When a water drop falls on an oscillating soapy water surface it is observed that coalescence of the
drop is inhibited because the drops are bouncing on the surface like on a trampoline. In our
research we made experimental and theoretical investigat…

The Chain Experiment is an annual competition which originated in Slovenia in 2005 and later
expanded to Poland in 2013. For the purpose of the event, each participating team designs and builds
a contraption that transports a small steel ball from on…

Student competitions can act as potent enrichment measures and complement formal schooling in
fostering students’ motivation as well as promoting their skills. This article presents the German
Physics Olympiad, the national precursor to the Interna…

Practical solid state diodes and transistors have made glass valve technology nearly obsolete.
Nevertheless, valves survive largely because electric guitar players much prefer the sound of valve
amplifiers to the sound of transistor amplifiers. This …

The Slovene Science competition for primary school students aged between 6 and 12 years will be
explained briefly. The competition is based on experiments, which should be done well in advance
either at school or at home. An example of the proposed e…

The International Young Physicists’ Tournament (IYPT), is a competition for teams of secondary
school students, often referred to as the Physics World Cup. This year the 29th IYPT took place in
Russia with a new record of 29 competing teams from ar…

This review presents a new methodical approach to the classification of dimensionless numbers
as pair relationships of the main forces controlling transport phenomena in fluids at the
macroscopic level by using a tabulated form. To memorize the t…

When a water drop falls on an oscillating soapy water surface it is observed that coalescence of the
drop is inhibited because the drops are bouncing on the surface like on a trampoline. In our
research we made experimental and theoretical investigat…

The Chain Experiment is an annual competition which originated in Slovenia in 2005 and later
expanded to Poland in 2013. For the purpose of the event, each participating team designs and builds
a contraption that transports a small steel ball from on…

Student competitions can act as potent enrichment measures and complement formal schooling in
fostering students’ motivation as well as promoting their skills. This article presents the German
Physics Olympiad, the national precursor to the Interna…

Practical solid state diodes and transistors have made glass valve technology nearly obsolete.
Nevertheless, valves survive largely because electric guitar players much prefer the sound of valve
amplifiers to the sound of transistor amplifiers. This …

A simple diffraction experiment was designed using banana stem as natural grating. Coherent beams of
lasers with wavelengths of 632.8 nm and 532 nm that pass through banana stem produce periodic
diffraction patterns on a screen. The diffraction e…

A simple diffraction experiment was designed using banana stem as natural grating. Coherent beams of
lasers with wavelengths of 632.8 nm and 532 nm that pass through banana stem produce periodic
diffraction patterns on a screen. The diffraction e…

If a small object is placed under the front leg of a chair, the chair tilts backwards. If the object
is placed under a rear leg, the chair tilts sideways. The effect is surprising but can be analysed
in terms of elementary physics.

Full shadows, partial shadows and multilayer shadows are explained based on the phenomenon of the
linear dispersion of light. This paper focuses on progressing the understanding of shadows from
physical and mathematical perspectives. A significant re…

Student-generated questions and ideas about our universe are the start of a rich and highly
motivating learning environment. Using their curiosity-driven questions and ideas, students form
Knowledge Building groups or ‘communities’ where they pla…

The well-known demonstration of Pepper’s ghost can be enhanced by the use of linear polarisers,
which can make the image disappear.

A simple experiment is described where the tip of a metal ruler is used to strike a 50 g mass. Since
the ruler is very flexible, the impact duration is much longer than usual, giving the impression
that the ruler simply pushes the mass forward at lo…

We propose a laboratory experience aimed at undergraduate physics students to understand the main
features of the photoelectric effect and to perform a measurement of the ratio h / e , where h is
Planck’s constant and e is the electron charge. The …

An elementary treatment of the quantum harmonic oscillator is proposed. No previous knowledge of
linear differential equation theory or Fourier analysis are required, but rather only a few basics
of elementary calculus. The pivotal role in our analys…

In most textbooks, after discussing the partial transmission and reflection of a plane wave at a
planar interface, the power (energy) reflection and transmission coefficients are introduced by
calculating the normal-to-interface components of the Poy…

Surface passivation is of great technological importance due to the increasing miniaturisation of
electronic devices. It has been known for many years that under certain conditions surface states
can form; when they do so in a quantum well (QW) the r…

We have developed a new introductory physics/chemistry programme that teaches advanced science
topics and practical laboratory skills to freshmen undergraduate students through the use of
student-led, bona fide research activities. While many recent …

An elementary treatment of the quantum harmonic oscillator is proposed. No previous knowledge of
linear differential equation theory or Fourier analysis are required, but rather only a few basics
of elementary calculus. The pivotal role in our analys…

We have developed a new introductory physics/chemistry programme that teaches advanced science
topics and practical laboratory skills to freshmen undergraduate students through the use of
student-led, bona fide research activities. While many recent …

We propose a laboratory experience aimed at undergraduate physics students to understand the main
features of the photoelectric effect and to perform a measurement of the ratio h / e , where h is
Planck’s constant and e is the electron charge. The …

Surface passivation is of great technological importance due to the increasing miniaturisation of
electronic devices. It has been known for many years that under certain conditions surface states
can form; when they do so in a quantum well (QW) the r…

A simple experiment is described where the tip of a metal ruler is used to strike a 50 g mass. Since
the ruler is very flexible, the impact duration is much longer than usual, giving the impression
that the ruler simply pushes the mass forward at lo…

In most textbooks, after discussing the partial transmission and reflection of a plane wave at a
planar interface, the power (energy) reflection and transmission coefficients are introduced by
calculating the normal-to-interface components of the Poy…

The well-known demonstration of Pepper’s ghost can be enhanced by the use of linear polarisers,
which can make the image disappear.

Full shadows, partial shadows and multilayer shadows are explained based on the phenomenon of the
linear dispersion of light. This paper focuses on progressing the understanding of shadows from
physical and mathematical perspectives. A significant re…

Student-generated questions and ideas about our universe are the start of a rich and highly
motivating learning environment. Using their curiosity-driven questions and ideas, students form
Knowledge Building groups or ‘communities’ where they pla…

If a small object is placed under the front leg of a chair, the chair tilts backwards. If the object
is placed under a rear leg, the chair tilts sideways. The effect is surprising but can be analysed
in terms of elementary physics.

When connections between related observations and facts are not being made, introductory science
classes can be perceived as an accumulation of disjointed equations with the risk of losing both
students’ interest as well as their grasp of the mater…

When connections between related observations and facts are not being made, introductory science
classes can be perceived as an accumulation of disjointed equations with the risk of losing both
students’ interest as well as their grasp of the mater…

Maxwell’s equations are derived in terms of differential forms in the four-dimensional Minkowski
representation, starting from the three-dimensional vector calculus differential version of these
equations. Introducing all the mathematical and physi…

Harmonics arise naturally from the resonances in strings and pipes. A video demonstration (Ruiz 2016
YouTube: Tuba Harmonics ( https://youtu.be/souhEzOP9c4 [https://youtu.be/souhEzOP9c4] )) is provided
where a tubist (coauthor Holmes) produces a phen…

For this article, we use a 3D printer to print a surface similar to universal gravitation for
demonstrating and investigating Kepler’s laws of planetary motion describing the motion of a small
ball on the surface. This novel experimental method all…

Maxwell’s equations are derived in terms of differential forms in the four-dimensional Minkowski
representation, starting from the three-dimensional vector calculus differential version of these
equations. Introducing all the mathematical and physi…

Harmonics arise naturally from the resonances in strings and pipes. A video demonstration (Ruiz 2016
YouTube: Tuba Harmonics ( https://youtu.be/souhEzOP9c4 [https://youtu.be/souhEzOP9c4] )) is provided
where a tubist (coauthor Holmes) produces a phen…

For this article, we use a 3D printer to print a surface similar to universal gravitation for
demonstrating and investigating Kepler’s laws of planetary motion describing the motion of a small
ball on the surface. This novel experimental method all…

We propose the use of a smartphone based time-lapse and slow-motion video techniques together with
tracking analysis as valuable tools for investigating thermal processes such as the response time of
a thermometer. The two simple experimental activit…

We discuss strategies for the general solution of single-step 1D constant acceleration problems. In
a slightly restricted form, these problems have five variables (Δ x , v 0 , v , a and t ) and two
independent equations, so three variables must be g…

We propose the use of a smartphone based time-lapse and slow-motion video techniques together with
tracking analysis as valuable tools for investigating thermal processes such as the response time of
a thermometer. The two simple experimental activit…

We discuss strategies for the general solution of single-step 1D constant acceleration problems. In
a slightly restricted form, these problems have five variables (Δ x , v 0 , v , a and t ) and two
independent equations, so three variables must be g…

To the quantum mechanics specialists community it is a well-known fact that the famous original
Stern–Gerlach experiment (SGE) produces entanglement between the external degrees of freedom
(position) and the internal degree of freedom (spin) of sil…

We discuss the wobbling motion in a lens-shaped body rotation, focusing on the frequencies and the
amplitude of nutation by filming the rotational motion and wobbling of the body. The friction
coefficient of the surface is altered to examine its infl…

This letter describes an interesting optical phenomenon engaging the reflected images of a new tube
LED lamp (an array of high luminosity LEDs substituting the old fluorescent lamps) on any convex
glossy black surface.

To the quantum mechanics specialists community it is a well-known fact that the famous original
Stern–Gerlach experiment (SGE) produces entanglement between the external degrees of freedom
(position) and the internal degree of freedom (spin) of sil…

We discuss the wobbling motion in a lens-shaped body rotation, focusing on the frequencies and the
amplitude of nutation by filming the rotational motion and wobbling of the body. The friction
coefficient of the surface is altered to examine its infl…

This letter describes an interesting optical phenomenon engaging the reflected images of a new tube
LED lamp (an array of high luminosity LEDs substituting the old fluorescent lamps) on any convex
glossy black surface.

When a stethoscope is placed on the chest over the heart, sounds coming from the heart can be
directly heard. These sound vibrations can be captured through a microphone and the electrical
signals from the transducer can be processed and plotted in a…

In basic physics, often in their first year of study of the subject, students meet the concept of an
image, for example when using pinhole cameras and finding the position of an image in a mirror. They
are also familiar with the term in photography a…

In a dramatic physics demonstration, a professional flutist produces four resonances with a 12 ounce
Boylan soda bottle solely through her breath control. The 22 cm bottle acts like a Helmholtz
resonator for the lowest pitch. The three higher pitch…

There are five unique points in a star/planet system where a satellite can be placed whose orbital
period is equal to that of the planet. Simple methods for calculating the positions of these points,
or at least justifying their existence, are develo…

A time explicit fast converging exact power series solution to the pendulum equation is derived in
this paper. A novel series for the period results from it. The approximate formula that comprises
the first three terms gives an accuracy of 99.99% up …

We develop a simulation to facilitate the teaching of the photoelectric effect in an introductory
course on quantum mechanics at undergraduate level. Through a Visual Basic program we describe the
interaction of light with electrons in a metal conduc…

A time explicit fast converging exact power series solution to the pendulum equation is derived in
this paper. A novel series for the period results from it. The approximate formula that comprises
the first three terms gives an accuracy of 99.99% up …

We develop a simulation to facilitate the teaching of the photoelectric effect in an introductory
course on quantum mechanics at undergraduate level. Through a Visual Basic program we describe the
interaction of light with electrons in a metal conduc…

In a dramatic physics demonstration, a professional flutist produces four resonances with a 12 ounce
Boylan soda bottle solely through her breath control. The 22 cm bottle acts like a Helmholtz
resonator for the lowest pitch. The three higher pitch…

When a stethoscope is placed on the chest over the heart, sounds coming from the heart can be
directly heard. These sound vibrations can be captured through a microphone and the electrical
signals from the transducer can be processed and plotted in a…

There are five unique points in a star/planet system where a satellite can be placed whose orbital
period is equal to that of the planet. Simple methods for calculating the positions of these points,
or at least justifying their existence, are develo…

In basic physics, often in their first year of study of the subject, students meet the concept of an
image, for example when using pinhole cameras and finding the position of an image in a mirror. They
are also familiar with the term in photography a…

The velocity by which a disturbance moves through the medium is the wave velocity. Pulse wave
velocity is among the key parameters in hemodynamics. Investigation of wave propagation through the
fluid-filled elastic tube has a great importance for the…

A simple model is presented to explain Higgs boson physics to the grand public. The model consists
of a children’s ball pool representing a Universe filled with a certain amount of the Higgs field.
The model is suitable for usage as a hands-on tool…

Producing a deep bass tone by striking a large 3 m (10 ft) flexible corrugated drainage pipe
immediately grabs student attention. The fundamental pitch of the corrugated tube is found to be a
semitone lower than a non-corrugated smooth pipe of the sa…

The velocity by which a disturbance moves through the medium is the wave velocity. Pulse wave
velocity is among the key parameters in hemodynamics. Investigation of wave propagation through the
fluid-filled elastic tube has a great importance for the…

The inversion in the sphere or Kelvin transformation, which exchanges the radial coordinate for its
inverse, is used as a guide to relate distinct electrostatic problems with dual features. The exact
solution of some nontrivial problems are obtained …

Since Galileo used his pulse to measure the time period of a swinging chandelier in the 17th
century, pendulums have fascinated scientists. It was not until Stokes’ (1851 Camb. Phil. Soc. 9
8–106) (whose interest was spurred by the pendulur time p…

This paper describes a novel activity to model the dynamics of a Jupiter-mass, trans-Neptunian
planet of a highly eccentric orbit. Despite a history rooted in modern astronomy, ‘Planet X’, a
hypothesised hidden planet lurking in our outer Solar S…

The electric or magnetic field of an ideal dipole is known to have a Dirac delta function at the
origin. The usual textbook derivation of this delta function is rather ad hoc and cannot be used to
calculate the delta-function structure for higher mul…

The Doppler effect is a shift in the frequency of waves emitted from an object moving relative to
the observer. By observing and analysing the Doppler shift in electromagnetic waves from
astronomical objects, astronomers gain greater insight into the…

We illustrate a rigorous approach to express the totally symmetric isotropic tensors of arbitrary
rank in the n -dimensional Euclidean space as a linear combination of products of Kronecker deltas.
By making full use of the symmetries, one can greatl…

Education in physics and geosciences can be effectively illustrated by the analysis of earthquakes
and the subsequent propagation of seismic waves in the Earth. Educational seismology has matured to
a level where both the hard- and software are robus…

The momentum conservation law is applied to analyse the dynamics of a pulsejet engine in vertical
motion in a uniform gravitational field in the absence of friction. The model predicts the existence
of a terminal speed given the frequency of the shor…

It is shown that given a Lagrangian for a system with a finite number of degrees of freedom, the
existence of a variational symmetry is equivalent to the existence of coordinates in the extended
configuration space such that one of the coordinates is…

The electric or magnetic field of an ideal dipole is known to have a Dirac delta function at the
origin. The usual textbook derivation of this delta function is rather ad hoc and cannot be used to
calculate the delta-function structure for higher mul…

It is shown that given a Lagrangian for a system with a finite number of degrees of freedom, the
existence of a variational symmetry is equivalent to the existence of coordinates in the extended
configuration space such that one of the coordinates is…

Education in physics and geosciences can be effectively illustrated by the analysis of earthquakes
and the subsequent propagation of seismic waves in the Earth. Educational seismology has matured to
a level where both the hard- and software are robus…

The inversion in the sphere or Kelvin transformation, which exchanges the radial coordinate for its
inverse, is used as a guide to relate distinct electrostatic problems with dual features. The exact
solution of some nontrivial problems are obtained …

The Doppler effect is a shift in the frequency of waves emitted from an object moving relative to
the observer. By observing and analysing the Doppler shift in electromagnetic waves from
astronomical objects, astronomers gain greater insight into the…

Since Galileo used his pulse to measure the time period of a swinging chandelier in the 17th
century, pendulums have fascinated scientists. It was not until Stokes’ (1851 Camb. Phil. Soc. 9
8–106) (whose interest was spurred by the pendulur time p…

This paper describes a novel activity to model the dynamics of a Jupiter-mass, trans-Neptunian
planet of a highly eccentric orbit. Despite a history rooted in modern astronomy, ‘Planet X’, a
hypothesised hidden planet lurking in our outer Solar S…

The momentum conservation law is applied to analyse the dynamics of a pulsejet engine in vertical
motion in a uniform gravitational field in the absence of friction. The model predicts the existence
of a terminal speed given the frequency of the shor…

With special attention to the role of information theory in physical sciences we present analytical
results for the coordinate- and momentum-space Fisher information of some important one-dimensional
quantum systems which differ in spacing of their e…

More than 36 000 students and post-docs will be involved until 2025 in research at the Large Hadron
Collider (LHC) mainly through international collaborations. To what extent they value the skills
acquired? Do students expect that their learning expe…

Ultrabroadband electro-optic sampling is presented as an extremely sensitive technique to detect
electric field amplitudes in free space. The temporal resolution provided by few-femtosecond laser
pulses results in a bandwidth exceeding 100 THz, poten…

‘Das hätte ich einfacher sagen können (I could have said that more simply).’ was Einstein’s sigh
when he had a chance to remark on his own derivation of the Lorentz transformation (LT) in the 1905
seminal paper. In fact, in a popular science …

More than 36 000 students and post-docs will be involved until 2025 in research at the Large Hadron
Collider (LHC) mainly through international collaborations. To what extent they value the skills
acquired? Do students expect that their learning expe…

‘Das hätte ich einfacher sagen können (I could have said that more simply).’ was Einstein’s sigh
when he had a chance to remark on his own derivation of the Lorentz transformation (LT) in the 1905
seminal paper. In fact, in a popular science …

With special attention to the role of information theory in physical sciences we present analytical
results for the coordinate- and momentum-space Fisher information of some important one-dimensional
quantum systems which differ in spacing of their e…

Ultrabroadband electro-optic sampling is presented as an extremely sensitive technique to detect
electric field amplitudes in free space. The temporal resolution provided by few-femtosecond laser
pulses results in a bandwidth exceeding 100 THz, poten…

In downhill alpine skiing, skiers often exceed speeds of 120 km h −1 , with air resistance
substantially affecting the overall race times. To date, studies on air resistance in alpine skiing
have used wind tunnels and actual skiers to examine the r…

The aerodynamic properties of a spinning table tennis ball were investigated using flight
experiments. Using high-speed video cameras, the trajectory and rotation of an official ball
(Nittaku 3-Star Premium), which was launched by a three rotor machine, were recorded. The drag and
lift coefficients ( C D and C L ) were determined by analysing the video images. The measurements
covered the speed and rotation range of typical table tennis shots in the form of the Reynolds
number ( Re ) and dimensionless spin rate ( SP ), i.e. 3.0 × 10 4 < Re < 9.0 × 10 4 and0 < SP
 < 1.0, and C D and C L were obtained as functions of Re and SP . We determined that the lift
coefficient C L is not a monotonically increasing function of SP . A deep valley of C L was found
around SP = 0.5, and the lift force exerted …

Development of validated physics surveys on various topics is important for investigating the extent
to which students master those concepts after traditional instruction and for assessing innovative
curricula and pedagogies that can improve student …

Development of validated physics surveys on various topics is important for investigating the extent
to which students master those concepts after traditional instruction and for assessing innovative
curricula and pedagogies that can improve student …

In downhill alpine skiing, skiers often exceed speeds of 120 km h −1 , with air resistance
substantially affecting the overall race times. To date, studies on air resistance in alpine skiing
have used wind tunnels and actual skiers to examine the r…

The aerodynamic properties of a spinning table tennis ball were investigated using flight
experiments. Using high-speed video cameras, the trajectory and rotation of an official ball
(Nittaku 3-Star Premium), which was launched by a three rotor machine, were recorded. The drag and
lift coefficients ( C D and C L ) were determined by analysing the video images. The measurements
covered the speed and rotation range of typical table tennis shots in the form of the Reynolds
number ( Re ) and dimensionless spin rate ( SP ), i.e. 3.0 × 10 4 < Re < 9.0 × 10 4 and0 < SP
 < 1.0, and C D and C L were obtained as functions of Re and SP . We determined that the lift
coefficient C L is not a monotonically increasing function of SP . A deep valley of C L was found
around SP = 0.5, and the lift force exerted …

Water, which is the habitat for a variety of living creatures, has a maximum density at 4.0 °C. This
crucial property is considered to play a very important role in the biology of a lake and also has a
close relationship with the areas of environmen…

Magnetic and electric fields can cause a charged particle to form interesting trajectories. In
general, each trajectory is discussed separately in university physics textbooks for undergraduate
students. In this work, a solution of a charged particle…