

by Shane L. Larson

To my colleagues in professional science:

There has been a tremendous and acerbic backlash over the last week against a current popular practice of K-12 students emailing professional scientists with a list of questions they would like the scientists to comment on. I too have received these emails, and I have to very clearly state (in case you haven’t already been in one of these debates with me) that I have an unpopular view on this issue: I vehemently reject the view that we cannot respond to these emails. It is part of our professional obligation to society to respond to these notes.

In the spirit of intellectual debate, which is the purported hallmark of our discipline, let me recount some of the many aspects of the arguments that have been swirling around.

The Scenario. Emails will sail into our inboxes from (usually) middle-school science students, that asks the scientist if they could answer a series of questions.  Here is a typical one that made its way into my inbox.

examples

These emails are often clearly part of a classroom activity assigned by a teacher. There are those of us who diligently respond to as many of these as we can; we share them among our colleagues when we can’t get to them ourselves. But many of my colleagues simply don’t see the point in engaging scientists this way; they feel like they cannot or do not have the ability to respond to these requests.  Which is where the debate begins to swirl.

(*) They can just look this up on Wikipedia!  Perhaps. But even a casual inspection of science pages on Wikipedia will reveal that it has become an increasingly difficult resource to use, particularly for non-scientists. Wikipedians have taken the viewpoint that entries on the site should contain all the information one could traditionally find in a book. Many entries, especially those related to science, have wide ranging and rambling connections from all branches of science and more often than not divert into mathematical rambling. One earnest sixth grader asked me “Can you explain what a black hole is?” I would say the Wikipedia page on black holes is decidedly NOT for a sixth grader!

(*) These are thoughtless stream of consciousness questions about topics that they just picked out of a hat. They didn’t put any thought into these.  Perhaps in some cases that is true. But it is understandable — we’re talking about middle-schoolers.  For example, almost everyone has heard of black holes, but very few know enough to ask better questions than “what are they really?” But a carefully constructed answer from you can (and will) spark deeper interest, and can (and will) provide a better foundation for the next time they have a chance to ask a scientist a question — perhaps in class, perhaps in a public lecture, perhaps as part of an organized interface activity (like Adopt A Physicist).

(*) They should learn to read and process information from online and print sources; it’s a necessary skill.  That’s right, it is and they should. But they are perhaps 12 years old, and you are saying that from the far end of a PhD in modern science. Learning to read and process information, and more importantly learning how to find reliable sources of information, is something I spend time teaching my undergraduates and my graduate students. It is not as easy as you make it sound when you speak from behind your PhD. I’m sure if you talked to their teachers, you would find that they are doing activities to practice learning the skill you so ardently insist they must learn. But when you are a K-12 student, it is hard to exercise whatever mastery you have of that skill to glean something important about the modern frontiers of science.

(*) I don’t have time to respond to all the requests I get.  Does responding to a lot of emails from students and random members of the public take time? Of course it does. Just like answering your own students. Just like answering your collaborators. Just like answering your department chair or dean. Just like doing research. Just like writing grant proposals. We all have tremendous pressure on our time; that is a fact of life and simply the state that modern science finds itself in. And the truth is that we all spend time on what we value and prioritize; if you don’t value something, then you don’t do it or you don’t spend time on it. If you do value something, you make room for it and devalue something else — it all boils down to priorities and the calculus of not being able to do everything. If you aren’t doing something because it takes too much of your time to do it, you have to be willing to say, “this isn’t important enough for me to spend my time doing. I have other things that I think are more important.”

I get a handful of these requests, but not so many that I can’t answer them; far fewer than I get from my own students, to be perfectly honest. If I do get too many, I share them among colleagues. Given that our lives as scientists are dedicated to solving the hardest problems known to our species, I find it hard to believe that someone inundated by an unanswerably large number of these requests cannot figure out a way to get responses to these students.

(*) I don’t see the pedagogical value of having students email a scientist. Students shouldn’t have answers hand fed to them.  It is NOT for you to decide what is pedagogically useful, it is for the teacher who made the assignment. They have their own learning goals and their own objectives for everything they assign their students, just like you do in your own classroom. It is NOT for you to judge what they do in their classroom any more than it is for me to judge what you do in your classroom.

You should take one of the sets of questions you get, and try to find the answers on your own. Try not to view webpages and books through the lens of your professional degrees; if you find that hard, ask your own kids or a neighbors kids to evaluate a resource you think is useful.  I think you will be surprised — while there is much good science out there for people to find, there is a lot of not so good explanations as well. The signal to noise ratio is very low; you and I have been explicitly trained to work through that.

But the most important reason for me to respond to a student inquiry is they will get something different in a response from me and you than they can get from any book. Perspective, experience, personal reflection — the human side of science, the personal side of science, an illustration of what I think is important as a scientist, the history and heroes that I think are important that aren’t always described in books.

When I answered the questions above, what did I add that couldn’t be had elsewhere?

How long does it take to produce a star? Sure, you can look up the collapse time for a molecular cloud to stars, but I also talked about the scope of the question, pointing out that one could have also thought about the previous generations of stars that made the material that is needed to create a star system like ours.

Do stars have color? I made sure in my answer that the student heard the names Annie Jump Cannon and Cecilia Payne-Gaposchkin.

Do I believe in life elsewhere? An opportunity to talk about a personal belief, and where that interfaces with research science on the topic — a chance to illustrate the all too human part of science. I also pointed at one of the finest explorations of the question I have ever seen — Peter Mulvey’s song, “Vlad, the Astrophysicist” (YouTube video here); the intersection of science and society at its finest.

In the end, I think it boils down to this: we like to make loud noises about the current state of public understanding of science, but tucking our heads down is part of the reason the world is in the state it is in. It may have been okay 40 years ago to keep your attention narrowly focused on research; but 40 years ago the Cold War and the military-industrial complex allowed science to enjoy unprecedented support in the form of funding and societal tolerance.  That is not the world today; science is regularly challenged and questioned, in society and in the halls of government, much to the detriment of our civilization and the future of our planet.

But all is not lost. There is tremendous interest on the part of students and the public about science, in large part because of the very prominent and inspiring successes of our experiments that society has invested in: LIGO, the LHC, the Hubble Space Telescope, and many, many others. A few of our august bunch are very prominent in the public eye: Brian Cox, Lisa Randall, Neil deGrasse Tyson. Before them there was Rachel Carson, Carl Sagan, and (still!) David Attenborough. They have set a fire in the minds of your neighbors and in the minds of every science teacher on the planet who are now trying to light that same fire in the minds of their students. They will do their best to light an ember, but only you and I can fan the flames. There is something unique and special about communicating directly with someone who has seen the Cosmos through the eyes of the Hale Telescope, or someone who has stood over the arm of LIGO, or watched a vista of Mars slowly unfold as Curiosity sends us a picture from over the next rise.

Out of an entire class of 7th graders, will you move and inspire all of them to a life of science? Of course not, and you don’t need to. But many of them will remember later in life that they once talked to a scientist who took time out of their schedule to respond to them.  And a few will be inspired.

In one of the many dilapidated boxes that my mother has carefully preserved is a bundle of letters I received in my childhood. One is a letter I received in 7th grade from an astronomer (physicist?) at the University of British Columbia, who took time to write a paper letter in response to an earnest inquiry from a young boy who wanted to know what it took to become an astronomer. I have another letter (undoubtedly a form letter?) from someone at NASA in 1986, assuring a worried and spiritually crushed young boy that NASA would, eventually, return to space in the wake of the Challenger disaster. These are paper responses, with stamps and envelopes and everything; not even as easy as an email.

These were scientists who made the time in their busy schedules to respond to a inquiry from a student, and in the end I think it made all the difference in the world.

#AdlerWall 04: Look Up and Sketch the Moon

by Shane L. Larson

You and I live in the future. Our world is one where information is transmitted instantly to everyone, blasting out of large flat screens and small hand-held devices owned by a billion humans around the globe. Information comes in small blurts of text, a few funny pictures, and now and then in a short video. Electronic memory, captured forever in the ephemeral electronic nothingness of the internets.

It is hard to remember that there was a time, not so long ago, where moving pictures were a marvel, a wondrous example of the technological age that was just beginning to expand its blanket across our civilization. That by-gone age that introduced the world to moving pictures is usually called the “Silent Film Era” and spanned more than 3 decades, from 1894 until the late 1920s when “the talkies” began to take over. In the midst of this age of wonder, an ingenious filmmaker made his trade in France, experimenting with all manner of ways of filming and editing to take his audiences on journeys of imagination and wonder. His name was Georges Méliès, and in 1902 he released one of the great classics of film: Le Voyage dans la Lune — “A Trip to the Moon.”

(L) Georges Méliès. (R images) Scenes from "La Voyage Dans la Lune" [Images: Wikimedia Commons]

(L) Georges Méliès. (R images) Scenes from “La Voyage Dans la Lune” [Images: Wikimedia Commons]

Inspired by the novels of Jules Verne and H.G. Wells, Méliès imagined making a voyage across the cosmic gulf to visit our celestial companion. This was in the days before rockets — Méliès imagined sending a space capsule to the Moon after launching it from an enormous cannon, a perhaps not unreasonable idea given Newton’s cannonball diagram in his De mundi systemate to describe orbits!

(L) In his "De Munde Systemate" Newton imagined going into space via an enormous cannon; this was before rockets were known. (R) In 1902, rocketry still had not been developed, and Méliès imagined sending his voyaguers to the Moon by launching them in an enormous cannon.

(L) In his “De Mundi Systemate” Newton imagined going into space via an enormous cannon. (R) In 1902, rocketry still had not been developed, and Méliès imagined sending his voyaguers to the Moon by launching them in an enormous cannon.

The Moon at that time was a great mystery to us, the target of much speculation and many wild imaginings. Méliès’ vision built on that — the Moon was an alien landscape, populated by alien cultures that his explorers did not understand nor appreciate. It was perhaps an obvious target for Méliès’ imaginings. More than any other place in the solar system, the Moon is a place that we can all imagine visiting, if for no other reason than we can see it with the unaided eye.

Today, more than a century after Méliès’ voyage of imagination, the Moon is a known place. Like many worlds in the solar system, we have photographed it up close and mapped its surface in exquisite detail. But it still holds a certain mystique that other celestial destinations do not. Mostly because we can see it with the unaided eye, but more because it is the only other place in the Cosmos, besides Earth, where human beings have walked. It is a great wonder to step outside and see the distant orb of the Moon riding high in the sky, and know that people just like you once walked there. It still makes me a little breathless, and encourages me to look for the Moon every time I walk out the door. It seems unlikely that I will ever get to walk the craggy lunar landscape myself, so I fall back on the next best thing: I try to see what I can see with my own eyes.

adlerWall_sketchMoonThe #AdlerWall exhorts us to “Look up and sketch the Moon.” Most of us have seen the Moon, probably unconsciously the way we notice trees, flowers and other ordinary, everyday things. Part of the Wall’s desire for you is simply to be cognizant of noticing what you are seeing (in the same spirit of our earlier exploration in looking closely at what is under rocks). But the other part of the imperative is the sketching.

Why should we do that? Personally, I’m probably the world’s worst sketcher, but I do it anyhow. Sketching, no matter how crude and rudimentary, helps you notice things. There are many different sketching exercises that you can do, and all of them will bring the Moon a bit closer to you.  Let’s explore some of those ideas together.

Right now, picture the Moon in your mind. What does it look like? Without getting up to look at it, without pulling up a picture of it, make a crude sketch of what you see in your mind’s eye on the back of an old cell phone bill.

What did you draw? Perhaps you drew patchy patterns of light and dark. The variations in brightness across the face of the Moon are caused by the geology that shaped it. The darker areas are called maria, or lunar seas. They are basaltic lowlands, the youngest surfaces on the Moon created by vast lava flows in an earlier, active phase of the Moon’s life. The brighter areas are called terrae, the lunar highlands. These jumbled and broken landscapes are the older parts of the lunar crust, covered with craters and criss-crossed by mountain ranges, escarpments, and vast rilles.

Did you draw any craters? How about mountains? The understanding that such features are found on the surface of the Moon is almost ubiquitous. But unless you have looked at the Moon through a telescope, you probably have never seen a crater for yourself.  You cannot see any craters or mountains on the Moon with your naked eye. Until the time of Galileo, it was widely believed the surface of the Moon was smooth.

My two sketches of the Moon. (L) The Moon from memory [not very good!] (R) A direct sketch at full moon. [Images: S. Larson]

My two sketches of the Moon. (L) The Moon from memory [not very good!] (R) A direct sketch at full moon. [Images: S. Larson]

Now go out and make a sketch of the Moon, whatever phase it might be in. The patterns of light and dark are the same ones that have been seen by 40,000 generations of humans before us. The surface of the Moon is millions of years old, changing on slow geologic timescales — human lives, and indeed all of human history, are the merest flashes of an instant in the long history of the planets in the solar system. The face of the Moon you see today is the only one ever seen by humans.

Whenever we look at the sky we project all manner of human interests and problems on the sky, a manifestation of our deep and abiding desire to be part of the Cosmos. The Moon is no different than the rest of the sky in this regard. As our most prominent neighbor, it has oft been the target of imaginative musings. There is a long tradition of recognizing and naming patterns in the patchwork of light and dark — moonshadows.

The most famous of the moonshadows is the Man in the Moon, but if you look closely you can also see the Bunny in the Moon, and the Woman with the Pearl Necklace. Can you make up your own moonshadows that you can easily recognize and teach others to see?

Some of the classic moonshadows you can see in the full moon. Clockwise from upper left: the Full Moon, the Man in the Moon, the Bunny in the Moon, the Woman in the Pearl Necklace.

Some of the classic moonshadows you can see in the full moon. Clockwise from upper left: the Full Moon, the Man in the Moon, the Bunny in the Moon, the Woman in the Pearl Necklace.

The fact that you know the Moon is covered in craters and mountains and canyons is a testament to our civilization’s ability to share knowledge. But in reality, you can discover for yourself exactly what Galileo discovered, even if you don’t own an astronomical telescope. Common birding binoculars or small spotting scopes are all much better than Galileo’s first telescope, and will show you the wonders of the Moon.

You can turn your small scope or binoculars on the Moon at any time, but it is easiest to see surface features when there are strong shadows. This happens at any time during the month except near Full Moon (though you should certainly look at the Moon when it is full!). The boundary between the light and dark on the lunar surface is called the terminator — it is the dividing line between day and night on the surface of the Moon. The shadows of craters and mountains are strongest on the terminator, and if you focus your attention there, you can see some fantastic topography. If you’re inclined to carefully record the shadows you see, some simple mathematical investigations with geometry can be used to figure out how tall and wide the mountains and craters are.

Some of my sketches of the Moon. (L) The lunar terminator, made through a small birding scope. The numbers and letters are to an identification key, figured out after the observations with the aid of a detailed Moon map. (R) A telescopic sketch of the crater Archimedes. [Images: S. Larson]

Some of my sketches of the Moon. (L) The lunar terminator, made through a small birding scope. The numbers and letters are to an identification key, figured out after the observations with the aid of a detailed Moon map. (R) A telescopic sketch of the crater Archimedes. [Images: S. Larson]

If you look at Galileo’s classic sketches of the Moon, you may notice that he sketches the entire Moon. In your own viewings, especially during the crescent phases, you can often see the faint outline of the dark part of the Moon; through a telescope, you will see fleeting, ghostlike impressions of craters, lunar seas, and mountains in the ephemeral shadows. What is going on here?

This phenomenon is called “Earthshine” — sunlight hits the Earth, bounces off the Earth, and hits the dark side of the Moon, making it appear in ghostly shadows. This is the same effect that lets you see things in the shade of a tree at the park — light from the sunny parts of the park bounces off of everything and illuminates the parts of the park in shadow. The first person to explain the origin of this shadowy illumination of the Moon by Earth was Leonardo da Vinici, in his famous notebook, the Codex Leicester.

Galileo's sketches of the Moon always showed the unilluminated half of the Moon as well. You can and will notice this, with your naked eye and through a telescope, due to "Earthshine." [Image: Wikimedia Commons]

Galileo’s sketches of the Moon always showed the unilluminated half of the Moon as well. You can and will notice this, with your naked eye and through a telescope, due to “Earthshine.” [Image: Wikimedia Commons]

Even if you don’t want to sketch the craters and the mountains, even if you don’t want to peer at the Moon through a telescope or binoculars, you may still see the Moon in striking moments of beauty, framed by life here on Earth. A common experience many of us have had is witnessing a Moonrise or a Moonset against the landscape or against the skyline of the city. In many instances you get the overwhelming perception that the Moon is enormous, looking over the Earth like a gigantic cauldron of boiling light, waiting to pour itself out across the landscape.

The Moon Illusion at work over the Adler Planetarium. What my eye saw (sketch on the Left) and what my camera captured (picture on the Right) are significantly different! [Images: S. Larson]

The Moon Illusion at work over the Adler Planetarium. What my eye saw (sketch on the Left) and what my camera captured (picture on the Right) are significantly different! [Images: S. Larson]

This apparent enlarging of the Moon is an optical illusion known as the “Moon illusion.” While you can generically break the illusion by disrupting your normal viewing of the scene (try standing on your head, or looking at it upside down), the existence of the illusion does not diminish the awe-inspiring effect it has on your mind’s eye. Somewhat surprisingly, simply taking a picture often destroys the illusion — unless cropped very closely around the Moon, pictures flatten the perspective and bring peripheral parts of the scene into play, destroying whatever visual queues your brain was using to make the Moon look big. It’s weird.

The Moon is always up there, waiting for you to notice it, providing intriguing and beautiful opportunities to snap a picture or make a quick sketch. Look up! [Image: S. Larson]

The Moon is always there, waiting for you to notice it, providing intriguing and beautiful opportunities to snap a picture or make a quick sketch. Look up! [Image: S. Larson]

The Moon, like the Sun and stars, is one of the dependable denizens of the sky. Sometimes it is up during the day, sometimes it is up at night. It is constantly changing its shape, and adds majesty and brilliance as a backdrop to images of life on Earth. So the next time you’re out take a look around for the Moon; if you have a moment, snap a picture or make a quick sketch, so you can remember it.  See you out in the world — I’m the guy looking dumbstruck on the street corner, craning his head to see the Moon rising behind the city skyline!🙂

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This post is part of an ongoing series about the #AdlerWall. I encourage you to follow along with the activities, and post your adventures, questions and discoveries on social media using the hashtag #AdlerWall.  Links to the entire series are here at the first post of the #AdlerWall Series.

#AdlerWall 03: Look for Patterns

by Shane L. Larson

(L) John Trusler (R) William Blake

(L) John Trusler (R) William Blake

In August of 1799, the Reverend John Trusler commissioned a pair of watercolors to illustrate the concept of “malevolence.” As a philosophical construct, we often regard concepts such as malevolence as being aspects of human behaviour that are part of our free will, not as natural phenomena that are able to exist independent of our free thinking. Does malevolence exist outside of humans, in Nature itself? Philosophers may differ, and certainly artists’ interpretations may vary widely. Perhaps not surprisingly, Trusler was not happy with the first painting he received.

Blake's painting of "Malevolence." [From the collection of the Philadelphia Museum of Art]

Blake’s painting of “Malevolence.” [From the collection of the Philadelphia Museum of Art]

The painter commissioned by Tusler was none other than the great English artist, William Blake.  The two shared a contentious exchange in a pair of letters that month about Blake’s depiction. In a letter on August 23, Blake admonished Tusler that we all see the world differently, writing:

The tree which moves some to tears of joy is in the eyes of others only a green thing that stands in the way. Some see Nature all ridicule and deformity…and some scarce see Nature at all. But to the eyes of a man of Imagination, Nature is Imagination itself.

Blake’s exhortations to Trusler dance around an interesting and lovely conundrum — what is Nature and how do we separate what Nature is from what we perceieve or think of it?

Consider clouds. In your high school science class, you may have once been told that clouds are suspensions in the Earth’s atmosphere, huge agglomerations of tiny water droplets and ice crystals. Most of the familiar clouds form in the troposphere, the lowest part of the Earth’s atmosphere where weather happens. Gossamer and diaphanous, they are pushed around by the winds of the world, carrying weather and moisture to the far flung corners of our planet. Meteorologists, partnered with amateur cloud watchers, have categorized a large number of cloud types, though if you restrict your attention to the most common there are only ten or so that you encounter most often (see NOAA’s “Ten Basic Cloud Types”).

The most common types of clouds, only a few of the more than 60 types classified. [Image: Wikimedia Commons]

The most common types of clouds, only a few of the more than 60 types classified. [Image: Wikimedia Commons]

But many of us have, at some point in our lives, wasted away an afternoon staring at clouds in the sky. Part of those lazy gazings is calling out shapes and figures we see in the clouds — bunnies, turtles, ships, books, hands.

There are clearly patterns in the clouds. Nature made the clouds, so Nature made the patterns. After many long years of staring at the sky, we have elucidated some regular, recurring shapes and forms that Nature creates over and over again, and we’ve given them names: cumulonimbus, altostratus, cirrus, and so on. By a similar token, the shapes and figures we recognize as bunnies and sailing ships are also patterns we have elucidated from staring at the sky. What’s the difference between our observations and Nature’s patterns? What’s the difference between afternoon figures and the cloud archetypes?

Some clouds seen from airplanes. What do you see? On the left I see a trilobite, a kid blowing a bubble, and cauliflower. On the right I see a poodle, and a shaking fist.

Some clouds seen from airplanes. What do you see? On the left I see a trilobite, a kid blowing a bubble, and cauliflower. On the right I see a poodle, and a shaking fist.

One of the great realizations we have made about the world is that it is predictable. The world does not evolve randomly, changing each day in unpredictable and unexpected ways. Quite the contrary — when I throw a water balloon up in the air (or, possibly, at someone) it always comes back to the ground. The Moon moves through a steady progression of phases every 29 days, always in the same order, just as it has for all of recorded history. A popsicle always melts when left on the kitchen counter. All of these happenings, and the many others that surround us in the natural world, occur according to precise sets of rules that we call the Laws of Nature. The fact that we can recognize patterns, that we can deduce and use the Laws of Nature to improve our lives, provides the impetus for one of the great endeavours of our species — science.

When we look at the clouds, there are two sets of patterns in play. One set of patterns are the recognizable shapes and forms of the basic cloud types. Each of these different forms is governed by a particular realization of the Laws of Nature. They are predicable and repeatable, appearing anytime the same physical conditions appear in the atmosphere. Consider “Kelvin-Helmholtz clouds.” They can form when layers of wind are sliding across one another, with the upper layer moving faster than the lower layer, creating turbulence at the boundary between them.

A classic example of Kelvin-Helmholtz clouds, created when different layers of wind slide across one another. [Image: Wikimedia commons]

A classic example of Kelvin-Helmholtz clouds, created when different layers of wind slide across one another. [Image: Wikimedia commons]

By contrast, the picture patterns that you can pick out staring up at the sky are unique to your own experiences and interpretations. You can certainly point them out to friends and get them to see what you see. But left to your own devices, you may see a turtle whereas your dearest friend may see a hoagie sandwich.  These are patterns made by your mind; the difference between them and the patterns made by Nature is that the patterns of the natural world are predictable and subject to rules. Our job as scientists and observers of the world is to figure out what those rules are.

wall_patternsThe #AdlerWall this week exhorts us to “Look for patterns,” and that “patterns can be man-made or found in Nature.”

So what kinds of patterns can you find around you? There are clearly patterns that humans make, usually quite deliberately. Our brains crave the regularity and dependability of patterns. One of the most obvious places we encounter patterns is in woven textiles. There are global patterns — stripes, dots, space cats — that you can see standing next to your friend with the loud and colorful shirt. But there are smaller, more subtle patterns you can see if you look closely, notably the interwoven fibers that cross up and over one another to give the fabric its structure. The interlocking up and down, over and under pattern of individual fibers is a human invention, though who thought of it and when is now lost to history; the oldest known woven textile fibers date to about 6000 BCE.

There are many patterns to be seen in textiles, all of them made by humans. The patterns your eye can see, as well as the underlying patterns in the weave of fabric. Patterns occur on all levels. [Images: S. Larson]

There are many patterns to be seen in textiles, all of them made by humans. The patterns your eye can see, as well as the underlying patterns in the weave of fabric. Patterns occur on all levels. [Images: S. Larson]

Carpets are another great place to see human-created patterns. These grace the floors in the Salt Palace Convention Center in Salt Lake City. I want to know whose job it is to make up these patterns!

Carpets are another great place to see human-created patterns. These grace the floors in the Salt Palace Convention Center in Salt Lake City. I want to know whose job it is to make up these patterns!

In a similar way, there are impressive patterns visible in Nature too. On cold winter days, frost ferns can form on your windows. These beautiful displays of symmetry look almost organic in nature, but result from water molecules binding to other water molecules. As a large structure forms, the molecules are forced to remain near the cold surface of the glass, and the structure of the fern emerges. Frost ferns exhbit fractal structure — a repeating pattern that appears on many many different size scales. We see fractal structure in tree branches and clouds as well.

A classic frost fern that formed on my sliding glass door this spring. [Image: S. Larson]

A classic frost fern that formed on my sliding glass door this spring. [Image: S. Larson]

There are other patterns in Nature that you can notice. I just popped outside, and with a few quick sweeps found this rock on the gravel path next to my house. I could have picked up any old rock and found something interesting, but this one has a clear structural pattern. Look closely at the exposed, broken surface. It is comprised of a myriad of interlocking small crystal structures. I’m not a robust rockhound (I just pick up cool rocks and carry them around in my pockets), but this looks like a quartzite of some kind. Quartzite is a metamorphic rock — a rock that has formed by transformation under extreme heat. In the case of quartzite, extreme pressure and heat on sandstone variety rocks causes the glassy minerals in the sand to break down and reform in crystalline arrays, not unlike the one you see on the surface of this rock.

An everyday rock, picked up off a gravel path, shows a jumble of quartz crystals on its surface. [Image: S. Larson]

An everyday rock, picked up off a gravel path, shows a jumble of quartz crystals on its surface. [Image: S. Larson]

You can see much more robust crystal formation in a kind of rock known as a geode. Geodes are roughly spherical rocks with a hollow core, where crystals have slowly grown inside the core. Beautiful (and expensive!) specimens can be bought, but breaking open common geodes will reveal a beautiful little garden of crystals. Crystals are a special pattern of matter that arises from molecules that have regular geometric shapes that are preserved when the molecules are stacked together. The regular geometric shape of the crystal that you can see with your eye is a clue to the microscopic alignment pattern of the molecules that your eye cannot see.  Salt crystals and sugar crystals are other examples.

Geodes are known for their crystal structures. The crystals are macroscopic manifestations of the underlying molecular shapes -- large patterns building from small patterns. [Image: S. Larson]

Geodes are known for their crystal structures. The crystals are macroscopic manifestations of the underlying molecular shapes — large patterns building from small patterns. [Image: S. Larson]

Another example of patterns, where human and Nature’s patterns collide is in the layout of city streets. I grew up in the American west, on the fringes of the Great Plains of North America. There the landscape is vast and flat, and humans could have laid their streets out willy-niIly in any way they wanted.  But a quick glance on satellite shows the roads are usually in a nearly perfect grid, roads running straight north-south or straight east-west. This is not true everywhere. In central Pennsylvania, the rolling landscape of the Appalachian Mountains strikes across the state from the southwest to the northeast. If you look at a town along the rolling, folded ridges you see that the roads and streets are aligned parallel to the mountains — humans patterns have been influenced and shaped by the natural patterns of the world around them.

Human patterns [streets] often follow Nature's patterns [terrain]. (L) Fort Morgan, Colorado is in the Great Plains and streets run N-S and E-W, oriented to the cardinal directions defined by the spin of the Earth. (C) In central Pennsylvania the Appalachians form long ridgelines and valleys. (R) Cities like State College, PA have street grids aligned parallel to the terrain of the mountains in the area. [Images: Google Maps]

Human patterns [streets] often follow Nature’s patterns [terrain]. (L) Fort Morgan, Colorado is in the Great Plains and streets run N-S and E-W, oriented to the cardinal directions defined by the spin of the Earth. (C) In central Pennsylvania the Appalachians form long ridgelines and valleys. (R) Cities like State College, PA have street grids aligned parallel to the terrain of the mountains in the area. Click to enlarge. [Images: Google Maps]

But seeking patterns in everything is a dangerous proposition — while we certainly believe that the laws of Nature govern everything, recognizing repeating and organized patterns is not always so easy. One of the classic examples of this is the tale of wealthy Bostonian Percival Lowell, whose imagination was captured in 1877 by the announcement of Italian astronomer Giovanni Schiaparelli that he had observed canali (Italian, “channel” or “groove”) on Mars. Many people’s inexperience with the Italian language caused them to map the word onto the English word “canal” which has a definite connotation of being an artificial and constructed edifice. (This erroneous mapping of words between one another is a failure to correctly match patterns!).

Lowell was entranced by the idea of canals on Mars, and spent a not inconsiderable amount of money constructing what is now known as the Lowell Observatory in Flagstaff, Arizona. He himself spent many long hours at the eyepiece, staring at Mars and sketching what he saw. Looking at his sketches and records we find Lowell saw what he wanted to see — canals. Lots and lots of canals. Looking at Lowell’s exquisite maps of Mars a century later, after our robotic spacecraft have returned tens of thousands of pictures of Mars, we see none of it. The interwoven pattern of canals which Lowell saw appear to be a dramatic case of scotomathe mind sees what it wants to see.

(L) Percival Lowell observing on the 24-inch Clark Refractor at Lowell Obseratory. (R) Lowell's map of the canals he thought he was seeing on Mars, now a classic example of seeing patterns that are, in fact, not there at all. [Images: Wikimedia commons]

(L) Percival Lowell observing on the 24-inch Clark Refractor at Lowell Obseratory. (R) Lowell’s map of the canals he thought he was seeing on Mars, now a classic example of seeing patterns that are, in fact, not there at all. [Images: Wikimedia commons]

Which carries us back to the tale of Blake and Trusler. We all see the world through our own eyes. The goal of collecting knowledge and one of the purposes of doing science is to capture the world as it really is, and to use that knowledge to improve our lives. No single one of us can do it all on our own; it requires all minds on deck. No single one of us ever gets it right on first glance; we have to look at the world, examine what we have seen, ponder its meaning, and, if necessary, let go of what we once thought in favor of a more real picture of what Nature has laid out before us.

So head out and look for the subtle patterns in the Cosmos; it’s all there for you to see.  See you out in the world — I’m the guy trying to take a picture of the repeating tile pattern on the cafeteria floor!🙂

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This post is part of an ongoing series about the #AdlerWall. I encourage you to follow along with the activities, and post your adventures, questions and discoveries on social media using the hashtag #AdlerWall.  Links to the entire series are here at the first post of the #AdlerWall Series.