LMPS Science Journal Vol. 4

Science Journal Vol 4.

April 2023

Contents 1. Ichiro’s Laser Beam throw versus Usain Bolt – Keito Orii 2. Gene editing in high school; a matter of time – Gianna Gordon 3. PHYSICS BEHIND PARKOUR – Jerry Li 4. How do passwords work? - A dive into digital security – Cristobal Reyes 5. The Science behind Teen Depression – Tais Soto Vaca 6. Artificial Suns: Nuclear Fusion Energy in the foreseeable Future? – Tsz Fung Tsui 7. Intestine Probiotics: Common application and use in the intestines – Freya Feng

Edited by Mr. S Bonnar, Chair of Sciences

Ichiro’s Laser Beam throw versus Usain Bolt ———————————————————————

By Keito Orii Grade 9 Introduction Whether you like baseball or not, you have probably heard about the WBC (World Baseball Classic). It is an international championship played every four years where the best players from each country represent their countries to compete. Originally from Japan and currently studying in the US, I have mixed feelings of wanting to cheer for both Japan and America. However, I am excited for this year’s WBC, as the current Japanese national team is said to be the strongest of all time.

This is why I chose to research a topic related to baseball for this year’s science project.

Specifically, one legendary Japanese baseball player, Ichiro Suzuki, who gave great inspiration to Shohei Otani, triggered my curiosity to do an investigation on one of his most renowned ‘laser beam throws’.

Ichiro Suzuki came to the Major League Baseball (MLB), becoming the first Japanese position player in MLB history. He has been the only player in MLB history who won the three titles in the first season: American League batting title, the AL Rookie of the Year Award, and the AL MVP Award in 2001. Of all his incredible performances, his renowned Laser Beam throw particularly stands out to me. Watching his videos, I naturally started to wonder, “How far do batters need to hit in order for the third runners to score if Ichiro is in the right field? What if the fastest runner on earth, Usain Bolt, is on third base? How far does the batter need to hit in order for Usain Bolt to succeed on a sacrifice fly1 ?” Let’s try to answer this question from the perspective of science and mathematics.

Research Question If the third-base runner is Usain Bolt and the right fielder is Ichiro, what is the minimum distance that a batter needs to hit in order to achieve a sacrifice fly?

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Sacrifice fly is when the batter hits a fly ball in order to help a team player score a run. Typically used to help the third base-men run to home plate while sacrificing himself with an out.

Methodology In an effort to answer this research question, a simple model with basic trigonometry will be used to examine how long it will take for a ball thrown by Ichiro to travel according to the distance. Then, this data will be compared to the time it takes Usain Bolt to run from third base to home plate. Subsequently, we can identify the distance that a batter needs to hit in order to achieve the sacrifice fly. In this model, a ball is regarded as a mass point and assumed not to be influenced by any forces other than gravity.

Formula to be used 2

The formula used to create the model is 𝑠 = 𝑢𝑡 − 𝑔𝑡 . This formula represents the change in displacement, 𝑠 , of a mass point at time, 𝑡 , when a ball is thrown at initial velocity 𝑢.

Trigonometory With trigonometry, we can figure out the length of the sides of a triangle. In a right triangle, shown as Figure 3, the side which is opposite to the angle α is equal to the length of ℎ𝑦𝑝𝑜𝑡𝑒𝑛𝑢𝑠 × 𝑠𝑖𝑛α, while the adjacent side which lies next to the angle has the length of ℎ𝑦𝑝𝑜𝑡𝑒𝑛𝑢𝑠 × 𝑐𝑜𝑠α.

The value of 𝑠𝑖𝑛α and 𝑐𝑜𝑠α ranges between -1 to 1 depending on the value of the angle.

Initial conditions We will summarize the information that is known. Based on the data on 4/11/2001, the initial velocity of the ball thrown by Ichiro is approximately 94. 2𝑚𝑖𝑙𝑒𝑠/ℎ, which can be converted as 41. 9 𝑚𝑒𝑡𝑒𝑟/𝑠. The time it took Ichiro to throw the ball after catching it was approximately 0.95 seconds. I assumed that the ball thrown by Ichiro is released at a height of 1.80m which is the same height as his own. Supposing that the baseball stadium this game is played in is Citi Field, which is the closest from school, the right-field foul pole is 100.584 m away from home plate, which suggests the maximum distance the ball could travel is 101 m. Finally, the acceleration due to gravity is 2

9. 8 𝑚/𝑠 . Now that we have all the essential data, we are ready to start constructing the model, the ‘Ichiro model’!

Construction of the model To create the model, it is necessary to decompose the movement of the ball vertically and horizontally. The initial velocity of the ball can be determined by using trigonometric function: the initial vertical velocity 41. 9 𝑠𝑖𝑛α and the initial horizontal velocity is 41. 9 𝑐𝑜𝑠α.

Initially, we need to direct our attention towards the vertical movement of the ball. The vertical movement of the ball from when Ichiro throws it to when it reaches the home plate equals to a vertical toss with the displacement -1.8 m. Since the initial vertical velocity of the ball is 41. 9 𝑠𝑖𝑛α, by letting t represent the time it takes for ball to reach the home plate, the formula introduced in the earlier paragraph can be used, resulting in: 2

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− 1. 8 = 41. 9(𝑠𝑖𝑛α)𝑡 − 2 𝑔𝑡

Then, if the equation is solved as the quadratic equation in terms of t, t can be calculated as

𝑡=

41.9 𝑠𝑖𝑛α ±

2

( ) 𝑔

(41.9 𝑠𝑖𝑛α) +4· 2 ·1.8 𝑔

According to this formula, the time it takes the ball to reach the home plate when Ichiro throws it at an angle α can be obtained. If we let x represent the distance from where Ichiro catches the ball to home plate and the horizontal velocity remains constant at 41. 9 𝑐𝑜𝑠α; based on the formula of distance, velocity and time can be obtained as follows. 𝑥 = 𝑣0(𝑐𝑜𝑠α)𝑡 =

𝑣0𝑐𝑜𝑠α ⎰ 𝑔

𝑣 𝑠𝑖𝑛α + ⎱ 0

⎱

(𝑣0𝑠𝑖𝑛α)2 + 3. 6𝑔⎰

By adding the time it takes Ichiro to catch and throw the ball (namely, 0.95 seconds) and summarizing all the data, we obtain the following results shown in Table 1.

Table 1: The time it takes for the ball to travel the distance Angle (degree)

Angle (radian)

Time (second)

Distance (meter) Actual time (second)

1

0.01745329252

0.6848933911

28.69266239

1.634893391

2

0.03490658504

0.7729133366

32.36534069

1.722913337

3

0.05235987756

0.8692439571

36.37140765

1.819243957

4

0.06981317008

0.9730264261

40.67049405

1.923026426

5

0.0872664626

1.083273397

45.2164359

2.033273397

6

0.1047197551

1.19898354

49.96220453

2.14898354

7

0.1221730476

1.319218992

54.86326225

2.269218992

8

0.1396263402

1.443145454

59.87932611

2.393145454

9

0.1570796327

1.570044524

64.97494468

2.520044524

10

0.1745329252

1.699309377

70.11935876

2.649309377

11

0.1919862177

1.830432434

75.28601364

2.780432434

Speed of Usain Bolt The time it requires Usain Bolt to run 27.431m, which is the distance from the third base to home plate, can be calculated as follows. Assuming that it takes 9.58 seconds for Usain Bolt to run 100m, it takes 2.627 seconds based on the calculation below: 9. 58 ×

27.431 100

= 2. 627 (sec)

Conclusion Based on the results we obtained from Table 1 above, comparing the time it takes Usain Bolt to run from third base to home plate (2.627 seconds) with the time it takes Ichiro’s ball to reach home plate, it can be seen that a batter needs to hit a fly ball at least 70m. (cf. Table 2) To put the result into perspective, the average time it takes for a MLB player to run from home to first base, which is the same distance as the one from third base to home, is approximately 4.2 to 4.3 seconds. Therefore, we can conclude that Usain Bolt should probably play baseball! (And for Ichiro, it might be a nightmare…)

Table 2: The time it takes for the ball to travel the distance Angle (degree)

Radian

Time (second)

Distance (meter) Actual time (second)

9

0.1570796327

1.570044524

64.97494468

2.520044524

9.1

0.1588249619

1.582873654

65.48765947

2.532873654

9.2

0.1605702912

1.595725811

66.00083044

2.545725811

9.3

0.1623156204

1.608600457

66.5144297

2.558600457

9.4

0.1640609497

1.621497061

67.02842977

2.571497061

9.5

0.1658062789

1.634415106

67.54280359

2.584415106

9.6

0.1675516082

1.647354079

68.05752447

2.597354079

9.7

0.1692969374

1.66031348

68.57256614

2.61031348

9.8

0.1710422667

1.673292818

69.08790269

2.623292818

9.9

0.1727875959

1.686291608

69.60350862

2.636291608

10

0.1745329252

1.699309377

70.11935876

2.649309377

Analysis The model used in this study is with several approximations. To improve the accuracy, it is necessary to consider the air resistance on the ball and the air resistance when the ball is viewed as a rigid body. In addition, for Bolt’s time, by considering his reaction speed from Ichiro catching the ball to starting to run, as well as the fact that his running velocity is not consistent throughout the run, the final data may be disposed to minor changes. Therefore, when the approximations are included in the models, the accuracy of this model would improve.

Reference 1. Carozza, D., Johnson, S. and Morgan, F. (2009). Baserunner’s Optimal Path. The Mathematical Intelligencer, 32(1), pp.10–15. doi:https://doi.org/10.1007/s00283-009-9106-2.

2. Quinton, S. and producers, N.S.T. sports (n.d.). Ichiro’s most memorable moments with the Mariners. [online] The Seattle Times. Available at: https://projects.seattletimes.com/2016/sports/ichiro-top-9-moments/ [Accessed 5 Mar. 2023].

3. MLB.com. (n.d.). Citi Field Information Guide | New York Mets. [online] Available at: https://www.mlb.com/mets/ballpark/information/guide [Accessed 26 Feb. 2023].

4. MLB.com. (n.d.). Sacrifice Fly (SF) | Glossary. [online] Available at: https://www.mlb.com/glossary/standard-stats/sacrifice-fly [Accessed 6 Mar. 2023].

5. T ‌ he Hardball Times. (2014). A Physics Comparison of Great Throws From Years Past. [online] Available at: https://tht.fangraphs.com/a-physics-comparison-of-great-throws-from-years-past/ [Accessed 26 Feb. 2023].

6. www.youtube.com. (n.d.). イチロー レーザービーム集. [online] Available at: https://www.youtube.com/watch?v=YMwGl-GCgrc [Accessed 26 Feb. 2023].

Gene editing in high school; a matter of time Gianna Gordon Grade 10

The ability to edit genes has existed for decades but has only recently entered the mainstream conversation with the advent of CRISPR/Cas9, which is a type of technology that can quickly and efficiently make changes to almost any gene in any plant or animal. One may have seen a documentary about individual experimentation with CRISPR/Cas9 or heard about the more sensational potential uses of gene-editing technology such as the ability

There are three forms of genetic testing: diagnostic, carrier and predictive testing.

to engineer aspects such as physical attributes, intelligence, athletic ability, and more in your future children. But high school students are starting to experiment with 1

CRISPR/Cas9 in classrooms, opening a new chapter in the availability to learn about gene editing and a wider debate about the uses and ethics of the technology.

There are three forms of genetic testing: diagnostic, carrier and predictive testing.

Diagnostic testing involves identifying current disease states. This includes prenatal and newborn screening- the most common forms of genetic testing. Carrier testing determines whether an individual carries a certain genetic trait. Predictive testing is used to determine whether a person has a genetic mutation that will lead to a late onset disorder. CRISPR is usually used in this kind of testing, which is usually conducted in otherwise healthy individuals with a positive family history and no symptoms of disease.

CRISPR stands for Clustered Regularly Interspaced Short Palindromic Repeats. CRISPR works like this: scientists start with RNA which is a molecule that can read the genetic information in DNA. The RNA finds the place in the nucleus of a cell where edits need to be made and leads

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Cas9 to the precise spot on the DNA. Cas9 then attaches itself to the double-stranded DNA, unzips it, and snips the DNA at the spot to be edited. Scientists can then edit the DNA before the cell, sensing an issue, repairs the break. Scientists can also use the technology to turn genes on or off.

CRISPR is mostly being used as a solution to treat issues that already exist in animals and people. Some of the ways CRISPR is being used right now is in agriculture- to genetically modify crops to be more

It is estimated that in the future gene editing could cure almost 90% of genetic defects.

plentiful, or healthier, in animal husbandry- to create livestock with improved breeding traits, and, most recently, in patients with inherited blood disorders.

But the future of CRISPR is likely proactively changing human genomes to edit out genetic diseases, which has yet to be a widely accepted use. Think about it- if CRISPR can snip away a mutated gene in a person, then a child eventually born to that person would not carry the mutation, nor would any of that person’s children or grandchildren. The family’s genetic line would be permanently altered by the removal of the code for that genetic disease. It is estimated that in the future gene editing could cure almost 90% of genetic defects.

So should we learn about gene editing in high school? Some high school students are already starting to use CRISPR kits in biology classes or will soon. One such kit uses a specialty tool where students will be able to precisely edit genes in E. coli bacteria using CRISPR technology and learn about the relationship between genes, proteins, and traits. One of the advantages of learning in school would be the ability to do hands-on investigations of a realworld topical issue. One of the disadvantages is there could be personal opinions and views

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about the ethics of learning to edit DNA. Either way, it is likely that CRISPR or future technology will make its way into classrooms.

The use of CRISPR in the classroom brings up some serious ethical issues that might delay the timing of the rollout into classrooms, and could cause concerns if students have the power to use gene editing technology to experiment on themselves or others. For this reason, when CRISPR is eventually introduced into Biology classes at Leman Manhattan, it should be prefaced by a mandatory Bioethics course that would allow students to develop an understanding of biological 4

concepts and the philosophical debates underlying difficult questions stemming from new technology before doing any experiments.

CRISPR goes much deeper than the potential knowledge of future medical issues and that is something we must all prepare for. As the founder of CRISPR Jennifer Doudna stated, “The more we know, the more we realize there is to know.” So why postpone CRISPR - this gateway into the future - in which our children and generations after will have to navigate if we don’t first.

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References and further reading Anon, (2010). Genetic Ethics 101 | Bioethics.com. [online] Available at: https://bioethics.com/genetic-ethics-101.

Innovative Genomics Institute (IGI). (n.d.). CRISPR Made Simple. [online] Available at: https://innovativegenomics.org/crispr-made-simple/ [Accessed 1 Apr. 2023].

Fulda, K.G. and Lykens, K. (2006). Ethical issues in predictive genetic testing: a public health perspective. Journal of Medical Ethics, 32(3), pp.143–147. doi:https://doi.org/10.1136/jme.2004.010272.

Lutz, E. (2022). CRISPR in the Classroom. The New York Times. [online] 27 Jun. Available at: https://www.nytimes.com/interactive/2022/06/27/science/crispr-anniversary-classroomexplainer.html. www.uhnresearch.ca. (n.d.). CRISPR: The Promise and Controversy | UHN Research. [online] Available at: http://www.uhnresearch.ca/news/crispr-promise-and-controversy.

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PHYSICS BEHIND PARKOUR

By Jerry Li Grade 11

Have you ever seen parkour in an ac3on film, where the tracers are sprin3ng on top of buildings and take massive drops without injuring themselves? One of my favorite things to do in the city is parkour, and I enjoy physics the most at school. I’m here to explain parkour in physics terms with the best of my knowledge. Let’s jump right in!

WHAT PEOPLE THINK ABOUT PARKOUR? Allow me to clear something important first, in order to get you the right mindset to understand this content. Here’s a logical fallacy that people tend to easily fall into: the phrase “common sense” was defined in the English language to describe something that everyone is agreed with, but there’s really no existence of absolute common sense in this universe as it’s always depending on the unique personal backgrounds and experiences different people possess. Since parkour is not “common” for most of the popula3on in our daily lives, people who don’t know what parkour is tend to get it wrong. It’s neither an “insane dangerous sport” nor an “internet deep fake” as some might call it. Given an analogy: if a person doesn’t know how to walk, but tries to walk from standing posi3on without any knowledge and protec3on, that person is going to bang his head straight into the ground; It’s the same thing as someone who doesn’t know how to do parkour trying to leap a rooXop gap and end up falling off the building. I’m going to explain parkour in more detail using physics instead of giving the conven3onal “convincing” examples of people who already succeeded in parkour to “debate” about parkour in a subjec3ve way.

WHAT THE PHYSICS IS PARKOUR According to Wikipedia, Parkour (French: [paʁkuʁ]) is an athle3c training discipline or sport in which prac33oners (called traceurs) aaempt to get from point A to point B in the fastest and most efficient way possible, without assis3ng equipment and oXen while performing ar3s3cgymnas3c maneuvers. Couple of word equa3ons in my own understanding of the two main types of parkour: 1. Tracer = Escape Mar3al Arts; 2. Freerunner = Crea3ve Body Movements. Tracers purely train for gegng from point A to point B as efficiently fast as possible, while freerunners train for as many crea3ve movements as possible from anywhere possible. But that was the old

days when the parkour communi3es were very isolated. In the 21st century that we live in, the parkour community has grown larger around the world, thanks to the internet, the film industry, social media… Tracers and freerunners started to train together, become friends, and learn from each other, combining all possible skills into what is known as parkour today.

MOVEMENTS IN PARKOUR In the two main types of parkour, tracing and freerunning, all of them can be useful when implemented correctly. I know this because I do it myself, that the more movements you master, and the more you think about how you can implement these movements, the beaer you’ll be. For instance, a flip is oXen recognized as a freerunner’s maneuver, but in a real 3me escape, doing a flip is way beaer than doing a vault (a tracing skill) over an obstacle.

First of all, with good leg strength, it’s completely possible to just jump over an obstacle below chest height, but why sacrifice a lot of kine3c energies to gain those unnecessary gravita3onal poten3al energies instead keeping the center of mass low enough to go way faster?

How can physics be exploit so that a flip be more efficient than a vault?? Well, if you can keep running on a surface, then it must have fric3on force to support wherever you’re going: in this case, if you know how to do a flip and land a flip, in theory, your success rate over the obstacle is 100% 3mes the accidental rate –– the probability that you can make a mistake in a move; while your success rate in vaul3ng over the obstacle is (100% - x) 3mes your accidental rate, as “x” represents the probability of failing on the obstacle surface. Therefore, the accidental rate cancels out on both sides of the inequality, leaving 100% > (100% - x), a higher chance of success for doing a flip. The reason behind that is, you know the surface that you’re running on beaer than the surface that you’re about to vault over: what if the obstacle is not strong enough for your body weight; what if there isn’t much fric3on on the surface of the obstacle that you just can’t tell that you’re going to slip and fall…

Learning how to flip and improve flexibility are actually very helpful, as they get you a beaer understanding of the feel of the movements you can do with your body, while dealing with gravity on earth. For example, if you slip somewhere, or clip your foot on a curb between a huge 2 stories drop, knowing how to flip and being flexible can save your life! Think about it, if you’re not so flexible, you’d most likely get your tendons stretched before you could do anything else to control your muscles; and if you don’t know how to flip, you’d land a 2 stories drop on your head or back, which would not be ideal for your skeleton.

Speaking about landing, I would like to introduce to you… The great, fabulous, and pres3gious PARKOUR ROLL, being one of the most important moves if not THE most important move in parkour. The parkour roll is similar to a side roll in mar3al arts, but it’s a liale bit different, they have similar purposes, but different usage in terms of the needs for certain movements.

To do the parkour roll, place your hands on the opposite side of the shoulder that you’re going to roll over; keep your chin to your chest (looking to the side where you’re placing your hands would help), as you want to roll over from one side of the shoulder down across to the other side just before rolling on your hip bones. Since I’m right handed, in this case, I’m rolling over on my right shoulder. To do that, I have to place my hands to the mid-leX, look down to my chest and to the leX as I roll over. This way, I’m rolling over the soX parts of my body supported by adequate muscle groups. I also won’t hit my head because I’m 3l3ng it to the leX. (As shown in the images.)

WHY ROLL? The purpose of Parkour rolls and mar3al arts rolls are both to reduce the impact for landings.

Parkour rolls are generally done faster horizontally than mar3al arts rolls, since it’s usually used to land a speedy drop (over a gap or to the ground ) so that the pressures on the knees can be properly reduced; while mar3al arts rolls are designed for connec3ng fight moves; it is also commonly used to dodge an aaack in mar3al arts.

How exactly does the roll reduce impact? One way to think about it in physics terms is the study of mo3ons: rolling is the process of transi3oning impact from linear momentum into angular momentum. Bear with me. This is simply momentum, here’s a formula to set everything up:

p = mΔv (momentum = mass · the change in velocity) The momentum formula studies how much mass of an object is in how much mo3on.

Momentum is a vector, because velocity is a vector. If a scalar (mass) mul3plied by a vector quan3ty (velocity), it gives out a vector quan3ty. It’s important to understand the rela3onships these variables in physics even if the equa3on doesn’t make sense to you just now, which is completely normal. But what’s really intui3ve is that, once the rela3onships of these variables are crystal clear in mind, we can then apply them in the real world. In this case, it’s very easy to see that if either mass or velocity increases on the right side of the equa3on, with the premise that the rest of the variables stay the same (control variable), then the momentum increases.

Let’s think about the change in momentum derived from the ini3al momentum equa3on:

p = mΔv –> Δp = |mvf - mvi | Since we’re dealing with the mass of a human body, it will remain constant; Velocity however, changes, as shown in the formula. There’s an ini3al velocity (represented by the leaer “i” next to “v”), and a final velocity (represented by the leaer “f” next to “v”). All I did was opened up the Δv from the momentum formula to show that the change in velocity is the absolute value of the difference between the final velocity and the ini3al velocity. Now let’s move on to another formula that is defined to represent the rela3onship between the effect of the force ac3ng on an object over 3me and the momentum of that object––scien3fically known as impulse. As being said about the change in momentum, impulse is simply equivalent to the change in momentum, basically another angle to look at the same problem:

Δp = |mvf - mvi | –> Δp = Jnet = Fnet Δt Impulse, represented by the leaer J, is equal to the net force (the resultant of all forces ac3ng on the object) 3mes the change in Gme (from start of the landing to finish). We know that the smaller the force is, the beaer it is to our landing. Although, technically knee strength can be prac3ced properly to absorb quite large impacts, that is irrelevant for our mo3on analysis right now. This is the only rela3onship we need here: the greater the impulse, the harder the landing, the more force involved. What can we do to change this, in order to reduce the impact? Again,

but last 3me, I promise. Let’s rearrange the equa3on and see what can we find in terms of the rela3onships of these variables from all the formulas we derived and went through. If you’ve no3ced, the only equa3on that contains force (F) is the impulse formula, so let’s use that:

Jnet = Δp = Fnet Δt –> Fnet = Jnet /Δt = Δp/Δt = |mvf - mvi | /Δt By dividing on all sides of the equa3ons by “Δt”, we can see that, the greater “Δt” is, the smaller the force is, rela3vely in the equa3on. Note, that the net force is the average force during the landing, not the gravitaGonal field strength (the accelera3on of “gravity”: always about 9.81m/ s^2 on planet Earth) which is just a constant for accelera3on. Since a drop into a roll is a transi3on from linear momentum into angular momentum: it would result in a stretch in the 3me axis, which shrinks the peak force. Peak force reduced. Problem solved!

That is literally the whole purpose of rolling: crea3ng more 3me on the landing, and use that 3me to equally spread out the forces to different parts of the body to reduce impact.

PRESSURE ON THE LANDING Another important reason why a parkour roll can reduce so much impact and injuries is that, there’s way less pressure on your landing. Let me explain this:

P = F/A (Pressure = Force / the surface area that the force is applied) This is a formula for pressure. The rela3onship here can be represented such that, the larger the surface area that the force is applied on, the smaller the pressure - meaning less impact. Vise versa, the larger the force applied, the greater the pressure - meaning more impact, which is not what we want in this situa3on. From the impulse formula, we could already minimize the net force by increasing the 3me variable. Now, we can plug that minimized force into this equa3on corresponding to pressure. The only thing that we can really mess around with in this equa3on is the surface area. Since the surface area of human’s back is larger than the surface area of the shoes under the 3p of the toes, rolling on soX parts of the back can avoid all the bones that are connected to the skeleton. This can mange to take down quite a bit of impact.

The rela3onship between A (the surface area) and P (pressure), is inversely propor3onal –– meaning the greater A is, the smaller P is. And we’ve minimized our impact. Done! I know, it’s just that simple. AXer learning the parkour roll, you’ll be so much less painful in a situa3on where you have to jump off from a good amount of height in order to escape for your life.

DID YOU KNOW? The famous Newton’s (II) Law “F = ma” (force = mass · accelera3on) actually came from the intui3ve momentum and impulse formulas:

Fnet = Jnet /Δt = Δp/Δt = |mvf - mvi | /Δt = m · Δv / Δt = m · a If we can spot that the change in velocity over the change in Gme is actually in the formula, as it just might not be so obvious while the change in velocity is already jammed in the momentum part (mΔv), we can actually discover that it is just mass 3mes acceleraGon. Isn’t that FUN.

PARKOUR PARKOUR Physics does the work to assure safety concerns in parkour; It’s also fun to calculate something and implement it in reality. Knowing how to do something and understanding the purpose of doing something are two very different things. Some3mes, there are movements that I think are just too easy for me, but when I actually try to do them, it’s really not that simple. Hopefully you’ve got a beaer understanding of what parkour is aXer reading this ar3cle.

References, further reading, and links Universal Parkour Defini3ons: haps://en.wikipedia.org/wiki/Parkour Defini3on of Mar3al Arts Rolls: haps://www.akban.org/wiki/Roll Parkour Roll Tutorial: www.youtube.com. (n.d.). Ryan Doyle - Parkour Roll Tutorial. [online] Available at: haps://www.youtube.com/watch?v=RgPd29MlHpg [Accessed 13 Feb. 2023].

Momentum & Impulse Defini3ons: haps://byjus.com/jee/impulse/

How do passwords work?

A dive into digital security

Cristobal Reyes Grade 10

How many passwords do you know off the top of your head? Chances are you know the one for your Instagram account and the one for your email, maybe one or two more. But if you are like most people you have more than a couple of accounts. If you live in the United States the average is about 150 accounts, ranging from bank accounts, streaming services, online tools, and more.

Like most people, you probably have 2 or 3 passwords and reuse them; I'm sure you heard this is bad or that reusing password is harmful or unsafe. But why? What makes a good password? How do passwords work anyways?

Let’s start from the beginning; what is a password anyways? Where did it originate from? How do they work? Passwords have been used throughout history, from Romans using watch “watchwords” as a way to identify spies, to bars using paper cards with code phrases during prohibition to sell alcohol illegally. Modern iterations of passwords as we know them today started in MIT in 1961 when Fernando Corbato, trying to decipher a way to give students time to use computers (at the time when they occupied entire rooms), created a system where each student had a password memorized. The computer had a list of usernames and passwords (with minimal security), and it just checked if the student and password equaled the ones given and gave them access to the computer. This was the beginning of the modern password, a series of characters or words that, paired with an identifier like a username or email, work as a way to verify an identity or access an account.

Since the creation of the first password in 1961, the concept has remained the same, but the mechanisms that make it possible have undergone significant changes. Passwords have progressed from simple strings of characters and words to more complex methods. As the internet grew more popular, the need for increased security and passwords adapted to this. One of the most important developments came in the way of encryption. Encryption was basically a method to mix up characters with a method, so say a password was TheBestPassword123 this passed through a series of mathematical methods that made it into something like 7ajdl(k3kd0kdif9. The problem with this is that if a potential attacker got hold of the specific

mathematical equation it was as easy as reversing it and getting the password. This is why a system called hashing was developed; developers needed a way to store a password where even they didn't know what it was, so when a user creates a password, the password is encrypted

Most accounts are breached by the simple fact of using a simple or common password that has already been breached before.

as normal, but the password is never stored, so whenever the user logged in, the password just passed through this mathematical method and compared it to the one stored. And to make this even more secure, a “Salt” can be added that makes each hash random, so no hash is equal.

Password protection is incredibly important in today's computer-driven society. Passwords nowadays are the security methods for most accounts, including personal information like government services or health data. These security methods make most modern websites extremely hard to breach, but there are still websites that have not updated to these protocols, and these websites, once attacked, can reveal your passwords to more private websites. This is why reusing

passwords is potentially dangerous. Approximately 613 million individual passwords have been obtained this way globally. But most accounts are breached by the simple fact of using a simple

or common password that has already been breached before. Believe it or not, the most common password globally is the literal word “password” being used in over five million accounts globally.

So how can you make a strong unique password yourself to use in your accounts? The best option is to make a 12-letter-long password that is not made of words, contains lower and uppercase letters, and contains symbols and numbers; one example of this is: “th)jr-Ue-d24”. I know what you are thinking. How in the world can I memorize 150 of these weird passwords? And the honest answer is unless you are a memory wizard, your best bet is using password storage software. These programs securely store your passwords and even do neat things like autocomplete them and create extremely secure ones (as the one seen above).

So, there you have it, a deep dive into the world of passwords! It's essential to understand how they work and how to keep our online accounts safe. Next time you log in to your accounts, think about the complex process happening behind the scenes to verify your identity. And remember, a password is like a lock on your digital door; the stronger it is, the harder it is for unwanted visitors to break in! Happy password-ing!

The Science behind Teen Depression

Taís Soto Vaca Grade 9

Suicide is the fourth leading cause of death among 15-29 year olds.

Suicide is mainly caused by depression, with many of the symptoms of being suicidal being symptoms of depression too, yet little is known in regards to depression.

So what is depression? There are different types of depression however one of the most common types is MDD or major depressive disorder. Major depressive disorder is defined as two weeks of low mood with loss of interest in generally enjoyable activities and decreased self esteem. Characterized by sadness, hopelessness and low self esteem, major depressive disorder has seen a stark increase among adolescents.

Depression, which was often attributed to an abnormality in neurotransmitters such as serotonin and norepinephrine, is now known to be associated with glutamate and GABA, chemical messengers that regulate mood and emotion. (Neurotransmitters are chemicals that pass messages between nerves.)

One of the leading questions scientists have about depression is what exactly causes it, is it genetics, environment or both, and what is the extent that these factors play into developing this illness. Research has found that there are both a nurture and nature aspect to depression. One nurture aspect is in early childhood.

The brain has a high plasticity level during childhood, therefore childhood has a huge impact on the brain. Yet depression affects the plasticity of the brain.

Therefore childhood abuse and neglect are often associated with depression. Studies conducted on rats have found that with maternal deprivation there is a delay in the hippocampus and deterioration of synaptic transmissions. Another study conducted by the American Journal of Psychiatry followed 3200 siblings in different environments, Kenneth Kendler one of the authors of the study stated that “Although major depression has important biological and genetic components, the study shows evidence that rearing children in a nurturing environment also matters.”

“As we shift away from a single hypothesis about what causes depression, we are also learning more about the brain as a whole, in all of its complexities;” says Dr. Katz, a Yale Assistant Professor of Clinical Psychiatry that studies the neurobiology of depression. The Neurobiology of depression is the neurobiological basis of depression that involves functional and brain abnormalities. (Merriam Webster defines neurobiology as “a branch of the life sciences that deals with the anatomy, physiology, and pathology of the nervous system.”) One of the recent major findings regarding the neurobiology of depression was that metabolic

dysfunction, impaired immune response with increasing inflammation, and mitochondrial dysfunction are involved in depression. Another recent discovery is that major depressive episodes create similar changes in the brain as aging, linking accelerated aging to depression.

Depression was also found to lead to hyperactivity in various parts of the brain such as the amygdala. Said hyperactivity is lowered by antidepressants.

Scientists found that depressed youth recognize negative words more so than positive ones when compared to healthy teenagers.

Indicating that depression may create a Figure 1:PET scans comparing brain activity in a dysfunction in the frontolimbic cortical depressed mind (left) and normal brain and a (right). An regions. Other studies have found increase of blue and green colors, along with decreased white and yellow areas, shows decreased brain activity in depressed youth to recognize sad faces depressed minds. more accurately than their healthy peers.

This is still not of consensus as some experiments have found that adolescents with MDD recognize emotions less so than their healthy peers. All these studies indicate that depression affects the brain negatively, especially the nervous system.

So how do we use this knowledge to treat depression? Well, we use antidepressants, antidepressants increase the activity of neurotransmitters in the brain, such as serotonin, dopamine and norepinephrine. Antidepressants relieve symptoms of depression up to 70 percent though the reason for this is still unknown since recent studies have found little relation between serotonin deficiency and depression.

Though helpful for some, antidepressants do not work on everyone. Another way depression is treated is through talk therapy or psychotherapy. Therapy is believed to alter brain functions yet depressive psychotherapy is still under studied. What is known however is that talk therapy initially recorded hyperactivity in the limbic and subcortical regions of the brain, yet with more sessions the same regions reported

hypoactivity, so it is a long term type of treatment that requires various sessions.

Therapy can also vary some are individual while others are in groups.

Depression, especially teenage depression, is still an understudied “4.1 million adolescents in the United States have had at least subject, with little information available it is difficult to treat this mental illness. one major depressive episode “- Do Something Organization Though it is known that depression has negative effects in the brain little is known about its prevention, treatment and causes. This is concerning seeing as 20% of High School students report having suicidal thoughts. This is why it is necessary to further investigate depression in order to garner a better understanding on adolescent mental health and how it can be improved. As well as helping prevent the death of thousands of young adults.

References, further reading, and links Aliaksandr, M. (2023). 11,590 purple brain images, stock photos & vectors.

Shutterstock.

Retrieved February 17, 2023, from https://www.shutterstock.com/search/purple-brain Auerbach, R. (2015). Depression in adolescents: Causes, correlates and consequences2. American Psychological Association. Retrieved February 17, 2023, from https://www.apa.org/science/about/psa/2015/11/depression-adolescents CAMH, . (2012). Antidepressant medications. CAMH. Retrieved February 16, 2023, from https://www.camh.ca/en/health-info/mental-illness-and-addictionindex/antidepressant-medications

Clinic Staff, M. (2022, August 12). Teen depression. Mayo Clinic. Retrieved February 16, 2023, from https://www.mayoclinic.org/diseases-conditions/teendepression/symptoms-causes/syc-20350985 Health Organization, W. (2021). Adolescent mental health. World Health Organization. Retrieved February 16, 2023, from https://www.who.int/newsroom/fact-sheets/detail/adolescent-mental-health Henje Blom, E., Ho, T. C., Connolly, C. G., LeWinn, K. Z., Sacchet, M. D., Tymofiyeva, O., Weng, H. Y., & Yang, T. T. (2016, April). The Neuroscience and context of Adolescent depression. Acta paediatrica (Oslo, Norway : 1992). Retrieved February 16, 2023, from https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4779656/ Merriam-Webster. (n.d.). Neurobiology. In Merriam-Webster.com dictionary.

Retrieved February 17, 2023, from https://www.merriamwebster.com/dictionary/neurobiology Medicine, Y. (2021, June 17). How depression affects the brain. Yale Medicine.

Retrieved February 16, 2023, from https://www.yalemedicine.org/news/neurobiology-depression Palazidou, E. (2012). The neurobiology of depression. Academic.oup.com.

Retrieved February 17, 2023, from https://academic.oup.com/bmb/article/101/1/127/262645 Rachael Zimlich, R. N. (2020, July 14). Nurture may trump nature when it comes to depression risks. Contemporary Pediatrics. Retrieved February 17, 2023, from https://www.contemporarypediatrics.com/view/nurture-may-trump-nature-when-itcomes-to-depression-risks Writers, M. (2020). About antidepressants. Mind. Retrieved February 17, 2023, from https://www.mind.org.uk/information-support/drugs-andtreatments/antidepressants/about-antidepressants/

PET scan of the brain for depression. (n.d.). Mayo Clinic. Retrieved February 24, 2023, from https://www.mayoclinic.org/tests-procedures/pet-scan/multimedia/-petscan-of-the-brain-for-depression/img-20007400 Clinic, T. W. (2021, September 23). Parents in Conflict and the Children Who Live Through the Trauma. The Wave Clinic. Retrieved February 24, 2023, from https://thewaveclinic.com/blog/parents-in-conflict-and-the-children-who-livethrough-the-trauma/ Org, D. S. (2023, January 25). 11 Facts About Depression. DoSomething.org.

Retrieved February 24, 2023, from https://www.dosomething.org/us/facts/11-factsabout-depression Cohen, S. (2022, March 15). Suicide rate highest among teens and young adults.

UCLA Health. Retrieved February 24, 2023, from https://www.uclahealth.org/news/suicide-rate-highest-among-teens-and-youngadults Medicine, J. H. (2023, January 1). Teen Suicide. Johns Hopkins Medicine.

Retrieved February 24, 2023, from https://www.hopkinsmedicine.org/health/conditions-and-diseases/teen-suicide

Artificial Suns: Nuclear Fusion Energy in the foreseeable Future?

—————————————————————————————————————————— TszFung Tsui Grade-10

In Sci-fi games and novels, the energy requirement for advanced civilizations is always unbelievably high. To rationalize such high-energy consumption, authors of sci-fi works often set up fictional energy sources so the background logic makes sense. For example, in the first person shooter (fps) game, Doom, there is a fictional energy source known as “Argent”. And in another sci-fi video game, Halo, they used “Pinch Fusion” as the energy source. The Difference of the two is that “Argent” is something completely imaginary, while “Pinch Fusion” is more like an advanced and idealistic development of Nuclear Fusion Energy.

Fusion power, also known as nuclear fusion energy, is a more realistic and approachable energy source for human civilization.

Fusion power is a proposed method of generating electricity from the heat produced by nuclear fusion reactions. During fusion, two lighter nuclei combine to form a heavier nucleus (formed by electrically positive protons and electrically neutral neutrons, surrounded by a negative charged electron)[Figure .1], releasing energy at the same time.

An example of nuclear reaction in our daily life observation is the sun. The sun is a high temperature sphere of gas made up mostly of hydrogen where most of the gas is plasma, which is the fourth state of matter. The process of fusion in the sun is the conversion of hydrogen to helium. As shown in Figure 2, hydrogen collides with another hydrogen and one of the protons turns into a neutron as a positron is released.

Figure .1 Structure of an Atom This newly formed nucleus is known as a deuterium, a stable isotope of hydrogen. Then when another hydrogen collides with deuterium, gamma rays will be released and form a light helium isotope known as helium-3. And as a result, two helium-3 will fuse together, two hydrogens (protons) will be released, and a helium-4 is produced.

Figure. 2 Fusion reaction under the condition of the sun

So how much energy can be obtained from the fusion reaction? To understand the enormous amount of energy that fusion reactions can produce, we will need to set up a comparison. For example, in a general fission reaction, where a neutron smashes into Uranium-235 and splits into few neutrons, Barium and Krypton. The sum of the masses of these fission fragments is less than the original mass. The mass lost (about 0.1% of the original mass) has been converted into energy according to the renowned equation of Einstein “E=mc2”.

The binding energy from fission reaction (energy needed to separate an Atomic nucleus into neutron and proton) is shown from U238 to Fe56 on the graph [Figure.3], where we see the tiny uplifting gradient in the graph from right to left.

In contrast, the fusion reaction where we use the example of the sun mentioned in previous paragraphs, can produce energy represented by the almost vertical gradient from H1 to F56 as shown in the same graph left to right.

Figure 3. Graph that shows binding energy of nuclear fission/fusion reactions

In order to achieve nuclear energy by fusing Deuterium and Tritium, we need to reach a merit figure for the product. According to the Lawson Criterion, a figure of merit used in nuclear fusion research, plasmas must meet three conditions for fusion to occur: reaching sufficient temperature, density, and time.

Figure .4 Graph of Lawson Criterion Countries like the United States and China are striving for sustainable fusion power technologies. Among all the facilities exploring fusion power, Lawrence Livermore National Laboratory (LLNL) is one of the most advanced and for the first time had a result where they had greater energy exported than imported.

The facility used 192 lasers to import 2.05 megajoules of energy to a small gold cylinder filled with frozen pellets of the hydrogen isotopes deuterium and tritium.

Figure.5 LNLL’s fusion ignition device

Energy from the lasers causes the capsule to collapse to temperatures high enough where hydrogen isotopes fuse into helium, releasing additional energy and creating fusion reactions. Laboratory analysis showed that the reaction released was about 3.15 MJ of energy, which is about 54% more energy than went into the reaction and more than double the previous record of 1.3 MJ. On the other hand, the HL-2M is a research Tokamak at the Southwest Institute of Physics in Chengdu, China. It was completed on November 26, 2019 and opened on December 4, 2020. HL-2M is now used in nuclear fusion research, in particular to study the extraction of heat from plasmas.

A Tokamak is a device that creates a very strong magnetic field which is able to restrict high temperature plasma and allow it to flow through the shape of a ring.

The HL-2M tokamak reactor is currently the largest advanced tokamak device in China with the highest parameters. It is the country's next-generation advanced magnetic confinement nuclear fusion experimental research device.

The device adopts an advanced structure and control method, the plasma volume is more than twice that of existing domestic devices, the plasma current capacity is increased to more than 2.5 megaamps, and the plasma ion temperature can reach 150 million degrees.

This means it can achieve high density, high specific pressure, and high bootstrap current operation.

Figure.6 HL-2M tokamak reactor Fusion power offers a potential long-term energy source that uses abundant fuel supplies and does not produce greenhouse gasses or long-lived radioactive

waste. Furthermore, it allows humanity to take a huge step forward in civilization advancement.

With the power of nuclear fusion, mankind will for the first time raise the tinder of civilization and set sail to the ocean of the vast universe.

Intestine Probiotics: Common application and use in the intestines

By Freya Feng Grade 11

Introduction Have you ever heard the word biological broom? That is the description for probiotics. Why is it called a broom? Well, you will know the reason after you read this article. In the intestinal tract of humans and animals, there are complex relationships such as habitat, partial growth, competition, or phagocytosis.

Through these relationships, probiotics improve the balance of the host's intestinal microbial flora, play a role in promoting beneficial food metabolism, improving and treating metabolic diseases. Beneficial bacteria or fungi in humans and animals mainly include Clostridium butyricum, lactic acid bacteria, bifidobacteria, Lactobacillus acidophilus, actinomycetes, and yeasts.

Probiotics have been defined by the WHO as "live microorganisms" that are beneficial to the health of the host. By colonizing the intestinal tract, they can

effectively improve the intestinal microenvironment, reduce the pH of the intestine, prevent the translocation of intestinal bacteria to prevent and treat intestinal diseases. This article is going to briefly introduce the beneficial effects of intestinal probiotics.

Positive Effects of Probiotics on the Intestine Enhance intestinal epithelial cell barrier function

(Figure 1.The mechanics of probiotics in the intestine) Probiotics increase mucus production and maintain the integrity of the barrier. It can also increase the amount of defensins secreted by intestinal epithelial cells, which can play a role in acute infectious enteritis. Probiotics can block the denaturation of tight-junction proteins and increase the electrical impedance of tight junctions through the protein kinase C pathway and the mitogen-activated protein kinase pathway. Probiotics increase intestinal epithelial barrier integrity by employing a mouse model of stress-induced intestinal barrier dysfunction. Figure 1 showed an overview of the mechanics of probiotics in the intestine.

Immunomodulatory effect The intestine is the largest immune organ. The area of the intestinal mucosa is about the size of a tennis court, and its structure and function constitute a powerful mucosal immune system. The intestinal mucosal immune system includes gut-associated lymphoid tissue, lymphocytes and molecules.

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In a person's life, more than 95% of infectious diseases are directly or indirectly related to the intestine.

The effect of probiotics on non-specific immunity

Nonspecific immunity, also known as innate immunity, involves many immune cells, including macrophages and NK cells. Macrophages are important factors that cause non-specific immunity in the body, and can secrete cytokines to promote the proliferation and differentiation of immune cells or enhance immune responses. According to experiments, some probiotics can enhance the immune ability of immune cells and strengthen the immune ability of the human body.

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The effect of probiotics on specific immunity Specific immunity, also known as acquired immunity, includes cellular immunity and humoral immunity.

Cellular immunity is an immune response with T lymphocytes as the core.

When T cells come into contact with certain pathogens, with the participation of macrophages, T cells differentiate and proliferate into immune T cells. Lactic acid bacteria have a stimulating effect on intestinal lymphocytes, can produce interferon, enhance the phagocytosis of mononuclear phagocytes, and kill enteroviruses and other bacteria. Humoral immunity is an immune response in which specific antibodies play a major role. The body's immune system can

synthesize and secrete immunoglobulins, and these antibodies can recognize and specifically bind to antigens, mediate the activity of immune cells, and enhance the phagocytic function of phagocytes. Some animal experiments have shown that probiotics can improve the function of the intestinal mucosal barrier, promote the production of specific and non-specific antibodies, and enhance the function of the immune system. As figure 2 showed, the probiotics produce bioactive compounds by using the substrates from diet, and the bioactive compounds can affect the immune system.

Figure 2. Mechanisms of immunomodulation by beneficial microbes

The regulation of the enteric nervous system Regulating the enteric nervous system is mainly to increase the threshold value of neuronal action potential and corresponding receptors. Lactobacillus can reduce the sensitivity of dorsal root ganglion neurons of the spinal cord caused by colorectal expansion stimulation and can also relieve certain visceral pain.

Experiments by Rousseaux et al. have also shown that probiotics can significantly improve abdominal discomfort caused by some intestinal diseases by activating corresponding receptors in the intestine.

Furthermore, the result of medical experiment showed, “treatments with antibiotics or probiotics such as L. paracasei DSM 13434 and L. plantarum DSM 15312 resulted in alleviation of EAE clinical symptoms and inflammation by suppression of IL-17 production and accumulation of regulatory T cells in secondary lymphoid organs. These observations suggested that probiotics could result in changes in the composition of the intestinal microbiome and favorable outcomes in patients suffering from autoimmune diseases.”

Intestinal nutrition health regulation function Regulation of gut microbiota on host nutrient metabolism gut microbes take nutrients from the host gut for self-enjoyed tissue renewal and excrete unavailable substances. This form invisibly participates in the host's digestion, absorption and metabolism of nutrients. Most studies have shown that the way for intestinal flora to obtain nutrients is that after the food is degraded in the stomach and small intestine, it enters the gastrointestinal wall through the apical membrane transport carrier of the gastrointestinal epithelial cells, then transfers out through the basement membrane transport carrier, and enter the blood circulation for use by the intestines and other tissues.

With the deepening of research on the relationship between host nutrient metabolism and intestinal flora, especially after the study of the genome of the host and intestinal flora, researchers have found that the intestinal flora mainly participates in the sugar, protein and fats of the host, Affects the host's digestion, metabolism and absorption of nutrients, thereby regulating the host's nutritional level, health status, immunity and enteric brain nervous system.

Conclusion “Probiotics have been proposed as preventive and therapeutic measures, in order to restore the healthy composition and function of the gut microbiome.” It is powerful and has multiple important functions in our body. The way to gain more probiotics is to eat some yogurt, bread or even kimchi and many other things you like. Did you gain some interest in probiotics after you read this article? If yes, feel free to read more about it by reading further and start your own research!

References, further reading, and links Cleveland Clinic (2020). Probiotics: What is it, benefits, side effects, food & types. [online] Cleveland Clinic. Available at: https://my.clevelandclinic.org/health/articles/14598-probiotics.

Hemarajata, P. and Versalovic, J. (2012). Effects of probiotics on gut microbiota: mechanisms of intestinal immunomodulation and neuromodulation. Therapeutic Advances in Gastroenterology, [online] 6(1), pp.39–51. doi:https://doi.org/10.1177/1756283x12459294.

Kechagia, M., Basoulis, D., Konstantopoulou, S., Dimitriadi, D., Gyftopoulou, K., Skarmoutsou, N. and Fakiri, E.M. (2013). Health Benefits of Probiotics: A Review. ISRN Nutrition, [online] 2013, pp.1–7. doi:https://doi.org/10.5402/2013/481651.

Ravinder Nagpal, Ashwani Kumar, Manoj Kumar, Pradip V. Behare, Shalini Jain, Hariom Yadav, Probiotics, their health benefits and applications for developing healthier foods: a review, FEMS Microbiology Letters, Volume 334, Issue 1, September 2012, Pages 1–15, https://doi.org/10.1111/j.1574-6968.2012.02593.x.

Thanks for reading!

Coming soon:

Volume 5 Expected Trimester 1 2023-2024

If you are interested in writing for the Science Journal please see Mr. Bonnar in 19-33