IAPS 2022-2023 Interviews jIAPS

Interview with Zlatan Vasović (IAPS Fundraising Manager and Archivist)

The current jIAPS Editor-in-Chief has been interviewing IAPS EC members. Now it is the time for two Editor-in-Chiefs to interview each other. Zlatan Vasović was the jIAPS Editor-in-Chief last year in 2021–22, as well as the IAPS IT Manager. He is now the IAPS Fundraising Manager and the Archivist (and spoiler alert, he is hoping to apply for a position to continue in IAPS next year).

 jIAPS is currently looking for next year’s Editor-in-Chief. Could it be you? Email us at for more information on how to apply. 

What do you consider to be the most important aspects of IAPS?

What makes IAPS unique is that it is truly international. Through IAPS events, like ICPS and PLANCKS, you can meet people from the whole world. One aspect is less known and harder to access: becoming an IAPS volunteer, by joining a working group, the EC (Executive Committee) or jIAPS [Especially jIAPS; that of course is the most important aspect to IAPS – Editor].

What is the most challenging thing about being the past Editor-in-Chief?

Answering the questions from the current Editor-in-Chief, especially when she messages me every day and when I don’t know what to expect from the questions. I take it as a challenge and I love to see how jIAPS is developing.

I know you are always on the IAPS Discord, messaging people. How many IAPS members have you messaged in the last 24 hours?

About 20… but that includes people from NC Serbia and the EC. It was a busy day though. 

What do all past jIAPS Editor-in-Chiefs have in common?

One common trait is that they have a lot of interests – they are quite curious, versatile and multi-skilled. They can do a lot of things and be successful in all of them.

 What has jIAPS done this year that you would have done differently?


Actually, I’m not dissatisfied with anything in jIAPS. There are two main things I would have done differently: I would have pushed for a separate jIAPS website, like a real news site [For context, the plans for this have been ongoing for  while and haven’t reached completion yet, and it doesn’t look like it will be happening anytime soon – the IT Working Group has lots to do]. 

The second would be more online meetings. I am just addicted to online meetings, so I would’ve run them more often, like every two weeks. [What’s the record we are on now? Is it a grand total of three meetings since last August? – Editor]

What is your advice for anyone who is interested in applying to join the EC?

Go through the website, read the information about the roles there. Read the reports from people who have previously held the position [These are on the IAPS Cloud. If you don’t know where to find this, just email – Editor]. Reach out to the current EC members – the most recent source of information is the person who is currently in that position. And don’t forget the internet – just google around and find more information about what that role is supposed to do in general.

[What a technical answer… definitely an answer from an Archivist – Editor.]

You recently attended the finals of PLANCKS in Milan. What was your most memorable moment from this IAPS event?

The culinary exercises while everyone else was doing theoretical exercises – as the observers at PLANCKS, we had to prepare lunch for the competitors. It was a nice way to bond and connect with the other observers. We were split into teams preparing different kinds of food. I enjoyed organizing my team in the most efficient way possible, to finish our task first. It was a fun experience – food connects people.

What non-IAPS and non-physics activities do you do in your free time?

None. I don’t have any free time… okay, alright. My true hobby is socializing with people. Sometimes it’s mixed with work, but I just enjoy meeting new people.

I am a big fan of movies: not the mass produced ones, but high quality ones. Besides that, I like searching for random things on the internet and learning new things every day. [Other hobbies Zlatan has includes annoying Editor-in-Chiefs on a daily basis and lurking on the IAPS Discord waiting for new messages to be posted – Editor.]

Which movies do you most enjoy watching?

A lot of them, actually. Some of them are classic films, like Casablanca and the Godfather; then others are less well known, but still high quality, like some Serbian and Yugoslav movies. Then there are some films which are in many ways bad but still have something interesting or unique about them. Need movie recommendations? Message me on Discord!

Was there anything during your time as jIAPS Editor-in-Chief which didn’t work?

There were things we started doing and never finished, or planned to do and never did. It shows that throughout the year, you have to reassess your priorities. 

For example, we were slow to set up the online edition of jIAPS, only publishing one or two articles on the website… but that works well this year. We also thought about sponsors. To be financially sustainable, jIAPS could have advertisements. But that didn’t work out, not yet.

What is your favourite part of your role as IAPS Archivist? 

No one sees me. I can just hide in the archives, and it’s a refreshing change from the other roles I’ve had in IAPS. The most interesting part is that you get access to all the records of IAPS and can find out what happened in every year since IAPS started. It’s a great power and you have to use it carefully.

How do you overcome challenges in IAPS?

It’s not much different from the other challenges in life. I learn about the challenge, get more knowledge and skills, and then I can overcome it. Just like in your studies, you can learn more advanced topics from the current year, which in the previous year would have been a challenge. Now you can overcome that challenge.

 By this stage, Zlatan was starving and wanted to go and have dinner, by don’t worry, all is not over – this article only includes half of the interview. The other half, with Zlatan as the interviewer, is yet to come.

IAPS 2022-2023 Interviews jIAPS

An Interview with Dimitris Gkavakos (IAPS IT Manager and DPO Officer)

The jIAPS Editor-in-Chief is enjoying interviewing the EC members so much that we already have another interview for you. This time, the  jIAPS Editor-in-Chief interviewed Dimitris, IAPS IT manager, who is currently studying at the National Kapodistrian University of Athens, Greece. 

The interview opened with a sneak preview of the most recent developments in the world of IAPS IT and a discussion of possible future plans for jIAPS.

Then, the actual interview started. The jIAPS Editor-in-Chief began with the usual opening question…

What are you currently studying?

I’m studying Medical Physics. To be more exact, I’m doing a small piece of research on a Gamma Camera, but thinking of shifting my focus towards neural networks and image reconstruction techniques, especially with all the fuzz on AI. 

What is your favorite part of your role as IAPS IT Manager?

When I first took over as IT Manager, I had a completely blank canvas. There was room to create stuff and provide space to build things. It was the most amazing experience!

What does your role involve?

I can divide the tasks into two categories: first, developing new resources; making them from scratch; the creative tasks; like designing elements of the website  and creating new resources. Then there’s the ‘boring’ stuff, like maintenance and debugging, and doing the sysadmin stuff.

What are your tips for overcoming challenges as IT Manager of IAPS?

You need to think outside the box and always assess possible risks. So, focus on maintaining things and keeping them running, rather than fixing them when they break down. Work smart, not hard.

What have you enjoyed the most about being part of the EC?

Being a part of the EC was more of a self-actualization thing for me; I really love to provide and care for people. Especially now that we provide for physics students across the world, you might think that we differ a lot, but in reality the phrase is “Different continents…same problems”. 

Also by joining the EC you get the chance to meet some truly amazing people and some very interesting characters – the knowledge and cultural exchange is on another level.

What skills is it important to have to be part of the EC?

Time management is really important. You have to be able to keep to a strict schedule or you’ll be a goner. Being a team player and balancing tasks and supporting each other is necessary… it can be stressful at times; keeping that family vibe is very important. IAPS is just like a big family. What else? Do I need to think of another one? Communicating and being able to express yourself – that’s a big one. If you lose communication, it causes a lot of problems; a lot of problems. Communication is critical. 

What is it like being part of the EC?

…what’s it really like? 50% of the time is spent dealing with bureaucracy and the other 50% is spent listening to the Treasurer’s obsession with fund-raising. 

What has been your biggest success this year?

Being elected as IAPS Data Protection Officer (DPO); nah I’m messing with you. For me, overcoming the biggest challenge of IAPS IT infrastructure. Basically we managed to migrate to a different hosting provider, containerized everything and we have backups on top of backups. Before that, if something crashed, you had to pray that it would start again.

What is the role of the DPO?

Basically, it involves looking through the GDPR legislation. Every organization has one to ensure that the organization follows the legislation. In addition to that, the DPO acts as a legal in house advisor, assisting in creating Data Processing Agreements.

What advice would you give to someone who was considering the role of IT Manager?

Go for it! Just be sure to know the basics of sysadmin, PHP and network security. Without those you are a goner.

How can people get involved with the IT Working Group?

It is very simple: hit me up on Discord or throw me an email at

What advice would you give to someone who was considering joining IAPS?

When I first joined IAPS, I joined as the President of an already made NC (Greece). I started my journey through physics associations from EPS Young Minds and the American Physical Society, then I landed on IAPS.

If you ask me, why should you join IAPS…

IAPS has one of the most heart warming communities in the student association world, not just in Physics. You have the opportunity to meet new people, learn new skills and support your activities on a local level.

Aside from the aforementioned, IAPS is also a great opportunity to learn how to run an NC or an LC, join a Working Group and transfer the knowledge back to your country. The knowledge that we have has been battle tested from the late 1990s.

Article of the Month IAPS 2022-2023 jIAPS

jIAPS July Article of the Month: How Low Can We Go? – A Brief History of Nano-Scale Printing

Zofia Dziekan, University of Warsaw, Poland

The ability to create physical objects using 3D printers has taken the manufacturing industry by storm and opened up new ways for innovation in a variety of fields (1). But as impressive as it is to print a functional bicycle or a complex medical implant, some researchers have been pushing the limits of this technology in a different direction: down to a nanoscale. With nanoscale printing, we can create structures that are smaller than the width of a human hair, with intricate details and unique properties. In this article, we will explore the history of nanoscale printing, the underlying physics of this process, and the exciting possibilities it offers for the future.

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Fig. 1 Size comparison between (A) regular (2) and (B) nano-scale 3D printed object (3).

The Physics of Light-Matter Interactions

In 1930, a young mathematician – Maria Göppert-Mayer attended a Max Born seminar at the University of Göttingen (4). Mesmerized by quantum mechanics, she dedicated herself to the pursuit of theoretical physics, eventually becoming one of four women awarded the Nobel prize in Physics. While today she is best known for her work in the Manhattan Project and her postulation of the nuclear shell model, it is her earlier work that is of interest to our story. Göppert-Mayer’s groundbreaking research into molecular excitation, explored in her doctoral dissertation, demonstrated that molecules can be excited by the simultaneous absorption of two photons with energies smaller than the difference between the excited and ground state (Fig. 2A). Despite the lack of high-intensity light sources to test her theory at the time, Göppert-Mayer’s work laid the foundation for future discoveries. Three decades later, the invention of the laser finally provided the tools necessary to observe two-photon excited fluorescence for the first time in CaF2 crystal doped with europium atoms (5).

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Fig. 2 (A) Energy levels involved in one-photon and two-photon absorption (6). 

(B) One-photon and two-photon absorption of fluorescent die (7).

The Pulsed Lasers

The two-photon absorption process involves two photons instead of one, making the probability of absorption proportional to the intensity squared (5). As a result, increasing laser power has been crucial in the development of application for two-photon absorption. Pulsed lasers have been a game-changer in this regard, with their ability to release high-intensity bursts of energy that can be precisely controlled in terms of duration and frequency. Unlike their continuous-wave counterparts, pulsed lasers can vaporize materials without causing thermal damage, making them an indispensable tool for surgery and laser material removal (8). 

3D Printing Through Direct Laser Writing

In the late 1980s, researchers started investigating the potential of using pulsed laser technology to create nano-scale 3D printers (5). One promising technique that emerged in this process was direct laser writing (DLW), a form of 3D printing in which a focused laser beam scans over the sample in three dimensions until it solidifies the polymer solution into the desired shape. To fabricate structures below the diffraction limit, the intensity, duration and frequency of the laser pulses must be precisely controlled to achieve two-photon absorption that would initiate polymerization. The material is polymerized only in the focal spot of the beam where its intensity is the highest as stated previously, and the probability of the process grows with intensity squared (Fig. 2B). This small volume in the focal spot of the beam is known as a voxel and it serves as a building block of any 3D print in DLW (7). 

By moving the laser beam, it is possible to polymerize photosensitive material point-by-point, creating complex structures that are just several microns in size. Just imagine tree-lined avenues, dozens of miniature buildings and little polymer people comfortably sitting on a single strand of hair! It is truly incredible that there is no other method that allows printing on this scale. The resolution of the process is limited mainly by basic properties of an optical setup and material properties. Since its inception, nano-scale printing has come a long way and has found numerous applications in various fields, from micro-robots to drug delivery systems (9 – 10) (Fig. 3). While the technology still faces challenges, including a limited range of building materials and slow printing speed, continued research and development promise more exciting applications in the future. The history of nano-scale printing is a testament to human ingenuity and the power of scientific discovery – and who knows what incredible breakthroughs we’ll see in the years to come!

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Fig. 3  SEM images of objects fabricated using DLW. (A) Medical imagining system build by inserting into a needle an optical fiber with 3D printed lenses (9). (B) Light-fueled robot that can walk and jump, placed on a human hair for scale (10). (C) Microfluidic chip designed for the fabrication of drug carrier nanoparticles (11).


1. S. Mohr and O. Khan. “3D printing and its disruptive impacts on supply chains of the future.” Technology Innovation Management Review 5.11 (2015): 20

2. [Internet] Available from: 

3. Doherty RP, Varkevisser T, Teunisse M, Hoecht J, Ketzetzi S, Ouhajji S, et al. Catalytically propelled 3D printed colloidal microswimmers. Soft Matter. 2020 Dec 14; 16(46):10463–9. 

4. Sachs R.G. Maria Goeppert Mayer – A biographical memoir. 1978. 

5. Liao C, Wuethrich A, Trau M. A material odyssey for 3D nano/microstructures: two photon polymerization based nanolithography in bioapplications. Vol. 19, Applied Materials Today. Elsevier Ltd; 2020. 

6. Lavocat J.C. Active Photonic Devices Based on Liquid Crystal Elastomers. Dec 2013.

7. [Internet] Available from:

8. Shirk MD, Molian PA. A review of ultrashort pulsed laser ablation of materials. 1998. 

9. Gissibl T, Thiele S, Herkommer A, Giessen H. Two-photon direct laser writing of ultracompact multi-lens objectives. Nat Photonics. 2016 Aug 1; 10(8):554–60. 

10.    Zeng H, Wasylczyk P, Parmeggiani C, Martella D, Burresi M, Wiersma DS. Light-Fueled Microscopic Walkers. Advanced Materials. 2015 Jul 1;27(26):3883–7. 

11. Erfle P, Riewe J, Bunjes H, Dietzel A. Goodbye fouling: a unique coaxial lamination mixer (CLM) enabled by two-photon polymerization for the stable production of monodisperse drug carrier nanoparticles. Lab Chip. 2021 Jun 7; 21(11):2178–93. 

IAPS 2022-2023 Interviews jIAPS

An Interview with Gabriel Maynard, IAPS Vice President and Recruitment Officer

The Editor-in-Chief is continuing to make their way around the EC. Read the latest interview below:

What are you currently studying?

Well, today I am not studying – I’m in the transition period between the Bachelor’s and Master’s degree programs. In the autumn, I’ll start an Erasmus Mundus Master’s in Planetary Geophysics. I would like to emphasize my career towards Environmental Physics, as that was the focus of my four year undergraduate degree course at the University of Costa Rica . It’s nice to have a break – I was overwhelmed with choice at the end of my degree. Plus, I have time for other projects, including IAPS and NC Costa Rica. 

Which committee was it the most rewarding to recruit?

It’s the most rewarding to me working in the NC here in Costa Rica. Recruiting other committees in Central America and working with them to create a community, with the potential to grow is also very rewarding.  

Have you been involved with the recruitment of anyone who has gone on to do anything significant in IAPS?

Well… I helped to recruit most of the current EC! There’s NC Greece. I did the process of upgrade from LCs to the current NC, and Dimitris [current IT Manager] is part of that NC; then LC Singapore – Soe [External Relations Officer]; and LC Santo Domingo – Thara [Secretary, also see jIAPS’ interview with Thara]; and NC Guatemala – Marisol [PR Manager]. Have I missed anyone? [And that’s just the people on this year’s EC! – Editor]  

Which committee is the most difficult to recruit?

There’s one which we’ve devised a solution for, but they are stubborn. They want a national committee, but that would be a political statement… and then there’s the case no one talks about which is extremely difficult or impossible to recruit.

Which other tasks, apart from recruitment, have you been involved in?

I was the Data Protection Officer for half a term. It was only for a short time and it wasn’t much work. I’m also on the AC5 Council, organising meetings and trying to move further with the collaboration with IUPAP. As you know, I am Vice-President which has its set of tasks, including helping with the planning of the Mulhouse meeting and connecting with external relations. I’m helping with trying to organise another IAPS2CERN trip which is providing a challenge. There’s a financial problem with the organisation of that – it’s not one of IAPS’ major events, so it is more difficult to find sponsors who are willing to subsidise the laboratory visit [If you, dear reader, happen to be a millionaire, or know of any potential sponsors, please do get in contact with us –  Editor].

Which IAPS event have you enjoyed the most?

I really enjoyed PLANCKS 2022 in Munich. It was really special to see people from the committees you have recruited participating in the competition and enjoying the event. It was very rewarding, especially seeing countries from outside Europe becoming more involved in IAPS. 

PLANCKS 2022 was also the first time Costa Rica participated in person. They selected a team and entered the competition… and it’s fantastic to see it keep improving. Costa Rica participated this year too.

There were also so many activities at PLANCKS and I saw plenty of friends. 

How do you convince new members to join IAPS?

Depending on the area, I say different things. If they are in Latin America, I tell them about the events we are hosting. Then there’s the grants you can apply to in IAPS. I also promote that it is beneficial to have a greater representation from their continent in IAPS, and how they can use it as a platform for future collaborations and to improve their countries. For everyone, I mention the main events IAPS organises, and then the regional engagement and planning of events too. 

What are some of the skills you have learnt from being part of IAPS?

One of the benefits of IAPS has been learning management skills. I’ve learnt how to propose projects and have gained hands-on experience. Being part of the IAPS EC has changed my worldview completely. I have gained new tools and learnt so much.

On average, how many emails do you send a week relating to IAPS?

It varies a lot… maybe about ten a week. Some weeks it is only about three or five. Probably at least ten a week. This isn’t including messaging – that would go off the chart! [The Editor has just checked their email headcount and it is also at least ten IAPS emails a week]

I heard you recently completed some field work as part of your course. What was it like?

I completely like field work. You never know what is going to happen, whereas, in a lab, you have a very controlled environment. You also get to take nice pictures. 

It was a comprehensive experience. Sometimes we had to wake up at 3am and get on the University transport to go to a far-off place in the country. We had to take our measuring equipment with us which weighed about 20 kg and plant the stations we were setting up. This was done to measure carbon dioxide and methane fluxes from the soil to study the interaction between soil and boundary layer in different environments. The stations were to measure Greenhouse Gases in real time. Usually it was very hot – about 30 °C – and about 97% relative humidity so we were all sweating so much. 

[Here, we lapsed into a tangential discussion about snakes. The conclusion is that if you like snakes, go to Costa Rica. If you don’t, come to PLANCKS next year in Dublin.]

One funny story about the field work… we were setting up a station when we could hear a buzzing noise. We were in a field, with trees around it. The buzzing noise was getting stronger and stronger. “Let’s not panic,” said the professor, “Those are killer bees.”

“We’re going to finish setting up,” he continued, “and then run.”

He then encouraged us to start working faster. The buzzing noise was all around us, coming from all directions – we didn’t know where to run to, but we finished the task and got out of there. 

Can you think of anything unusual you’ve had to deal with in your role?

Well, there’s one thing that was very surreal and bothered me.

One Individual Member who was trying to sign up to join IAPS was very intense, following the procedure. There was lots of emailing and it was quite problematic. Then I received a WhatsApp call at 2am. I woke up in the middle of the night and thought ‘who’s calling? Who is this who has got my number?’ It kept calling, about seven times.

All they needed to do was to pay the ten euro membership fee, by either bank transfer or PayPal. This started a whole month of missed calls. They wanted guiding through each small step to pay by PayPal… at that point, I lost patience. ‘I don’t care! Leave me alone!’ I thought… so I gave up and paid the fee for them. ‘Just go away.’ [Note – don’t expect Gabriel to pay your membership fee for you. You have to annoy him sufficiently to get that result, and next time, he is likely to resort to a different tactic instead.]

The lesson here is to never give your phone number in a situation to do with IAPS. 

What is your favourite thing about your role?

I really enjoy engaging with more physics students and hearing the reality through their perceptions of IAPS. I like knowing the different perspectives and connecting with students. 

Thank you so much Gabriel! 

[Gabriel then left the video call to have a well-deserved lunch break, whilst it was the end of the day for the Editor-in-Chief, who returned home and typed up this interview.]

IAPS 2022-2023 jIAPS

jIAPS June Article of the Month Part Two: Which of these Trucks are Driving?

Author: Ali Mohammed Redha, King Abdullah University of Science and Technology, Saudi Arabia

Overthinking a Simple Question

Figure 1: Showing a famous post popularized by World of Engineering social media accounts asking: “which of these trucks are driving?” [1]

1 Motivation

You have probably come across this post (Figure 1) somewhere on social media. It is a famous “trick question” that is meant to stir up discussions, of which there are many. I came by this post numerous times, often going to read the comments, be amused by how many incorrect answers to the question, and then moving on. Being a physicist, I knew the answer and it was as clear as it can be. Having such a question answered incorrectly most of the time was not a big deal, as the question is meant for fun. 

Recently, I came across the post again on Instagram, this time as part of a Ramadan daily quiz made by an academy that I am part of. I waited anticipatingly for the results to be announced. The answer was announced, and it was “C”. “Hmm…Surely they are not serious”, I thought. An attempt by multiple participants was made to clarify the correct answer, but the organizers insisted on the answer. In the end, the clarification attempts failed, and the answer remained “C”.

Although it has been a while now since that incident, I still have it roaming around my head. “The question is simple. How could they have gotten it so obviously wrong?” Thus, I decided to dig deeper into the problem, hoping to find an answer.

2 What Exactly Does the Question Want?

When a physicist thinks about a problem, they immediately start thinking about the exact meaning behind the question. Here, we want to know which of these trucks are moving in the indicated direction. 

Based on your background, this is either “very easy” or “impossible”. The obvious answer is “A” is moving backward, “B” is stationary, and “C” is moving forwards. Problem solved right? Not quite. There are more details underneath this problem than what is immediately thought. Let us take into consideration all the different cases instead of talking about the problem abstractly. Consider this thought experiment.

Imagine you are in a car and the car is stationary. Suddenly, the car starts accelerating fast reaching 100 km/h in 5 seconds, what will happen to you? You will feel a strong pushback due to inertia, almost clinging you to your seat. This is similar to the case “C” in the question. Imagine afterward the car stays moving steadily at 100 km/h for a while. Then, all of a sudden, the brakes are hit, and the car decelerates to 20 km/h in 5 seconds, what will happen to you? You will feel a push also caused by your inertia, but this time it will push you forward. Think about it, the car was still moving forward, yet you felt a push forward. This is like case “A”. We have shown that both cases “A” and “C” are possible to be moving in the forward direction. 

Even case “B” is possible to be moving forward. Imagine if the car brakes are not hit, and the car keeps moving at 100 km/h for a long time. What will happen? You will stay still as if you are not even moving. As you can see, all of the cases are possible to be moving in the direction stated in the problem. Except there is more to it than just this.

Consider now that everything is reversed. The stationary car, with you in it, starts moving backward reaching 100 km/h in reverse. What will happen to you now? You will feel a push forward (opposite the direction of motion). If the car then stays moving at that speed for a while, you will feel as if you are stationary. And again, when the car decelerates from 100 km/h to 20 km/h, you will feel a push backward (with the direction of motion). This means that all the cases are possible to be moving in the opposite direction as well!

It can get even more counterintuitive, as one can make an argument that they all can be stationary, and it would be true in certain circumstances. For a physicist, this should not be surprising, as physics tells us everything we need to know about these answers.

3 The Physics Behind It

In physics, motion means the change of position in the direction specified and that has a name. We call it velocity. So, to answer the question, we need to know the direction of the velocity of each truck. However, the three images given do not give any indication whatsoever about the direction of the velocity. Instead, it gives us the direction of the force applied to the liquid, or in other words, the direction of the acceleration.

According to Newton’s first law, a stationary object would stay stationary, and a moving object would stay moving at constant speed unless a net force acts upon it [3]. This in a way, is the case “B”. A moving object with constant speed cannot distinguish (physically) whether it is moving or not. This is known as the principle of relativity (first made famous by Galileo Galilei) [2]. This means that we cannot physically sense speed (by touch at least). Newton’s second law gives us what an applied force does, and that causes acceleration [3]. Acceleration is the change of motion (velocity). A change backward would give us the answer “A” and a change forward would give us the answer “C”, due to the famous phenomena of inertia. See, this does not tell us in any way what is the direction of velocity. The directions of the velocity and acceleration are independent of each other. So, in each of the three cases, the object can be moving in any direction. As a matter of fact, it can even be moving sideways, vertically, or even at an angle! 

If you go back to the post, the answers with the most likes are those saying all choices are possible [1]. In fact, some say that the wording of the question supports this answer (“are” not “is”). However, some other comments come up with a good counterpoint. The question says “driving” and generally, driving is done by hitting the gas pedal, not the brakes! Therefore, the answer is “C”. Maybe this is what the organizers meant in that answer? To that I say, yes you got a point. But I would still argue that the answer is not just “C”, not just from the previous argument (as the car still can decelerate even with pushing the gas pedal), but also for another entirely different one. Let me show you why.

4 Overthinking the Question

For those observant, there is a slight flaw in our theoretical experiment. We used a solid object – you dear reader – as a replacement for the liquid in the problem. And this is a technical issue in the experiment, as liquids behave differently than solids. 

Liquids, unlike solids, do not have a fixed shape. And so, a force acting on a liquid would produce vastly different results than a force acting on a solid. A rigid solid object would remain intact upon a simple touch, and a liquid, like water would start vibrating, with waves rippling on its surface. That is just a simple touch of the hand. A strong force would cause a larger vibration on the water’s surface and would cause its shape to deform significantly. 

Now apply this to the case we have. The truck is stationary with all the liquid on it, then it starts accelerating strongly forward abruptly. The liquid will be pushed backward at first, but upon hitting the back of the container will start waving back and forth. What we will get is chaos, in the logical and physical sense. The motion of liquids in such cases is chaotic, similar to tossing a coin or using [4]. Hence, case “C” would not be replicated precisely during a forward acceleration of the truck. If you take 1000 images of the truck accelerating forward, maybe you will be able to replicate image “C”, except do not hedge your chances of having it stay constantly the same. Fun fact, you might be able to get images of “B” or even “A” if you were lucky enough! Things need to go a specific way, but it is possible! Thus, you might be able to get images “A”, “B” and “C” in the same “photo shoot”. Even with the notion that hitting the brakes is not driving, we still got all the images which means all of the answers are possible. Let us take one more thought experiment to explore another possibility. 

5 Overthinking It to Absurdity 

Imagine the truck with the fluid inside it, and we take that truck and shake it violently. After that, we let it rest in a pure isolating chamber, where it cannot interact with anything at all. During this time, we took our special x-ray camera and took a large number of photos (theoretically an infinitely large number of them). If we then filter out these photos, we will see the three cases among them. The point is that the force applied on the truck does not have to be by the truck (engine) itself. It can be caused by other means. 

The complexity of the problem does not stop there. I mentioned previously that the reaction of liquids to forces is chaotic, meaning it depends on many factors. These factors include, but are not limited to: the type of liquid (determining its density, viscosity, etc.), the volume and temperature of the liquid, the material the container is made of, the type of gas (if any) with the liquid inside the container and its temperature, ambient air temperature, wind currents, amount of sun radiation incident, the surface of the road and the tiers, vibrations caused by the car engine and motors, and the remaining is left for the reader to figure out as an exercise [5]. This adds layers upon layers to the already, too complicated simple problem . 

6 Conclusion

The final answer to this question is: all and none of the above (this is a first!). This problem highlights one trick of mother nature. How our senses fool us and build our intuition on a physically incorrect notion. This is why we have to be careful when dealing with physics, as more often than not, physics can be counterintuitive (which in and of itself is counterintuitive). Ultimately, the answer to this question does not matter. It is for fun. What matters is how people perceive this problem. Everyone is going to understand it in their unique way, which opens the floor for some great discussions. It is astonishing to come across a question occasionally where there can be no winner or loser. Just different perspectives on a fascinating, tricky problem. In such a scenario, the true winner is everyone who got enlightened by a nice, eye-opening discussion. Not everything has to be a competition after all… and yes, I did write this to prove a point.

7 References

[1] World of Engineering. Which of these trucks are driving?: 2022 Nov 14 [cited 2023 April 27] [Tweet]. Available from: @engineers_feed. 

[2] Wikipedia contributors. Principle of relativity [Internet]. Wikipedia, The Free Encyclopedia; 2023 Mar 27, 20:46 UTC [cited 2023 Apr 27]. Available from:  

[3] Glenn Research Center. Newton’s Laws of Motion [Internet]. Glenn Research Center – NASA. [Cited 2023 May 21]. Available from: 

[4] Bishop R. Chaos. The Stanford Encyclopedia of Philosophy; 2017 Mar 21 [cited 2023 May 21]. Available from: 

[5] Wikipedia contributors. Fluid dynamics [Internet]. Wikipedia, The Free Encyclopedia; 2023 May 4, 18:13 UTC [cited 2023 May 21]. Available from:  

IAPS 2022-2023 Interviews jIAPS

An Interview with Thara Caba, IAPS Secretary

For the next in the series of jIAPS interviews. The Editor-in-Chief spoke to Thara Caba, IAPS Secretary:

What are you currently studying?

I graduated from my Bachelor’s course in April. I was studying General Physics for my undergrad in Dominican Republic. I’ll start my Master’s in September, where I’ll be studying Astrophysics and Space Science; so I’m actually in between degree programmes at the moment. I’m doing some extracurricular courses in General Relativity and Cosmology, and some programming courses. 

What have you enjoyed most in IAPS?

I really enjoy the community in IAPS. Here [in the Dominican Republic], we only have a small community of physics students. In IAPS, you get to meet people from all over the world. I enjoy attending events and getting to meet so many physics students. It’s not ordinary for me; so I like the events and the community. 

What’s your IAPS journey been like – what previous roles have you had?

A few years ago, I was the President of my student association and I was contacted by Gabriel [now Vice-President of IAPS], who was part of the recruitment working group of IAPS. Gabriel found the email addresses of all the student physics societies in Latin America and contacted them to tell them about IAPS. I got a message from him and that’s how we started the process to become a LC [Local Committee of IAPS]. That was in 2021 I think. After that, I was a volunteer at the online edition of PLANCKS in 2021. I became more involved with IAPS. I was a staff member of jIAPS 2021 [and Thara is still helping with jIAPS now – Editor]. Then I ran for PR Manager in 2021 and became part of the EC. 

And so, why did you decide to apply to become IAPS Secretary?

As part of the EC [Executive Committee], I saw the importance of having a good secretary. Then I was like, hey, I’m good with time management and organising stuff, why shouldn’t I apply for Secretary of IAPS? I was also finishing my studies, so I knew I’d have more time for IAPS. So that’s what I did in 2022, and here I am now. 

What does your role involve, other than minute taking at meetings?

Taking minutes every two weeks for the EC meeting is the most consistent thing I have to do, but it actually isn’t the biggest thing. I also make sure that everyone’s doing their tasks that they were allocated in the meetings and remind them to do their tasks. 

Organising the EGM (Extraordinary General Meeting) and now the AGM (Annual General Meeting) is a lot of work. There are a lot of moving parts and this is the biggest thing I have to do. Whenever there’s a letter of recommendation or a letter for an event to be written, that’s my job. Those are the biggest things I have to do in my role. There are also unallocated jobs in the EC that anyone can do too. 

What’s your most memorable moment from IAPS?

My most memorable moments are from PLANCKS Milan 2023. I really liked meeting and talking with the Nobel Prize Winner, Didier Queloz, who discovered the first giant planet outside the solar system. [You can ask Thara for her other memorable moments – Editor

What are IAPS meetings really like?

They are usually very long and very heavy – there is a lot to discuss. Before doing it, no one is aware how much work being on the EC really is. There are lots of things to do, but it’s really rewarding. 

What’s your top tip for taking minutes?

Don’t write everything anyone says, or you’ll fall behind and start to miss stuff. Just write the general idea and that’s okay. People don’t want to have to read a ten page long document for every meeting. 

Can you think of anything unusual or particularly interesting that you’ve had to include in the minutes of a meeting?

I’ve included lots of unusual things in the minutes! I want people to read them. I don’t want them just to approve the minutes without reading them. Once, I wrote that one of the EC members was in the bathroom in the minutes to see if people were paying attention to what I wrote. 

Have you had to do a lot of travelling in IAPS?

Yes! It is one of the most rewarding things about being on the EC, or just being in IAPS in general. I have two favourite events that I travelled to with IAPS. The first is the Opening Ceremony of the IYBSSD (the International Year of Basic Sciences for Sustainable Development), which was really fancy and held in Paris. I got to meet ministers and Nobel Prize winners… and afterwards, we went to the Eiffel Tower. It was an amazing day.

The second event is the IUPAP (International Union of Pure and Applied Physics) Centenary Symposium in Trieste, which was near the beach. We got to go to the beach almost every day. It was an event with physicists from all around the world. I got to learn about the diverse jobs a physicist can do – not just becoming a researcher, but there were also journalists, business managers and policy makers.   [You can read more about both of these events in jIAPS 2022 – Editor]

What advice would you give to someone who was thinking of joining IAPS?

Just do it! It is really fun! You get to meet lots of people, make lots of friends! 

I’ve found that physics students all like the same things; we have similar personalities. If you join, you won’t regret it. 

Thank you Thara; is there anything you’d like to add?

Hmm…  just ‘thank you for interviewing me!’ 

IAPS 2022-2023 Interviews jIAPS

An Interview with the Coordinator of the Music Group Sessions, Aleksandar Stojcheski

Interviewer: Fabiola Cañete Leyva, Benemérita Universidad Autónoma de Puebla, Mexico

Music and physics have always been intertwined. That is the main motivation behind the Music Sessions led by Aleksandar Stojcheski at IAPS.

For the next in a series of jIAPS interviews, we feature a conversation with Aleksandar where we discuss the objectives of this initiative.

You can listen to the New Year’s song or the 35th Anniversary’s song produced by the Music Group at IAPS!

Graphic designed by Harvey Sapigao

Hello, Aleksandar. Can you share with us what you are studying and where?
Hello. I’m currently studying for my undergraduate degree. I’m in my third year and my major is physics. I study at the Faculty of Natural Sciences and Mathematics in Skopje, North Macedonia. My intentions for future studies are in the field of fusion and nuclear energy. 

How did this initiative begin?

Well, music has always been there. It’s not just something that I started to do recently. Listening to music has always been a huge part of my life. 

I started playing the guitar because my father used to play and he taught me. That’s how I started with the acoustic guitar. Then, you know, with time, after practicing more I decided to get myself an electric guitar. Although, my first wish was to play the drums, you know? And that wish remained. So much that several months ago I finally got my drum set. I have always loved music and instruments are a big part of my life. I have plans for future instruments. I would like to play a little bit of everything. It is a passion I always carry with me, even when I go to physics events. 

Actually, that is how all this initiative began. It was very interesting how it happened.

Last year I went as a delegate to the EPS forum in Paris. It was my first participation as an IAPS member and it was great. I met incredible people: the president, the business committee, everyone. We had a great time and I learned a lot. 

At the end of the event, many of us remained in Paris for one or two days more to enjoy the city. Some of us gathered to walk around and we ended up visiting Montmartre, a place full of culture. There were some theaters, very nice cafes and of course, music.

I remember there was a street musician who played the guitar and he really interacted with the audience. All of us ended up singing together and, at one point I even joined the stage. It was really an amazing experience.

Afterwards, while talking with Ruhi —the IAPS president at that time— I said, why not try to do something like this in IAPS? She was very excited about the idea. And after returning to my country we really talked about it. I gave some proposals, she also gave some ideas and that is how it all happened. It was very spontaneous.

What is the main objective of the Music Group at IAPS?

Well, music always brings people together. So the idea is to recreate, in some way, the experience we all had in Paris. The music sessions give space for people to express themselves, to share some music and also part of their culture. I was really honored when people entered the first couple of sessions and started to play their instruments. 

Slowly, some ideas came up. During sessions I started to think about what more we could do and that is how the idea of making a song for the 35th anniversary of IAPS was born. We thought that it was a great opportunity to come together and produce something. 

The coolest part of being an international community is that you don’t just gather in a room and play. Being all in different parts of the world, we had to, sort of, make it like a puzzle. Everyone played individually and in production all the pieces came together. The collaboration was amazing.

How many participants are there in the Music Group?

On average, about 10 people. There is always a different number of people in each session, it depends on their availability. I usually try to post the date early so that everyone can see it. Anyone can join. We actually had new members the last time.

Being a group formed by physics students, do you think that your approach to music is different from that of the general public?

Maybe. I would say that as a physicist you get inspired in a different way because physics is a science that consists of amazing theories that can influence the way you think about music. For example, there have been people who play the Fibonacci sequence and get inspired by incorporating those mathematical and physical concepts into their music.

Which music genre is addressed by the Music Group?

We don’t approach just one style. There have been sessions where we play traditional songs. Sometimes we play jazzy stuff, like the New Year song we composed. And other times we also go with a classical perspective, like with the anniversary song.

Personally, I love rock music and sometimes I also listen to classical music but I try not to impose my preferences in the music sessions. I am always open to suggestions and I am happy to try new things.

Do you have a role model or an inspiration, like a physics professor with a music background?

Not really, that is not my way of thinking. I don’t have role models. I follow inspiration instead. Music is a great part of my life and I have understood that I need that balance between art and science. When I do music I get inspired by the process. 

Finally, what advice would you give to anyone who is thinking of joining the music group or learning to play music?

Well, the main requirement, in a way, is to have a passion for music. The objective is to have fun, to relax a little bit and if something comes out of it, that is fantastic. If someone has a music project that requires collaboration or if someone just wants to learn about other cultures through music, this is the place to do that.

Aleksandar, thank you so much for this interview and for the wonderful work done leading the Music Group at IAPS.’

Find out more about the Music Group Sessions in the #music channel of the IAPS Discord.

Article of the Month IAPS 2022-2023 jIAPS

jIAPS June Article of the Month: Can We Feel Speed?

Ali Mohammed Redha and Asif Bin Ayub, University of Bahrain, Bahrain

1 Introduction: The Question

One day, as I was driving my car back to my house after a long day at the university. A question popped up in my mind that caught my attention for the whole drive: “Can we feel speed?” Being a physicist, I am used to thinking of questions like this for hours straight. But this, this was different. I began thinking of the topic from multiple perspectives. How would a physicist answer this question? How would a non-physicist answer this question?

Figure 1: Shows a search result of the word “speed” on Pixabay. Can you feel speed from that? Source: Pixabay

The question was so intriguing to me that I decided to resort to the most scientific method of questionnaires, Instagram polls. I asked in the poll, “Can we feel speed?” and 59% of the respondents said YES, the other 41% of course answered NO. What was most interesting about the poll is that physicists following me took both sides. Some said YES while the remaining said NO. I thought the answer would be obvious to physicists, NO is definitely the answer, right? That made me think deeper about the question, particularly about the word feel.   

Figure 2: The scientific poll conducted. The question is: “Do we feel speed?” 27 participated with 16 answering YES and the remaining 11 answered NO. The participators are all from Bahrain with various backgrounds and specialties. Source: Self-made.

2 What Do We Mean by “Feel”?

To feel is to experience something emotionally or physically [1]. We can feel emotions: happiness and joy, love and passion, sadness and sorrow – which are abstract constructs of our mind. But the type of “feel”-ing we are interested in is rooted in physical experience: such as touch, heat, and texture. In this physical notion of “feel”, which we might call “sensing”, can we truly sense speed?

We sense our physical surroundings using our five senses: vision, hearing, taste, touch, and smell. Think about them as detectors. Thus, to see if humans can sense speed, we need to see if these senses can detect motion. Imagine yourself driving a car and applying each of your senses separately. Which ones can detect speed?

Figure 3: Shows the senses of a normal human. Us physicists, we do have 6th, 7th, 8th, and 9th senses but we don’t talk about those… Source: Self-made

Identifying speed with vision is no problem. And although speed does not have any sound in and of itself, minuscule collisions, friction, engine sound and other interactions generate sound and can be heard. Combine both visions and hearing together and you get a good motion detection apparatus.

However, take vision and hearing away, and we lose almost all notion of speed. As far as we know, speed cannot be identified by smell or taste – though, it would be interesting to see how an avant-garde chef might imagine the flavor of speed. As for touch, it counterintuitively, cannot sense speed. This is one way that nature tricks us into thinking we are sensing something when we are sensing something else entirely. Our inability to sense speed does not stem from a flaw in the human sensory apparatus, rather, it is a consequence of a fundamental principle of nature. 

3 Finally, Some Physics 

There is no physical way to distinguish between a moving object at a constant speed and a stationary object. This is known as the (special) principle of relativity and was first theorized by Galileo Galilei in his theory of relativity [2]. Formally, an object/observer that is moving at a constant speed or is stationary is known as an inertial frame of reference. Therefore, according to the (special) principle of relativity, there is no fundamentally preferred inertial frame of reference [2].

To put this simply, this means that everyone has the right to claim themselves to be stationary. Me, I see myself as always stationary so I can claim to be always stationary, “I am the center of the universe”. You, dear reader, always see yourself as stationary and so you have the right to claim that you are always stationary and that you are the center of the universe. No one is wrong here; we are both correct. Someone else might also jump in and claim they are stationary, and we are not, and they will still be right. All of these are physically identical, just seen from different perspectives.

This explains why we cannot sense speed physically by touch. After all, I am always stationary according to myself. There is nothing changing about me, whether I was sitting down, having a walk or driving a car. Everything else around me is moving, but me? No, I am always stationary (keyword: according to me). 

What humans physically sense are forces, we feel forces (more accurately, energy transmission). If you hit a wall, then you get hurt by it, because of the force the wall enacts on you. When driving a car, the car vibrates due to friction and minuscule collisions which act as forces on our bodies. Add to that the force exerted by the seat belt and through this nature tricks us into thinking we sense speed when we in fact sense forces. A more in-depth dive regarding our sense of touch is found in [3]. 

It is important to note that Galileo’s relativity does not give the full picture, and one should resort to Einstein’s relativity for a more accurate representation of reality. Einstein’s relativity agrees with Galileo’s principle of relativity in the case of inertial frames. However, when forces are involved the frames of reference become non-inertial. In that case, there would be preferred frames of reference and that has many implications [4]. Still, how does that answer our question? 

4 Conclusion: The Answer

This question goes beyond just science, just answering the question with physics does not feel right. The answer to it is heavily dependent on how we, humans, function. It is always awe-inspiring how complex the human system is. Not just biologically, but socially and psychologically as well. I mentioned how scientifically, we always think of ourselves as being stationary and everything around us to be moving. In the theory of relativity, you are the center of the universe. Go ahead and apply this way of thinking to the social norm and things would be confusing and overly complicated. We sacrifice accuracy for easiness. We pick perceptions and logical systems that would lead us to the simplest, most straightforward path. Everyone is ready to throw away their title of “center of the universe” to live harmonically and in symphony. Ultimately, it does not matter if we believe that we can feel speed or not. What matters is that we can communicate our situation in a way that others would feel. So, is the answer YES, or NO? Well… whatever makes you feel better.

5 Acknowledgement

Many thanks to my friend and colleague Asif Bin Ayub for his help in writing this article. He had a large input and helped me in it throughout. 

6 References 

[1] Cambridge University Press. Meaning of feel in English [Internet]. Cambridge Dictionary; cited 2023 Apr 27. Available from:

[2] Wikipedia contributors. Principle of relativity [Internet]. Wikipedia, The Free Encyclopedia; 2023 Mar 27, 20:46 UTC [cited 2023 Apr 27]. Available from:  

[3] Fulkerson M. Touch, Edward. The Stanford Encyclopedia of Philosophy; 2020 June 21 [cited 2023 May 21]. Available from:[4] Wikipedia contributors. Preferred frames [Internet]. Wikipedia, The Free Encyclopedia; 2022 Feb 16, 21:04 UTC [cited 2023 May 21].  Available from:

Interviews jIAPS

An Interview with the coordinator of the Mental Health and Well-being sessions, Cihad Gözsüz

Interviewer: Fabiola Cañete Leyva, Benemérita Universidad Autónoma de Puebla, Mexico

Mental health is a rising concern among students and academics all over the world.

Along with the coronavirus pandemic, many university members have noted in their peers— and in themselves—an increase in mental health issues such as depression, anxiety, and burnout syndrome.

In order to mitigate this problem, many academic communities have started to talk openly about the subject, as a way to promote awareness and offer support to their members. That is the main motivation behind the Well-being Sessions initiative led by Cihad Gözsüz at IAPS.

In this interview, the next in a series of jIAPS interviews, we feature a conversation with Cihad where we discuss the objectives of this initiative and the mental health challenges that many physics students face through their academic journeys.

‘Hello Cihad. Can you tell us about what you are studying and where?
I was studying physics in Dortmund, Germany. But, I have recently switched to studying psychology at the University of Braunschweig, also in Germany.

If you don’t mind me asking, why the sudden change?
There were several reasons but everything was triggered by the recent pandemic. During Covid, a lot of things happened. In terms of mental health, I was not feeling very well and neither did a lot of my friends. That is why I became invested in the direction of mental health and started volunteering in that area. Ultimately, that is what led me to want to study psychology full-time.

Why is it important to address mental well-being among physics students?
Mental health is essential for everyone but it is crazy to realize how many science students struggle, especially during their Ph.D., which is an intense and time-consuming period. You often hear students talk about things like burnout and other stress-related issues. By listening to people, you notice that mental health is not often talked about in the physics community. That is why I believe it is important to start addressing this topic.

Is there a personal experience that you may want to share?
Yeah, so, I was actually never in real therapy. My worst days were during the Covid pandemic. At that time it was really difficult to get a place in therapy. And in my case, I didn’t notice that I had anything to worry about. No symptoms from my childhood or anything. But, I had self-esteem problems that do trace back to childhood trauma, I believe. There were some problems with the way my parents raised me. I don’t blame them, of course, because they had their own experiences as well. But I consider that there was a lack of care given, I think. They never really showed that I had value for them or maybe the way that they expressed it was not very obvious.

Then, unfortunately, I also had a bad time in school.

On top of that, another circumstance that has had a big impact on my life also was a romantic relationship of seven years. When it ended, things that I didn’t notice before came rolling back to me. The breakup led me to believe that suddenly I was not important to the people around me. I started to feel like a burden to everyone and to think that it would be better not to have friends at all, in that way I would not be able to hurt them as well.

Then, with the loneliness from the pandemic, those feelings escalated. I started to punish myself, in my head, and eventually, I even had suicidal thoughts.

I am just very grateful that at that point other things happened that helped me. I met people that showed care and with time I got over that phase in my life. All this motivated me to show more care to others. I realized that I did not care much about others or myself before. So, I wanted to change. My main motivation was that I knew how difficult it can be to go through this on your own, so I wanted to help others in the same situation.

Mental health is a relatively new topic, do you think that mental health has worsened over the last few years? If so, what do you think are the reasons?
This is a difficult question! Personally, I don’t know if there are any statistics on this topic. The modern world does not feel like it is made for mental health though. When you consider things like digitalization, for instance. We spend a lot of time on social media, and paradoxically, while it does connect people, it also creates some distancing among us. There is some kind of masking going on when people post online how well they are doing, when maybe, in reality, they are not doing so great. But then again, the digital age has also brought us awareness about mental health and other topics that were not openly discussed before. And social media has also played a part in this. So I can’t really say if things are getting better or worse.

What is the main objective of the Mental well-being chat sessions?
The objective is to create a safe atmosphere for whoever wants to participate and discuss how they are doing so we can be there for each other. For the mental well-being sessions, I start by inviting people to a meeting. And then I ask people how they are feeling right now or if there is anything that they are dealing with at the moment. We also talk about the good things that happen to us, of course. Sometimes there is a funny story to tell, sometimes not. And if you don’t want to share anything that is also ok. The point of all these sessions is to share our thoughts and connect with other people. The more open we are, I feel like the bond between us gets stronger.

In your perspective, what is the principal barrier faced by students with mental health problems? Can it be society, their family, or maybe even themselves?
I think there can’t be just one thing to blame here. It is usually the sum of everything. Maybe the school system can be better. Society also plays an important role but I would say it is hard to pinpoint a single reason here. This is a hard question!

What kind of impact do these setbacks have on the academic performance of physics students?
I think it is different for everyone. Some students can perform well, even in these circumstances, and other students struggle a lot. Physics is usually a topic that is very time-consuming. There’s a lot to study in a really short time. But sometimes, people have said to me that it is precisely this kind of anxiety that helps them push themselves harder. In the long run though, in the majority of cases, you can expect burnout at some point.

I remember a study indicating that people with high neuroticism can perform well. However, on average they perform worse than the people who act as a friend to themselves. In summary, being harsh to yourself works well but being nice to yourself has better results.

One observation I can make is that physics students can mask their feelings very well and they can perform efficiently even in hard circumstances. Unfortunately, this can have an impact on the dynamics of the academic environment. For example, if a teacher perceives that students are doing well, they can expect students to start delivering more and so they may increase the workload.
In one of my internships, people often complained about how little time they had for themselves but they pushed themselves anyways so at the end of the day if you are having a hard time you start thinking, it sucks but if people get through it then I can do it too. What I am trying to say is that because people in physics might be great at masking their emotions and being high performers, the expectations in the field rise even more.

Do you think that physics students are somehow at a higher risk of suffering mental health problems?
Yeah, I think that there are some statistics on this topic. Ph.D. students are more often struggling than the average student. A certain percentage of normal students themselves suffer from some kind of disorder involving anxiety or depression, but this number goes up if we are talking about Ph.D. students. I once read that about fifty percent of Ph.D. students battled with these problems. I was so impressed that I talked about this with some friends and I remember that one person said, I can’t believe it is just fifty percent! The truth is that a Ph.D. is in itself a hard thing to do and these kinds of experiences just discourage people from pursuing it, sadly.

What kind of initiatives do you think are necessary to mitigate this problem?
I wish I had an answer here. There are too many aspects that play a role in this phenomenon. One thing that can help mitigate this problem, I believe, is to encourage people to be open about this topic, to look for help, and also to hold the kind of sessions we do here in IAPS.

What has been your favourite IAPS event or activity so far?
Any in-person event is great for me because I get to meet most of my IAPS friends. The last big event I remember is the PLANCKS event. We organised it in Munich and I got to spend a lot of time with the friends that I made through the Internet. It was quite a surreal experience.

What advice would you give to anyone who is thinking of coming along to a Mental Health and Wellbeing Session?
I would tell them that the sessions are a safe place to share whatever they want and it is also a great place to make friends. For the people that may not be so sure about joining, I would tell them that their participation during the sessions is completely up to them. They can opt to be there and just be willing to listen to people and if at some point they feel uncomfortable, they can leave, of course. I always give a disclaimer. People in the mental health chat session are not professional. So if someone feels that they need some serious mental health help, I always encourage them to seek professional help. The mental health sessions are just like regular conversations where we talk about different things. It is normal to be afraid but usually when you have joined two or three times that feeling goes away. The best part is to connect with people and just be there for each other.

Cihad, thank you so much for your answers and for the wonderful work done leading this mental health initiative.

Find out more about the Mental Health and Wellbeing Sessions on the IAPS Discord.

IAPS 2022-2023 jIAPS

jIAPS May Article of the Month: Beautiful Birefringence

Author: Jan (Jack) Beda, University of Edinburgh, UK

Let’s begin with polarized sunglasses. You may have them. Why did you get such a fancy pair? Maybe you’ve been told they reduce glare? They do, in fact. All the light that bounces around in our universe has a polarization. A “direction” in which the electromagnetic fields wiggle. Light can wiggle up-down or left-right (and in a few other ways). It turns out that when light is reflected off of water and other substances, it becomes “partially horizontally polarized” (1). That is to say, more of the light wiggles left-right than up-down. Your fancy polarized sunglasses include a polarizer that only lets through the up-down light, and so all of the horizontally polarized light (the glare off the water) gets cut out.

Now, you can probably already figure out what happens if I take two polarizers and put them perpendicularly on top of each other. Let’s say the first one blocks the up-down light, then the second one blocks the left-right light, and so if you put them together, all of the light is blocked, and you see nothing. As you rotate the polarizers with respect to each other, you are able to change how much light gets through. The transmission of light depends whether the polarizers are aligned in parallel (maximum transmission) or perpendicular (minimum transmission) to each other.

Fig. 1: Various pieces of packing tape placed between a computer, and polarized sunglasses. (Image created by the author).

Now, we can take these two perpendicular polarizers and slide a piece of transparent tape  between them. Better yet, we slide a big mash-up of pieces of tape in between. What happens? Suddenly the polarizers fill with colour (Fig. 1 and 2). In fact, I encourage you to do this right now! You might not have polarizing sheets lying nearby, but if you have polarized sunglasses and a computer screen, you can do it. Most computers produce polarized light, and your sunglasses act as the second polarizer. Just zoom your computer screen into some white section of this article, increase the brightness, throw some pieces of tape together, and look at them between your computer and polarized sunglasses (nearly all tape will work, but some work better than others). You should see a stained-glass window-like array of colours which changes as you rotate the tape. 

Fig. 2: A more involved piece of art by physicist Aaron Slepkov [5, p. 619]

What in the world is going on here? The tape demonstrates the phenomena of birefringence. When light passes through the back polarizer (or your computer screen), it has one polarization. Then the tape does something very neat, and rotates this polarization of light by some amount. Importantly, the amount by which the light is rotated depends on both the wavelength of the light, and the thickness of the tape. For example, in the centre of Fig. 2, we see a bright green section. The polarised light is rotated by just the right amount as it passes through the tape so that the resulting polarisation is perfectly aligned with the second polariser to pass through unchanged. Perhaps the red light, on the other hand, was rotated just enough to be completely cut out by the second polarizer. The amount that the light gets rotated depends on the thickness of the tape as well, meaning that places with more layers of tape will display different colors than places with fewer layers. By varying the number of layers, we can get a wide array of colours.

Now, how do birefringent materials rotate light? When light passes from one medium to another, the light refracts, and its direction changes as a result of a difference in index of refraction across the mediums. Some objects, like the tape, are birefringent, and due to their molecular structure, the index of refraction is different depending on the polarization of the light incident (2). When unpolarized light is passed through a birefringent object for a long enough time, the beam can split into two separate beams, each with perpendicular polarization. In many cases, the light does not travel for long enough in a birefringent material to fully split the incident beam. Instead, the different indices of refraction will create a phase shift in the two polarizations of light resulting in a change in the polarization of the exiting light. This often results in partially elliptically polarized light but can be approximated as a net rotation of the polarized light.

The world of birefringence is far and wide. This technique of viewing birefringent objects between two polarizers can be used to analyse stress patterns in plastic ( look at your plastic ruler between two polarizers) (3) and in geology (a number of rocks are birefringent) (4). Most importantly, we can create some beautiful pieces of art: birefringence is a fascinating concept to study..

Works Cited

1. Halliday D, Resnick R, Walker J. Fundamentals of Physics. 10th ed. Wiley; 2014. p. 997–998. ISBN 978-1-118-23061-9

2. Belendez A, Fernandez E, Frances J, Neipp C. Birefringence of cellotape: Jones representation and experimental analysis. European Journal of Physics. 2010;31(3):551-561.


3. Redner AS, Hoffman BR. Measuring residual stress in Transparent plastics. 2017.

4. Alderton D. Other Silicates: The Al2SiO5 Polymorphs, Cordierite, Staurolite, Epidote, Chlorite and Serpentine. Encyclopedia of Geology. 2nd ed. Academic Press; 2021. p. 368-381. ISBN 9780081029091. 

5. Slepkov AD. Painting in polarization. American Journal of Physics. 2022; 90 (617): 617-624.