Categories
Announcements IAPS 2022-2023

IAPS Extra-Ordinary General Meeting, Sunday, 2nd April 2023 at 12:00 pm UTC

Agenda:

1 – Welcome

2 – Election of the Chair, Minute Takers and Tellers

3 – Membership

 3.1 – Voting Rights

 3.2 – New Members

 3.3 – Quorum

4 – Approval of the 2022 AGM Minutes

5 – Charter and Regulation Changes

6 – Information about the 2023 AGM 

7 – School Day Reform

8 –  Outreach Manager Elections

9 – Other Points

Most of the documents are uploaded on the IAPS Cloud.. The meeting link, voting tokens and further details will be sent directly to the registered delegates of each committee so please make sure to register your delegates here.

We are looking for volunteers for meeting officials so please write to us if you are interested 🙂

If you are interested in becoming the IAPS Outreach Manager, please send your CV and a cover letter to us at ec@iaps.info.

Categories
Events IAPS 2022-2023 Uncategorized

The Countdown to PLANCKS 2023, Milan, Italy

Authors: Matteo Vismara and Valentina Raspagni

Imagine being in Milan, Italy, together with a Nobel Prize Winner and 245 of the best minds in the world in the field of Physics: this is not imagination; it is PLANCKS, the world finals of the Physics Olympics.

PLANCKS is one of IAPS’ most significant annual events. The best physics students from all over the world, winners of national competitions, compete in solving problems concerning numerous physics disciplines. Every year, PLANCKS is organized by a different local committee. For the 2023 edition, the Milano Statale section of AISF has been entrusted with this role. AISF, the Italian Association of Physics Students, is the Italian National Committee of IAPS. The students of AISF will take care of the management and the correct execution of all the activities. They will help all the participants to enjoy the event, catering for their needs and requirements.


The tenth edition of PLANCKS will be held in Milan from 12 to 16 May 2023. In addition to the actual competition, which will take place in the Physics Department of the State University of Milan, there will also be presentations, seminars, guest lectures and visits to laboratories and centres of research in the Milan area. The event will allow students to discover new frontiers of scientific research, learn about Italian excellence and evaluate possible study paths in Italy, while making new personal and academic contacts. These activities also aim to help students from Bachelor’s, Master’s, and Doctoral degree courses to orient themselves in the world of work.

Since the first edition, which was held in Utrecht in 2014, the entire academic world has recognised PLANCKS as an opportunity for dialogue between students, researchers and professors. As evidence of this, there is a succession of guest lectures held by illustrious scientists of the calibre of Stephen Hawking and by many Nobel Prize winners for physics, such as Reinhard Genzel.


This year, Milan will have the honour of hosting: Marco Liscidini, associate professor of the Physics Department of the University of Pavia, recognised as a fellow by the Optical Society of America (OPTICA, ex OSA) and expert in the fields of photonics and optics classical and quantum nonlinear; Claudia Pasquero, associate professor of Oceanography and Atmospheric Physics at the University of Milan Bicocca and vice-president of the Mathematical Geophysics committee of the IUGG (International Union of Geodesy and Geophysics); and Didier Queloz, Nobel Prize winner in 2019 for the discovery of the first exoplanet orbiting a primary sequence star.

Some of these lectures will take place in the classrooms of the University of Milan; others will be held in public spaces in the city of Milan to widen participation and include the local community. In fact, dissemination is one of the main objectives of IAPS and AISF: our mission is to take physics as far as possible, making sure that this splendid science, which links the abstract beauty of mathematics to the origin and transformation of our universe, is accessible to as many people as possible.
Opening these guest lectures to citizens makes the city of Milan an open-air laboratory, sharing the beauty of the ideas that have marked and still mark the path of science and technology in the history of humanity. It shows the importance of a scientific language, of a method, a
fundamental tool in the challenges that humanity must and will have to face.

PLANCKS is organised in collaboration with the Italian Physical Society (SIF) and is also supported by the European Physical Society (EPS), the Italian Society of Optics and Photonics (SIOF), the International Union of Pure and Applied Physics (IUPAP) and the International Association of Geomagnetism and Aeronomy (IAGA).

Follow the countdown to PLANCKS 2023 on Instagram and stay tuned for future jIAPS articles featuring PLANCKS Preliminaries.

Categories
IAPS 2022-2023 jIAPS

A Teacher’s Journey to the Roof of the World

Author: 🇳🇵 Rabin Thapa, Dolpo Buddha Rural municipality, Dolpa

Rabin has shared his experiences of being a Science teacher in a mountainous region of Nepal with jIAPS:

After completing my Master’s degree in physics, I applied for the post of teacher of mathematics and science in Crystal Mountain School (CMS) which is located in upper Dolpa at an altitude of 4300 meters. Inside me, the answer to the question: ‘why did I apply for this professional vacancy as a late twenties Nepalese citizen , is still an unanswered conflict or chaos tumbling in a wave of thought whenever I close my eyes.

Passing through the physical interview process and orientation, I was ready for an hour flight from Kathmandu to Nepaljung, followed by two days road travel and three days uphill trek to the school. However, my plans were disrupted by a domestic flight cancellation. 

Vision Dolpo, an organization managing the seven months academic terms during summer with an ambition to uplift the local literacy potential, can be highly praised. During the six days’ journey, the pressure related to finance and socio economic fluctuation was clearly visible. Meanwhile, we reached our destination on 17th April. A day’s rest was scheduled to face altitude sickness before starting regular teaching on 19th April.

Considering the harsh geographical navigation of CMS coupled with the local living standard, the encounter of limited stationary, student’s uniforms, teaching resources, regular food and IT access was inevitable. In this context, everything apart from basic requirements had to be brought from the capital, to be able to conduct regular academic activity. These supplies were  transported from Dolpa’s district headquarters to the school’s location by mules and donkeys. In April, around hundred shacks of school material were on the way to our location. During dinnertime a few days after I arrived, I heard that Dolpo Buddha Rural Municipality was facing official blockage due to political turbulence, which resulted due to per-planned local elections announced by the government. Due to this blockage, whatever its cause, CMS’s administration had to face the scarcity of food for the staff. Most prominently, the 250 students who come to school here are struggling with availability of stationary, learning material, laboratory tools and uniforms. The stark reality, the real image of public education as experienced by me, is really heartbreaking. I can remember wishing that my heartache could be consoled and thinking of the passenger’s song entitled, “Survivor”.

After a long wait of three months, the supplies, including the stationary for the students, finally arrived. However, the staff, along with the administration team, had to overcome the challenge of continuing regular academic activities with limited resources. At a general meeting, I was assigned to initiate the lead in STEAM activities and upgrade the science laboratory. Selecting extracurricular projects was pivotal because I found that very few students in the school were interested in classical or analog projects. Consequently, to motivate interest in modern science and technology, we established a ‘Makers’ Club’. The annual projects selected were: the construction and installation of electric bell, execution of robotics design and designing a smart dustbin. Fifteen students initially enrolled in the ‘Makers’ Club’. In the ‘Maker’s Space’, we came to a mutual agreement with the students that all the members had to contribute two hours to the club every day after their regular class. 

These two hours of the school day are the most precious time for the students. They can explore a variety of engineering tools, through regular workshops where they are instructed in practical electronics, magnetism, wiring, working principle of switches, AC, DC, transformers, software coding, hardware and basic design principles, to name a few activities. Sometimes, the students became so enthused by their projects that we used to work for hours, even without sleeping. When all our annual projects were accomplished, after four months of hard work, we showed our finished products to the other students and we were able to attract more students to join the ‘Makers’ Club’. Now, at the altitude of 4100 m, in a remote mountainous region of Nepal, we have a self-made electric bell in operation; an inter-house robotic battle; and smart dustbins with software and hardware developed by the students. In our corner of the world, we are introducing modern science and technology to children in their regular learning environment, in a region where these scientific advances were unknown. 

Photo Credits: Rabin Thapa

Categories
IAPS 2022-2023 jIAPS

Article of the Month – March 2023

Implications of Relativistic Effects on the Global Positioning System (GPS)

Raghav Sharma, BSc Physical Science with Electronics, University of Delhi

Abstract

Relativity has no obvious consequences in daily life, but one close look at the working of a GPS device is sufficient to highlight the enormous implications of relativistic effects on situations where velocity, gravity, and accuracy are involved. Clocks on a moving satellite do not appear to tick at the same intervals as clocks on Earth. This is especially problematic in high-accuracy systems like the GPS. Understanding the mathematical principles behind these effects allows for a derivation of precise offset values- adjustments that need to be made to satellite clocks to correct any time difference caused by relativity.

Introduction

The Global Positioning System (GPS) is a highly accurate, satellite-based positioning and navigation system.[1] To maintain that accuracy, time-dilating relativistic effects arising from both the general and special theory of relativity need to be taken into account. This is achieved by adjusting the rates of onboard satellite clocks and incorporating mathematical corrections. This article explores time dilation effects on GPS and describes some calculations and adjustments that are made to account for them. The correction for special relativistic time dilation is derived in detail.

  1. An Overview of Time-Dilation Effects

A handheld GPS receiver can determine the absolute position on the surface of the Earth to within 5 to 10 metres.[1] Achieving a navigational accuracy of 5 metres requires knowing the onboard GPS satellite time to an accuracy of about 17 nanoseconds, which is the time taken by light to travel 5 metres. Because satellites are constantly moving with respect to the Earth-centred (approximately inertial) frame and are further away from the Earth’s gravitational well, one must consider time dilation caused by both special and general relativistic effects. If these effects were left uncompensated, navigational errors would accumulate at a rate in excess of 10 kilometres per day, rendering the system unusable within about 2 minutes.[2] 

  1. Special Relativity

GPS Satellites are not geosynchronous because that would limit coverage. They have a time period of about 12 hours (so that any satellite passes over the same location each day) and a corresponding orbital velocity of about 3874 m/s relative to the centre of the Earth.[3]

According to the Special Theory of Relativity, moving clocks run slower.[2] The time dilation amount is determined by Lorentz transformations. The time measured on-board the satellite is reduced by the Lorentz factor γ:

where τ_{Ground} and τ_{GPS} are time intervals measured on the Earth’s surface and by the satellite clock, respectively.

The derivation of the time by which satellite clocks lag behind surface clocks, Δτ, is given below: 

Using binomial expansion for small values of (v/c):

Taking v=3874 m/s and c=2.998×108m/s:

 For a time-interval of 1 day (86,400s) on the Earth’s surface:

Therefore, GPS clocks lose about 7μs a day due to special relativistic time dilation.

  1. General Relativity

GPS satellites have an orbital altitude of 20,184 km measured from the surface.[3] According to the General Theory of Relativity, a clock in a gravitational field runs slower. This effect is given by:

Where τ_0 is the time interval measured near a mass (i.e., in a gravitational well), and is the time interval measured far away from the mass. 

For small values of (M/r):

The clocks on the Earth’s surface are a distance of R_Earth=6378.1 km from the gravitational centre, so the time dilation with respect to GPS satellites is twofold. It is stated without proof that due to general relativistic time dilation effects, clocks onboard the satellites gain about 45μs per day, with respect to ground-based clocks.[1]

  1. Error Correction

The combination of general and special relativistic time dilation means that GPS clocks gain about 38μs a day. As stated before, the desired accuracy can be as high as 17 nanoseconds. Thus, it is crucial to correct any time difference. 

A time offset of 38μs corresponds with a fractional change of +4.465×10^-10, i.e. the satellite clocks need to be slowed down by this fraction. The fundamental L-band frequency produced by the atomic clocks on-board is 10.23 MHz. This needs to be offset by the aforementioned fraction. Therefore, the actual frequency of the GPS clocks is set to 10.22999999543 MHz before launch.[3-4]

The variation in these changes due to the eccentricity (deviation from circularity) of the satellite orbit also needs to be taken care of. Built-in microcomputers used in GPS receivers help in any additional timing calculations required using satellite-provided data.[1]

Conclusion

Relativity dictates that clocks aboard GPS satellites do not tick at the same rate as those on the Earth. Both general and special relativistic time dilation effects are at play. Neglecting to adjust for these would render GPS useless in a few minutes. Correcting them involves giving the onboard atomic clocks a slight offset in frequency, so that they may appear to run at the same rate as ground-based clocks. This correction is one of many needed to maintain a navigational accuracy of up to a few metres.

References:

  1. Pogge, Richard W. (2017): Real-World Relativity: The GPS Navigation System
  2. Will, Clifford M.: Einstein’s Relativity and Everyday Life
  3. Nelson, Robert A. (1999): The Global Positioning System- A National Resource
  4. Oxley, Alan (2017): Uncertainties in GPS Positioning- A Mathematical Discourse, Pages 71-80

Categories
jIAPS

jIAPS Article of the Month

Introducing the jIAPS Article of the Month, a new feature of jIAPS for 2023:

Every month we will showcase a scientific article written by an undergraduate or postgraduate physics student. Read the first article in this new series here.  Is there a topic you would like to write about? Just email jiaps@iaps.info . 

For guidance on how to write an article, see http://iaps.ovh/wp-content/uploads/2019/01/How-to-write-an-article.pdf and http://iaps.ovh/wp-content/uploads/2022/04/jIAPS-Submission-Guidelines.pdf

The only rule is that there is a word limit of 1000 words. We are looking forward to seeing your articles.

Categories
jIAPS

Happy New Year 2023!

Happy New Year 2023! from jIAPS

The IAPS Music Group has recorded a new song to celebrate the holiday season – check it out here.

What will 2023 bring? What will you contribute to jIAPS in 2023?

The jIAPS Advent Calendar is still going for the next few days. Today’s post includes Juan Ignacio Iribarren’s description of a traditional Christmas or New Year in Argentina – read more here.

There are lots of opportunities for you to be a part of jIAPS in 2023. The Article Contest and Creative Contest are now open with amazing prizes to be won. We’re always looking for Physics-related news stories too – just email us at jiaps@iaps.info – and don’t forget the jIAPS Monthly Photography Competition.

Categories
IAPS 2022-2023

Have you seen jIAPS’ Advent Calendar 2022?

jIAPS has created an online Advent Calendar, featuring contributions from Physics students from over twenty countries across five continents. Find it at:

Categories
IAPS 2022-2023

jIAPS Advent Calendar 2022

This year, we have created an online Advent Calendar, featuring contributions from Physics students from over twenty countries across five continents. We will be posting the Advent Calendar on our Instagram (@j.iaps, https://www.instagram.com/j.iaps/) each day in December.

Learn about festive traditions across the globe, create Physics-themed Christmas tree decorations and listen to music played by our own international music group of Physics students. With puzzles, and recipes to try, there is something for everyone.


jIAPS also organises a monthly photography competition. During December, the theme will be photos of the Festive Season. We would love to see your photos – just email us or tag us on social media. You don’t have to be a current physics student to enter. If you would like to learn more about jIAPS, please email us at jiaps@iaps.info.

Categories
IAPS 2022-2023

jIAPS Article Contest 2023 is now open

Do you love to write? Put your writing skills to the test for the chance to win a free place at ICPS 2023 Philippines! Your article will also be published in jIAPS 2023, the journal of IAPS. The runner-ups will receive certificates and a small prize. 

All you have to do is write a physics related article of 600-800 words. You can find more details at jIAPS Article Contest.

The Article Contest will be open for submissions until 28th February 2023.