Oil Drop Experiment Research Articles

About the 3D virtualization of the Millikan oil drop experiment

Abstract Robert Millikan’s experiment, conducted in 1909, aimed to measure the charge of the electron. This experiment holds immense significance in the fields of electricity and magnetism and is widely performed by physics and chemistry students worldwide. While there are simplified two-dimensional recreations of this experiment available, obtaining measurements that closely resemble reality through a three-dimensional recreation is not easily accessible. This article delves into the development process of this three-dimensional recreation, achieved through reverse engineering of the original experiment using the Unity video game engine. Additionally, it incorporates laboratory equipment, user manuals, and a student guide to ensure a comprehensive experience. By comparing the data obtained from the virtual recreation with that of the real experiment, it was observed that the precision of the virtual experiment resulted in a mere 7% error. Consequently, the virtual experiment can be used as a substitute for the real experiment when circumstances prevent its execution, without compromising the hands-on experience.

Programming experiment course for innovative and sustainable education: A case study of Java for Millikan Oil-Drop experiment

A teaching approach of programming experiment courses with a new education process is proposed in this study to improve the sustainability of engineering education and extend the accessibility of lab experiments across experiment courses, with the goal of encouraging innovative and scientific thinking among students. The Millikan Oil-Drop experiment combined with Java object-oriented programming is demonstrated as a case study to validate the feasibility and advantages of this teaching approach. The new education process of the experiment course is designed based on Jean Piaget's cognitive development theory, which has high practical potential for popularization among tertiary institutions without additional cost. Additionally, this work discussed the relevance of the general criterion of the Accreditation Board for Engineering and Technology on student outcomes to educational accreditation, further indicating that introducing programming into experiment education can improve students' all-round ability and strengthen the triangular relationship among the three main subjects in tertiary education, namely, students, faculty, and higher educational institutions. This study may serve as an educational guide for teachers and tertiary institutions to pursue innovative and sustainable education.

The undecidable charge gap and the oil drop experiment

The undecidable charge gap and the oil drop experiment

Polarization Measurement of Light Scattered by Small Airborne Particles using the Millikan Experiment Kit

Polarization Measurement of Light Scattered by Small Airborne Particles using the Millikan Experiment Kit

Search for relativistic fractionally charged particles in space

More than a century after the performance of the oil drop experiment, the possible existence of fractionally charged particles FCP still remains unsettled. The search for FCPs is crucial for some extensions of the Standard Model in particle physics. Most of the previously conducted searches for FCPs in cosmic rays were based on experiments underground or at high altitudes. However, there have been few searches for FCPs in cosmic rays carried out in orbit other than AMS-01 flown by a space shuttle and BESS by a balloon at the top of the atmosphere. In this study, we conduct an FCP search in space based on on-orbit data obtained using the DArk Matter Particle Explorer (DAMPE) satellite over a period of five years. Unlike underground experiments, which require an FCP energy of the order of hundreds of GeV, our FCP search starts at only a few GeV. An upper limit of $6.2\times 10^{-10}~~\mathrm{cm^{-2}sr^{-1} s^{-1}}$ is obtained for the flux. Our results demonstrate that DAMPE exhibits higher sensitivity than experiments of similar types by three orders of magnitude that more stringently restricts the conditions for the existence of FCP in primary cosmic rays.

Millikan Again

Recognized as one of the most beautiful experiments of all time, the oil drop experiment performed by Robert Millikan and his graduate students (primarily Harvey Fletcher) is a standard in the repertoire of experiments performed by undergraduate physics students. However, “as a teaching lab it does not enjoy a good reputation for three reasons: eyestrain, tedium, and poor, unconvincing results.” Several have attempted to make this experiment more student-friendly by improving the optics and replacing the stopwatch with a computer, replacing the eye with a video camera, and utilizing video analysis tools. Currently available versions of the oil drop apparatus for high school and college students have incorporated a number of these features. On the other hand, others are ready to replace the experiment with interactive computer-based simulations. There is another alternative: Have students analyze pre-recorded videos of the Millikan experiment. Besides the “Millikan Movies” produced at the California State University at Chico, the collection “Physics: CINEMA CLASSICS” (“PCC”) contains the essential nuggets from a Physical Science Study Committee (PSSC) educational film made in 1959 sufficient to compute the elementary electric charge.

Effect of Application of Electric Force to Diesel Fuel Droplets Charged Through Millikan Oil-Drop Experiment on Physical and Thermal Characteristics of Flame

Abstract This paper proposes a new feasible method to allow continuous change in the primary injection spray cone angle of liquid fuel droplets, which are injected from nozzles in liquid fuel combustion systems, to control the flame shape and thermal characteristics of the flame. The method is based on electric force applied to fuel droplets charged through frictional effects between the internal surface of the nozzle and the fuel flow as the liquid fuel is sprayed (based on the Millikan oil-drop experiment). A sprint computational fluid dynamics code was developed to investigate the effect of application of electric force to charged diesel fuel droplets, which were injected from a pressure swirl atomizer, on physical and thermal characteristics of a two-dimensional axisymmetric turbulent jet diffusion flame. The results show that an electric field applied to charged fuel droplets (electric force) changes the spatial distribution of the liquid fuel droplets in the flame reaction zone. An applied electric force in (−y) direction diverts the fuel droplets towards the axis centerline of the furnace and, consequently, decreases the primary injection cone angle and increases the concentration of the evaporated droplets around the axis centerline, which enhances the fuel-oxidant mixing rate and raises the flame temperature. Unlike an applied electric force in (−y) direction, an applied electric force in (+y) direction decreases the flame temperature. However, as the primary injection cone angle is decreased, an applied electric force in (+y) direction increases the flame temperature.

A Logico-Linguistic Inquiry into the Foundations of Physics: Part 1

Physical dimensions are {\it not numbers}, but used as {\it numbers} to perform dimensional analysis by the physicist. The law of excluded middle falls short of explaining the contradictory meanings of the same symbols. The statements like ``$r\to 0$'', ``$q\to 0$'', used by the physicist, are inconsistent on dimensional grounds because ``$r$'', ``$q$'' represent {\it quantities} with physical dimensions of $[L], [Q]$ respectively and ``$0$'' represents just a number devoid of physical dimension. Consequently, the involvement of the statement ``$\lim_{q\to 0}$, where $q$ is the test charge'' in the definition of electric field leads to either circular reasoning or a contradiction regarding the experimental verification of the smallest charge in the Millikan-Fletcher oil drop experiment. Considering such issues as problematic, by choice, I make an inquiry regarding the basic language in terms of which physics is written, with an aim of exploring how truthfully the verbal statements can be converted to the corresponding physico-mathematical expressions (involving physical dimensions). Necessarily I demonstrate the meaning of the terms ``self inquiry'', ``middle way'', ``dependent origination'', ``emptiness/relational existence'', which signify the basic tenets of Buddhism. In light of this, I explain my view of ``definition''; the relation among quantity, physical dimension and number; the logico-linguistic fallacy of ``zero quantity''; difference between unit and unity. I present a critical analysis of the definitions of electric field due to Maxwell and Jackson. A postulate regarding the existence of charges becomes necessary which, however, resolves the contradiction regarding the oil drop experiment. This work is an appeal for the dissociation of the categorical disciplines of logic and physics and on the large, a fruitful merger of Eastern philosophy and Western science.

Correction: Isabel Bishop, Siyu Xian, and Steve Feller, “Robert A. Millikan and the Oil Drop Experiment,” Phys. Teach. 57, 442–445 (Oct. 2019)

Correction: Isabel Bishop, Siyu Xian, and Steve Feller, “Robert A. Millikan and the Oil Drop Experiment,” <i>Phys. Teach.</i> 57, 442–445 (Oct. 2019)

A CMB Millikan experiment with cosmic axiverse strings

We study axion strings of hyperlight axions coupled to photons. Hyperlight axions — axions lighter than Hubble at recombination — are a generic prediction of the string axiverse. These axions strings produce a distinct quantized polarization rotation of CMB photons which is mathcal{O} (αem). As the CMB light passes many strings, this polarization rotation converts E-modes to B-modes and adds up like a random walk. Using numerical simulations we show that the expected size of the final result is well within the reach of current and future CMB experiments through the measurement of correlations of CMB B-modes with E- and T-modes. The quantized polarization rotation angle is topological in nature and can be seen as a geometric phase. Its value depends only on the anomaly coefficient and is independent of other details such as the axion decay constant. Measurement of the anomaly coefficient by measuring this rotation will provide information about the UV theory, such as the quantization of electric charge and the value of the fundamental unit of charge. The presence of axion strings in the universe relies only on a phase transition in the early universe after inflation, after which the string network rapidly approaches an attractor scaling solution. If there are additional stable topological objects such as domain walls, axions as heavy as 10−15 eV would be accessible. The existence of these strings could also be probed by measuring the relative polarization rotation angle between different images in gravitationally lensed quasar systems.

Robert A. Millikan and the Oil Drop Experiment

In 2018, we celebrated the sesquicentennial birthday of Robert A. Millikan, a Nobel laureate in physics who worked among the greats such as Niels Bohr and Albert Einstein. His name, however, is perhaps not as widely known. He was born in 1868 in Morrison, IL, and moved with his family to the small town of Maquoketa, IA, at age nine. It was in this tiny Iowan town that Millikan spent his foundational years. He passed the time playing baseball and cooling off in the Maquoketa River. Millikan’s interest in experimentation showed early on. Local changes to the rules of baseball sparked controversy over a new type of pitch: the curve ball. Silas Millikan, Robert’s father, was a college-educated man and staunchly maintained that the curve ball was simply an optical illusion, but young Millikan knew better. With the help of brothers and cousins, Millikan set up a simple experiment to prove the point. Millikan and his family set up three poles in a line out in the yard and repeatedly pitched curveballs at one another. With careful observation, Silas could see the ball travel straight along the first two poles, then visibly curve and land on the opposite side of the third. This experiment was a small victory for Millikan, and only foreshadowed his later investment in scientific study.

Can virtual labs become a new normal? A case study of Millikan’s oil drop experiment

The present digital era has brought a paradigm shift in the learning behaviour of students and has provided innovative teaching and learning strategies that extend beyond the four walls of a classroom or a laboratory. One such innovation is the implementation of online or virtual laboratories. A virtual lab is seemingly an economically feasible and effective means to reach out to large audiences in schools, colleges, and universities. In a virtual lab, software simulates the lab environment and provides a step-by-step opportunity to perform an experiment, which can be performed anywhere, any time, on mobile or a notebook or a laptop. Millikan’s oil drop (MOD) experiment is one of the key experiments performed in the broad area of modern physics by undergraduate students to estimate the value of charge on an electron and confirm its quantization. Performing this landmark experiment requires good hands-on experimental skill with a lot of patience. It involves managing various parts of the equipment in sync with an effort to keep a charged oil drop in the field of view of the telescope in the presence of gravitational force, buoyant force, viscous force of air and electric force. It simultaneously requires recording of the observations during the upward and downward motion of the charged drops. This paper presents a study to understand the efficacy of performing the MOD method in a virtual environment vis-à-vis the learning outcomes of the students. The study revealed that there was an improvement in the conceptual understanding of the students. The students appreciated the use of the virtual lab, but at the same time they did not see it as a replacement for the traditional method involving an actual laboratory and teachers: they still have an urge to touch and feel the real apparatus in the presence of a human facilitator to clear their doubts.

Millikan e a questão do potencial de contato no experimento do efeito fotoelétrico

Resumo Apresenta-se neste artigo o tratamento teórico e experimental dado por Millikan à questão do potencial de contato em seus experimentos sobre o efeito fotoelétrico. O prêmio Nobel concedido a Millikan em 1923, teve como motivação seus experimentos que resultaram na medida da carga do elétron (experimento da gota de óleo) e da constante de Planck (experimento sobre o efeito fotoelétrico). A precisão com que Millikan obteve a constante de Planck deve-se à importância que ele atribuiu ao potencial de contato entre dois metais eletricamente conectados. Ao apresentar seus cálculos para o potencial de contato em um dos artigos publicados em 1916, Millikan exibe um resultado sutilmente errado que aparentemente passou despercebido pelos estudiosos do assunto. Em 1921, Millikan corrige o equívoco sem mencionar o erro de 1916. Se este erro não resultou de má digitação, aparentemente não há justificativa plausível para que ele tenha ocorrido.

Improving undergraduate labs

The April 2017 issue of Physics Today included a report by Toni Feder on the current poor state of student advanced physics labs and efforts by the Advanced Laboratory Physics Association to improve the situation. But a few aspects need discussion to complete our understanding of the situation.Some colleges advertise that all their undergraduates have the opportunity to participate in faculty research projects. I wonder whether such arrangements are an attempt to compensate for poor or nonexistent advanced labs.As the US population ages, an increasing share of federal revenue will go for Social Security and health care benefits. Less money will be available for discretionary federal spending, such as for student lab equipment, so petitioning NSF for funds is not promising. Physics teachers should be petitioning their own universities to make some tuition money available for that purpose.The typical department budget for lab equipment and supplies is approximately $1000, according to the report. If the college charges $30 000 annual tuition, why not use $1000 of that to upgrade lab equipment? If 20 students took the lab each year, that lab would receive $20 000, which should be enough to pay for one new or refurbished experiment set-up. If we assume student pairs rotated through 10 experiments and that each required only one apparatus set, after 10 years all experiments would be upgraded or refurbished!The article reports complaints about century-old lab experiments. Yet there is nothing wrong with letting students perform a few classic experiments such as the Millikan oil drop, the Michelson interferometer, or the Franck–Hertz tube. Recent Physics Today pieces (July 2016, pages 8 and 38; March 2017, page 11) have suggested that students should learn the history of physics. Doing classic experiments allows students to experience using simpler equipment and getting meaningful results without using computerized black boxes. I never appreciated how hard it is to measure the universal constant of gravitation G until I used a Cavendish balance.Feder reports that new professors are reluctant to get involved with maintaining student lab equipment because such activity does not contribute to obtaining tenure. Perhaps we need a reform of the tenure process so that ratings include those activities that directly help undergraduate students. For their tuition dollars, students should be getting good laboratory training.In a separate editorial (Physics Today, June 2016, page 8), Charles Day commented that the student labs he took did not inspire him to become an experimental physicist. I think his complaint is invalid. Student labs are not recruiting events for the field but training sessions that should Teach some laboratory techniques and practices. Give experience in analyzing real-world data whose error distribution does not follow a Gaussian distribution. Observe physics phenomena firsthand. Verify firsthand that some textbook theory is borne out by experiment. Allow one to learn some physics topics not covered in other courses. As demonstrated by the effort required to become proficient at playing a musical instrument, learning a craft is hard work, and not all of it is inspiring.[Editors’ note: Some of the issues Victor Slabinski mentions are also discussed in the feature article “Introductory physics labs: We can do better” by Natasha Holmes and Carl Wieman on page 38 of this issue.] Section:ChooseTop of page <<© 2018 American Institute of Physics.

Performing the Millikan experiment at the molecular scale: Determination of atomic Millikan-Thomson charges by computationally measuring atomic forces.

An atomic version of the Millikan oil drop experiment is performed computationally. It is shown that for planar molecules, the atomic version of the Millikan experiment can be used to define an atomic partial charge that is free from charge flow contributions. We refer to this charge as the Millikan-Thomson (MT) charge. Since the MT charge is directly proportional to the atomic forces under a uniform electric field, it is the most relevant charge for force field developments. The MT charge shows good stability with respect to different choices of the basis set. In addition, the MT charge can be easily calculated even at post-Hartree-Fock levels of theory. With the MT charge, it is shown that for a planar water dimer, the charge transfer from the proton acceptor to the proton donor is about −0.052 e. While both planar hydrated cations and anions show signs of charge transfer, anions show a much more significant charge transfer to the hydration water than the corresponding cations. It might be important to explicitly model the ion charge transfer to water in a force field at least for the anions.

Millikan's experiment revisited. Description of the Millikan experiment using the mass-charge force

Millikan's experiment revisited. Description of the Millikan experiment using the mass-charge force

On spinless null propagation in five-dimensional space-times with approximate space-like Killing symmetry

Five-dimensional (5D) space-time symmetry greatly facilitates how a 4D observer perceives the propagation of a single spinless particle in a 5D space-time. In particular, if the 5D geometry is independent of the fifth coordinate then the 5D physics may be interpreted as 4D quantum mechanics. In this work we address the case where symmetry is approximate, focusing on the case where the 5D geometry depends weakly on the fifth coordinate. We show that concepts developed for the case of exact symmetry approximately hold when other concepts such as decaying quantum states, resonant quantum scattering and Stokes drag are adopted, as well. We briefly comment on the optical model of the nuclear interactions and Millikan's oil drop experiment.

Slip length measurement of gas flow

In this paper, we present a review of the most important techniques used to measure the slip length of gas flow on isothermal surfaces. First, we present the famous Millikan experiment and then the rotating cylinder and spinning rotor gauge methods. Then, we describe the gas flow rate experiment, which is the most widely used technique to probe a confined gas and measure the slip. Finally, we present a promising technique using an atomic force microscope introduced recently to study the behavior of nanoscale confined gas.

Phenomenological Understanding of Laboratory Education: Focusing on the Millikan Oil-Drop Experiment and the Hall Effect Experiment

Phenomenological Understanding of Laboratory Education: Focusing on the Millikan Oil-Drop Experiment and the Hall Effect Experiment

Robert A. Millikan: measuring the controversies of an electron’s charge [scanning our past

This month’s article takes a look at how Robert A. Millikan’s oil-drop experiment led to the measurement of the charge of an electron. A hundred years ago physicist Robert A. Millikan published his paper on the value of Planck’s constant ðhÞ, which he used to prove Albert Einstein’s photoelectric equation. Seven years later, in 1923, Millikan received the Nobel Prize for this work. Perhaps more than any other number, h symbolizes the rise of modern physics.