arXiv subjects

David Blair

Publications and source records attributed to David Blair.

At least 19 recordsLinked to original sources

arXiv2024

Communicating the gravitational-wave discoveries of the LIGO-Virgo-KAGRA Collaboration

The LIGO-Virgo-KAGRA (LVK) Collaboration has made breakthrough discoveries in gravitational-wave astronomy, a new field that provides a different means of observing our Universe. Gravitational-wave discoveries are possible thanks to the work of thousands of people from across the globe working together. In this article, we discuss the range of engagement activities used to communicate LVK gravitational-wave discoveries and the stories of the people behind the science, using the activities surrounding the release of the third Gravitational-Wave Transient Catalog as a case study.

astro-ph.IM↗

arXiv2024

Spin(ing) into the classroom: Quantum spin activities for Year 6-10 physics

Quantum science is in the news daily and engages student interest and curiosity. A fundamental quantum science concept that underpins medical imaging, quantum computing and many future technologies is quantum spin. Quantum spin can explain many physical phenomena that are in the lower secondary school curriculum, such as magnetism and light, making its inclusion a great motivator for students. Here we present an activity sequence for teaching quantum spin in the classroom using spinning tops and gyroscopes to highlight the common properties of classical angular momentum and quantum spin. These toys can provide an easily understood window to the quantum world for lower secondary school students. Students who have engaged in these activities reported enjoying the content and appreciating its relevance.

physics.ed-ph↗

arXiv2023

On the effectiveness of the early introduction of modern physics in school curriculum: the case of the structure of atom versus wave-particle duality

The dual nature of matter and radiation and the concept of the structure of an atom share a number of key conceptual elements from quantum mechanics. Despite the similarities, we find that the concept of the structure of an atom is well understood by students, in contrast to the wave-particle duality. The study analyzes students' comprehension of these two concepts by conducting a semi-structured focus group interview and questionnaire. Through students' performance in the questionnaire and their descriptive responses, we find that the difficulties in their learning and understandings reflect the treatment of the respective topic in the curriculum. The introduction of the structure of an atom is early and repeated, whereas the dual nature of matter and radiation is introduced late and abruptly. Based on our findings, we propose reforms in the present curriculum that are necessary for an improved way of introducing the concept of modern physics, like wave particle duality, to Indian students.

physics.ed-ph↗

arXiv2023

Developing and implementing an Einsteinian science curriculum from Years 3 to 10 : Part A Concepts, rationale and learning outcomes

There has been a growing realisation that school science curricula do not adequately reflect the revolutionary changes in our scientific understanding of the 20th century. This discrepancy between current school education and our modern scientific understanding has led to calls for the modernisation of the science curriculum. Although there have been attempts to introduce topics of Einsteinian physics (i.e., quantum physics and relativity) to school education, often at the secondary level, we still lack a seamless curriculum in which modern science concepts are gradually introduced in primary and middle schools. Guided by the Model of Educational Reconstruction and following a mixed-methods research design, the Einstein-First project aims to address this gap. Einstein-First has developed and implemented an Einsteinian curriculum from Years 3 to 10 (students aged 7- 16) that resolves the disconnect between science in schools and the modern world. This paper presents the concepts, rationale, and learning outcomes of the curriculum implementation in six Australian schools with 315 students across Years 3 to 10. Our findings lay the foundation for informed curriculum development towards a school education that can enhance students' understanding and appreciation of the fundamental concepts of modern science and its impact on our society.

physics.ed-ph↗

arXiv2023

Maths for Einstein's Universe Tools for Understanding Modern Reality

Aversion to mathematics is a recognised and widespread problem. Following a review of the literature on this subject, this paper presents an education program which has been developed to test the hypothesis that transferring attention from traditional school arithmetic to a broad range of mathematical skills relevant to modern science at an early age (ages 7-12) will improve students' attitudes to mathematics, reduce the incidence of maths anxiety and prepare students for topics normally introduced at more senior levels. The program entitled Maths for Einstein's Universe includes five modules covering extreme numbers, estimation, probability, vectors and curved space geometry taught through group activities, games and plays. The modules complement appropriate early learning of modern physical concepts from the subatomic world to cosmology. While connected to science, the program aims to provide meaning and comprehension for socially relevant topics from national budgets to pandemics and opinion polls. The program has been trialled in multiple short workshops and extended learning programs as well as training programs for school teachers. Analysis of knowledge and attitude tests and questionnaires from about 170 participants demonstrate strong student enthusiasm and positive learning outcomes in areas normally considered beyond the ability of students in this age group. Trial results were used to identify strategies for enhancing school mathematics based on creation of stronger links between mathematics and science. We summarise results of pilot trials. In the paper we present the results of learning powers of ten and vectors. In total, around 700 participants have trialled Maths Einstein's Universe with nearly 200 hours of teaching for students and teachers.

physics.ed-ph↗

arXiv2023

Developing and implementing an Einsteinian science curriculum from Years 3 to 10: Part B Teacher upskilling: response to training and teacher's classroom experience

Recent years have seen a growing interest in modernizing physics and science curricula around the world. While many science educators and curriculum developers design instructional resources to successfully introduce topics of Einsteinian physics to young learners, it is clear that successful curriculum development needs to rest on successful teacher professional development.Teachers with or without science backgrounds were trained in short professional learning workshops or completed micro-credential courses. The courses enabled teachers to gain knowledge and confidence to deliver the Einstein-First program. Detailed lesson plans and instructional videos for teachers define the lessons. Questionnaires were used to collect data, and teacher interviews were conducted following the various teacher training programs. The research results show that teachers effectively deliver the Einsteinian physics programs and that their subject matter and pedagogical content knowledge increased. In addition, teacher attitudes were favorable towards modernizing the physics curriculum. We conclude that it is feasible to upskill teachers from diverse backgrounds in Einsteinian physics and break the cycle that has inhibited the modernization of school curricula.

physics.ed-ph↗

arXiv2023

Seismic noise characterization at a potential gravitational wave detector site in Australia

A critical consideration in the design of next generation gravitational wave detectors is the understanding of the seismic environment that can introduce coherent and incoherent noise of seismic origin at different frequencies. We present detailed low-frequency ambient seismic noise characterization (0.1--10~Hz) at the Gingin site in Western Australia. Unlike the microseism band (0.06--1~Hz) for which the power shows strong correlations with nearby buoy measurements in the Indian Ocean, the seismic spectrum above 1~Hz is a complex superposition of wind induced seismic noise and anthropogenic seismic noise which can be characterized using beamforming to distinguish between the effects of coherent and incoherent wind induced seismic noise combined with temporal variations in the spatio-spectral properties of seismic noise. This also helps characterizing the anthropogenic seismic noise. We show that wind induced seismic noise can either increase or decrease the coherency of background seismic noise for wind speeds above 6~m/s due to the interaction of wind with various surface objects. In comparison to the seismic noise at the Virgo site, the secondary microseism (0.2~Hz) noise level is higher in Gingin, but the seismic noise level between 1 and 10~Hz is lower due to the sparse population and absence of nearby road traffic.

astro-ph.IM↗

arXiv2022

Low coherency of wind induced seismic noise: Implications for gravitational wave detection

Seismic noise poses challenges for gravitational wave detection. Effective vibration isolation and methods to subtract unsheildable Newtonian Noise are examples. Seismic arrays offer one way to deal with these issues assuming seismic coherency. In this paper we find that wind induced seismic noise is incoherent and will dramatically reduce the projected low frequency sensitivity of future gravitational wave detectors. To quantify this, we measure the coherence length of wind induced seismic noise from 0.06--20~Hz in three distinct locations: close to a building, among tall trees and in shrubs. We show that wind induced seismic noise is ubiquitous and reduces the coherence lengths form several hundred meters to 2--40~m for 0.06--0.1~Hz, from $>$60~m to 3--16~m for 1.5--2.5~Hz and from $>$35~m to 1--16~m around 16.6 Hz frequency bands in the study area. This leads to significant loss of velocity and angular resolution of the array for primary microseism, 5 times worse Newtonian Noise cancellation by wiener filtering at 2~Hz, while it does not pose additional challenge for Newtonian Noise cancellation between 10--20~Hz.

physics.geo-ph↗

arXiv2022

Can 8-Year-Olds understand concepts of Einsteinian physics?

This paper reports the first study on the ability of Year 3 students (ages 7 to 8) to conceptualize Einsteinian concepts. This paper reports that children aged 7-8 are not too young to learn key Einsteinian concepts, and the benefits of reinforcement indicate that longer programs are needed for ideas to be consolidated.

physics.ed-ph↗

arXiv2021

Long-term impact of a primary school intervention on aspects of Einsteinian physics

The physics that underpins modern technology is based on Einstein's theories of relativity and quantum mechanics. Most school students complete their compulsory science education without being taught any of these Einsteinian concepts. Only those who take a specialised physics course have the opportunity to learn modern physics. In 2011, the first study of a modern physics teaching intervention with an Australian upper primary (aged 10{11) class was conducted. The initial intervention was the first step of the Einstein-First collaboration towards challenging the current paradigm of Newtonian teaching in schools. It was found that modern physics concepts could be taught to these students. In 2020, 11 participants of the initial study (out of a total of 26) were contacted for a follow-up questionnaire and interview to investigate any long-term impact. The results of the follow-up indicate that the intervention maintained a positive impression on participants. The models and analogies used during the six-week intervention were highly memorable. The participants indicated that they found the intervention to be beneficial to their future learning. Even close to ten years after the intervention, the participants remembered several key concepts (such as curved space-time). The long-term follow-up indicates that Einsteinian physics can be taught at the upper primary level and be recalled several years later.

physics.ed-ph↗

arXiv2020

A Cryogenic Silicon Interferometer for Gravitational-wave Detection

The detection of gravitational waves from compact binary mergers by LIGO has opened the era of gravitational wave astronomy, revealing a previously hidden side of the cosmos. To maximize the reach of the existing LIGO observatory facilities, we have designed a new instrument that will have 5 times the range of Advanced LIGO, or greater than 100 times the event rate. Observations with this new instrument will make possible dramatic steps toward understanding the physics of the nearby universe, as well as observing the universe out to cosmological distances by the detection of binary black hole coalescences. This article presents the instrument design and a quantitative analysis of the anticipated noise floor.

astro-ph.IM↗

arXiv2020

Ground Based Gravitational Wave Astronomy in the Asian Region

The current gravitational wave detectors have identified a surprising population of heavy stellar mass black holes, and an even larger population of coalescing neutron stars. The first observations have led to many dramatic discoveries and the confirmation of general relativity in very strong gravitational fields. The future of gravitational wave astronomy looks bright, especially if additional detectors with greater sensitivity, broader bandwidth, and better global coverage can be implemented. The first discoveries add impetus to gravitational wave detectors designed to detect in the nHz, mHz and kHz frequency bands. This paper reviews the century-long struggle that led to the recent discoveries, and reports on designs and possibilities for future detectors. The benefits of future detectors in the Asian region are discussed, including analysis of the benefits of a detector located in Australia.

gr-qc↗

arXiv2019

Ground-Based Gravitational-Wave Astronomy in Australia: 2019 White Paper

The past four years have seen a scientific revolution through the birth of a new field: gravitational-wave astronomy. The first detection of gravitational waves---recognised by the 2017 Nobel Prize in Physics---provided unprecedented tests of general relativity while unveiling a previously unknown class of massive black holes, thirty times more massive than the Sun. The subsequent detection of gravitational waves from a merging binary neutron star confirmed the hypothesised connection between binary neutron stars and short gamma-ray bursts while providing an independent measurement of the expansion of the Universe. The discovery enabled precision measurement of the speed of gravity while shedding light on the origin of heavy elements. At the time of writing, the Laser Interferometer Gravitational-wave Observatory (LIGO) and its European partner, Virgo, have published the detection of eleven gravitational-wave events. New, not-yet-published detections are announced on a nearly weekly basis. This fast-growing catalogue of gravitational-wave transients is expected to yield insights into a number of topics, from the equation of state of matter at supra-nuclear densities to the fate of massive stars. The science potential of 3G observatories is enormous, enabling measurements of gravitational waves from the edge of the Universe and precise determination of the neutron star equation of state. Australia is well-positioned to help develop the required technology. The Mid-term Review for the Decadal plan for Australian astronomy 2016-2025 should consider investment in a scoping study for an Australian Gravitational-Wave Pathfinder that develops and validates core technologies required for the global 3G detector network.

astro-ph.IM↗

arXiv2019

Gender response to Einsteinian physics interventions in School

There is growing interest in the introduction of Einsteinian concepts of space, time, light and gravity across the entire school curriculum. We have developed intervention programs and measured their effectiveness in terms of student attitudes to physics and ability to understand the concepts with classes from Years 6 to 10. In all cases we observe significant levels of conceptual understanding and improvement in student attitudes, although the magnitude of the improvement depends on age group and program duration. This paper reports an unexpected outcome in regard to gender effects. We have compared male and female outcomes. In most cases, independent of age group, academic stream and culture (including one intervention in Indonesia), we find that females enter our programmes with substantially lower attitude scores than males, while on completion their attitudes are comparable to the boys. This provides a strong case for widespread implementation of Einsteinian conceptual learning across the school curriculum. We discuss possible reasons for this effect.

physics.ed-ph↗

arXiv2018

Angular instability in high optical power suspended cavities

Advanced gravitational wave detectors use suspended test masses to form optical resonant cavities for enhancing the detector sensitivity. These cavities store hundreds of kilowatts of coherent light and even higher optical power for future detectors. With such high optical power, the radiation pressure effect inside the cavity creates sufficiently strong coupling between test masses whose dynamics are significantly altered. The dynamics of two independent nearly free masses become a coupled mechanical resonator system. The transfer function of the local control system used for controlling the test masses is modified by the radiation pressure effect. The changes in the transfer function of the local control systems can result in a new type of angular instability which occurs at only 1.3 \% of the Sidles-Sigg instability threshold power. We report experimental results on a 74~m suspended cavity with a few kilowatts of circulating power, for which the power to mass ratio is comparable to the current Advanced LIGO. The radiation pressure effect on the test masses behaves like an additional optical feedback with respect to the local angular control, potentially making the mirror control system unstable. When the local angular control system is optimized for maximum stability margin, the instability threshold power increases from 4~kW to 29~kW. The system behavior is consistent with our simulation and the power dependent evolution of both the cavity soft and hard mode is observed. We show that this phenomenon is likely to significantly affect proposed gravitational wave detectors that require very high optical power.

astro-ph.IM↗

arXiv2018

Public and Teacher Response to Einsteinian Physics in Schools

Einsteinian physics represents a distinct paradigm shift compared to Newtonian physics. There is worldwide interest in introducing Einsteinian physics concepts early in school curriculum and trials have demonstrated that this is feasible. However introducing Einsteinian concepts from an early age requires more than suitable curriculum and teaching resources - it also requires teacher training and public support. This paper describes a pilot study used in an attempt to gauge public and teacher support. This entailed giving teachers, who included the entire staff of a primary school, and self-selected family groups an in-depth understanding of proposed curriculum content through public outreach and professional development workshops. We assessed their attitudes through questionnaires. Comments and opinions from the public were also collected from online resources. Results show overwhelming support from both teachers and the public. We assessed attitudes of children as well as adults and obtained opinions regarding the appropriate age at which to begin to introduce Einsteinian concepts.

physics.ed-ph↗

arXiv2018

Enhanced detection of high frequency gravitational waves using optically diluted optomechanical filters

Detections of gravitational waves (GW) in the frequency band 35 Hz to 500 Hz have led to the birth of GW astronomy. Expected signals above 500 Hz, such as the quasinormal modes of lower mass black holes and neutron star mergers signatures are currently not detectable due to increasing quantum shot noise at high frequencies. Squeezed vacuum injection has been shown to allow broadband sensitivity improvement, but this technique does not change the slope of the noise at high frequency. It has been shown that white light signal recycling using negative dispersion optomechanical filter cavities with strong optical dilution for thermal noise suppression can in principle allow broadband high frequency sensitivity improvement. Here we present detailed modelling of AlGaAs/GaAs optomechanical filters to identify the available parameter space in which such filters can achieve the low thermal noise required to allow useful sensitivity improvement at high frequency. Material losses, the resolved sideband condition and internal acoustic modes dictate the need for resonators substantially smaller than previously suggested. We identify suitable resonator dimensions and show that a 30 $μ$m scale cat-flap resonator combined with optical squeezing allows 8 fold improvement of strain sensitivity at 2 kHz compared with Advanced LIGO. This corresponds to a detection volume increase of a factor of 500 for sources in this frequency range.

astro-ph.IM↗

arXiv2017

Evaluation of 14 to 15 Year Old Students' Understanding and Attitude towards Learning Einsteinian Physics

There is an increasing recognition regarding of the importance of introducing modern Einsteinian concepts early in science education. This study investigates the efficacy of an innovative educational programme "Einstein-First", which focuses on teaching Einsteinian physics at an earlier age than usual through the incorporation of appropriate hands-on activities. This paper presents an analysis of 14 to 15-year-old students' conceptualisation of Einsteinian physics and their attitudes towards science as a result of this programme. We have investigated the students' understanding of modern physics concept after a term of 20 lessons. We report on two such 20-lesson programmes, one delivered in 2013 and a second, improved programme delivered in 2014; each to 50-60 students across two classes designated by the participating high school as "academically talented" students. We found, as expected, that the students' possessed little prior knowledge of Einsteinian physics. the significant improvement in the students' knowledge, as tested before and after the course, showed that they could comprehend Einsteinian physics at the level it was given. The findings also showed that the short programme improved students' attitude towards physics.While the male students initially showed greater interest in physics compared to their female counterparts, the female students showed a significantly increased interest in physics after the programme. Also, students' memory retention of Einsteinian physics concepts was tested in two different years, one class was tested after one year of the programmes and the other was tested after three years of the programme. The results show that the Einstein-First programme had a lasting impact on the students involved in the study.

physics.ed-ph↗