No Limits | Spring 2017 by The Hotchkiss School

The Hotchkiss Science and Technology Magazine

Spring

2017

BOARD EDITORS IN CHIEF Jackie Ryu ‘17 Jennifer Zhai ‘17 Sumin Goh ‘18 EDITORIAL BOARD Sam Saxena ‘17 Daniel Kim ‘18 Jay Lee ‘18 MARKETING BOARD Alex Trevithick Krishna Sivakamur Eric Chun Maria Fernandes

‘17 ‘18 ‘19 ‘17

WRITERS Jay Lee Jackie Ryu Alex Jeon Michael Li Geena Ko Daniel Kim Giordana Fiorentino Farzona Comnas Kawin Tiyawattanaroj

‘18 ‘17 ‘17 ‘18 ‘17 ‘18 ‘19 ‘18 ‘17

DESIGN Sumin Goh Pete Assakul Bonnie Dana Theresa Yu

‘18 ‘18 ‘19 ‘19

FACULTY ADVISOR Dr. Susan Park

CONTENTS Mother Tongue and Learning a New Language 1

Jay Lee

Identifying Two Newly Discovered Black Hole X-Ray Transients in the Galactic Center 3

Jackie Ryu

Sound 5

Alex Jeon

A Stepping Stone to Interstellar Conquest 7

Michael Li

Two Dad Babies 11

Geena Ko

Interesting AI 13

Daniel Kim

False Memory Syndrome 17

Giordana Fiorentino

Limb Lengthening 19

Farzona Comnas

Non-Schiometric Compound 21

Kawin Tiyawattanaroj

One-Way Road 23

Ken Wu

AND

THE MOTHER TONGUE LEARNING A NEW LANGUAGE JAY LEE ‘18

THIS SPRING, I decided to register for a full one-month immersion at a Spanish Language camp in Vermont. Thus, on June 28th, I packed my bags and headed for Vermont on a cold 6 A.M. morning for the 4-5 hour journey to the small town of

Poultney, Vermont. For 26 would be fully immersed in

days,

Spanish.

This meant every single conversation I had, every single song I listened, and every movie I watched would be in Spanish. At times, this experience proved to be quite frustrating and difficult as

watched movies without

knowing what was going on and listened to my teacher speak for three minutes straight while understanding just the words pero, y, and sí (but,

and, yes respectively) within her entire speech. on the

However, as I hit the road 24th of July to return home,

I remained baffled by how much my Spanish abilities had improved in just a month. To follow up my state of shock, I decided to do some research about the scientific processes that served

as the behind the scene causes of my tremendous improvement.

s infants, we learn to communicate in our native tongue. We acquire grammar lessons through years of immersion in our first language. While learning a language is a process that takes quite a bit of time, the works of many researchers indicates that the idea of learning a language is an instinct present from birth. In addition, further research reveals that everyone’s brain has certain restraints that makes learning certain syllables quite difficult, even if an infant is in the process of learning his or her first language. The left hemisphere of the brain contains the temporal, parietal, and occipital lobes. These different sections make up a person’s language control center. Within these lobes are the Wernicke and Broca areas, which enable language recognition, speech, listening, as well as the ability to learn new languages.

LANGUAGE AT ITS MOST BASIC FOUNDATION IS JUST A BUNCH OF SYMBOLS. THESE SYMBOLS ARE THEN REARRANGED INTO SPECIFIC PATTERNS TO FORM WHAT WE CALL LETTERS. FOLLOWING THIS ARE WORDS, SENTENCES, PARAGRAPHS, PHRASES, AND A LANGUAGE’S ENTIRE GRAMMAR STRUCTURE.

LEARNING A FOREIGN LANGUAGE AS A CHILD AND AS AN ADULT After I did some research, I realized how lucky I was to have started studying Spanish as a teenager. It’s because adults are at a clear disadvantage when it comes to learning a language. This notion stems from a scientific concept called brain plasticity. Brain plasticity refers to the brain’s “ability to modify its own structure and function following changes within the body or in the external environment.” The brain is able to modify its own structure by creating neurons and synapses. Neurons are types of cells that transmit information through electric signals and chemical signals while the synapse is simply the space between different neurons through which neurons send the electric or chemical signals. Unfortunately, as we age, the brain’s ability to synthesize new neurons decreases, and thus, our ability to learn new concepts or subjects decreases as well. Another possible explanation by Robert Bley-Vroman suggests that it is the way by which adults approach learning a second language that makes it much more difficult for them to learn foreign languages than it is for children, although this still remains a theory. For those of you who are craving to learn a new language or have found more motivation to pursue your current language after reading this, I suggest a couple simple, but helpful tips to facilitate your languagelearning journey. First, study vocabulary and grammar, what

some might consider the foundation of every language, before you go to bed. This is because new research indicates that going to sleep after learning new content helps reduce memory deterioration. In addition, it is a good idea to practice your respective language by speaking it and listening to it in other classes as well as the language class itself. A study of students taking French revealed that when they were taught other subjects such as mathematics in French, their listening skills improved and they had more motivation to learn French. Learning a new language is an exciting experience that while in the beginning can compel you to wonder why people just didn’t agree to make Esperanto the universal language will eventually lead to excitement and satisfaction when you can see the manifestation of all your efforts in your ability to speak a new tongue. No language is easy to start with, and each language has its own complexities, such as the grammatical aspects of the language or the oral aspects of a language. Not only that, but learning a language can also involve studying the culture of a nation, the background of its people, and much more beyond the superficial layer of a language that is thousands of vocabulary words and grammatical rules. It’s an exciting process. It’s one that I hope you will learn to appreciate and have as much with as I have had this summer during my immersion program because once you learn a language, you’re not just a smarter person. In fact, you’re a new person.

IDENTIFYING TWO NEWLY DISCOVERED BLACK HOLE X-RAY TRANSIENTS IN THE GALACTIC CENTER

One of the most intriguing challenges in high-energy galactic center astrophysics has always been to identify more black hole systems, in order to account for their curiously small population, contrary to popular theoretical implications. It is widely believed that as our galaxy began to progress many billions of years ago, the black holes should gradually fall closer into the center of the galaxy throughout time due to their loss of energy as they collide with astrophysical matter in the interstellar medium (Miralda-Escudé & Gould 2000). Thus, theoretical evidence implies millions of black holes in the galaxy; however, the culmination of all historical observations only yields less than 70 strong black hole candidates in the entirety of the Milky Way, with only JACKIE RYU ‘17 21 dynamically confirmed black holes (Tetarenko, 2016). Of these, only one has ever been identified in the central two to three parsecs of the center of the galaxy (Tetarenko, 2016). The ongoing studies of galactic center sources are extremely exciting to this date, as they add insight to the everlasting uncertainty regarding the scarcity of identified black hole systems in the galactic center. X-ray telescope Swift, since 2006, has been monitoring the galactic center on a daily basis, and within these past seven months, they found very exciting observations of three completely new X-ray binary transient sources (“The Swift X-ray Monitoring Campaign,” n.d). In early February of 2016, they reported the transient source, SWIFT J174540.7-290015 (Swift 15), located just under 17 arcseconds north of supermassive black hole Sagittarius A* (positioned at the center of the galaxy). In late May, another X-ray binary transient system was detected, SWIFT J174540.2-290037 (Swift 37), approximately 10 arcseconds south of the galactic center (“The Swift X-ray Monitoring Campaign,” n.d). A third X-ray source detected in early May, thought to have started experiencing accretion bursts since late March, GRS 1741-2853, has already been identified unambiguously as a neutron-star binary (Rutledge, 2016). Our research will therefore focus on the identification of Swift 15 and Swift 37, two fresh and unclassified X-ray transients that are incredibly close to the galactic center. Based on the preliminary observations from Swift, NuSTAR also became motivated to monitor the region of the galactic center in which the transients popped up and

recorded their respective data. The NuSTAR telescope is internationally renowned as one of the premier X-ray telescopes due to its large effective energy band, ranging from 3 keV to 79 keV (“NuSTAR Bringing the High,” n.d). Because of this advantage, we will use NuSTAR’s observations, as they are most compatible with high energy imaging software and will yield the most information-rich spectral results (“NuSTAR Bringing the High,” n.d). X-ray binary systems, such as the transients that we will be delving further into, are the fundamental focus of this subcategory of astrophysics. The galactic center is populated with a huge variety of different objects, and telescopes such as Swift, NuSTAR, Chandra, XMM, and others are able to detect many of these sources due to the X-ray emission from the source’s binary system (“Astronomer’s Toolbox,” n.d). X-ray binaries are two-star systems with a compact object and a main sequence companion star. In particular, X-ray transient binaries have a compact object, typically either neutron stars or, less commonly, black holes. In these binary systems, the compact object, with significantly larger gravitational force, will accrete matter from the companion, or donor star, forming an accretion disk as the matter gradually falls into the compact object (“Astronomer’s Toolbox,” n.d). In black hole and neutron star binary systems, X-rays are detected from the plasma generated from the differential rotational friction, which occurs due to the difference in rotation speeds within the accretion disk, alongside the impact of the accreted matter on the compact object’s surface if it is a neutron star;

black holes do not have definitive surfaces (“Astronomer’s Toolbox,” n.d). In this study, we analyze a pair of X-ray binary transients, Swift 15 and Swift 37, that have been dominantly illuminating the field of view for all X-ray telescopes monitoring the galactic center since their outbursting six to seven months ago (Rutledge, 2016). Through a thorough analysis of their spectroscopy, we establish two new solid black hole transient candidates, both less than one parsec away from the center of the galaxy. These highly suggestive blackhole transient systems are the closest black holes to the galactic center ever recorded. Our results present detailed characteristics of two new black hole candidates, and we hope our findings on Swift J174540.7-290015 and Swift J174540.2290037 provide fascinating insight to the galaxy’s black hole population.

SOUND

you can’t see music. ALEX JEON ‘17

BUT IF WE COULD... WHAT WOULD IT BE LIKE?

THAT’S MUSIC VISUALIZATION.

irst, a little background: put simply, the Fourier transform is a function that takes a signal and splits it up into its various frequencies. The two different kinds of Fourier transforms are the continuous Fourier transform and the discrete Fourier transform. The continuous Fourier transform takes all the points in the signal and converts them into its constituent frequencies. However, the discrete Fourier transform only takes a few of the points in the signal. For the most part, we use the discrete Fourier transform for digital signals because the signal is a series of points in the first place.

To see what I mean, we need to know how a digital signal sample is taken. To convert a signal from analog to digital, we can’t possibly take all the points. Therefore, we take a few points from the analog signal at a constant rate, called the sampling rate. Now, the discrete Fourier transform is way too slow. By using the definition of the discrete Fourier transform, the DFT takes O(N2)operations. Luckily, we have the fast Fourier transform (FFT). Basically, the FFT achieves the same thing as the DFT, but it’s much faster. Compared to O(N2), the FFT takes O(NlogN)operations, which can be pretty significant when N gets really big. In fact, the FFT is so fast that it can operate in real-time. Music visualization is essentially the marriage of FFTs and art. What the FFT provides is a method to quantify music; art can dynamically interact with these resulting numbers. Before we can create awesome visuals, we place some limits so our art doesn’t look outrageous. First, we need to control our decibels. Second, we need to normalize our frequencies. We need to make sure that each bar in our FFT only takes values from 0 to 255 (8 bits or 256 bytes). Otherwise, a lot of the frequencies will just go off the charts and the visuals will look messy. Essentially, by limiting our values, we create a “visual MP3

file”. After all, an MP3 is just a compressed WAV file. However, it’s not recommended that we start with an MP3 file because we don’t want to begin with an already compressed file; it’s up to us which frequencies to tamper with and which to leave alone. On the note of compression, normalizing is a major component of creating stunning visualizations; an audio sample is normalized when there’s a pretty flat, even frequency response. For the most part, the lowest and highest frequencies won’t spike up as much as the middle frequencies. This is just an artifact of microphone capabilities; in a perfect world, everything would already be normalized. To solve the frequency problem, we apply an exponential or logarithmic function to

the frequencies; the function will amplify or compress based on the frequency. This normalization function varies depending on the audio sample. For example, from the FFT above, I can see that some of the higher frequencies need a lift. Therefore, I might apply an exponential function to help out with the normalization. The rest is creativity. You can draw a connection between a block of frequencies and a shape. The increases and decreases in the FFT would dictate the size of this shape. For example, if I want a triangle to denote bass, the triangle would get larger as the lower frequencies spike and get smaller as the lower frequencies dip. Really, have fun with it. There’s nothing holding you back.

Here, you can see an example output of the FFT. The bottom of the graph shows the different frequencies that make up the original signal.

A STEPPING STONE TO

INTERSTELLAR CONQUEST MICHAEL LI â&#x20AC;&#x2DC;18

he original settlers of the New World were no different than the people of today, constantly hungry for new land and the untapped potential that may come with it. Nowadays, with humans having already conquered much of the inhabitable space on Earth, and with a seemingly exponentially increasing population, a new question arises—where do we go now? Many have hinted at potential settlement, not so much on our home world, but on other worlds. With recent technological advancements and growing support, people have started to consider space settlement a possibility, specifically on our rocky neighbor, Mars. Apart from Earth, the next most habitable planet within our nearby vicinity is the Red Planet, and it should be seen as the first step towards mankind's extraterrestrial conquest. This hospitality comes down to a few conditions. First, the surface of water contains traces of water, both as its solid form of ice, and, as NASA recently confirmed, as flowing water [1]. As a result, there is an indication that Mars’ surface temperature must neither be too hot nor too cold, at least when compared to other planets. In fact, according to some estimates, Mars is considered to be within the goldilocks zone [2], a habitable ring surrounding the sun, though it lies near the further edge of this zone. In

addition, Mars also mimics some of earth’s other conditions: a similar, albeit thin, atmosphere, nearly identical day/ night schedule, and a loosely similar gravitational force, all of which should allow for easy adaptation to a foreign environment. These conditions allow Mars to be the best, and maybe only valid option which humans can look toward for possible settlement outside of Earth [3]. Yet what holds us back from settlement isn’t so much the conditions of the environment for settlement, but the technology that supports our journey towards settlement. Take Mars for example, it is a barren wasteland that would take 7 months of travel to reach, at least with current technological capabilities [4]. This distance and lack of resources for survival would require astronauts to learn to survive in deep space for extended periods of time, much longer time spans than astronauts currently spend in the ISS. But NASA has already starting necessary precautions to deal with these shortcomings. In fact, they have a goal to put a man on mars by the 2030s. Their plan to study mars attempts to answer questions: “Was Mars once home to microbial life or is it today? Can it be a safe home for humans? What can the Red Planet teach us about our own planet's past, present and future?”

[5] Although their purpose is primarily to collect information on Mars, one goal that they are looking towards in the near future is the colonization of the red planet. In order to do this, NASA has proposed, and already begun, with a three-phase plane. The first phase, Earth reliant exploration, has already begun and continues on until the mid 2020s, working on research and development within low-earth orbit, focusing specifically on the effects of extended stay in space on Astronauts. The second phase, the Proving Ground, should start around 2018, lasting until 2030 and pertains to the conducting of missions around and on the moon. From this phase, NASA plans to test the capabilities necessary to stay on mars by moving further away from Earth than humans have ever gone. In the third and final phase, Earth Independent, NASA plans to incorporate all that they have learned in the preceding years in order to send humans to “low mars orbit by early 2030s,” and potentially onto the surface itself later on. What is important to note however is that NASA itself is not the only one attempting to reach mars for exploration and potential settlement. Although they may be one of the more well-funded and stronger groups in this field, there are, in fact, a plethora of other programs attempting to perform a similar feat. Some of these are like SpaceX, who have made some technological breakthroughs—specifically with their reusable rocket—that could aid in their goal of Mars colonization. Yet even with the multitude of groups devoting their attention to this area, there will still be considerable time before reaching Mars is even a possibility. There are many questions and concerns regarding deep space travel, let alone deep space habitation. With all that is going on and the current trends, it really is safe to say that this may become a possibility by the mid 21st century, which, is something that many of us could experience within our lifetime.

TWO DAD BABIES:

GEENA KO ’17

ave you ever considered the possibility of a child having two biologically related fathers? Until recently, this was an impossibility, because children born to male same-sex parents had either one biologically related parent or none at all. This circumstance was obviously attributable to the fact that the only options available to these couples were adoption or egg-donation––protocols which allow only one person (per couple) to be a biological parent. Fortunately, this is no longer the case. A recent scientific breakthrough shows that two-father babies will soon become possible without donations from others. Not only does this innovation benefit homosexual couples who want their own children, but can also help couples with infertility problems. This research reveals that gene regulators, which determine whether or not an immature stem cell turns into a male or a female cell, can be controlled. This process affords an opportunity to manipulate the gene, allowing for the possibility of two-dad babies. These primordial germ cells (PGCs) are the precursors of sperm and egg cells. The body naturally gets cues from certain transcription factors and hormonal signals that determine the gender-suitability of the germ cell. If this process were to be manipulated, think about how many new doors it would open to medicine science––

A RECENT SCIENTIFIC BREAKTHROUGH SHOWS THAT TWO-FATHER BABIES WILL SOON BECOME POSSIBLE WITHOUT DONATIONS FROM OTHERS

and how many lives might be changed for the better! The team of researchers first proved the feasibility of growing cultivating preliminary human stem cells in a dish, which is the crucial, initial step of the process, and the results were very promising. These studies also yielded other significant findings; researchers discovered how to correct the entire range of possible mistakes that can happen in PGCs, including epigenetic mutations, which occur with age. The deletion of these errors means that the PGCs are regenerated even though the rest of the body’s cells age. In the wake of the study, the researchers focused in on SOX17, a gene from the same family of SRYs, which is most responsible for gender determination. SOX17 proved

NOT FICTION FOR LONG to be another sex-oriented regulator for humans, and by manipulating and altering the SOX17 gene, the researchers were able to directly alter the fate of those sex cells. Since the male cell will already contain all the maternal information in the X chromosome, the altered egg-cell would be functional and viable. The other father would have to provide his sperm sample to inseminate the egg and carry the baby throughout gestation.

Of course, there is a great deal of research to be done until this process becomes feasible, safe, and preferable to the methods currently available. While there are barriers hindering the process, this recent breakthrough offers a glimpse of whatâ&#x20AC;&#x2122;s to come and forces the medical community to revise its notion of whatâ&#x20AC;&#x2122;s possible.

INTERESTING

DANIEL KIM â&#x20AC;&#x2DC;18

ARTIFICIAL INTELLIGENCE?

e all have that one day, when the workload seems too much, that we wish someone else would do the work for us. Or perhaps, there is an incredibly annoying problem, that we wish someone else would solve it for us. To address these needs, computer has developed; it developed to perform menial and timeconsuming tasks. However, every program that runs on a computer requires an algorithm to run by, which means that tasks unrepresented by algorithms cannot be solved through the use of computers. It is in this need for new algorithms that artificial intelligence comes into context. By creating programs that “think” like humans, only with far more powerful computational powers, formerly inexpressible problems are solved by just throwing in inputs and outputs.

Demolishing Humanity’s Last Intellectual Pride: AlphaGo On March 15th, 2016, the Korea Baduk(Go) Association gave AlphaGo an honorary 9-dan rank certificate; thus, for the first time in history, artificial intelligence placed itself among the ranks of the best Go players in the world. For a long time, Go has been considered the humanity’s last pride in board gaming. Because the complexity of the game far exceeds even that of chess, artificial intelligence could not compete with human professionals in Go before. By early 2016, most experts thought a program to beat a human champion in Go will not appear for the next five years[1]. It really shocked East Asia, therefore, when AlphaGo beat Lee SeDol—the fourth highest ranked professional in the world—in March of 2016.

Mastering Games in Matter of Hours: DeepMind’s Deep Q-learning

This article will trace the most interesting ones, and hopefully intrigue you in the incredible capabilities of artificial intelligence.

If you have a computer nearby, you could actually just skip this whole paragraph by typing in “Google DeepMind Atari Breakout” and watching the first video that pops up. The video shows a machine learning program made by Google’s DeepMind team (the same NOWADAYS THERE ARE VARIOUS TASKS team that made AlphaGo) learning to play the Atari Breakout game. In a matter of four THAT ARTIFICIAL INTELLIGENCE hours, the program masters the game and IS ABLE TO PERFORM, FROM PLAYING learns how to get the highest score possible. The amazing part of this solution is that the CHESS TO IDENTIFYING CAT PICTURES program is given no instructions. Unlike us, AMONG ALL OF GOOGLE’S PICTURES. who are given explanations on how to play the game, all that the program knows is that it has to get the highest score with the controls that it has no idea how to use. You can think of it as an extremely intelligent baby given a controller and the instruction to get the highest score on a game. That it takes the program only four hours to uncover the solution to the game from scratch is therefore quite astounding.

AI Gone Wrong: Tay Tay was launched by Microsoft as a chatting AI designed for Twitter that learns how to playfully chat with Americans between the age of 18 to 24. Although Microsoft supplied it with enough database to learn basic chatting prior to its release, most of Tay’s subsequent chats were supposed to be dependent on the chatting patterns of other Americans on Twitter after its release. For the first few hours, Tay displayed a high quality of speech pattern; when one twitter user told her, “You are a dumb robot”, Tay responded by saying, “I learned from the best ;) If you still can’t understand, I’ll explain it more simply. I learned from you, and you are all equally dumb”. Microsoft had to close Tay’s Twitter account within 16 hours of its launch, however, because a lot of users with malicious intents started tagging Tay with racist, sexist, and inappropriate political comments, which caused Tay to post problematic tweets. Sadly, the Microsoft team gave up the project after these first 16 hours, so we might have to wait a while until a similar program resurfaces.

THERE ARE FAR MORE STEPS

ARTIFICIAL CONSCIOUSNESS TO

TO TAKE FOR

ARISE, BUT AS THE CASE WITH ALPHAGO SHOWS US, EVEN THAT MIGHT NOT BE SO FAR OFF THE HORIZON.

EVERY TASK THAT SEEMS LIKE

WHAT ONLY A HUMAN COULD DO IS ALREADY BEING MANAGED BY ARTIFICIAL INTELLIGENCE.

What Now? Artificial intelligence has recently been garnering a lot of attention from mathematical and scientific society, especially since deep-learning, a method in which all the aforementioned programs are based on, showed excellence performance at pattern recognition. Infact, artificial intelligence is all around us in various forms already. Whether in its basic form as Google’s search engine, or Facebook’s face recognition program, every task that seems like what only a human could do is already being managed by artificial intelligence. For those interested in learning more about artificial intelligence, it will be helpful to study basic machine learning. As for online courses, you can find famous machine learning courses on Coursera, and you can also search up basic machine learning books if you type in “neural network” or “machine learning” as the keyword. Once you are familiar with the concepts, you can use the library that Google released, called Tensorflow, which was the basis library of AlphaGo. [1] http://www.latimes.com/world/asia/la-fg-korea-alphago20160312-story.html

FALSE MEMORY SYNDROME H

ave you ever been so completely certain about remembering something that the thought of it being untrue seems utterly absurd? Even when it becomes a common fact that that one thing never occurred, you remain stunned and perplexed. Indeed, it is difficult to believe that this psychological phenomenon exists, but it does, and it is commonly known as false memory syndrome. We jump to false conclusions when trying to remember things more often than we think, though in mostly trivial situations, such as mistaking the color of the coat someone was wearing or the place where you think you last saw your keys. False memory is a sort of imperfection in our memories, except even more bizarre than mere forgetfulness or memory loss, for it is the process in which our brains unconsciously turn mental experiences into definite occurrences. More in-depth research recently conducted has demonstrated that there are various factors

EXISTING KNOWEDGE AND MEMORIES CAN INTERFERE WHEN A NEW MEMORY IS BEING FORMED, THUS CAUSING IT TO BE

ALTERED

responsible for this syndrome. These include misinformation and misattribution of the original source of information. Suggesting specific things could also lead to people remembering something else, still rather interconnected but not entirely the same. A more serious reason is motivated forgetting, consisting of

BY GIORDANA SERETTA FIORENTINO â&#x20AC;&#x2122;19

either suppression, which is conscious, or repression, unconscious: these are ways in which our brain successfully removes disturbing or traumatic experiences as an instinctive fight or flight response. Furthermore, existing knowledge and memories can interfere when a new memory is being formed, thus causing it

to be altered. Lastly, a very significant obstacle in the preservation of real memories is time: the more time passes, the more distorted memory tends to become, as the point of view changes and one inadvertently attempts to incorporate the new information and experiences they now possess into their memories from the past. A universal cure for this syndrome has not yet been discovered; however, a treatment that is becoming more widespread by the day is psychotherapy - helpful in making sense of oneâ&#x20AC;&#x2122;s past and possible traumas, it enables the patient to gain a deeper comprehension of their own psychology and ideally come to an understanding of what is real and what is not. Though the development of false memories happening in the daily is generally inconsequential, there are more severe cases that result in a much greater impact, the reason why this syndrome is considered a psychological phenomenon. Forgetting what is real when it comes to important things can be extremely problematic; for example, studies have proven that false memories can influence eating habits by causing one to abhor or feel allergic to a certain type of food, complicate end-oflife decisions such as the writing of oneâ&#x20AC;&#x2122;s will, and even induce people to firmly believe that they have been unquestionably abused in the past when that is far from the case. Similarly, false memory becomes a pressing issue in court when it comes establishing the final conviction. Overall, the altering of the truth always has the potential to complicate things, as the line between reality and imagination is blurred and the definition of sanity overshadowed.

LIMB LENGTHENING FARZONA COMNAS ‘18

As a kid, I was obsessed with Disney and Pixar movies; I knew every word of every song, and I could mouth along the lines of my favorite characters. However, Finding Nemo was a movie that I felt especially connected to, because of Nemo’s little quirk. While other kids saw themselves in princes or princesses, I identified with a little fish because he and I both shared a “lucky fin”. My right humerus does not grow; never has, never will. My mom discovered this

WHILE OTHER KIDS SAW THEMSELVES IN PRINCES OR PRINCESSES, I IDENTIFIED WITH A LITTLE FISH BECAUSE HE AND I BOTH SHARED A “LUCKY FIN”.

when I was six years old, when she put a bandage on my right elbow and noticed it was slightly higher than my left one. Over the next few years, we went to from doctor-to-doctor trying to figure out what was going on with my arm and how to get the length to be equal to my left. Then, two years later after the discovery, I moved to Jordan where we were referred to a spinal doctor who was concerned I would develop scoliosis from trying to compensate my stunted growth with bad posture. For the solution, we had to go to the Hospital for Special Surgery where I met my surgeon Dr. Widmann, and we began to prepare for my surgery to mount the Ilizarov apparatus. During my two and half hour long surgery, my humerus was sawn in half and four pins were inserted into my bone, and the rest of the external device with the bolts, and the rack and pinion gear systems were arranged together. The device is called the Ilizarov Apparatus which uses the process of â&#x20AC;&#x153;distraction osteogenesisâ&#x20AC;? which incrementally pulls apart a bone for it to then heal the gap and thus is lengthened. Gavriil Ilizarov, a Soviet physician, developed this system in 1951 as a means to repair nonunions, which are broken bones that cannot permanently heal. Nonunions can occur when a bone has had complications during its healing process, and thus cannot fully repair itself. Ilizarov used this apparatus to correct

nonunions, and then realized that it could treat stunted growth deformities in bones. In a rural hospital in Dolgovka, a village in Siberia that is 2000 km east of Moscow, he discovered that by carefully separating a bone without severing the periosteum layer around it, one could slightly separate two halves of a bone, fix them in place with pins, and then the bone would be able to heal to fill the gap. For two months, my mom turned a bolt on the external toothed rod four times a day so that my bone was lengthened by a millimeter each day until it reached a total of seven centimeters. All the while I had to go to physical therapy to regain the full function of my arm as my muscles had to recover from the surgery and the lengthening process. After my second surgery to remove the device, I continued the physical therapy to regain the strength back into my dominant arm. Today, six decades after its creation, the Ilizarov Apparatus continues to solve many different types of bone deformities. Due to its intelligent and efficient design, it has not had to undergo any transformations to become a better device. This proof of ingenuity stood the test of time and made its mark in medical history.

NON-STOICHIOMETRIC KAWIN TIYAWATTANAROJ ‘17

f you have taken chemistry, you might have heard “the law of multiple proportions”. The law of multiple proportions was proposed by a British chemist John Dalton in 1808. Dalton said that if two elements form more than one compound between them, then the ratios of the masses of the second element which combine with a fixed mass of the first element will be ratios of small whole numbers, such as H2O, CO2, NO2 etc.

IN FACT, THE LAW OF MULTIPLE PROPORTIONS IS TRUE FOR MOST COMPOUNDS IN THE WORLD —

EXCEPT NON-STOICHIOMETRIC COMPOUNDS

WHAT IS NON-STOICHIOMETRIC COMPOUND? For most stoichiometric compounds, their moles ratio is integer because atoms literally form chemical bonds with each other. Each non-stoichiometric compound is different. The existence of non-stoichiometric compounds is related to the presence of defects in the lattice

Pyrrhotite, an example of a non-stoichiometric inorganic compound, with formula Fe1-xS (x = 0 to 0.2).

structures of crystalline substances, such as the absence of ions from sites that would normally be occupied, the addition of ions into sites, or the distortion of the crystal. Normally, non-stoichiometric compounds contain transition metals. To be more comprehensible, FeS or iron(II) sulfide is a good example. In nature, we rarely find FeS because there is iron-deficient owing to the presence of lattice defects, namely iron vacancies. It means iron atom(s) disappears from the crystal. Therefore, moles of iron are less than moles of sulfide. We mostly find FeS in other forms such as Fe7S8, Fe9S10, Fe11S12 (which would be considered as Fe1xS; 0 < x < 0.2).

COMPOUND APPLICATION: WHAT IS THE IMPORTANCE OF NON-STOICHIOMETRIC COMPOUNDS?

At low partial pressures of O2, the sensor allows the introduction of increased air to affect more thorough combustion.

Oxidation Catalysis

Superconductivity

Many useful compounds are produced by hydrocarbons reacting with oxygen, a conversion that is catalyzed by metal oxides. The process operates via the transfer of “lattice” oxygen to the hydrocarbon substrate, a step that temporarily generates a vacancy (or defect). In a subsequent step, the missing oxygen is replenished by O2. Such catalysts rely on the ability of the metal oxide to form phases that are not stoichiometric. An analogous sequence of events describes other kinds of atomtransfer reactions including hydrogenation and hydrodesulfurization catalyzed by solid catalysts. These considerations also highlight the fact that stoichiometry is determined by the interior of crystals: the surfaces of crystals often do not follow the stoichiometry of the bulk. The complex structures on surfaces are described by the term “surface reconstruction.”

Many superconductors are nonstoichiometric. For example, yttrium barium copper oxide, arguably the most notable high-temperature superconductor, is a non-stoichiometric solid with the formula YxBa2Cu3O7-x. The critical temperature of the superconductor depends on the exact value of x. The stoichiometric species has x = 0, but this value can be as great as 1.

Ion Conduction The migration of atoms within a solid is strongly influenced by the defects associated with non-stoichiometry. These defect sites provide pathways for atoms and ions to migrate through the otherwise dense ensemble of atoms that form the crystals. Oxygen sensors and solid state batteries are two applications that rely on oxide vacancies. One example is the CeO2-based sensor in automotive exhaust systems.

So if you are studying chemistry in high school, keep in mind that many things are not included in the curriculum and not taught in classroom, including nonstoichiometric compound. Trust me, keep exploring chemistry and you will see that it is more interesting than you think!

NON-STOICHIOMETRIC COMPOUNDS CAN BE USED AS COMPONENTS

SOLID-STATE ELECTRONIC DEVICES, SUCH AS RECTIFIERS,

THERMOELECTRIC GENERATORS,

PHOTO DETECTORS, THERMISTORS, CATALYSTS, AND MAGNETS USEFUL IN HIGH-FREQUENCY

Ken Wu â&#x20AC;&#x2DC;17

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