Friday, August 25, 2017

What You Thought You Knew about Artificial Sweeteners

Are Artificial Sweeteners a Sign of the Apocalypse?

I have a chemistry minor and a biology major.  Most people don't.

With that out of the way, let me be frank in the observation that most of the things people tell you are wrong.  I have found it nearly axiomatic that nearly all things people tell you about diet and health are wrong, sometimes so stupendously, irresponsibly wrong as to constitute wrongdoing.  

Sometime in 2013 my dad came home from work and even before grabbing a beer, seized a box of Splenda from the pantry said, "We gotta throw this stuff out.  That stuff's poison.  I heard it on the radio on the way home."

The things that people say about artificial sweeteners fall under this category.  My dad was not alone in his uncritical acceptance of the proposition that artificial sweeteners like Splenda are "poison" or carcinogenic.  So let me take the opportunity to school you on this unique and misunderstood class of compounds.
Image result for sucralose microscope
At left is common table sugar.  You can easily make out the cubic crystals.  The ones at right are crystals of Splenda, whose main component is sucralose.

Sugars Vs. Non-Sugar Sweeteners

First, a few notes on sugars.  Yes, I said "sugars."  There are hundreds of known of sugars, and we can broadly define sugar as any water-soluble short chain or cyclic carbon-based compound with multiple hydroxide groups, for which the ratio of carbon to hydrogen to oxygen is generally 1:2:1.  So you can have C3H6O3, or C7H14O7, or glucose, whose formula we learned in middle school science is C6H12O6.  Most sugars have names that end in "ose," such as glucose, lactose, and sucrose.  Sugars are carbohydrates and supply living things with quick access to cheap calories.  They can make long chains called polysaccharides, more commonly known as starches.  There are usually about 3.9 nutritional calories in a single gram of sugar.  Many sugars taste sweet.

From left to right, we see a lactulose- a disaccharide, and glucose and fructose- monosaccharides.  Table sugar (sucrose) is a common disaccharide.  The sugar in your blood is modulated by glucose.  Most sugars have ring structures.  The grey is carbon; the white is hydrogen; and the red is oxygen.

Non-sugar sweeteners comprise a wide and diverse menagerie of organic, or carbon-and-hydrogen-based, compounds, most of which are derived from glucose or sucrose, although many have more exotic origins (such as mushrooms).  Some artificial sweeteners are sugars; others are non-sugars.  A natural non-sugar sweetener such as stevia or erythritol is usually referred to as a "sugar substitute," while sweeteners made in an industrial chemical process, such as saccharine or Splenda, are called "artificial sweeteners."  Here we will focus on the latter, as they lie at the center of much more controversy and misinformation than benign ol' stevia.  Artificial sweeteners are often made by taking sugars and shotgunning them with a variety of catalysts and extremes of temperature and pressure.  In the case of Splenda, sugars are force-chlorinated in towering pressurized tanks to produce sucralose.  Trucks come in bearing sugar, they leave with loads of Splenda.  (However, the marketing slogan "It's made from sugar, so it tastes like sugar" is bullocks on a few levels, not the least of which is the fallacy that a derivative tastes like what it is derived from.  Do you suppose that manure really tastes like grass?  "It's made from grass, so it tastes like grass" is clearly not true in this case.  But we are barely a short way in and I am already on an unproductive tangent.)  Because artificial sweeteners are man-made and are considered food additives, they must be tested and approved by the Food and Drug Administration or (if not in the US) other food safety authority.  Stevia and the like get around this by being essentially "herbal," which means their safety is actually much more questionable than FDA-approved sweeteners.  I'm just being honest here.

From left to right we see aspartame, sucralose, and saccharine.  All of them maintain the basic ring structure found in nearly all sugars, but they have extra chemical groups attached that stimulate your taste buds.  (The scientific community is still a little confused about how and why they work on the human tongue.)  The same colors apply as the ball-and-stick models of sugars above, but here blue is nitrogen; green is chlorine; and yellow is sulfur.  Most artificial sweeteners have one or more of these added chemical groups.

First, why are artificial sweeteners non-caloric?  What about them makes a soda "diet"?  It is common to suppose that the body somehow "cannot process" or "absorb" these compounds, so they leave the body without contributing calories.  But the truth is that they certainly possess calories that are able to be absorbed by the body.  Indeed, a gram of pure aspartame has about the same energy content as table sugar.  But the sweetness of, say, sucralose (the main component in Splenda) runs about 1,000 times that of table sugar, while saccharine runs at 300 times, and aspartame at about 200.  Stevia and erythritol don't run as high but are almost non-caloric.  So instead of using, say, 60 grams of sugar per 8 ounces of soda, we can use 0.060 grams of sucralose, which possess maybe 0.2 calories, and be done with it.  Artificial sweeteners aren't actually non-caloric; they are instead super-sweet, and so their caloric contributions to food and drinks is negligible.

Why We Think that Artificial Sweeteners Will Not Kill You

Next, why the bad reputation of artificial sweeteners?  The most common, and almost absurdly ignorant, mis-belief is that they cause cancer in humans:

"There was a study," someone assures me, "A study done in the 70's, I think, on rats that shows that aspartame [or saccharine, or whatever] causes bladder cancer."

"I read that study," I respond.  "Did you know it was debunked based on its poor methodology only a few years after it was published?  Did you know that they fed the rats absurdly huge quantities of aspartame, more than any human could possibly consume?  Did you know that rats produce a unique compound in their urine that crystallizes with aspartame's metabolites and causes bladder ulcers, which are precursors to cancer?  Did you know that the same study done on mice showed no such result because mice do not produce said compound, and the same with gerbils, guinea pigs, cats, horses, monkeys and even humans? Did you know that the huge bulk of subsequent studies [like this one, and this one, and the European Food Safety Authority (they ban everything) and this government health resource] indicate no connection between human consumption of artificial sweeteners and the incidence of cancer?  Even this study shows that Splenda in particular has no such impact on rats."

"Aspartame turns into formaldehyde when it is metabolized," he says.

"Yes.  Aspartame is metabolized into some amino acids and a small residual amount of formaldehyde.  Did you know an orange has 600 times as much formaldehyde in it than a can of diet Pepsi?  Did you know that formaldehyde's cousin acetaldehyde is produced as an intermediate in the metabolism of alcohol?  You should stop drinking all alcohol and orange juice.  Definitely no more screwdrivers."



The science is really unequivocal on this: artificial sweeteners are not known to cause cancer in humans, period.  Aspartame itself is one of the most rigorously tested and studied substances the FDA has ever approved.

If this bothers you, then I advise you do what I do: ease up on the soft drinks.  I hardly ever drink any sort of soda because it is so bad for my teeth.  Plus, if you drink regular soda, it's gut-punching your pancreas as it is metabolized.  I go for flavored seltzer water, like the stuff made by La Croix or Kroger.  Even Dry is a less sugary alternative.  These fizzy drinks are super delicious, refreshing, and you don't have to suffer the guilt of consuming extra calories or chemicals you suspect of causing cancer (even though you're wrong about that last part).

The 2017 Total Solar Eclipse: The Experience

This is really a set of three blog posts. 

In the first post, I detail my attempt to record the 2017 Total Solar Eclipse using my camera phone and telescope with solar filter.

In the second, I explain what the 2017 TSE felt like in Gallatin, Tennessee, starting at 11:59am, ECT and extending through 2:54pm, with a local totality duration of 2 minutes and 37 seconds.

In the third, I give a quick explanation of how I turned my 1200 photographs into a short film of the TSE, which I will post as soon as it is done.


The 2017 total solar eclipse in Nashville, Tennessee easily ranks in my top 5 greatest life experiences.  It’s probably number 2, topped only by my wedding day.  Here I try to explain just what this event felt like.  It is easy to Google lots of images of total solar eclipses.  It is hard to get a real sense of the feelings before and during the TSE, the whole sensory experience of totality.  If you missed the 2017 TSE, please- for the love of God- start making plans right now to see the 2024 TSE as it passes on a northeast path through Mazatlán, Durango, Torreón, and Piedras Negras, Mexico; Dallas, Texas; Indianapolis, Indiana; Cleveland, Ohio; Buffalo, New York; Plattsburgh, New York; Miramichi, New Brunswick; and Newfoundland.  My wife and I are musing about the possibility of seeking the 2026 TSE in Iceland, and/or the 2028 TSE as it passes through the entire width of Australia.  I am now insatiably, permanently addicted to total solar eclipses.

My friend Michael Genau texted me a few weeks before the 2017 TSE, suggesting we should road trip down to Nashville to see it, where our other friend Sam Girwarnauth currently works and lives.  At first I vacillated, because August 21 was pretty close to school starting, and my wife Kristin was already working and would not be able to come with me.  Finally, about a week before the TSE, I decided to go, and made plans.  Starting early on Saturday morning, August 19, I made the 3.5 hour drive from Shelby Township, Michigan to Goshen, Indiana, where Mike lives.  Next morning we took Mike’s Toyota Camry the rest of the way down to Nashville, where we met up with Sam and Brittany and stayed the night.  I lugged along my banjo, my 6-inch  Dobsonian reflector telescope, and some non-essentials like food and clothing.

We rose early on August 21 and began planning.  The previous night was spent catching up on Sam’s back balcony, but now it was time for business.  After searching around online for a while, we found that the arc of totality would pass pretty closely to Gallatin, TN, which was about an hour’s drive northeast from Nashville, just north of the Cumberland River.  At 9:41am I texted Kristin to let her know we were doing our eclipse planning.  Using Google Maps, we located a tiny spit of land jutting south from Lock 4 State Park, forming a little peninsula that appeared to be mostly free of trees and was quite out of the way.  We chose that as our Plan A, and Mike and I planned to head back to Goshen immediately after the eclipse.  So we packed up our gear into the cars, including some snacks and water.  We left around 10am, and the TSE was scheduled to begin at 11:59am, just barely enough time to get there and set up.

As soon as we hit the highway we knew traffic would be an issue.  Sam and I began discussing contingency plans: If the TSE began while we were in traffic, we would simply pull off and set up shop wherever we were.  Not ideal, but acceptable as a last resort.  Thankfully we got through to Gallatin and swung into Lock 4 State Park at just about 11am.  As we slowly tooled into the park, we were encouraged: although there were many people here, the park was large enough to rarify the crowd, so that people were pretty spread out. 

We probably snagged two of the last parking spaces on the grass, one adjacent to the other.  There was plenty of open grassy space in the sun, but also enough trees that we could get some shade if we needed it.  Already it was around 85 degrees, and we were hot.  Cicadas buzzed as we walked down to the southern tip of the park to prospect the lay of the land and decide if we could find an acceptable space.  On our way, we weaved between rows of cars parked along the service road, and a wide diversity of eclipse-seekers milled about.  Some of them had set up tents or claimed the handful of pavilions that dotted the park.  There must have been 100 telescopes with solar filters already set up, their operators sitting at the ready.  But I only saw refractor telescopes, not a single reflector like mine.  The service road was elevated, above the rest of the park, and it terminated at the park’s southern tip with a needle-eye loop with a grassy teardrop-shaped area in the middle.  South of the loop the grass sloped gently to a small rounded promontory that extended out into the gently flowing river.  Reeds and rushes jutted out of the shallows in scattered tufts, and piles of shrubs and small trees on the water’s edge provided some narrow strips of shade.  Boats blaring Bonnie Tyler’s “Total Eclipse of the Heart” trolled along the Cumberland River, and we could also make out a few areas on the river’s far banks were other eclipse-seekers were setting up camp.  Just uphill from where the slope levelled off was an enormous maple that shaded a clump of eclipse seekers.  Downhill from that tree was the place.  It was unclaimed, flat, and had an unobstructed view of the sun.  I told the guys that I thought that was the best place.  We dropped off two folding chairs and some umbrellas, and Mike stayed to stake our claim.

Sam and I marched back to the car to grab my telescope and our bags of snacks.  The sun was blazing.  By now the temperature had climbed to 95 degrees.  We hauled the equipment down the slope, and I began to put the telescope together and calibrate the spotting scope.  Check out this post for a descriptive explanation of how I prepared for this event.  I gave Mike and Sam each a pair of viewing glasses, the kind with the mirror finish that you can use to look right at the sun.  It was so hot in the sun that I took off my shirt, but the sun on my skin actually made me hotter.  Plus, somehow we had forgotten to pack sunscreen, and I did not need to take that particular souvenir on the 7-hour drive back to Goshen.  (The drive actually lasted 12 hours thanks to traffic.)  By the time we were all set up and ready, it was around 11:15am, and just shy of 100 degrees.  There was a worrying preponderance of towering cumulus clouds, but for now they were staying at bay.

In the hour or so leading up to the beginning of the TSE at 11:59am, the park had the air of a sort of carnival or fairgrounds, except that there was not the slightest trace of commercialism.  There was not one vendor hawking viewing glasses, t-shirts, drinks, snacks, shot glasses, refrigerator magnets, or any of the trappings of modern kitschy consumerism.  There was a single port-a-john near the park’s entrance, which had a permanent line for nearly the whole time we were there.  The joy of the experience was purely the interactions among people and nature, not between them and their possessions.  Some college kids were throwing a Frisbee around, some youngsters were playing in the river, lots of people had brought their dogs, and of course, the amateur astronomers fondled their telescopes.

Once we claimed our territory and I set up the telescope, I saw that there were 6 sunspots visible on the face of the sun.  From left to right there was a fat, dark spot about three times the size of Earth, then a tiny, pale one near it, then a diffuse blurred sunspot nearly four times Earth’s diameter but longer, then a similar one that was tilted a little differently and darker at its center; then near the very right edge of the sun’s disc I could make out a stark spot like the first one, and a jumbled blob of a sunspot about four times the size of Earth and fairly dark.  You can see them below, which was the view through my objective lens at exactly 11:56am, just 3 minutes before the eclipse began.  I kept asking Sam to update me on the time.

And then, with a remarkable slowness, the moon’s edge appeared in my eyepiece.  It was so gradual a movement that I couldn’t perceive it unless I looked away, then back again a minute or two later.  That was when I started furiously snapping pictures.  I had to document this.  My knees got rubbery and my heart raced as a few scattered cheers went up.  I was covered in sheets of sweat.  And still I shot dozens of pictures at a time.

As the minutes wore on, the moon slowly- so slowly- ate up the disc of the sun.  It got easier to gauge its movement by comparing its distance from the sunspots.

It was at around this point that small clusters of eclipse-seekers started to come down to my setup and ask to look through the eyepiece.  My large, black reflector telescope was prominently positioned at the base of the hill, and it had attracted notice even as we lugged it down the slope.  I was more than happy to allow everyone a glance through the telescope, and they were truly wowed by the Dobsonian reflector’s resolution and magnification.  Over the course of the TSE we were probably visited by around 50 people from all over the region, many of them Michiganders, Ohioans, even an Aussie.  There were groups of friends who had road-tripped like us, there were retired folks, there were parents with children, there were newlyweds, and all number of other demographics.  Everyone was extremely friendly and just wanted to enjoy this experience together.  It was possibly the most optimistic, positive, and cynicism-free crowd I’ve ever seen.  An amiable man named Greg from Ohio complimented my setup and invited me to see his.  He had taped one side of eclipse glasses over the aperture of his telescope, and it did a commendable job of filtering the light.  We exchanged pleasantries and I admired his ingenuity.  It was all very exciting.  I enjoyed pointing out the sunspots, and by this time there were gently sloping mountains faintly visible on the moon’s surface.  You might just be able to spot them in the photo below, along the moon’s upper edge.  All the same, I was a little worried about the cumulous clouds piling up.  Totality would last only 2 minutes and 37 seconds, and the passage of a single dark cloud at the wrong moment could dash the whole thing.  The moon slid onward.

It was still extremely warm, but the temperature had dropped to perhaps around 90 degrees.  Several times Mike and Sam asked if I wanted a peanut butter and jelly sandwich, but I declined because of my excitement.  I was also worried that the food would distract me from photographic opportunities, and that I would miss unacceptable spans of the TSE’s duration.  Not to mention, PB&J sandwiches are sticky, and I was working with lenses that I could not afford to smear up with peanut oil and jelly residues.

By 12:50pm it was noticeably darker and cooler, although you still couldn’t safely look up at the sun.  The sliver of the sun’s disc that peeked out from behind the moon seemed just as bright as a full sun, and it was blinding to look at without eye protection.  Every minute it got cooler and darker.  A comfortable, gentle breeze picked up. 

The strange thing about this moment was that although the light began to fade away- as you might expect on a clear summer evening just after sundown- the source of the light was still very high.  The sun cast sharply-outlined shadows beneath us, but the shadows took on the same eerie appearance of shadows formed by moonlight.  The buzz of cicadas faded a little, and then they were replaced by the stridulation of crickets. 

Totality was predicted to start at 1:27pm and last exactly 2 minutes and 37 seconds at our location.  By about 1:20 my camera began to have trouble with the exposure and focus, and my photos started turning out like the one below.  Notice how it is washed out and a little blurry at the edges. 

About 5 minutes before totality, I put away the camera and just tried to enjoy the moment.  I looked at the tiny crescent of sun through my NASA-approved solar glasses and also enjoyed the coolness, the breeze, and the ever-dimming sky.  It had cooled by about 20 degrees.  The piles of cumulous clouds were taking on a twilight purple tinged with cool blue, but it looked as though they would hold off for totality.  The cicadas and birds had fallen asleep.  It was eerily dark and cool.  My heart beat so fast it hurt my chest.  My knees were shaking.  I was excited and somehow frightened.  It was too many conflicting emotions for my head to make sense out of.  The collective anticipation was so thick that it asserted itself as its own electric presence in the air, like a silent, thrumming music that made your feet and fingers tingle, made your stomach flutter.  It dimmed and dimmed.  It was dreadful.

And then, at 1:27pm local time, totality occurred.  The tiny smidgen of sun on the far right edge of the disc was extinguished with a startling suddenness, and a horrible, haunting darkness swept across the park.  It was the visual equivalent of a thunderclap.  The crowd cheered, wild and uninhibited.  The sky was a glistening, glowing lavender hue; the planets Venus and Mercury popped into existence, along with a scattering of stars.  All 360 degrees of the horizon became a red and orange sunset, with the towering clouds purple and dark.  Then the crowd hushed into gasps and whispers.  Boats on the lake honked their foghorns.  I heard the staccato report of fireworks.

And in the sky, where the disc of the sun had been, was the total solar eclipse.  The most acute superlatives cannot grasp the horrible beauty of this sublime event.  As I gazed, transfixed by the awful, haunting object in the sky, I was utterly dumbfounded.  It was at once smaller than I expected and also shockingly more real.  The disc of the moon was the blackest thing I had ever seen.  No ink, no dark well, no black coal, no night sky, no image can ever approach the immaculate, pure black of that horrifying object’s color.  It was almost hard to imagine that there had ever been light there.  And surrounding this awful black disk was a glaring, white, fiery mist- the fabled corona.  It spewed out from the black disc in three main regions: one spire on the lower left, one on the upper right, and another on the lower right.  They did not appear to move and shift as I expected.  The corona’s combined width was at least three times that of the black disc, which meant it must be millions of miles across.  Even after the moon had devoured the sun, this pure white crown of plasma was bright enough to illuminate the sky, although it could not produce shadows because the light was too diffuse.

I could barely take my eyes off of this event, but I managed to get out my camera and start stupidly narrating a hastily improvised video.  The only words I came up with to describe it at the time were “Too bizarre” and “Too strange.”  And that was true, but the video fails to resolve the black disc of the moon, which is extremely disappointing.  Mike and Sam’s cameras also wouldn’t resolve the disc, so all we have to remember that transcendent image is our minds and this blog post.  I’ve done a little photographic manipulation to simulate exactly what it looked like.  Alas, although this is an excellent simulation, it is not the same.

What words could best encapsulate this experience?  Exciting, dreadful, joyous, sublime, horrible, haunting, heavenly, divine, hellish, frightening, awe-inspiring, awful, wonderful, beautiful, terrifying, magnificent.  Although appropriate, even these words cannot quite capture the feeling of the total solar eclipse as viewed from Gallatin, Tennessee at 1:27pm on August 21, 2017.

157 seconds passed between the start of totality and its end.  As I continued to shoot video and snap pictures, the crowd began to cheer again.  The disc of the sun appeared on the other side, and with the suddenness of flicking on a kitchen light, our shadows reappeared and the park glowed under the sun’s illuminating rays.  The crowd continued to cheer against the renewed backdrop of foghorns and the pop of fireworks.  At 1:47pm I texted Kristin to tell her “It was indescribable!”  I had been sending her photographs from my telescope for the last hour or so.  My hands were still shivering.

Over the next hour and a half, the crowd cleared out, but the guys and I stuck around so I could capture the rest of the eclipse through the telescope.  As the light and heat grew, I again became drenched in sweat.  The angle of the sun had changed significantly since the beginning of the eclipse, and because it was now shining directly on my telescope’s eyepiece, more and more aberrations and blur worked their way into the photographs.  Its heat and light were beating on the left side of my neck, which would later turn crispy and red with a mild sunburn.

Finally, thankfully, the moon ended its futile 175-minute assault against the sun and eased out from in front of its disc.  I snapped a few more shots and fell to my knees in utter exhaustion.  I claimed the rest of our dwindling supply of water- rightfully by my estimation- as Sam and Mike helped haul the telescope and other materials into the car.  We said our goodbyes with hugs and pats on the back.  It had been an absolutely incredible experience and a fun journey with my two best friends.  As I pored over my photographs and began weeding out the bad ones, Mike drove us out of Lock 4 State Park, and we headed north for Goshen, Indiana.

The trip back north was bad and required our skillful avoidance of heavy traffic spots.  It was all the eclipse-seekers trying to race each other home.  We skirted Louisville and Elizabethtown- two central hubs which Google Maps reported were choked for miles around- and managed to circumvent the worst of it.  Out of our twelve total hours of travel between Gallatin and Goshen, a full five hours were spent sitting in bumper-to-bumper traffic.

And it was worth every second.

Here's an excellent shot that my friend Sam Girwarnauth was able to take with his camera.  Still, the photograph just doesn't do the experience justice.

The 2017 Total Solar Eclipse: Telescopic Observations

This is really a set of three blog posts. 

In the first, I detail my attempt to record the 2017 Total Solar Eclipse using my camera phone and telescope with solar filter.

In the second post, I explain what the 2017 TSE felt like in Gallatin, Tennessee, starting at 12:03pm, ECT and extending through 2:17pm, with a local totality duration of 2 minutes and 37 seconds.

In the third, I give a quick explanation of how I turned my 1200 photographs into a short film of the TSE, which I will post as soon as it is finished.

In this post, I’m going to discuss just what I did to capture the photographs of the 2017 TSE.  I focus on the techniques and the hardware.

Sometime in high school- I think it might have been around 2003- I was lucky enough to get a telescope for Christmas.  It was and still is a superb telescope.  It is a 6-inch Orion 8944 SkyQuest Dobsonian reflector.  That means it’s a 6-inch wide tube with a very fine parabolic mirror mounted against the back, and the mirror reflects the image onto a small objective mirror, which subsequently sends the light of the image through an eyepiece fitted with a compound lens.  It is this compound objective lens that determines the magnification; it is the width of the telescope that determines the aperture, or the amount of light it can gather; and it is the length of the telescope (multiplied by 2) that determines the focal length, which determines the resolution of the final image, or how crisp and precise it looks once you stick your eye in there.  It sits on a chunky, pressed particleboard base that swivels so you can adjust where it is pointed.  (No, I do not have a motor drive- one of those fancy, expensive, computerized setups that orients the telescope automatically... Although I sincerely wish my telescope could be fitted with one.)

Then, perhaps a year later, I received a solar filter.  I don’t recall what the occasion was- Christmas, my birthday, or my own money- but I do recall that the filter alone ran around $250 at the time, and remains one of the best solar filters that money can buy.  It looks like a perfectly flat, double-sided mirror.  I can fit the solar filter onto the telescope simply by pressing it over the telescope.  You can see it in the photo above as a grey cylinder fitted over the telescope’s aperture.  That’s Sam checking out the eclipse through a pair of solar glasses.

The telescope is fitted with a single optical spotting scope with a 2x zoom.  That sounds like a small magnification, and it is, because the spotting scope has a much wider field of view, Though the view through the spotting scope is of a low magnification, the point of this instrument is simply to find the object you wish to observe and then orient the telescope manually, making little adjustments once you spot the object through the objective lens.  At night you can look straight through the spotting scope.  If you are observing the sun, you can’t, because you will instantly burn a hole through your retina at the back of your eyeball, resulting in permanent vision loss in that eye.  (Imagine what happens when you create a beam of heat with a magnifying glass in the sun.  Then imagine that happening inside your eye.  Then imagine the fascinating sound you’d make.)  So while orienting the scope to the sun, I just placed my hand 2 or 3 feet behind the spotting scope, and adjusted the telescope so that the sun’s image appeared in the crosshairs.  In order for this to work, I had to calibrate the spotting scope the day before in broad daylight.  To do this, I just pointed the telescope to the very top branches of a distant tree- because it is easy to find through the objective lens- and compared that image to the one in the spotting scope.  I made adjustments as necessary so that the two images matched as perfectly as I could manage.  Now the spotting scope was precisely oriented with the telescope’s field of view.  In the shot below you can see how the sun’s image projected onto my hand.  The sun’s image looks a little like Pac Man in this shot because the moon has begun to occlude the light on one side.

So once I had made these preparations to the telescope itself, I drove with my friends Sam and Mike to Gallatin, Tennessee, near where the duration of totality was greatest for our region: 2 minutes and 37 seconds.  We were staying in Nashville, but the duration there was only 1 minute and 30 seconds.  So we chose to brave the heavy traffic in order to chase those extra 67 seconds of totality.  We are grateful that we did.

After parking our two cars, lugging out the telescope, its base, our supply of snacks and water- the heat was equatorial- we marched down to a sunny spot just on the northern edge of the Cumberland River.  The sky was dotted with fat, drifting cumulus clouds, just enough to give us some trouble if we were unlucky.  Thankfully, not a single cloud obscured the sun from start to finish.

I knew that I would be able to observe the TSE through my telescope, and that it would be phenomenal.  What I did not know was whether any of our 3 sets of digital cameras would be able to capture it through the objective lens.  Sticking a camera up to a telescope lens and snapping away is a notoriously finicky operation, because of the optics involved.  If I had really prepared, I would have bought a camera adapter and fixed a digital camera to the telescope itself.  Alas, the best laid schemes of mice and men.

Michael and Sam had each brought their own digital cameras.  Mike’s even had manual settings, which is ideal if I was to try controlling exposure time and f-stop.  But neither Sam nor Mike seemed to be able to line up the optics of their cameras with those of my telescope’s objective lens.  Anticipating failure, I stuck my camera phone up to the lens as a last resort and began to experiment.  I have an LG K20 V smart phone (model number VS501) with a resolution of 13 megapixels.

Improbably, the camera was able to autofocus on the objective mirror surface, meaning that my photographs were crisp and crystal clear.  My phone has an exposure feature that lets you tap a region of the image, and the phone adjusts the exposure and aperture for the brightness.  That was helpful near totality, when the exposure time became an issue.  I was even able to capture not only high-resolution sunspots, but even the mountains on the edges of the moon.  They appear as gentle bumps or hills, not as jagged as I imagined.  See if you can spot them here.  If you look for them using the Moon feature in Google Earth, they are near the lunar coordinates 34ºN, 73ºE.  The most prominent mountains visible here stretch for a distance of about 400 miles.

Lining up the phone’s camera with the objective lens was a challenge.  If I didn’t position it manually in exactly the right location and angle, aberrations blurred the resolution and glare obscured the edges of the sun and moon.  I was very liberal with my shooting: in the 175 minutes of the eclipse, I snapped about 1200 photographs, many of them in clusters of 5 or 10 at a time.  This ensured that as the camera focused and adjusted the exposure, I was almost guaranteed to snap at least a single decent shot for that cluster.  All the images produced for the video are the highest quality I was able to fish out of my total gallery pool.

Immediately before, during, and after the totality of the TSE, I stopped shooting through the telescope objective lens, because the light meter was having trouble trying to figure out what I was doing.  It would over-expose while also letting in too much light with a wide aperture, so the slender image of the sun’s remaining sliver shone much too bright.

Of course, in those moments before totality, I really just needed to soak up the experience of the eclipse, and I attempt to describe it in my next post, which will soon be posted at this link: 2017 Total Solar Eclipse: The Experience.  Here's a video I started shooting about halfway through totality.

After totality, the hundreds of eclipse-seekers quickly disbanded, and we were more or less left alone.  Sam and Mike could have left, but I really wanted to capture the remainder of the eclipse so I could document the full approach and recession of the moon from the sun’s disc.  My friends appreciated this and stuck around in spite of the oppressive heat.  (At least they had the option to relax in the shade while I became soaked in sweat in the amplifying sunlight and heat.  You can’t shoot an eclipse from the shade.)

Finally, mercifully, the eclipse ended for Gallatin, Tennessee and we packed up.  Now I had a preponderance of photographs to manipulate and try to figure out how I’d turn them into a movie of the moon’s occlusion of the sun, the 2017 Total Solar Eclipse.

Friday, June 20, 2014

What the Banjo has Taught me about Learning Curves

Learning Curves

My friend Sam once told me in a conversation about the subject of philosophy, "There's a steep learning curve."  Understatement of the century.

But the aphorism has surfaced again in my flailing attempts to produce music with the banjo.

Generally speaking, a "learning curve" is a progression of difficulty in learning a skill or subject over a course of time.  A steep learning curve means that you have to learn a lot, pretty quickly, in order to learn the skill.  It can be represented with a graph.

Region A represents the slope in the first period of learning.  Region A may take a few minutes, or maybe several months.  It may be steep, as indicated, meaning that the learning rate is initially grueling.  I interpret this phase as being when the learner is at the highest risk of quitting.  In the case of banjo, a suite of skills need to be picked up.  Obviously chords, a few things about scales, and- most importantly- right-hand technique need to develop as integral foundations to the amateur player.  A learner may respond to region A with "Wow, this is challenging, but I'm learning noticeably day to day," or with "This is hard; screw it."

I have spent a lot of time trying to make music, and I find that something critical to learning is that the learner is able to reflect on his progress as substantial and noticeable over a reasonable period.  When I started to learn claw-hammer technique, it took me at least 10 days before I found that I had made any progress; honestly, this is a long time to spend waiting for something to click.  And in this case it took those 10 days just to realize that I could do it.  It took about another 10 before I could admit that I was doing it.  And another 10 to put it into practical, interesting use.  And another 10 before I could do it in a way that felt fluent.  Then, scarcely had I journeyed those 40 days before I realized that I was getting bored with my limited ability and began to break out into a technique called "drop-thumb," which I discuss below.

Region B represents the last 10 days of my intensive hammer-claw learning.  By this time I felt that I understood what I was doing, though there was room for improvement.  I was learning a lot of simple little tunes for hammer-claw but felt restricted in my ability to diversify them (they all sounded too similar to me).  Drop-thumb is a technique in which the thumb is liberated from the fifth string and bounces around from the fifth to other strings.  This may not sound sexy to you, but to a new hammer-claw player, this sounds almost heretical.  I gave it a shot- badly- for a few hours until I started to get the hang of it.  The rate of learning here was nowhere near as steep as when I first began to familiarize myself with claw-hammer, but it is keeping me interested at the moment.

Region C is, like A, another trouble spot and, I think, presents the next highest risk of quitting an instrument.  I have reached Region C again and again on the guitar, and sometimes I seem stuck there.  In Region C, the learner is essentially a sophomore.  I've learned all the basics, he says, and there's not much more substantial material to learn.  I guess I'll plink around and see what happens.  This of course sounds pretty stupid.  Stevie Ray Vaughn, Jim Croce, Jimmy Hendrix, Preston Reed, George Harrison, and Eric Clapton (to name a tiny fraction of great artists) probably never thought this.  But the attitude slips into new learners' thinking all the time.

It is in Region C that the learner needs to be pushed by an instructor to explore new areas or have the discipline to seek out those challenges for himself.  Each new challenge is represented by a new bump, in the region represented as Region D.  In Region D, the little waves may individually be much steeper and larger than Region A, depending on the increased level of difficulty.  For instance, if I leveled off in Region C for hammer-claw and began to intensify my attention on finger-picking- a different technique- I would end up in another steep curve, the qualities and length of which may be greater or less than Region A.

The Rub

What do I mean with all these abstruse musings on "learning curves" and "regions" of said curves?

Notice that the curve goes up.  And the curve goes up at a rate roughly proportional to the learner's effort (in my view).  So this is really applicable to learning any skill.  If you suppose yourself to be incapable of learning some new skill, look at the curve.  Yes, it starts steep.  You may even run out of momentum a few times and have to put the breaks on or change gears.  But it levels out eventually.  Maybe you are content to stop at Region B, fine.  But remember that you can do it.

I have had to remind myself that I can do it a hundred times in the short duration of learning to play the banjo.  And I have- so far- always been right.

Wednesday, June 18, 2014

Some Early Thoughts on Learning to Play the Banjo

Perceptions of the Banjo
Your appreciation of this miraculous instrument is contingent upon your exposure to it.  If the only tune you know is the one from Deliverance, then it might creep you out.  Or if you consider the banjo to be the guitar's retarded cousin, fit only for stump-jumpin, inbred, hillbilly mountain folk who run a little short in the dental department, then you might think it to be below your sophisticated modern taste.

But if you have developed a love and deep appreciation for the musical genre of bluegrass, then the banjo is something more.  It is majestic, dignified, thoughtful, and the defining sound of bluegrass.  It is mysterious and sometimes somber, an acoustic mountain of mystery that invites you to explore.  For a small taste of what you might be missing if you don't appreciate the banjo and bluegrass in general, see some of the links below:

The Punch Brothers (covering the Cars)
Pine Mountain Railroad (covering Journey)
Iron Horse (covering Elton John)

These players are mostly modern and are not traditional bluegrass, but if you listen to them I think your schema of "banjo" will expand exponentially.

Playing the Banjo
I got a banjo for Christmas of 2012.  I learned some chords and a few rolls, but it never really clicked with me.  I've played guitar for 4 or 5 years and have always stuck with it as my standard instrument of choice, but the banjo always stood as that guilty I-wish-I-played-it-more instrument in the corner, usually in its case and usually out of tune.

The guitar is tuned to no particular chord.  Any chord requires a few fingers thrown down against the fret board.  It has a rich sound with a long sustain (as long as around 10 to 15 seconds), so it can be strummed as a supporting instrument.  A banjo, on the other hand, is often (but not always) tuned to the key of open G, meaning that you can play it without putting any fingers down, and it makes the musical sound of a G chord.  So songs in the key of G are easy to play.  The banjo has a shorter sustain (maybe 5-7 seconds) and therefore must be part of a continuously moving melody in order to be relevant to the song.  Usually this is achieved by what are called rolls- plucked sequences that involve an alternating pattern of thumb, middle, and index fingers engaging the 5 strings.  One odd thing about the banjo is that the string closest to you is tuned to the highest note, instead of the lowest as in the guitar.  This is because banjo players pluck the hell out of that string to produce the signature ring quality of banjo music.  This is something I never understood until around early March, when I saw video of a banjo instructor playing in the "claw-hammer" style.  Get a little taste of claw-hammer Cripple Creek here or here on a guitar (you have never seen this before).

Now the claw-hammer style is really a departure from what I had considered as traditional banjo playing.  It turns out to be more traditional than what is called picking, which you can see here in another version of Cripple Creek.  In the claw-hammer style, melody notes are struck between "brush strokes-" in which all strings are struck to fill in the musical gaps- and the thumb-pluck or the "down beat," where the thumb pulls up on that fifth string to produce the signature sound.  It is probably called claw-hammer because the shape of the hand is in a claw, and the hammer-on is a technical skill that lends this style its unique sound.  Go here for another great claw-hammer tune, Ole Joe Clarke.

The Claw-Hammer Project
I started getting serious playing the banjo around early March of this year, and I have come close to mastering the claw-hammer technique.  What I would like to do is chronicle my stump-jumping inbred ramblings while I learn to play the banjo, and maybe I'll invite any unwary traveler along for the ride.

I hope this entertains you rather than making you want to tear your ears off.

More to come.

Sunday, January 26, 2014

My Students are Joining the Army Corps of Engineers

Inquiry in Chemistry

...Is pretty difficult to pull off.  Here is why:

Inquiry education refers to letting students ask and answer their own questions, and arming them with the tools and some of the background knowledge to generate their own knowledge.  It's about putting them in charge- making them responsible- for their own learning.

An uncritical chemistry instructor bent on doing inquiry labs with inexperienced sophomores is likely to set his lab ablaze with a chemical fire or suffocate the southwest wing of the building with hydrogen sulfide.  You will find that many early chemists perished by means of their own experiments (one notable exception being Antoine Lavoisier, who was beheaded at the climax of the French Revolution after being [falsely] convicted selling adulterated tobacco and giving money to France's enemies).  But it was precisely this debonair chemical playfulness and curiosity that landed some of the greatest foundational discoveries of the chemical sciences.  How can a chemistry teacher encourage this curiosity without also encouraging a building evacuation?

Here I am going to put forward an example of how I am encouraging inquiry in chemistry, and propose a model for how it can be implemented in a wide array of science lessons.

Reactions and Stoichiometry

Being able to categorize reactions by their type is crucial for students of chemistry, because it helps them develop a framework for the behavior of compounds and elements when they combine, break apart, or rearrange.  In inorganic chemistry there are 5 recognized reaction types:

Synthesis- 2 or more elements combine to make a new compound.  A + B --> AB
Decomposition- A compound is broken down into smaller pieces.  EF --> E + F
Combustion- A compound is combined with oxygen to produce 2 or more oxides.  JK + O2 --> JO + KO
Single-replacement- An element reacts with a compound to replace one ion.  A + BC --> B + AC
Double-replacement- Two compounds react and exchange ions, resulting in a gas, precipitate, or water.  AB + CD --> CB + AD

The SUPER important thing to recognize with the last two bolded reactions is that they can be used to selectively remove an ion from a solution.  For instance, if my solution is contaminated with aqueous (dissolved) silver nitrate, I can add a little sodium chloride and form what is a called a precipitate, or the visible, white, insoluble compound silver chloride:

AgNO3(aqueous) + NaCl(aqueous) --> NaNO3(aqueous) + AgCl(solid)

Now we can just filter out the white AgCl crystals, and the silver is gone forever!  

Or suppose the water is contaminated with iron(III) chloride, the same nasty stuff at the center of an earlier blog post.  I can perhaps selectively precipitate out the iron(III) ion if I can replace it with a metal that is higher in what is called the "activity series" of metals.  A metal higher on the activity series will kick out a lower metal, resulting in a precipitate, through a single-replacement reaction.  I might try the reaction below.

FeCl3(aqueous) + Ca(solid) --> CaCl2(aqueous) + Fe(solid)

As long as I add just enough calcium metal to the dissolved iron(III) chloride, I convert that acidic, carcinogenic substance into harmless calcium chloride salt, a common food preservative.  I would be able to tell whether this reaction worked because iron(III) chloride is a dirty ochre color; if it is removed from the solution and replaced with calcium chloride, then the solution should go from dark yellow to clear (or at least less yellow).

You need to have some background in chemical reactions- and a sense of creativity- to make the predictions I made above.

The aim is for my own students to see this on their own and realize that they can do the same thing with a little research and creativity.  For them to do this, they will have to have a clear sense of how replacement reactions work, understand the solubility rules (only certain compounds are soluble in water), and also predict if a reaction will happen based on the activity series of metals.

"Stoyk- Stoykee- wait, what?"

These are the words of one of my male students upon first hearing the term "stoichiometry" [stoyk-ee-om-etree].  This science combines a knowledge of molar mass and reactions to allow the chemically curious to predict the outcomes of reactions as far as reactant mass, yield, and percent yield.  In other words, stoichiometry allows you to know exactly how much of your ingredient substance(s) you should measure in order to get the desired amount (usually mass) of product(s).  We use a unit called the "mole," which represents 6.02x10^23 particles, to describe quantitative relationships in chemistry.  If we know how much a mole of a certain element or compound weighs, we can use this conversion to correctly assign masses to our substances in the reaction.

Now this is all a little abstract or abstruse to most, but understanding stoichiometry is absolutely essential to describing the mass-relationships of chemical reactions and how do do actual lab work.  There is literally no other way to do it.  And it is very math-intensive.

So how do we turn a stoichiometry lesson into an inquiry unit?  What follows is how I am going to try.

How My Students are Joining the Corps

I have come to find that one of the pillars of inquiry education is concrete goal-setting and, to a small extent, role-playing.  The goal is a freshwater lake cleanup, and the role is a chemist in the Army Corps of Engineers.

In class we will suppose that there has been a major spill of a toxic salt in Lake Saint Clair, indicated by the white X at left.  In 2003 there was a toxic vinyl chloride spill in Lake Saint Clair, and people had to stay out of the water and not eat any Saint Clair fish for a while.  We'll use that as a hook.

Each pair of students will act as a team to rid the water of the contaminant, using their knowledge of reactions and stoichiometry.  I will assign different chemicals to different groups, partly by difficulty (some salts are easier than others to clean up).  Below are the amounts and types of salts that students will be responsible for removing from Lake Saint Clair.

14,200 kg of copper(II) sulfate: CuSO4
19,900 kg of potassium chromate: K2CrO4
26,300 kg of barium chloride: BaCl2
11,150 kg of sodium hypochlorite: NaClO
27,500 kg of lead(II) nitrate: Pb(NO3)2 (maybe)

The bold ions are the toxic ones, so these are the particles that students are trying to remove from the water supply.  Free copper, barium, and lead ions are all pretty toxic, and chromate and hypochlorite are pretty nasty too.

Not only will students need to perform reactions that will remove the offending ions from a solution, they will then have to do stoichiometric calculations to predict the mass of reactant(s) they will need to perform this procedure.

The key to solving the problem lies in research, understanding reactions, and devising creative lab solutions.

What My Corps Engineers Will Do

The teams will first have to do some background research and make a general proposal of how to remove the toxic compound from the water.  Following are the steps they must take in this process.
  1. Research the chemical's properties: taste/smell, color, density, solubility, toxicity, reactivity, etc.
  2. Identify at least 2 reactions that can remove the offending ion from the water.  Any solution will (probably) require a single-replacement or double-replacement reaction.
  3. Calculate how much reactant will be required to remove 2.0 g of the offending compound from a solution.
  4. Identify how they will know whether they have removed the offending ion. 
  5. Compile the above information into a formal lab proposal.

Next they will need to do some work in the lab.  After I have gone over their lab proposals and OK'd one of the reactions they think will work, they will perform that reaction to see if it is effective in removing the substance.  The steps they will need to take are as follows.
  1. Dissolve 2.0 g of the toxic substance in a small amount (maybe 100 ml) of water.
  2. Perform the reaction using the mass of reactant that they calculated in the formal lab proposal above.
  3. Evaluate the effectiveness of their reaction.
  4. Record all materials and methods of their lab procedure.
  5. Propose how to scale up the successful reaction so that it can be used to remove the given mass of toxic substance.  Show calculations.
  6. Compile the above information into a formal lab report.

What this Unit Will Look Like

Let me put a human touch on the whole proposition so it is clear what I intend for this unit to look and feel like to me- and more importantly- to my students.

Students will immediately feel uncomfortable, because I will not be giving them a single set of instructions on how they are to perform their lab procedure.  Upon assigning the work, they will not be very strong with the whole idea of stoichiometry, but this will improve over the course of the unit.

Students will have to collaborate closely in order to uncover how to remove their respective offending ions from the solution, and this is where I will have to put in a lot of effort in guiding them toward lab work that will be productive.  The purpose of the first research assignment is simply to let them explore their compound on their own, make predictions about reactions, then get my approval on how to proceed (I want them to succeed, so I will have some say on how they may wish to go about working in the lab).

The scary part will be when they get into the lab and start employing the methods they have devised.  They will have to be able to predict stoichiometric relationships so they do not waste chemicals or perform an inefficient reaction.  They will have to weigh and record their reactants and infer whether the reaction has worked, as I did in my examples above.  

They will have to work to express professionally what they are considering and what they have done to solve the problem.  They need to communicate their progress to a boss in writing.  

This is high-level depth of knowledge that I hope to see them achieve on their own.  It is the dream of every imaginative educator.

The Proposed Model

I said I would propose a general model of what I do to support inquiry learning, and it is outlined below.
  1. Students are presented with a clearly-defined problem that implies a clearly-defined goal.
  2. Students are allowed the ability to research their problem independently, then refer to instructor for guidance and advice.  If working with others, this is a good opportunity for group collaboration.
  3. Students attempt their solution in an "as-close-to-reality" setting as possible.
  4. Students evaluate the efficacy of their solution.
  5. Students may also make recommendations on how to enhance their solution: How to scale it up, How to improve its efficiency, How to apply it to other scenarios.