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"Marinyo" is a culture left by the Portuguese around the 15th century in Maluku. The purpose of this study was to find out to what extent students' misconceptions about the concept of sound in the "Marinyo" case in the Kepuluan Tanimbar Regency. The method used was a qualitative study in ethnography in ten villages in two sub-districts. In addition, they conducted a survey in the form of a diagnostic test in the form of questions related to the "Marinyo" case on 300 elementary school students. The findings in the field show that students experience relatively high misconceptions. It was because teachers did not accustom students to learn from natural phenomena around them and were given scientific questions to seek, find and provide answers and solutions related to these natural phenomena. The teacher was more pursuing the conditions and problems of physics in textbooks and less exploring contextual matters. Future researchers are suggested to develop physics or science teaching materials based on regional local advantages that are oriented towards understanding concepts, mental models, critical thinking, problem-solving, creativity and innovative thinking so that teachers and students can learn well so that knowledge of science becomes better.

Thanks to its superior imaging resolution and range, light detection and ranging (LiDAR) is fast becoming an indispensable optical perception technology for intelligent automation systems including autonomous vehicles and robotics 1-3 . The development of next-generation LiDAR systems critically needs a non-mechanical beam-steering system that scans the laser beam in space. Various beam-steering technologies 4 have been developed, including optical phased array 5-8 , spatial light modulation 9-11 , focal plane switch array 12,13 , dispersive frequency comb 14,15 and spectro-temporal modulation 16 . However, many of these systems continue to be bulky, fragile and expensive. Here we report an on-chip, acousto-optic beam-steering technique that uses only a single gigahertz acoustic transducer to steer light beams into free space. Exploiting the physics of Brillouin scattering 17,18 , in which beams steered at different angles are labelled with unique frequency shifts, this technique uses a single coherent receiver to resolve the angular position of an object in the frequency domain, and enables frequency-angular resolving LiDAR. We demonstrate a simple device construction, control system for beam steering and frequency domain detection scheme. The system achieves frequency-modulated continuous-wave ranging with an 18° field of view, 0.12° angular resolution and a ranging distance up to 115 m. The demonstration can be scaled up to an array realizing miniature, low-cost frequency-angular resolving LiDAR imaging systems with a wide two-dimensional field of view. This development represents a step towards the widespread use of LiDAR in automation, navigation and robotics., (© 2023. The Author(s), under exclusive licence to Springer Nature Limited.)

The purpose of this study is to review the postgraduate theses on science/physics education in Turkey to guide the teaching of the sound concept. Although the theses examined within the scope of this study belong to a certain region, the previous literature shows us that the learning difficulties/misconceptions are generally independent of culture. Thirty-three theses in the database of The Council of Higher Education Thesis Center were analyzed inductively in the semi-systematic review process. For this, the stages of content analyses were used: Elimination and coding, placing them in themes, ensuring reliability and validity were followed respectively. Unit of analyses was conclusions of the theses and suggestions of the theses. In conclusion, both conventional and contemporary approaches have a positive effect on achievement or conceptual change on the sound concept. On the other hand, students and teachers/ candidates, in general, cannot relate their knowledge of sound to daily life, their level of knowledge is inadequate, and they have misconceptions/errors and confusions. It is beneficial to consider this situation in education. The most important output of this study is the lists of possible misconceptions or confusion about the concept of sound. Teachers and researchers can use these lists in their lessons or research. [Note: The page range (257-278) shown on the PDF is incorrect. The correct page range is 257-275.]

This study examines future secondary physics teachers' knowledge related to the teaching of sound waves, and specifically the topics of sound level and sound intensity. The data is comprised of future teachers' responses to a task in which they had to compose a script for an imaginary dialogue between a teacher and a group of students and to provide a commentary elaborating on their instructional choices. The topics selected for the task were chosen intentionally as they provide authentic and rich opportunities to bridge mathematics and science concepts, while challenging future teachers to consider the logarithmic measurement scale and its role in science. The task provided the participants with the beginning of a dialogue that featured student confusion about the measurement of sound level using a decibel scale. Future physics teachers were asked to extend this dialogue through describing envisioned instructional interactions that could have ensued. The instructional interchange related to the relationship between sound intensity and sound level, and particular teachers' responses to the student ideas related to the meaning of a decibel sound level scale were analysed. These responses were categorized as featuring superficial or deep, and conceptual or procedural knowledge for teaching. We describe each category using illustrative excerpts from the participants' scripts. We conclude with highlighting the affordances of scriptwriting for teachers, teacher educators, and researchers.

This work presents the evaluation of a practical experience on noise pollution based on the use of smartphones to check if it helps students to better understand the concepts related to this phenomenon. This evaluation has been done with a pre-post design in which 112 students, enrolled in the "Physics and Chemistry" course of the 1st year of non-compulsory high school, have first filled in a diagnostics questionnaire with 5 free response questions about their knowledge on the topic and then a pre-post questionnaire with 4 free response questions. The results show that the proposed practical experience is effective since a statistically significant improvement is obtained both globally and in each of the questions of the questionnaire. The practical experience has also been highly valued by 38 students enrolled in the "Physics and Chemistry" specialisation of the Master in Secondary Education Teaching.

In this research, the teaching of mechanical waves was realized with inquiry-based learning; the aim was to determine the changes in students' conceptual understanding of spring, water, and sound waves. It was designed as action research. The study group comprised 58 upper-secondary school students enrolled in 10th grade at an Anatolian upper-secondary school in Turkey. Data collection tools used in the research were the form for conceptual understanding of mechanical waves, semi-structured interviews, video recordings and photographs, student journals, and hand-made materials. Moreover, researchers designed an action plan that was composed of activities on spring, water, and sound waves. Descriptive and conceptual content analyses were utilized in data analysis. At the end of the research, it was determined that there was a change in students' conceptual understanding of spring, water, and sound waves. Moreover, it was determined that teaching based on inquiry-based learning contributed positively to students' learning. In this respect, it is thought that such applications should become widespread. There should be online training for lecturers which in return would contribute to students' learning.

This research aims to examine: (1) how Physics teachers who participated in a STEM project, adopted and implemented a STEM activity in the context of a pandemic; (2) from the perspective of Physics teachers, what were the effects on students' learning of a STEM activity implemented in the context of the pandemic; and (3) what challenges had Physics teachers faced in implementing the STEM activity during the pandemic. A qualitative and interpretive methodology was used. The participants are four Physics teachers who implemented a STEM activity on sound, during the pandemic. Data were collected through interviews and written reflections. The study has shown how, in a crisis context such as COVID-19, which affected schools all around the world, teachers were able to deal with it and kept developing a STEM activity, revealing the main challenges and effects on student learning, from the teachers' points of view. Moreover, it was clear that carrying out with success a STEM activity, in such an adverse scenario, was strongly related with teachers who found new strategies and keep students motivated, by guiding them proficiently, and that requires to merge scientific and technological knowledge.

The Mayan city of Chichen Itza is full of legends and mysticism. There, in the temple of Kukulkan, in front of a great pyramid with 91 central staircases, an interesting physical-acoustic phenomenon occurs that has fed mythical stories attributed to the Mayas. When clapping your hands in front of the steps, the echo sounds very different from the sound emitted: The echo presents a 'tonality' that resembles a kind of bird chirping (chirp) which is said to be the response of the Quetzal, sacred bird of the Mayas. Earlier work has discussed the convolution method to find a simulation of the spectrum of the echo sound captured at Kukulkan. In this article we are going to present an analysis of the reflected sound using the wave superposition method, and thus obtain a sound with musical 'Pitch' as a result of the superposition of multiple reflections of a percussive sound, using the AUDACITY audio software, as demonstrated in the supplementary material.

The reflection and refraction of light are more familiar to students than the reflection and refraction of sound. Reflection and refraction that occur during the transmission of sound waves are common phenomena in everyday life but are often difficult to understand during actual learning. In this study, we developed a sound reflection and refraction test apparatus that can measure sound's reflection and refraction angles by injecting sound using a super directional speaker with excellent straightness. Consequently, moving the sound sensor made it possible to find a point with high sound pressure and measure the sound's reflection and refraction angles. Since this device is similar to the experimental device that measures the angle of reflection and refraction of light, it is expected to be able to phenomenologically compare and confirm the reflection and refraction paths of light and sound.

We present a novel method for demonstrating the physical principles of ultrasound imaging at a level suitable for educational programmes up to the university level, using a simple mechanical model that is very inexpensive and accessible to a broad variety of educational institutions. The method revolves around the use of one or two steel springs that can be extended on a flat surface. The spring represents a tissue and the longitudinal wave traveling along the spring represents the propagation of an ultrasound wave in tissue. This method allows students to gain direct experience with wave propagation, reflection and transmission in tissue as well as insight into the physical processes underlying ultrasound imaging. These include equally the ultrasound diagnostic device measurement of the depth of various tissue boundaries, modelled as a simple measurement of the time elapsed between the emission of a wave and the detection of a wave reflected from an object intersecting the spring. An ultrasound device probes the boundary between a formation (an organ or a lesion) and surrounding tissue by registering the amplitude of reflection on the formation, which is proportional to a difference in acoustic impedance between the formation and the tissue. The amplitude of the reflected wave in our apparatus is also proportional to acoustic impedance between the spring and an object like a plastic ruler intersecting the spring, whose stiffness and consequently acoustic impedance can be adjusted by its offset. It is also easy to clearly see the reflected wave on the boundary of two coupled springs (two tissues) with different acoustic impedances. We represent a series of representative measurements using our mechanical model demonstrating its good precision.

We present an experiment designed to study standing waves in a tube with one closed end. Two smartphones are used, one to emit a sound signal with a chosen frequency and another equipped with a microphone to detect the sound pressure level inside the tube. Due to the finite diameter of the tube, the standing wave node (or antinode) appears slightly outside of its opened end so the end correction is applied. Results show a good agreement with the theory, making this proposal suitable to be applied to secondary school classes. It is a low cost experiment and has the potential to increase the understanding of this physical phenomenon by secondary students.

Félix Savart (1791-1841) was both a physician and a physicist, and also a pioneer of acoustics and psycho-acoustics. In 1819 Savart scientifically devised and contructed a trapezoidal violin with the advice of Paris string-instrument maker J-B Vuillaume. This violin drew the attention of J-B Biot who suggested young Savart to work with him on such acoustic researches. From this collaboration proceeded the so-called "law of Biot-Savart" about magnetic power which was in fact formulated by Pierre Simon de Laplace (1749-1827). Savart worked on numerous and diversified acoustic researches. Lord John Rayleigh described them as "beautiful experiments", and he became a foreign correspondant member of the Royal Society in 1839.

The udu is a traditional Nigerian percussion instrument that can be thought of as a Helmholtz resonator with two apertures. We use a simple two-particle mechanical analogue to study the behaviour of such a resonator and find that the model describes quite well the main features of udu acoustics.

Similar to how stealth materials were developed to reduce the radar wave energy returning from an aircraft, here we explore a low-cost laboratory demonstration that uses similar principles to prevent detection of an object by an ultrasonic sensor. This demonstration setup can be used as a starting point to encourage students to explore the surface properties of materials and the ways in which ultrasonic ranging sensors operate.

This article presents the study of Fourier series experimentally, using the "ExpEYES"-17 kit in a different way. This familiar undergraduate experiment has been performed for teaching online laboratory classes when face-to-face classes were not possible, due to the "COVID"-19 pandemic. We chose parabolic and sawtooth waveforms, which are not generally considered for this experiment. The amplitudes A[subscript n] of different harmonics were measured to compare with the theoretical predictions and the ratios A[subscript n]/A[subscript 1] were found to agree well.

The determination of the speed of sound in air is a classical experiment, usually performed with a resonance tube apparatus. The measured value can be checked against Eq. (1), which describes the temperature dependence of the speed of sound in dry air. A modern implementation of this speed of sound investigation uses an Arduino Uno microcontroller board, an HC-SR04 ultrasonic distance sensor, and a DS18B20 temperature sensor. The distance sensor's transmitter produces a burst of eight ultrasonic rectangular pulses that travel through the air, reflect on an object placed in front at a distance d, and then return to the sensor's receiver after an echo time t. This Arduino investigation, unfortunately, is harder to perform than one might expect after a first reading of Ref. 1 or 2. In this article we discuss some sources of experimental errors that can complicate this laboratory activity, and we describe some important steps that must be included in the data collection and analysis procedure, in order to obtain successful results every time.

We describe an educational activity that can be completed with mobile media devices in order to understand the working principle of a pair of tuning forks, from the Historical Collection of Physics Instruments of the University of Palermo, and how they were used to explain acoustic interference and beats with the Lissajous optical method. This approach can be used with any tuning fork and it is a valuable teaching strategy that does not require specific laboratory equipment.

We present a modernization of the undergraduate physical chemistry laboratory experiment for determining the speed of sound in various gases from resonant frequencies in a spherical resonator. The resonator (schematic IR = 7.5 cm) is constructed by 3D printing with eco-friendly poly(lactic acid), a commercially viable alternative to traditional construction methods. We provide a schematic stereolithographic CAD file for printing the cavity and Octave (or MATLAB) code for the fast Fourier transform of time-based signals to the frequency domain. Student results for argon, air, carbon dioxide, and R-134A refrigerant show excellent agreement with published values, with less than ±0.2% error in most cases. This module provides an introduction to and practical example of the use of 3D printing technology and fast Fourier transform algorithms in the undergraduate chemistry lab.

The integration of physics, music, and mathematics has long been used to increase students' interest and motivation in these subjects. For example, previous articles in this journal have shown how to teach physical concepts in a musical context, use a smartphone to check the resonant frequencies of whistles, use a smartphone to examine the spectra of sounds, and apply Fourier analysis to the study of musical intervals. This article is devoted to the audio recordings analysis of saxophone sounds, violin, guitar, piano, hand bell, and ocarina in the Audacity editor. The purpose of this analysis is to determine the amplitude-frequency structures of musical notes and obtain information for the classroom about the physical characteristics of musical instruments and some playing techniques.

The typical sound of George Lucas' laser blaster in the "Star Wars" series is well known. What does a laser blaster in "Star Wars" sound like, and why? Here we show a simple way to produce this sound by using low-cost lab material, like a spring or a Slinky. Building on the work of Crawford, who analyzed the sound of a Slinky using oscilloscopes, we present a technique for analyzing the sound using mobile devices. For a deeper quantitative analysis, a PC with open-source software is used.

Sound is one of the most commonly used physical phenomena that most of us use without considering its nature. Moreover, students often face difficulties in understanding acoustic phenomena, the most frequent one of which is the substance-based view of sound instead of a process of pressure and density differences. The current study introduces sound to the physics class through a combination of history of science (HOS) and dialogic teaching, which, although research in science education shows that they both may benefit students for a variety of reasons, are frequently absent from traditional science classrooms. We present four HOS-based whole class dialogic discussions (WCDD): the first and second are about the nature of sound; the third is about sound amplification in a stethoscope; and the fourth is about sound propagation in a tight string of a "lovers' telephone." The WCDD were held with a group of 27 university students. We further examine students' concepts regarding acoustical phenomena as expressed in these WCDD, show how insights and perspectives learned from HOS could be used to structure WCDD in order to guide students' thinking, and analyze the conceptual flow patterns of the discussions. Finally, we discuss the possible contribution of HOS to dialogic teaching and the parallelism of historical and students' misconceptions today that often appears.

This research was intended to analyze the use of Physics Education Technology (PhET) as a virtual laboratory in learning waves and sounds. The analysis was in terms of the implementation of waves on a string student activity as a lesson plan, the profile of students' cognitive, and the profile of science laboratory environment. The method which is used in this research was a descriptive method with methodological triangulation as the research design. The sample was taken on the convenient situation at grade 8 in an international school in Bandung. According to the analysis of the result, the waves on a string student activity can be adopted as the lesson plan with several recommendation to be improved such as in part A, changing some sentences in the data table, changing some settings in obtaining data activity, and adding clear example in determining the base and peak point in measuring the height of wave at start and at the end. Moreover in part B, adding clear instruction on how to use the ruler to measure the wavelength, and changing the picture to obtain the data of wavelength with the picture of simulation with the instructed setting are important. In part C, it needs to add the instruction to do the practice session together with the teacher and to add the instruction to make the starting point in counting the wave similar in each trial. The use of Physics Education Technology (PhET) as a virtual laboratory in learning waves and sounds shows the favorable result on both the cognitive aspect and science laboratory environment.

Like many other universities, Musical Acoustics is offered at our school as a lab-based course fulfilling general science requirements for non-majors. The course has been team-taught by a physics professor and music professor since its earliest inception and, by far, the most popular unit explores room acoustics through a variety of activities and experiences. The purpose of this article is to share the ways we engage students in the process of learning the conceptual elements related to room acoustics.

The most important question for anyone born in London is 'Are you a Cockney?' Only those born within the sound of Bow bells can truthfully answer the question with a resounding 'yes.' 'Cockney' is a term of pride in the heart of the East End, an area recently made internationally famous to a new audience due to the global success of the TV series 'Call the Midwife,' set in Poplar. Here we use simple physics to determine the greatest distance that you can be born and still hear the peal of the bells. As such, it should appeal to all those teaching the physics of waves, or sound, in the Greater London area--and beyond.

By building a schlieren optical system, the visualization of a 40 KHz sound wave is realized. By using the schlieren system, the demonstration of acoustic reflection, interference and diffraction can be easily realized. At the same time, the visual acoustic field provides another simple way for the measurement of sound velocity. In this paper, the experimental device is simple in structure and low in cost. The experimental content combines the optical and acoustic content, which can be used as the acoustic experimental content for undergraduate students.

This work shows the redesign of an elemental experience based on the Helmholtz resonator using 3D printing. A Helmholtz resonator is based on a volume and at least one opening that can include a tube or not. The air column inside the tube can be considered the mass of the system, whereas the volume represents the system's stiffness. Due to these analogies between acoustics and mechanics, the Helmholtz resonator is an interesting example of a harmonic oscillator. The relevance of harmonic motions is well known, and this topic is present in the syllabus of many technical and scientific education degrees. In this work, a bottle has been designed and fabricated using 3D printer technology. The design aimed to create a Helmholtz resonator with a variable frequency of resonance. Different mouthpieces have also been designed. The bottle is composed of a set of cylindrical sections that can be attached, enlarging the length of the container. For ensuring that the different parts set a tight enclosure, an O-ring seal has also been designed and fabricated. As more rings and O-seal junctions are attached, the volume of the resonator grows. By blowing the mouth of the Helmholtz resonator with different sections, different resonance frequencies can be measured. From these measurements, several parameters can be estimated indirectly, such as the speed of sound waves, the room temperature, and air density. 3D printing permits to analyse several scenarios without using uncomfortable strategies to vary the bottle's volume, such as water, reducing the hazard in a laboratory with electronic instrumentation.

We reexamine the approximate formula for the path difference in the double-slit interference experiment, establish its limits of applicability from a geometric perspective and discuss its validity for the two-source interference of acoustic and surface waves.

We theoretically investigate the intraband relaxation of quantum dots in the terahertz regime due to two acoustic phonon scattering by applying a lattice relaxation approach based on the deformation potential coupling between electrons and acoustic phonons. In particular, we find that the relaxation time depends strongly on the ratio of two acoustic phonons. The influences of the energy separation between the ground and first excited state, the quantum dot height, and the lattice temperature on the relaxation time are also discussed. Our theoretical results not only give a reasonable explanation for the current experimental measurement but also provide some insight into two-phonon intraband relaxation in quantum dots.

We report experimental observations of sound waves in a granular material during resonant silo discharge called silo music. The grain motion was tracked by high-speed imaging while the resonance of the silo was detected by accelerometers and acoustic methods. The grains do not oscillate in phase at neighboring vertical locations, but information propagates upward in this system in the form of sound waves. We show that the wave velocity is not constant throughout the silo but considerably increases toward the lower end of the system, suggesting increased pressure in this region, where the flow changes from cylindrical to converging flow. In the upper part of the silo the wave velocity matches the sound velocity measured in the same material when standing (in the absence of flow). Grain oscillations show a stick-slip character only in the upper part of the silo.

This paper reports on an experimental technique to determine a response function of a thermocouple using a short acoustic pulse wave. A pulse of 10 ms is generated in a tube filled with 1 bar helium gas. The temperature is measured using the thermocouple. The reference temperature is deduced from the measured pressure on the basis of a laminar oscillating flow theory. The response function of the thermocouple is obtained as a function of frequency below 50 Hz through a comparison between the measured and reference temperatures.

Our world is shaped profoundly by science and technology, which are strongly interrelated. The importance of integrating technology in science teaching is acknowledged by many international science-teaching standards in recent decades. The present study aims at examining how undergraduate students utilize what they have learnt about the physics of waves to explain the principles of simple acoustic apparatuses. The study includes 90 participants in 14 clinical interviews as well as 4 focus group interviews. Four categories of misconceptions were identified: direct views of sound, emergent transverse wave views of sound, explanations based on a device's salient feature, and wrong applications of physics knowledge. The most frequent category was "explanations based on a device's salient feature." We explain these findings in terms of Vosniadou's framework theory. Finally, we provide practical implications to education.

In the violin, the fundamental air cavity mode (the A0 mode) is associated with the sound radiated by the f-holes. The dependences of the sound velocity of the A0 frequency on gaseous temperature and mass were investigated. It was found that the frequency of the A0 mode changed, depending on the molecular weight and the temperature of the gas filling the violin's body. From these results, it was deduced that a temperature change in the room in which musical instruments are played may be reflected in their tones. The measurement of the A0 modal frequency of a violin, focusing on the molecular weight and temperature of the gas, would be useful to students of physics to help in the understanding of sound velocity.

Every branch of science attracts its share of cranks and pseudoscientists, and acoustics has been no exception. A brief survey of those who touched on acoustics is given with quotations from the more interesting or egregious examples. A contrast is drawn between the nineteenth century contrarian's quarrel with particular theories and the modern new age wholesale rejection of theory. This world-view is traced back to the later scientific writings of Goethe. Examples of pseudoscience applied to biomedical acoustics, architectural acoustics, and audio reproduction are given.

Optoacoustic (OA) imaging is an emerging technology that combines the high optical contrast of tissues with the high spatial resolution of ultrasound. Taking full advantage of OA imaging requires a better understanding of OA wave propagation in light-absorbing media. Current simulation methods are mainly based on simplified conditions such as thermal confinement, negligible viscosity, and homogeneous acoustic properties throughout the image object. In this study a new numerical approach is proposed based on a finite-difference time-domain (FDTD) method to solve the general OA equations, comprising the continuity, Navier-Stokes, and heat-conduction equations. The FDTD code was validated using a benchmark problem that has an approximate analytical solution. OA experiments were also conducted and data were in good agreement with those predicted by the FDTD method. Characteristics of simulated OA waveforms and OA images were discussed. The simulator was also employed to study wavefront distortion in OA breast imaging.

Despite its unparalleled success in the field of surgery, the precise mechanism of ultrasonic phacoemulsification cataract extraction remains controversial. We review the relevant peer-reviewed literature on the subject of power generation and tip-tissue interactions to clarify the current status of our knowledge. We conclude that phacoemulsification most likely operates by a combination of mechanisms, including direct action of the vibrating tip against tissue and indirect cavitational effects. Surgeons will benefit from understanding the physical principles underlying phacoemulsification because they will be better able to evaluate the performance of various parameters and different machine settings.

Inelastic light scattering by acoustic phonons (Brillouin scattering) is a useful tool for probing material properties at the submicrometre scale. In media which are statistically homogeneous at this scale, it gives access to the acoustic properties and the elastic moduli. In nanostructures it probes the vibrational properties at the mesoscopic scale. Applications to carbonaceous materials are reviewed.

We investigated shape relaxation of liquid drops in a microgravity environment that was created by letting the drops fall freely. The drops were initially levitated in air by an acoustic/electrostatic hybrid levitator. The levitated drops were deformed due to the force balance among the levitating force, surface tension, and gravity. During the free fall, the deformed drops underwent shape relaxation driven by the surface tension to restore a spherical shape. The progress of the shape relaxation was characterized by measuring the aspect ratio as a function of time, and was compared to a simple linear relaxation model (in which only the fundamental mode was considered) for perfectly conductive drops. The results show that the model quite adequately describes the shape relaxation of uncharged/charged drops released from an acoustically levitated state. However, the model is less successful in describing the relaxation of drops that were levitated electrostatically before the free fall. This may be due to finite electrical conductivities of liquids, which somehow affects the initial stage of the shape relaxation process.

Conditions are summarized for manipulating and stabilizing fluid objects based on the acoustic radiation pressure of standing waves. Examples include (but are not limited to) liquid drops, gas bubbles in liquids, and cylindrical liquid bridges. The emphasis is on situations where the characteristic wavelength of the acoustic field is large in comparison to the relevant dimension of the fluid object. Tables are presented for ease of comparing the signs of qualitatively different radiation force parameters for a variety of fluid objects.

Sound is an interesting topic for physics lessons at all ages. However, it is difficult to illustrate this ubiquitous phenomenon and many models do not adequately represent the properties of sound and thus promote unwanted conceptions. The experiment presented here avoids this by visualising sound itself with the help of the schlieren technique. For this purpose, an easily reproducible variant of a schlieren setup is presented. The simple setup is described in detail.

Kundt's tube is a popular experiment commonly used in schools, in which standing sound waves are made visible inside a glass tube. A fine powder is stirred up in areas of high sound particle velocities, so that one can measure the wavelength of the sound waves by examining the patterns created. In this way, the 'invisible' can be made visible. However, when looking at educational contexts, Kundt's tube is an experiment with several shortcomings--despite its popularity and prevalence: The glass tube is big, expensive and fragile. Additionally, during the experiment itself, the sound tends to be quite loud due to the high sound pressure needed so that communicating during the experiment becomes hard or even impossible. In this article, we propose a silent and low-cost alternative to commonly used setups which can easily be constructed by using 3D-printed parts as well as readily available ultrasonic transmitters. This makes Kundt's tube even implementable as an experiment done by students themselves.

Science and technology play an important role in modern medicine and experience shows that, although school students and their relatives are likely to have experienced some of the complex procedures available today, they are generally not aware of the science behind them. Demonstrations that link school science to medical procedures can therefore be a powerful way of both reinforcing some basic physics ideas and of encouraging students to think about careers in medical physics or engineering. Simple, and often low-budget, demonstrations relating to X-rays, ultrasound, endoscopy and pulse oximetry are described, along with suggestions for further sources of information.

Science labs should promote reasoning that resembles the work that scientists do. However, this is often not the case. We present a lab in which students strive to find out which of two models best describes a physics experiment. The quantification of measurement uncertainties--another topic that is often neglected in high school curricula--determines the quality of the data, and will play a central role in the final decision between these models and is a vital skill in the modern world.

Since its commercial introduction as a diagnostic tool in 1984, MR imaging has undergone dramatic improvements in all the features that define image quality. This article discusses what a modern MR imaging scanner should look like and how the components of an MR system, especially the magnet, gradient, and RF components must be matched with one another to ensure optimal performance.

The aim of this paper is to provide physics teachers and physics students with interdisciplinary cultural and scientific related content. The "dombra" is on the one hand a cultural symbol of Kazakhstan with a long tradition. On the other hand, the dombra as a musical instrument is an object of interest in acoustics. The topic can lead to deeper insights into theory of musical instruments and acoustics and to positive motivational effects as well. The idea of this article originated in a guest lecture in physics at Taraz State Pedagogical University (Kazakhstan), where one of the authors introduced physics teacher students to "New Technologies in Physics Education." This course was about good practice examples of integration of mobile devices and their built-in sensors in physics classes. An overview of this innovative educational field is given in Ref. 1. There is a wide range of smartphone-enhanced experiments, from simple hands-on experiments to complex digital data collection and modeling tasks in particular in the field of acoustics.

Teaching alternating currents, ac or sound waves, is incomplete without an introduction to the oscilloscope. An oscilloscope is a tool that graphically displays electrical signals and shows their time dependence. However, due to the pandemic, triggered by the SARS-CoV-2 virus, many students do not have the opportunity to master the use of an oscilloscope. Face-to-face teaching activity has been interrupted in both schools and higher institutions. The sudden change to online teaching created problems among educators, especially for laboratory activities. The central issue is creating laboratory activities without going into the labs for the students to acquire the required skills, especially the basics of how to operate an oscilloscope. In order to create an opportunity and engaging environment, we suggested the use of the 'web-based and stand-alone oscilloscope'. The software consists of a low-frequency (signal) generator (LFG), a direct current power supply, and an oscilloscope. The LFG is capable of producing several types of signal and the software is designed to aid the undergraduate engineering and physics students in learning the operation and functions of a digital storage oscilloscope. It can be used as an alternative to face-to-face laboratory activity for physics experiments. It is free and easy to use. The experiments enable students to develop the experimental and measurement skills related to signal generators and oscilloscopes. Hence it opens the opportunity of 'doing' virtual physics investigations individually at home.

In recent years, with the more powerful functions of smartphones, the use of sensors integrated by mobile phones as an auxiliary tool for physical experiment teaching has become more popular. Combined with the related mobile phone apps, people easily can develop and expand the physical experiment contents of mechanics, optics, acoustic phenomena, and so on. These experiments not only help students master the relevant laws of physics, but also permit or encourage students to carry out experimental research, greatly increase students' interest in learning, and meet the training requirements of the Next Generation Science Standards. Recently, some experiments about measurement of speed of sound have been introduced. It is amazing and interesting that people can use simple tools to measure the speed of sound.­ This kind of experiment is very helpful to improve students' practical ability in experiment design, data acquisition, and analysis. Inspired by the above experiments, especially the Kundt's tube experiment, we demonstrate the acoustic resonance in an air column using a plastic tube, a mobile phone, a loudspeaker, and a tape measure. Through the resonance phenomenon of an air column, the speed of sound in air can be calculated conveniently. The experimental results are in good agreement with the reference value. This kind of homemade experiment can provide guidance for students to carry out relevant research in a non-laboratory environment.