Physics & Astronomy Archives - Faculty of Science

Cosmic honour for �첥��Ƶ astrophysicist

kseo — Mon, 14 Apr 2025 13:20:14 +0000

In the asteroid belt between Mars and Jupiter, an asteroid measuring up to 1.5 kilometres across quietly traces its orbit, tilted 15 degrees from the planetary plane.

This celestial body, officially named Marshall McCall, honours a �첥��Ƶ Faculty of Science professor emeritus whose research has illuminated the intricate structures of galaxies and their evolution.

^{Marshall McCall}

For McCall, the recognition carries personal significance. “I was deeply honoured,” he says. “The recognition makes me feel that my work in astronomy had some value.”

The initiative to name the asteroid was led by Canadian astronomers Paul Wiegert (a former postdoctoral fellow at �첥��Ƶ) and David Balam, who sought to recognize McCall’s contributions to astronomy. “Marshall McCall’s research has had a lasting impact on our field,” says Balam, an asteroid hunter based in British Columbia who first encountered McCall’s work decades ago.

McCall’s fascination with the universe began on Vancouver Island, where he pursued an undergraduate degree at the University of Victoria before earning his PhD at the University of Texas at Austin. In 1988, he joined �첥��Ƶ’s Department of Physics and Astronomy, where he not only advanced research, but also helped shape academic programs that have inspired generations of astronomers.

Among those mentored by McCall was Wiegert, now a professor at Western University. “My time at York deeply shaped my career,” Wiegert says. “It’s a true pleasure for me to have been involved in naming an asteroid after Marshall McCall. This feels like a meaningful way to give back to that community.”

McCall’s scientific career is marked by discoveries that have revealed hidden gems in the cosmos. While studying galaxies whose light is obscured by interstellar dust within the Milky Way, McCall and Ronald Buta of the University of Alabama identified four previously unknown celestial objects. Named MB 1, MB 2, MB 3 and MB 4 – after their initials – the discoveries include two nearby galaxies (MB 1 and MB 3) located just 10 million light years away. MB 2, once thought to be a galaxy, turned out to be an unusual nebula within the Milky Way whose origin remains a puzzle. MB 4 is another nebula, likely formed from gas expelled during the birth of twin stars. “You never know what you will find when you penetrate the fog,” McCall says, capturing the thrill of exploring the unknown.

Building on his discovery of MB 1 and MB 3, McCall’s work mapping galaxies within 30 million light years of Earth uncovered larger patterns that reshaped how astronomers view the cosmic landscape. Among these findings, he confirmed that the Milky Way is embedded in a vast, flattened arrangement of galaxies known as the “Local Sheet,” a structure stretching 34 million light years across but only 1.5 million light years thick.

He also identified the “Council of Giants,” a ring of massive galaxies 24 million light years in diameter encircling the Milky Way and its companion Andromeda. These galaxies act as cosmic gatekeepers, siphoning intergalactic material away from the “Local Group” and limiting its ability to grow.

McCall’s work reflects a deep curiosity about the universe’s interconnected structures.

In a public lecture, he outlined how the Milky Way fits into the broader celestial arrangement: “We live on a planet around a star in a galaxy in the ‘Local Group,’ encompassed by the ‘Council of Giants of the Local Sheet’ next to the ‘Local Void’ at the periphery of the ‘Local Supercluster of Laniakea.’”

While these terms are technical, they describe how galaxies like ours are shaped by their surroundings – how gravitational forces and spatial patterns influence their evolution within the vast cosmic web.

For those who have worked alongside him or followed in his footsteps, McCall’s contributions transcend scientific achievements; they represent landmark discoveries that inspire further exploration and wonder. Now immortalized by an asteroid bearing his name, his legacy reaches beyond Earth into the cosmos he has spent his life studying.

“It is nice to feel that my efforts were not completely in vain and that there will be a memory of them up there when I am gone,” McCall says. “Most importantly, I feel privileged to have had even had this chance – to seek knowledge for its own sake as part of a society willing to enable such pursuits.”

McCall joins a distinguished group of �첥��Ƶ faculty members who have had asteroids named after them, including: Professor Emeritus Paul Delaney, Professor Michael Daly, Department of Earth & Space Science & Engineering, Lassonde School of Engineering; Professor Patrick Hall, Department of Physics & Astronomy, Faculty of Science; the late Professor Emeritus Kim Innanen, Department of Physics & Astronomy, Faculty of Science; and the late Professor Richard Jarrell, Department of Science, Technology & Society, Faculty of Science.

Courtesy of YFile

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�첥��Ƶ prof makes astronomy history with largest-ever observation grant

kseo — Wed, 02 Apr 2025 13:06:00 +0000

Adam Muzzin, a professor at �첥��Ƶ's Faculty of Science, is "over the moon" about making astronomy history.

Granted 260 primary hours and 127 parallel hours of observation time with the James Webb Space Telescope (JWST) – which is orbiting in space near the sun – means Muzzin is the recipient of the largest single program ever given to an observer. He will use the JWST to study the universe's most distant galaxies and the first stars – in order to enhance our understanding of cosmic history.

^{Adam Muzzin}

Muzzin knew the science from this program could be revolutionary if approved, but the size of his request made it a longshot. Securing any amount of time with the world’s most powerful telescope is highly competitive – only 10 per cent of applications are successful – and he was asking for nearly six times his previous allocation in 2023 to explore the depths of the universe.

His new request would expand on Muzzin and his team’s earlier researcher with JWST’s multi-colour imagery, which uses multiple filters to produce detailed and highly colorized images of distant galaxies, revealing cosmic objects previously hidden from traditional methods.

The previous project looked at three small pieces of the sky. The new one proposed to survey a much larger region of the sky – approximately 20 times larger – as long as the JWST time request panel agreed to it.

Then the news came.

"I almost fell out of my chair," Muzzin says. When he was informed of the approval, his cry of joy was so loud his graduate students came running down the hall outside his office to check if he was okay.

It was a milestone achivement.

With the new historic allocation – the largest JWST has ever given – Muzzin and his team will conduct an extensive astronomical survey with an eye towards, among other goals, capturing images of distant galaxies and uncovering the first stars that formed after the Big Bang.

^{James Webb Space Telescope (image by NASA)}

“They have to be out there, but we’ve never seen them,” says Muzzin. “This program gives us arguably our best shot at finding them.”

Detecting these stars is challenging because they lived in the early universe and had short lifespans. Muzzin’s program is uniquely positioned to discover these stars by capturing subtle color variations that indicate their presence. Identifying the stars, he says, will prove essential for understanding how the universe evolved, as they are the origin of all the heavier elements found today. “This is about uncovering the origin story of our galaxy, our sun and ultimately, humanity,” says Muzzin.

Muzzin is thrilled not just for the opportunity for himself and his team, but for the chance to produce important data for the wider scientific community. The JWST is part of a treasury program, which means any data Muzzin’s allocation produces will be made publicly available for future research long after the program’s completion. “That’s very gratifying,” he says.

But, it’s not just that. As a colleague told him: “A program of this size is really making astronomy history.”

Courtesy of YFile

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Faculty of Science prof launches �첥��Ƶ’s first astronomy podcast

kseo — Wed, 04 Dec 2024 19:45:23 +0000

Elaina Hyde, a professor in the Department of Physics & Astronomy in �첥��Ƶ’s Faculty of Science and director of the Allan I. Carswell Observatory, has launched York’s first-ever podcast dedicated to astronomy.

Hyde’s existing Monday night audio program, “�첥��Ƶniverse” – already boasting an archive of more than 500 episodes as a radio show, internet program and YouTube broadcast – can now be found on all podcast-streaming platforms, further expanding its potential reach and impact. Listeners can join the Allan I. Carswell Observatory’s group of professors, students and alumni for an astronomical adventure, covering history, news and telescope-viewing insights.

^{Elaina Hyde}

“�첥��Ƶniverse” started in 2009 as an online radio show on astronomy.fm. When that station went off air in 2023, the show’s audio broadcast was incorporated into the Observatory’s online public viewing program on YouTube. Since radio shows have been reaching fewer and fewer members of the public, and podcasts have conversely risen in popularity, the Observatory realized offering the show in podcast format was the natural next step.

With a team of seven regular hosts and 10 repeating guests, the podcast covers topics including what the Observatory is up to, current research at �첥��Ƶ and life on other planets. Some recent episodes have focused on retro rockets and spooky stars – a Halloween episode that coincided with the Observatory’s Halloween event.

“Since most of the hosts, cohosts and organizers of ‘�첥��Ƶniverse’ are current York students and Observatory alumni, it is a great chance for the community to share in the accomplishments of some of our most accomplished grads – and undergrads,” says Hyde. “The student perspective and knowledge included in the broadcasts offers a chance for everyone to join in the exciting Observatory discoveries and observations.”

All episodes of “�첥��Ƶniverse” are recorded live from the Allan I. Carswell Observatory on �첥��Ƶ’s Keele Campus, making it easy for students and researchers to join in person. Videoconferencing programs like Zoom make it possible to welcome guests from anywhere in the world.

Past guest speakers have included Blake Nancarrow from the Royal Astronomical Society of Canada (episode 512), and science communicators Emily Lakdawalla (episode 270), Sara Mazrouei (episode 124), David Levy (episode 117) and many more.

Looking ahead, listeners can look forward to more interesting guests and more astronomy news in the episodes to come. Given astronomy’s new focus on machine learning and data science, Hyde and her team plan to provide a window into some of the latest developments in those fields.

“One of our big plans for 2025 is to set up an episode from our Killarney Provincial Park collaborators in Ontario,” explains Hyde, referring to the Allan I. Carswell Astronomer in Residence program held annually at Killarney’s dark sky preserve. “We are looking forward to bringing one of our astronomers live from the site during residence to discuss astronomy, stargazing and, of course, the telescopes.”

The team also plans to convert past archived episodes of the show into podcast format, increasing the public’s access to valuable astronomical information.

“Reaching into the fields of history, physics, chemistry and biology is one of the things that astronomy does best,” says Hyde. “With the ‘�첥��Ƶniverse’ podcast, we can do all of that and include a York perspective as well. With this new format, we hope to reach a wider audience of both student scientists and science communicators.”

The “�첥��Ƶniverse” podcast is available on the and can be streamed on all podcast platforms. The live broadcast takes place every Monday night at 9 p.m. on YouTube in conjunction with the Observatory’s online public viewing program, where live or archival images from the telescope are shown, depending on the weather.

With files from Elaina Hyde

Courtesy of YFile

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York students shine as astronomers in residence

kseo — Tue, 22 Oct 2024 18:47:17 +0000

Two �첥��Ƶ graduate students recently made history in the annual Astronomer in Residence program, a partnership between York’s Allan I. Carswell Observatory and Killarney Provincial Park. Sunna Withers, finishing her master’s degree, and Anna Skrinnik, a PhD candidate, completed a combined tenure, marking a first for the initiative.

The Astronomer in Residence program allows qualified astronomers to provide astronomy tours and programming at the certified dark sky preserve located on the Georgian Bay. Now in its third year, the program continues to offer unique opportunities for aspiring astronomers.

“This one-of-a-kind combined tenure allowed our two students to tag-team on events, support each other with telescope operations and provide a wonderful experience for the general public who participated on their tours,” says Elaina Hyde, director of the Allan I. Carswell Observatory.

At Killarney, Withers and Skrinnik independently created observing campaigns, set up telescopes and developed educational materials. This hands-on experience proved invaluable, offering a rare opportunity to work under truly dark skies.

Hyde emphasizes the rarity of such an experience, even for professional astronomers, due to increasing light pollution in urban areas. She notes that viewing objects such as the Andromeda Galaxy and the Milky Way with the naked eye can be truly inspirational.

The students’ �첥��Ƶ background prepared them well for this role. Hyde points out that York offers astronomical resources rarely found elsewhere, including the largest telescope on any Canadian campus.

Both Withers and Skrinnik have received extensive training at the observatory, with Skrinnik working on the Quail instrument mounted to the 60-centimetre telescope for her master’s thesis. This experience, combined with York’s weekly public viewing sessions, honed their skills in telescope operation and public outreach.

During their residency, Withers and Skrinnik captured impressive astrophotography, showcasing their work on the observatory’s blog. Their images not only highlight celestial objects but also demonstrate their ability to integrate astronomy with an appreciation for the park’s natural environment. “It was wonderful to spend time under dark skies, to see the Milky Way for the first time and to share this experience with the campers at Killarney park,” Withers says.

The students’ Drop in on the Night Sky program attracted more than 70 park visitors. “Sunna and Anna showed visitors Vega, the Ring Nebula and Saturn through the 16-inch scope,” says Kate Ward, senior park naturalist at Ontario Parks. “They did a good job adapting their delivery to different audiences, including lay people, astronomy enthusiasts and children.”

Hyde adds that the experience allowed the students to enhance their public speaking skills and gain valuable experience in setting up astronomical programming independently. “This program development is exactly what they will need to be able to do should they decide to become educators, scientists or even go into the realm of business after graduation,” she says.

Courtesy of YFile

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New Faculty of Science members to advance student learning in cutting-edge fields

aburtin — Thu, 12 Sep 2024 14:28:21 +0000

�첥��Ƶ’s Faculty of Science is welcoming five new full-time, permanent faculty members this year.

“The Faculty of Science has hired fantastic new faculty members that will contribute to enhancing our Faculty’s academic excellence, diversity, and research and teaching capacity,” says Faculty of Science Dean Rui Wang. “I look forward to working with our outstanding new colleagues, who bring diverse experiences and perspectives that will strengthen our Faculty as a destination of choice for students and aspiring scientists.”

Divya Sharma

Sharma joins the Department of Mathematics & Statistics as an assistant professor in the data science stream. She holds a PhD in computer science with a specialization in machine learning (ML) from the Indian Institute of Technology Jodhpur.

Following her doctoral studies, Sharma completed a postdoctoral fellowship in the Biostatistics Department at the Princess Margaret Cancer Centre, part of the University Health Network, in Toronto. During this time, she was awarded the Canadian Institutes of Health Research STAGE (Strategic Training for Advanced Genetic Epidemiology) Fellowship for 2020-22. Following that, she worked as a senior biostatistician and clinician investigator at the University Health Network, where she developed artificial intelligence models to address various health outcomes, including liver disease, cancer, sepsis and osteoarthritis. She did so through interdisciplinary collaborations at Toronto General Hospital, the Krembil Research Institute and the Princess Margaret Cancer Centre.

Sharma’s research program focuses on developing novel deep learning models for integrative, high-dimensional modelling of multi-modal big health-care data, comprising clinical, imaging and genomic domains. Her work places a strong emphasis on clinical interpretability and deployability, with innovative ML modelling approaches published in high-impact journals such as Lancet Digital Health and Bioinformatics.

Sharma has recently received the Natural Sciences & Engineering Research Council of Canada Discovery Grant and Launch supplement for 2024, as well as a Resource Allocation Grant 2024 from the Digital Research Alliance of Canada, which will help steer her research program at York and provide computational resources to develop deep learning models for guiding personalized medicine. In her teaching at York, she wants to provide students with a strong foundation in statistics, mathematics and computational principles behind complex concepts in machine learning and data science. Her goal is to equip students so they can become future leaders in the application and development of robust modelling approaches.

Divya Sharma

Yi Liu

Liu joins the Department of Mathematics & Statistics as an assistant professor. He received his PhD in statistical machine learning from the University of Alberta in 2023, following his postdoctoral fellowship and experience as an assistant lecturer at the same institution. Liu also holds a master’s degree in mathematics from Beijing Normal University.

Liu’s research focuses on developing robust algorithms for differential privacy, functional data analysis and reinforcement learning. His work seeks to balance data utility with privacy preservation, exploring innovative approaches to protect user information while maintaining the integrity of statistical analysis. His research has been presented at top-tier conferences and published in leading journals like Statistica Sinica and Bernoulli.

Liu’s contributions are advancing both theoretical and applied aspects of statistical machine learning, particularly in privacy-preserving technologies and optimization in dynamic environments.

Yi Liu

Tianyu Guan

Guan joins the Department of Mathematics & Statistics as an assistant professor. Guan received her PhD in statistics and MSc in actuarial science at Simon Fraser University. Before joining York, she was an assistant professor at Brock University from 2020 to 2024. Guan’s research spans several cutting-edge areas, including sports analytics, functional data analysis, machine learning and data science. She specializes in developing novel statistical and data science methods to analyze data across various fields such as sports, public health and economics.

In recent years, Guan’s research interest in sports analytics has particularly grown. She analyzes sports data to craft better strategies, improve team and player performance, and influence betting odds. She has collaborated with various organizations to advance the use of statistical techniques in sports decision-making. Her goal is to use sports analytics to help teams and players gain a competitive edge.

Bruce Howard

Howard joins the Department of Physics & Astronomy having received his undergraduate degree in physics and astronomy from the University of Pittsburgh and his PhD in physics from Indiana University. Following this, Howard held a postdoctoral position as a research associate at Fermilab, near Chicago.

Howard’s research focuses on experimental particle physics, specifically neutrinos. His main interest is in furthering our understanding of the properties of neutrinos and antineutrinos, especially around the properties at work in the process known as neutrino oscillation. Neutrino oscillation is the phenomenon where a neutrino or antineutrino created as one type can later interact as another type.

Howard’s research efforts at York in the next years will primarily use liquid argon (LAr) time-projection chamber (TPC) detectors to study neutrinos. One focus is on realizing and performing studies with an upcoming, powerful neutrino experiment (DUNE) in which an international collaborative effort will deploy detectors near the beam at Fermilab and far away in South Dakota. The other focus will be on conducting studies with a smaller LAr TPC detector that is currently operating and enabling interesting neutrino studies as well as key opportunities to prepare for the next-generation experiment.

Stephanie Jones

Jones will join the Department of Chemistry as an assistant professor in February 2025. Her research is focused on atmospheric aerosols and environmentally relevant surface films. In particular, she is interested in understanding how atmospheric transformations impact the fundamental properties of aerosols and films. Jones uses single particle levitation methods, as well as neutron and X-ray scattering, to study transformations of aerosols and films in the laboratory to determine their fundamental physicochemical and optical properties.

Jones has an integrated master’s in chemistry from the University of Bristol and a PhD from Royal Holloway University of London. Following her PhD, she undertook a postdoctoral fellowship at the University of Victoria in Canada, before moving back to the U.K. where she worked in industry for a brief period as a product manager at Laser Quantum. She then transitioned back to academia and chemistry, completing a second postdoc in environmental chemistry at the University of Toronto where she expanded her research interests to include the indoor environment.

After successfully obtaining funding for her own position from the German Research Foundation, Jones then moved to the Institute of Meteorology & Climate Research’s Atmospheric Aerosol Research Department at the Karlsruhe Institute of Technology (KIT) in Germany, where she is currently based. Her research at KIT involves the study of photochemically induced transformations of wood smoke aerosol using single droplet studies and large-scale cloud simulation chamber experiments.

Jones is excited to return to Canada and looks forward to contributing to the atmospheric chemistry community.

Stephanie Jones

Courtesy of YFile

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Gravity of famous Newton apple tree not lost on York researchers as they plant descendants

aburtin — Thu, 05 Sep 2024 18:00:38 +0000

Media Release from September 5, 2024

York’s Newton tree descendant was the first in Ontario to take root and blossom. It’s now joined by two more seedlings.

A thunk to the head, so the myth goes, planted the seed for Sir Isaac Newton’s law of gravity, and while the law bore fruit – Gravity Day is now celebrated every Sept. 8 – so too has the original apple tree’s lineage at �첥��Ƶ.

Thought to be from the same tree that sprouted the young physicist’s imagination in 1666, a descendant of Newton’s apple tree was planted at �첥��Ƶ a quarter century ago. Although it is now leaning – giving in to the pull of gravity – it has birthed offspring donated to another research institution and its seeds have travelled into space.

One of the two new Newton apple tree descendants planted at �첥��Ƶ’s Keele Campus in what was once a secret location

Now, two more descendants planted in the courtyard outside the physics building from grafted cuttings stand together to continue a lineage that not only connects them to York’s original tree, but an academic tradition that spans much of the globe.

York Associate Professor Cody Storry, who spearheaded the grafting and planting of the new additions and who was a PhD student at the University around the time the first descendant was planted here, says: “I love the fairy tale aspect of the Newton-gravity story, but in fact, probably what happened was as Newton was looking out his window, he saw the apples falling. It’s unlikely that one knocked him on the head.”

A self-described “apple tree person,” not to mention also a gravity person as a physicist who up until about five years ago studied the subject, Storry remembers celebrating the man and the myth in his Grade 13 physics class. When York needed someone to take on the project, he was excited to take the lead. “I quickly put up my hand to be the guardian and to help propagate these new trees.”

Although, as a young physics student he didn’t pay a lot of attention to the first sapling of a Newton tree at York, he definitely thinks its pretty cool now to have original descendants on the Keele Campus, and to be part of ensuring its legacy continues. There is also another tree in a top-secret location. “I feel like the lineage is safe now,” he says. Ensuring that legacy is what was most important.

It will take a few years to see if the new plantings, or scions, will also bear fruit like York’s first tree which produces a rare, old variety of cooking apple, Flower of Kent, like Newton’s original tree. Not a great eating apple, Storry points out, but perhaps good enough for a future apple pie, or maybe some cider.

Around and round the apple tree

How did the Newton descendant first arrive at York?

Former dean of what was then York’s Faculty of Pure and Applied Science, Professor Emeritus Robert Prince, a mentor to Storry in his undergraduate years, arranged to have Newton descendant cuttings sent to York from the University of York in the United Kingdom while on an exchange visit there in 1990. If you’re confused, you’re not alone as people from all over mix up the two universities. This was after he met with that university’s Newton scholar who had experience in arranging for a descendant to be sent to the United States.

Still, it was a rather winding route. In the 1930s, new owners of Newton’s family home, Woolsthorpe Manor in Lincolnshire, saw the importance of sending cuttings of the infamous tree to Belton Park, a fruit research station in the UK’s East Malling, where they could be preserved. Cuttings were then sent to the Cambridge Botanical Gardens then on to Kew Gardens, followed by the University of York and finally to Canada They arrived in British Columbia, where they were in quarantine for about four years, before finally landing at �첥��Ƶ in Toronto.

The newest Newtonians also had a bumpy route. Their planting was delayed a few years by the COVID-19 pandemic and an Uber driver that got lost on campus. Oddly enough, it was during the Great Plague when a young Newton, then a student at Cambridge University, was home following the school’s temporary closure when he made his discovery.

From left, York Professor Emeritus Robert Prince, Associate Professor Cody Storry, former Chair of the Physics and Astronomy Department Marshall McCall and Faculty of Science Associate Dean Research and Graduate Education Vivian Saridakis at the planting of the two new Newton apple trees on the Keele Campus

Branching Out

The original Newton apple tree descendant planted at �첥��Ƶ a quarter century ago

Although the National Research Council (NRC) first tried to plant what was then thought to be a descendant of the original Newton tree in Ottawa, the trees perished in the cold of winter. A later attempt worked, but the NRC discovered some years after, through DNA testing, that they weren’t actual descendants.

When physicist Susan McCall heard the news from Marshall McCall, then her husband and Chair of the Faculty of Science’s Physics and Astronomy Department, she drove a small sapling she grew from a seed of the York apple tree descendant in their backyard to Ottawa where it still thrives.

Both York and the NRC, along with the TRIUMF physics laboratory in B.C., appear on the , although there are now an additional four young trees at Banjo Cider and in Storry’s backyard.

Sowing Seeds – a Space Odyssey

Two of the seeds collected by McCall at the time from a fruitful season accompanied astronaut and York alumnus Steve MacLean, a former student of Prince’s, into space in 2006, where a lack of gravity would have prevented Newton from developing the core of his theory, and back. They now reside in the Physics and Astronomy Department, a part of space travel history.

Although, Storry says due to the amount of radiation they would have received in space, combined with their age, the two seeds are unlikely to ever grow into trees, it’s still an interesting part of the Newton legacy story.

With respect to Gravity Day, Newton and the newest descendants, Storry says: “Gravity is a type of physics that everyone can kind of relate to in an easy way.”

That includes physics students at York who can gain their own inspiration as they stare out their classroom window at the three York-Newton trees and experience the gravity of the situation that seeded the theory they are currently learning about firsthand.

From left, Professor Emeritus Michael Boyer, Gary J. Smith, former vice-president university advancement, and former Dean of then Faculty of Pure and Applied Science Robert Prince plant the original Newton descendant at York

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Does an antimatter apple fall up or down? Scientists solve longstanding mystery

aburtin — Wed, 27 Sep 2023 16:01:51 +0000

Media Release from September 27, 2023

�첥��Ƶ is part of an international collaboration that has resolved the enigma of whether antimatter follows the rules of gravity

As Newton observed, an apple falls from the tree and hits the ground. But what would an antimatter apple do? That was the question an international collaboration with �첥��Ƶ Professor Emeritus Scott Menary set out to answer.

�첥��Ƶ Professor Emeritus Scott Menary holding an apple under an apple tree. Credit: �첥��Ƶ

Ultimately, the team is testing Einstein’s General Theory of Relativity, one of the twin pillars of 20th century physics alongside quantum mechanics. The idea was to see if General Relativity also held true for antimatter or, in this specific case, antihydrogen.

What they found is yes, antihydrogen, like hydrogen, falls down, not up.

“The result is a technical tour de force given the difficulty of measuring the effect of gravity – a force much weaker than most people realize – on just a small collection of antihydrogen atoms,” says �첥��Ƶ Professor Emeritus Scott Menary of the Faculty of Science. “If Newton had observed an anti-apple instead of an apple, he would have seen nothing unusual, as it turns out, an anti-apple would also fall down.”

The antimatter gravity measurement was carried out by the Antihydrogen Laser Physics Apparatus (ALPHA) collaboration using the new ALPHA-g apparatus now in operation at CERN, the European Organization for Nuclear Research. Menary was co-project manager of construction for ALPHA-g’s radial Time Projection Chamber (rTPC), which he also helped design. The rTPC was one of two new detectors used in the experiment to observe where the antihydrogen annihilated with matter in the apparatus.

The rTPC on the bench at CERN before being installed in ALPHA-g. Credit: CERN

The experiment works by first creating a sample of antihydrogen atoms and trapping (holding) them in an extraordinarily cold magnetic bottle. ALPHA-g physicists then released the antihydrogen by varying magnetic fields so as to witness and measure its gravitational behaviour. It was the first direct freefall measurement of the force of gravity on antimatter.

But Menary points out that they aren’t finished, “We are upgrading our apparatus, including using laser cooling, in order to improve the precision of our measurement.”

ALPHA has previously carried out precise tests of the charge and colour of antihydrogen, which to-date constitutes the sternest test of the quantum mechanical description of nature. These results combined with the new measurement on the effect of gravity on antimatter relate to one of the central questions of modern physics – what happened to all of the antimatter created in the Big Bang?

Applied physicist Pierre Grandemange coordinates the construction of the ALPHA-g apparatus at CERN in Switzerland. Credit: CERN

“Right now, we don’t have an explanation about where all the antimatter in the universe is. To find a solution for this conundrum, what we do is test the element of physics of antimatter to see if we can find an inconsistency. In this case, we tested to see if the gravitational characteristics of antihydrogen mirror those of hydrogen, which is significant because it’s never been done before,” says physics Professor Robert Thompson, associate vice-president (research) at the University of Calgary and principal investigator of the ALPHA-g Canada Foundation for Innovation Project.

ALPHA-g is an international partnership of research institutions including, on the Canadian side, �첥��Ƶ, the University of Calgary, Simon Fraser University, TRIUMF, the University of British Columbia, and the British Columbia Institute of Technology as well as post-secondary institutions and research institutes in Europe, the United Kingdom, the United States, Israel and Brazil.

"This milestone is a culmination of nearly 20 years of dedication and teamwork. The contributions of the members of ALPHA-Canada were critical to our success,” said Dr. Makoto C. Fujiwara, senior scientist, TRIUMF, and ALPHA-Canada spokesperson. "ALPHA-Canada is a pan-Canadian collaboration made up of a diverse group of students, postdoctoral scholars, academics and staff members, each who played a vital role in this project."

The finding is a significant scientific and technical achievement that marks a leap forward in the world of antimatter research.

The paper, , is published today in the journal Nature.

This is the first major result from the ALPHA-g apparatus, which was funded through the Canada Foundation for Innovation. Major contributing partners include the Government of Alberta, the British Columbia Knowledge Development Fund, the Ontario Research Fund, Carlsberg Foundation (Denmark), and UK Government funding through the University of Manchester and Swansea University.

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Observe magic of the sky over winter break and beyond

aburtin — Mon, 19 Dec 2022 19:09:31 +0000

Take in the night sky over the holiday break, and watch as some magical astronomy events unfold in December and into the new year.

Located at York’s Keele Campus, the Allan I. Carswell Observatory supports student learning and research and is a hub for public engagement and outreach. It is home to a one-metre telescope – the largest telescope on a university campus in all of Canada – and a 60-centimetre Cassegrain, both equipped with state-of-the-art electronic cameras. As well, the Observatory has five 20-centimetre telescopes available for outdoor viewing during special celestial events.

The Observatory offers a variety of free programming for the public, including public viewing sessions, group tours, our online radio show, online public viewing and more.

Here’s what to watch for in December, as suggested by Elaina A. Hyde, director, Allan I. Carswell Observatory.

Ursids meteor shower peaks on Dec. 22 and 23

Dec. 21: The December solstice will take place at 21:48 UTC. Also known as the winter solstice, it is the shortest day of the year in the northern hemisphere. In the southern hemisphere, it is the longest day of the year and is called the summer solstice.

Dec. 21: Mercury will be at its greatest elongation, which makes it a good time to try and spot the planet. Mercury will appear at its farthest distance from the sun in the evening sky.

Dec. 22/23: Ursids meteor shower peaks on Dec. 22 and 23. The Ursids meteor shower is active annually between Dec. 17 and 24. According to Hyde, the shower usually peaks around Dec. 23. At its peak, observers may be able to view as many as 10 meteors in an hour.

Dec. 23: Super new moon. This new moon takes place very close to its perigee – the point on its orbit closest to the Earth.

Events to watch for in the new year

Venus and Saturn conjunction: In January 2023, the brightest planet Venus will become easier to spot as it climbs slightly higher in the twilight sky each evening. Meanwhile, Saturn will start January 2023 high in the twilight sky. But it’ll drop closer to the horizon as January proceeds. And – on Jan. 22, 2023 – Venus and Saturn will appear to brush past each other.

Additionally at York’s Keele Campus, the Allan I. Carswell Observatory does online astronomy viewings accessible to the public on Mondays and Wednesdays.

�첥��Ƶ’s 40-cm telescope

Mondays: The �첥��Ƶniverse Radio Show is broadcast on Monday nights (9 to 10 p.m. EST October to March; 9 to 10 p.m. EDT April to September) on the online radio station astronomy.fm. Tune in every week for a new exciting broadcast about what is new in astronomy, this week in history, and amazing interviews with scientists from around the world. Running simultaneously with the �첥��Ƶniverse Radio Show is the weekly experience on YouTube. Anyone can tune in to see live images from the Observatory’s four telescopes/cameras when possible, view reduced astronomical images, and chat with Observatory staff, who are happy to answer questions. Requests for objects to observe will be entertained.

Wednesdays: Prior to the pandemic, the Observatory was open for in-person public viewing every Wednesday night. In the absence of weekly in-person public viewings, the Observatory hosts a live on its YouTube channel every Wednesday night at 7:30 p.m. This online version of public viewing is followed by a Q-and-A session with the Observatory team. In-person public viewing is only available a few days each month. Keep checking the Observatory homepage for dates.

“The next in-person viewing will be at the end of January, so bring your warmest jackets,” says Hyde.

Those who want to view old broadcasts or join in live can get the schedule with all the links from the Observatory’s new website: /science/observatory/ or join directly on YouTube at: .

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Mysterious dead cluster galaxy found in thriving ancient galaxy city

aburtin — Fri, 11 Feb 2022 13:59:43 +0000

The discovery of a massive dead cluster of galaxies in a young universe full of star producing galaxies, close to 12 billion light-years away from Earth, has surprised an international team, including researchers from �첥��Ƶ.

Adam Muzzin

York researchers discovered a large galaxy structure, also known as a protocluster, and partnered with international collaborators and researchers at the University of California, Riverside, who led the effort to explore it in further detail using the largest telescope in the world at the W. M. Keck Observatory in Hawaii.

“The Universe is filled with these clusters of galaxies. They’re everywhere,” says Professor Adam Muzzin of the Faculty of Science, �첥��Ƶ. “One of things we were looking at was these galaxies very far in the past and when you look at them in the past, they are all still forming stars, but this one is really different. It was no longer forming stars, while all its neighbours were.”

The newly discovered growing galactic metropolis, named MAGAZ3NE J095924+022537, is a massive newborn galaxy cluster consisting of at least 38 member galaxies. When viewing the galaxy, scientists are looking back in time to when this universe was less than two billion years old.

Image caption: In the early Universe, all previously discovered distant protoclusters like, for example, “The Spiderweb” (left: artist’s impression) are full of vigorously star-forming galaxies. In contrast, the newly-discovered protocluster “MAGAZ3NE J095924+022537” contains a high fraction of red and dead galaxies like the nearby “Coma” cluster (right). The discovery of an ancient cluster containing galaxies which resemble those found in modern clusters was a huge surprise. Image credits: Spiderweb: M. Kornmesser/ESO; Coma: Russ Carroll, Robert Gendler, & Bob Franke/Dan Zowada Memorial Observatory.

“What we were trying to do initially is see how far in the past can we see these massive galaxies and whether or not they have started forming or accumulating this cluster like structure,” says York Visiting Professor Cemile Marsan. “What we found is surprising. Not only do we see an over density of galaxies around this one massive galaxy, we also found that they have already advanced quite a bit in their evolution.”

Cemile Marsan

Researchers weren’t expecting to see this dying out of galaxies at this epoch in time. Galaxy clusters grow over time under gravity and, in the present-day universe, can contain hundreds or even thousands of galaxies, as well as hot gas and dark matter. As time goes by, their galaxies burn through the fuel available and evolve from vigorously star-forming galaxies into red and dead galaxies.

“In the early universe, all protoclusters discovered until now are full of vigorously star-forming galaxies,” said Ian McConachie, a graduate student at the University of California, Riverside, and the lead author of the research paper. “But incredibly, unlike all of the other protoclusters which have been found at this epoch, many galaxies in MAGAZ3NE J0959 appear to have already stopped forming stars.”

The finding raises many questions and could test the current paradigm of how protoclusters are formed, especially if more dead cluster galaxies are found. In the future, Muzzin and Marsan hope to be able to explore further using the new as there could be others like it out there that have yet to be found.

How do you find something like this?

The team used spectroscopic observations from the W. M. Keck Observatory’s Multi-Object Spectrograph for Infrared Exploration, or MOSFIRE, to make detailed measurements of MAGAZ3NE J0959 and precisely quantify its distances.

“There is a degree of serendipity about it. It’s like with archeologists – you see a building sticking out and you start digging, and sometimes it’s just a wall and sometimes it’s an entire city with pots and pans,” says Muzzin. “You don’t know until you actually start digging and that’s the same with astronomy. Sometimes you look and there isn’t much there, and then other times you find something surprising and different.”

Closely associated to the question of how ultramassive galaxies (UMGs) form, is the question of the environment in which they form. Are they always found in over dense environments like protoclusters or can they also form in isolation? Next, the team plans to study the neighbourhood of all of the other UMGs in the MAGAZ3NE (Massive Ancient Galaxies At z>3 NEar-infrared) survey to answer this question.

“We don’t think we’ve mapped out the whole structure. We’ve kind of looked at one corner of it and saw an over density of galaxies, but there are the other sides of it we haven’t looked at,” says Marsan, adding, “It’s one of the most distant structures discovered – and the oldest in such a young universe by far – so that’s what sets it apart.”

The paper, “,” is published in the Astrophysical Journal.

Other researchers involved in the study are Gillian Wilson of University of California, Riverside; Benjamin Forrest of University of California, Davis; Michael Cooper of UC Irvine; Marianna Annunziatella and Danilo Marchesini of Tufts University; Jeffrey Chan and Mohamed Abdullah of UCR; Percy Gomez of Keck Observatory; Paolo Saracco of the Astronomical Observatory of Brera, Italy; Julie Nantais of Andrés Bello National University, Santiago, Chile.

The study was supported by grants from the National Science Foundation and NASA.

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