Catching Meteors

Meteors or “falling stars” are an annual visual treat for casual observers and amateur astronomers alike, all around the world. I had my first experience of observing a meteor shower with the Perseids last weekend.

In what turned out to be an unforgettable experience, my girlfriend Leina, and I took a late-night road trip to Prairie Gardens, located near Bon Accord, a small town in central Alberta and an International Dark Sky community.

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A sample picture of the night sky at Prairie Gardens.

As a waning gibbous moon rose prominently above the distant horizon, we alighted upon a parking spot near an open field watching the night sky gradually come alive with the familiar band of the Milky Way Galaxy, and the luminous freckles of innumerable stars. Grabbing some popcorn, we would spend the next few hours watching a wonderful show of celestial beauty.

Of course, the night wasn’t complete without a short monologue (thanks to my background in astrophysics) on the phenomenon itself, before the show got underway. I will be treating you, my fellow readers, to the same today while providing further information and resources for all who are interested in catching the next similar astronomical event.

What are meteors?

Meteors are bits of interplanetary material falling through the Earth’s atmosphere. The same objects are also identified as meteoroids while they are hurtling through space, becoming meteors for the few seconds they streak across the sky and create glowing trails. Meteorite essentially refers to the same phenomenon, the major distinction being it is a meteoroid that survives its passage through the Earth’s atmosphere and impacts the planet’s surface.

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It is estimated that about 44,000 kilograms of meteoritic material falls on the Earth every day. Several meteors per hour can be observed on any given night. It is when the number increases dramatically that these events are termed meteor showers.

What causes a meteor shower?

Taking the Perseid meteor shower as an example, the phenomenon we are observing is caused by the Earth’s motion through the dust and debris left behind by the comet Swift-Turtle, the largest object known to repeatedly pass the Earth. The comet last passed our planet during its orbit around the sun in 1992, and its next visit will be in 2126 (I should be 135 years old then, but don’t worry, I will give you all a heads-up). It is Earth’s passage through the leftover comet debris that results in meteor showers. The Perseid meteor shower is particularly popular, and peaks around August 12 every year. Most of the meteors in the Perseids are about the size of a grain of sand, and rarely make it all the way to the Earth’s surface.

Are there others?

Other meteor showers and their associated comets include the Leonids (Tempel-Tuttle), the Aquarids and Orionids (Halley), and the Taurids (Encke), most of which are modest showers. The Geminids, coming up on December 13, are typically one of the best and most reliable of the annual meteor showers with peak rates of about 120-200 (at best) meteors per hour.

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Photo by David Kingham of the Perseid meteor shower, awarded Greenwich’s Astronomy Photographer of the Year award in 2013,  combining 23 individual stills over several hours.

What do you need to see them?

Very simple. All you need to catch the show is darkness, somewhere comfortable to sit, and a bit of patience. The best thing to do is drive away from the city lights, and go to a nice dark place by the suburbs or countryside. Prepare to sit outside for a few hours, and bring some snacks and bug spray. Finally, let your eyes adjust to the darkness, and enjoy the show!

Where can I follow up on all of this?

The World Wide Web is a wonderful resource. Space or Astronomy, and even more obviously, NASA, all provide wonderful updates and articles on the various astronomical events throughout the year. So, whenever you feel like indulging in your inner astronomer, and something out of this world, just check out these resources.

In that vein, I leave you all with a reminder that we do have a solar eclipse coming up tomorrow. The eclipse will primarily be featured across America where people will have the chance to observe a total solar eclipse, while Canada will see a partial solar eclipse. To all my readers in America and Canada, have your eclipse glasses ready for this! To all my readers elsewhere around the world, for more information and live streams, you can always check out: Solar Eclipse!

Happy observing everyone!

Adventures in Drawing!

Making good progress on my dreams to be a mangaka in the future, I’ve spent the past two months attending a basic drawing class, and so far, I’m having a blast. This post is dedicated to my fellow amateur artists, or anyone interested in drawing; I thought it would be a worthwhile effort to provide a summary of what I have learned so far, and share my efforts with all my readers.

Art, in general, is a highly subjective field. At the first session, it was a relief to hear my instructor recite the philosophy, “Anybody can learn how to draw,” mentioning that one’s drawing ability isn’t measured by how gifted they are, but is rather a reflection of their perseverance, and efforts to hone their skills.

Though I’m only halfway through the course (four sessions out of eight in total), I’ve learned a lot. Much of this learning has involved the transcription of my observations, and perspectives of a random subject onto a paper, following three fundamental principles of drawing.

Techniques aside,  drawing is the ability to closely observe your subject. It is an exercise in learning to actively see things, and deduce differences.

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Figure 1 – My first work, a shoe!

 Lesson 1 – Learn to actively see things. Figures 1-2 describe this principle. Both figures were drawn within the same period of time, with Figure 1 drawn initially, prior to instruction, and Figure 2, after learning to remediate my ability to observe, and focus on the details of the shoe.  

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Figure 2 – The same shoe, after really learning to observe my subject.

Rather than have a passive approach, I was instructed to use continuous lines, which provided a sense of structure, and certainty to my artwork. Now, drawing a straight line in itself is difficult, continuous lines even more so, and it is here I found the value of repetition.

Lesson  2 The value of repetition. It is imperative that you repeat the exercises you learn in drawing. Figure 3 presents simple exercises in “doodling,” such as drawing circles of varying sizes, and figure eights, using continuous curves (without lifting the pen). Such activities helped with hand-eye coordination, particularly with blind contour drawings. 

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Figure 3 – Part of aggregating your skills in drawing is to practice, repeatedly. 

I spent many an hour practicing my hand/eye coordination by simply doodling around on a piece of paper. This also helped big time in learning to draw with my arm rather than my wrist which is essential when one wishes to draw continuous lines.

Lastly, I was encouraged to draw what I plainly see in my subject, and not give in to the natural urge of presupposing what I believe the subject should be from prior knowledge.

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Figure 4 – The botched pepper.

Lesson 3 – Draw what you see, not what you know. This makes a big difference. Figure 4 presents the infamous drawing of a pepper from memory (looks more like a pumpkin). Figure 5 presents a pepper drawn from observation.

Now, does this make a difference when it comes to drawing from imagination. I think it does, but we have to realize that our imagination is in many ways an exaggeration or extrapolation of what we observe in our reality. Learning to draw what I see in reality helped nurture my imagination.

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Figure 5 – Pepper from observation. Seeing versus knowing makes a difference in drawings!

These three principles have formed the foundation of my progress in the class so far. Supplemented by lessons in individualizing one’s artwork, and finding a measure of focus, and shape consciousness (which calls for basic interaction with your subject) my drawings have come a long way (Figures 6-7).

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Figure 6 – A half-finished portrait of Natalie Portman using graphite pencils, cheese cloth, and blending stumps.

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Figure 7 – Another exercise in graphite. A portrait of Marcus Aurelius. I’ve still got a long way to go!  

In this review, I wished to provide a generalization of the primary lessons that were essential to getting me started in drawing. Of course, there is always more to learn especially when it comes to the various techniques that can supplement your skills such as the use of guidelines, sighting angles, drawing upside down etc. But ultimately, practice makes perfect.

In my case, drawing has served as an extension to my imagination, as well as an entertaining activity in interpreting the world around me. As an art, it stresses our abilities to interact with the environment using our physical, and mental faculties, providing a medium through which one can express his/her individuality.  Most of  all, it is a lot of fun!

On a conclusive note, for those among my readers who live in Edmonton, I attend my drawing classes at the Edmonton City Arts Center.

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The course is 8 sessions long, and is well worth the money. The City Arts Center boasts a variety of programs for adults, and children alike. If you’re interested in polishing your basics for drawing, certainly give the Drawing 1 & 2 course a try.

And for my readers who occupy various other corners of the world, but are aspiring artists, I would highly suggest Bert Dodson’s Keys to Drawing.

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It is an excellent resource to learn the principles of drawing, and is a great complementary reference for any basic drawing course.

A Walk In The Spring Rain

With winter’s departure at my doorstep, I alight upon the memory of a day in a rainfall that caressed me with the soothing warmth of your touch.

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Falling upon the blankets of water that condensed from the gray skies, I clung to you, slipping amid the warmth of your skin.

Time awaits no one, and in a moment that carried me away in the bliss of a cool breeze, you walked by my side.

Ripples in the ponds of life stemmed forth in our every step together, your smile, a reflection amid the mirrors that coalesced at every turn.

Observing our progress along the white of clouds that brushed our feet, gently ascending, leading us to where the stars lay hidden, and our spirits flew free.

In a story that is to be told, your eyes reflected the words of my heart, our laughter resonating amid the silent melodies of the world.

A beautiful blossom, you remained, weathering the winds of time that passed our wake, embracing me into the petals of your life.

Into a stillness that resounded in the minute strikes of my heart, my eyes met yours, the cold moisture of the crystals giving way to the warmth of your lips.4b9b99b1_o

Serenaded by the orchestral pitter-patter of the rainfall surrounding our feet, I indulged in the moment, falling and rising about your heartbeat.

Carried by the whims of nature, our shadows basking in the gentle ray of sunshine that awakens the distant horizon, in an adventure to continue, with the coming of spring.

Reminiscing On the Promise I Made To You In Our Early Days…

February 14, an annual holiday celebrating the feast of St. Valentine, otherwise popularly known as Valentine’s Day. The day was first associated with romantic love in the 14th century by Geoffrey Chaucer, a time period when the tradition of courtly love flourished. As such, it became an occasion when lovers expressed their love to one another by various means from presenting flowers, offering confectionery, or sending greeting cards.

A poet myself (from a young age), I’ve always celebrated Valentine’s Day by putting my creativity to the test, writing several poems on the occasion, mostly of romantic nature. As a teenager, I exercised my inspiration from experiences at home, in the company of the love I witnessed between my parents, to the ordinary circumstances of life that were my adventures at school. In fact, my first published work, Our Last Summer, found its beginning in a poem. With its end came the realization of a truth that aptly described my first infatuation when I fell in love with love itself.

Shortly after, I would fly away from home, pursuing a future in the star spangled skies that awaited me in Edmonton. In the solitude of the years that followed, I would contemplate much about the nature of love and life, finding peace in my own isolation, and yet constantly seeking for company in my dreams. And in that manner, on the venue of this 14th, I would write a poem experiencing for the first time my own inability to express my feelings in a question that required no answer.

Yet, for what it’s worth, my voice was heard on that day by someone I hold dear to my heart, and to her I now say, in what has become a melodious sonata of our time together as friends, as partners, and as soulmates I find myself running out of words to describe the beautiful poem that has been the four years of our life together. So for now, I shall stutter, and stumble into the comfort of the night’s silence as I reminisce about us, and the promise I made you in our early days, and one I intend to keep for all my life…

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Watashi wa itsumademo anata wo airisu desho, Leina-chan!

Why Is Snow So Bright?!

If one wishes to experience the full spectrum of the annual cycle of the four seasons, Edmonton is certainly the place to visit. Though it varies every year, you can expect an early start to spring around March, with summer setting the pace in June, autumn settling in with September, followed closely by winter arriving around October at the earliest. Winter, in fact, is the chief minstrel of Edmonton’s seasonal ballad (Figure 1), with Boreas providing for the brittle winds, and dense snowfall that sweep across the city during this season.

Figure 1. Edmonton’s winter skyline

Who doesn’t like snow? I myself have never denied an opportunity to jump into or wade my way through a dense pools of snow (just make sure you are wearing the appropriate gear for the occasion), or on some occasions push others into them (my partner, Leina, in particular, could relate to a few “sweet” memories). In fact, it was only after arriving in Edmonton, 19 years old to boot, that I first saw snow in my life. This was back in 2009, and now that 2016 has come to an end, I have rounded off seven years to my predominantly snow-filled life in Edmonton, Alberta, Canada. Despite all of this, if there is one thing that I could never get used to in all these years, it would have to be waking up in the early hours of the day to the bright, and mildly annoying  pure, ambient white light emanating from the snow outside my apartment, leading now to the subject of our post, “Why Is Snow So Bright?”

The answer is quite simple. Snow has the highest albedo of any naturally occurring substance on Earth. Albedo is the percentage of reflectance (of light) off the surface of an object. Snow is ~ 90% reflective, which is why it is so damn bright. This begs the question of how a reflective surface may appear brighter than its diffuse illuminant (the sky, in this case). Having done a little bit of back-reading, it is reported,

“Three factors are largely responsible for this visually striking effect: the law of darkening for the cloud cover, the reflectivity of the snow and the average landscape albedo, and the observer’s contrast sensitivity function.”

 J.J. Koenderink, and W.A. Richards, Why is snow so bright?, J. Opt. Soc. Am. A, Vol. 9, No. 5, May 1992. 

We find that the explanation for the brightness of snow is a mixed physical, and psychophysical phenomenon. While the paper provided by J.J. Koenderink, and W.A. Richards go into great detail on the scientific methods that support these observations, I will provide a summary covering some of the interesting facts found in the paper. The three factors, aforementioned, are examined in a sequential manner, and the necessary conclusions derived accordingly.

The Scattering of Light

We begin with the law of darkening for the cloud cover. This involves intuitive observations we often make about the radiance or illuminance of the sky. The sky is not uniformly illuminated. This is quite noticeable depending on the elevation of our line of sight with respect to the horizon. Two factors are largely responsibly for the darkening that is usually observed from the maximum brightness we find at the zenith (point in the sky directly above us) to the grayish haze that we identify as the horizon:

“The angular distribution of the forward scattering (average differential scattering cross section) and the backreflectance to the clouds off the surface of the Earth.”

Light, or electromagnetic radiation, from the sun is scattered by particles in the atmosphere. This is commonly known as Rayleigh Scattering named after the British physicist Lord Rayleigh (Figure 2), a principle that describes the scattering of light by particles much smaller than the wavelength of the radiation.

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Figure 2. Lord Rayleigh

These particles can be individual atoms or molecules. The light from the sun is a mixture of all colors of the rainbow. Using a prism one can separate the “white” light from the sun to its different colors forming a spectrum (Figure 3). These colors are distinguished by their different wavelengths. Our vision is limited to what is known as the visible part of the spectrum ranging between red light at wavelengths of 720 nm to violet with a wavelength of 380 nm.

Figure 3. The visible spectrum (ROYGBIV)

In between, we have orange, yellow, green, blue, and indigo. The retina of the human eye has three different types of color receptors that are most sensitive to red, green, and blue wavelengths providing us the colored vision of our environment. On a clear cloudless day, we observe that the sky is blue. This is because molecules in the air scatter blue light from the sun more than they scatter red light. Meanwhile, at sunset we see the familiar red, and orange haze because the blue light from earlier has been scattered out, and away from our line of sight (Figure 4).

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Figure 4. Why is the sky blue?

Similarly, forward scattering is a subset of radiation scattering which involves changes in direction of less than 90 degrees. In contrast, the effect of the backreflectance of the surface of the Earth is found to be largely independent of the visual angle of observation as the clouds of an overcast sky are roughly Lambertian. No matter from what angle the observer views a Lambertian surface, the brightness of the surface apparently is the same. Unfinished wood is known to roughly exhibit Lambertian reflectance, while a glossy/coated wooden surface does not. These two factors, forward scattering and backreflectance, contribute to the radiance of the sky, and the observed darkening of the sky from the bright zenith to the grayish horizon.

What about our eyes?

From here onwards, it is smooth sailing. The paper discusses the last two major factors including the reflectivity of snow and the average landscape albedo, and the observer’s contrast sensitivity function. It is found that the albedo of snow typically ranges from 80% to 95% across the spectrum with lower values for higher snow densities. Though snow is not a true Lambertian surface, the approximation is satisfactory. The landscape albedo figures into much of the calculations involved, and we find that it is only in extreme situations that the radiance of the snow is equal to the radiance of the horizon sky. In general, a whiteout (Figure 5),  is only possible if the reflectance of the landscape is above 50% which rules out most effective natural landscapes with the exception of snow itself.

Figure 5. Whiteout, a weather condition where visibility and contrast is severely reduced by snow (or sand). As can be observed, the horizon disappears completely.

Much of what is demonstrated in the paper shows that the contrast effect of snow can cause the sky at the horizon to appear darker than the zenith sky. But, the zenith sky is still found to be brighter than the snow, so why is it that we are not able to recognize this difference, and identify that the sky is indeed brighter than the snow? The answer is once again quite simple. The sky at the horizon is darker than at the zenith owing to the law of darkening described earlier. This results in a gradient over the circular dome above us, but one that is so shallow that the gradient is generally not noticeable to the comparative resolution of our eyes, thus leading us to believe that the snow is in fact brighter than the sky that illuminates it.

References

  •  J.J. Koenderink, and W.A. Richards, Why is snow so bright?, J. Opt. Soc. Am. A, Vol. 9, No. 5, May 1992.