Tag Archives: University of Warwick

Graphene and its magnetism

I have two news bits about graphene and magnetism. If I understood what I was reading, one is more focused on applications and the other is focused on further establishing the field of valleytronics.

University of Cambridge and superconductivity

A February 8, 2021 news item on Nanowerk announces ‘magnetic work’ from the University of Cambridge (Note: A link has been removed),

The researchers, led by the University of Cambridge, were able to control the conductivity and magnetism of iron thiophosphate (FePS3), a two-dimensional material which undergoes a transition from an insulator to a metal when compressed. This class of magnetic materials offers new routes to understanding the physics of new magnetic states and superconductivity.

Using new high-pressure techniques, the researchers have shown what happens to magnetic graphene during the transition from insulator to conductor and into its unconventional metallic state, realised only under ultra-high pressure conditions. When the material becomes metallic, it remains magnetic, which is contrary to previous results and provides clues as to how the electrical conduction in the metallic phase works. The newly discovered high-pressure magnetic phase likely forms a precursor to superconductivity so understanding its mechanisms is vital.

Their results, published in the journal Physical Review X, also suggest a way that new materials could be engineered to have combined conduction and magnetic properties, which could be useful in the development of new technologies such as spintronics, which could transform the way in which computers process information.

A February 8, 2021 University of Cambridge press release (also on EurekAlert), which originated the news item, delves into the topic,

Properties of matter can alter dramatically with changing dimensionality. For example, graphene, carbon nanotubes, graphite and diamond are all made of carbon atoms, but have very different properties due to their different structure and dimensionality.

“But imagine if you were also able to change all of these properties by adding magnetism,” said first author Dr Matthew Coak, who is jointly based at Cambridge’s Cavendish Laboratory and the University of Warwick. “A material which could be mechanically flexible and form a new kind of circuit to store information and perform computation. This is why these materials are so interesting, and because they drastically change their properties when put under pressure so we can control their behaviour.”

In a previous study by Sebastian Haines of Cambridge’s Cavendish Laboratory and the Department of Earth Sciences, researchers established that the material becomes a metal at high pressure, and outlined how the crystal structure and arrangement of atoms in the layers of this 2D material change through the transition.

“The missing piece has remained however, the magnetism,” said Coak. “With no experimental techniques able to probe the signatures of magnetism in this material at pressures this high, our international team had to develop and test our own new techniques to make it possible.”

The researchers used new techniques to measure the magnetic structure up to record-breaking high pressures, using specially designed diamond anvils and neutrons to act as the probe of magnetism. They were then able to follow the evolution of the magnetism into the metallic state.

“To our surprise, we found that the magnetism survives and is in some ways strengthened,” co-author Dr Siddharth Saxena, group leader at the Cavendish Laboratory. “This is unexpected, as the newly-freely-roaming electrons in a newly conducting material can no longer be locked to their parent iron atoms, generating magnetic moments there – unless the conduction is coming from an unexpected source.”

In their previous paper, the researchers showed these electrons were ‘frozen’ in a sense. But when they made them flow or move, they started interacting more and more. The magnetism survives, but gets modified into new forms, giving rise to new quantum properties in a new type of magnetic metal.

How a material behaves, whether conductor or insulator, is mostly based on how the electrons, or charge, move around. However, the ‘spin’ of the electrons has been shown to be the source of magnetism. Spin makes electrons behave a bit like tiny bar magnets and point a certain way. Magnetism from the arrangement of electron spins is used in most memory devices: harnessing and controlling it is important for developing new technologies such as spintronics, which could transform the way in which computers process information.

“The combination of the two, the charge and the spin, is key to how this material behaves,” said co-author Dr David Jarvis from the Institut Laue-Langevin, France, who carried out this work as the basis of his PhD studies at the Cavendish Laboratory. “Finding this sort of quantum multi-functionality is another leap forward in the study of these materials.”

“We don’t know exactly what’s happening at the quantum level, but at the same time, we can manipulate it,” said Saxena. “It’s like those famous ‘unknown unknowns’: we’ve opened up a new door to properties of quantum information, but we don’t yet know what those properties might be.”

There are more potential chemical compounds to synthesise than could ever be fully explored and characterised. But by carefully selecting and tuning materials with special properties, it is possible to show the way towards the creation of compounds and systems, but without having to apply huge amounts of pressure.

Additionally, gaining fundamental understanding of phenomena such as low-dimensional magnetism and superconductivity allows researchers to make the next leaps in materials science and engineering, with particular potential in energy efficiency, generation and storage.

As for the case of magnetic graphene, the researchers next plan to continue the search for superconductivity within this unique material. “Now that we have some idea what happens to this material at high pressure, we can make some predictions about what might happen if we try to tune its properties through adding free electrons by compressing it further,” said Coak.

“The thing we’re chasing is superconductivity,” said Saxena. “If we can find a type of superconductivity that’s related to magnetism in a two-dimensional material, it could give us a shot at solving a problem that’s gone back decades.”

The citation and link to the paper are at the end of this blog posting.

Aalto University’s valleytronics

Further north in Finland, researchers at Aalto University make some advances applicable to the field of valleytronics, from a February 5, 2021 Aalto University press release (also on EurekAltert but published February 8, 2021),

Electrons in materials have a property known as ‘spin’, which is responsible for a variety of properties, the most well-known of which is magnetism. Permanent magnets, like the ones used for refrigerator doors, have all the spins in their electrons aligned in the same direction. Scientists refer to this behaviour as ferromagnetism, and the research field of trying to manipulate spin as spintronics.

Down in the quantum world, spins can arrange in more exotic ways, giving rise to frustrated states and entangled magnets. Interestingly, a property similar to spin, known as “the valley,” appears in graphene materials. This unique feature has given rise to the field of valleytronics, which aims to exploit the valley property for emergent physics and information processing, very much like spintronics relies on pure spin physics.

‘Valleytronics would potentially allow encoding information in the quantum valley degree of freedom, similar to how electronics do it with charge and spintronics with the spin.’ Explains Professor Jose Lado, from Aalto’s Department of applied physics, and one of the authors of the work. ‘What’s more, valleytronic devices would offer a dramatic increase in the processing speeds in comparison with electronics, and with much higher stability towards magnetic field noise in comparison with spintronic devices.’

Structures made of rotated, ultra-thin materials provide a rich solid-state platform for designing novel devices. In particular, slightly twisted graphene layers have recently been shown to have exciting unconventional properties, that can ultimately lead to a new family of materials for quantum technologies. These unconventional states which are already being explored depend on electrical charge or spin. The open question is if the valley can also lead to its own family of exciting states.

Making materials for valleytronics

For this goal, it turns out that conventional ferromagnets play a vital role, pushing graphene to the realms of valley physics. In a recent work, Ph.D. student Tobias Wolf, together with Profs. Oded Zilberberg and Gianni Blatter at ETH Zurich, and Prof. Jose Lado at Aalto University, showed a new direction for correlated physics in magnetic van der Waals materials.

The team showed that sandwiching two slightly rotated layers of graphene between a ferromagnetic insulator provides a unique setting for new electronic states. The combination of ferromagnets, graphene’s twist engineering, and relativistic effects force the “valley” property to dominate the electrons behaviour in the material. In particular, the researchers showed how these valley-only states can be tuned electrically, providing a materials platform in which valley-only states can be generated. Building on top of the recent breakthrough in spintronics and van der Waals materials, valley physics in magnetic twisted van der Waals multilayers opens the door to the new realm of correlated twisted valleytronics.

‘Demonstrating these states represents the starting point towards new exotic entangled valley states.’ Said Professor Lado, ‘Ultimately, engineering these valley states can allow realizing quantum entangled valley liquids and fractional quantum valley Hall states. These two exotic states of matter have not been found in nature yet, and would open exciting possibilities towards a potentially new graphene-based platform for topological quantum computing.’

Citations and links

Here’s a link to and a citation for the University of Cambridge research,

Emergent Magnetic Phases in Pressure-Tuned van der Waals Antiferromagnet FePS3 by Matthew J. Coak, David M. Jarvis, Hayrullo Hamidov, Andrew R. Wildes, Joseph A. M. Paddison, Cheng Liu, Charles R. S. Haines, Ngoc T. Dang, Sergey E. Kichanov, Boris N. Savenko, Sungmin Lee, Marie Kratochvílová, Stefan Klotz, Thomas C. Hansen, Denis P. Kozlenko, Je-Geun Park, and Siddharth S. Saxena. Phys. Rev. X 11, 011024 DOI: https://doi.org/10.1103/PhysRevX.11.011024 Published 5 February 2021

This article appears to be open access.

Here’s a link to and a citation for the Aalto University research,

Spontaneous Valley Spirals in Magnetically Encapsulated Twisted Bilayer Graphene by Tobias M. R. Wolf, Oded Zilberberg, Gianni Blatter, and Jose L. Lado. Phys. Rev. Lett. 126, 056803 DOI: https://doi.org/10.1103/PhysRevLett.126.056803 Published 4 February 2021

This paper is behind a paywall.

Get better protection from a sunscreen with a ‘flamenco dancing’ molecule?

Caption: illustrative image for the University of Warwick research on ‘Flamenco dancing’ molecule could lead to better-protecting sunscreen created by Dr. Michael Horbury. Credit:: created by Dr Michael Horbury

There are high hopes (more about why later) for a plant-based ‘flamenco dancing molecule’ and its inclusion in sunscreens as described in an October 18, 2019 University of Warwick press release (also on EurekAlert),

A molecule that protects plants from overexposure to harmful sunlight thanks to its flamenco-style twist could form the basis for a new longer-lasting sunscreen, chemists at the University of Warwick have found, in collaboration with colleagues in France and Spain. Research on the green molecule by the scientists has revealed that it absorbs ultraviolet light and then disperses it in a ‘flamenco-style’ dance, making it ideal for use as a UV filter in sunscreens.

The team of scientists report today, Friday 18th October 2019, in the journal Nature Communications that, as well as being plant-inspired, this molecule is also among a small number of suitable substances that are effective in absorbing light in the Ultraviolet A (UVA) region of wavelengths. It opens up the possibility of developing a naturally-derived and eco-friendly sunscreen that protects against the full range of harmful wavelengths of light from the sun.

The UV filters in a sunscreen are the ingredients that predominantly provide the protection from the sun’s rays. In addition to UV filters, sunscreens will typically also include:

Emollients, used for moisturising and lubricating the skin
Thickening agents
Emulsifiers to bind all the ingredients
Water
Other components that improve aesthetics, water resistance, etc.

The researchers tested a molecule called diethyl sinapate, a close mimic to a molecule that is commonly found in the leaves of plants, which is responsible for protecting them from overexposure to UV light while they absorb visible light for photosynthesis.

They first exposed the molecule to a number of different solvents to determine whether that had any impact on its (principally) light absorbing behaviour. They then deposited a sample of the molecule on an industry standard human skin mimic (VITRO-CORNEUM®) where it was irradiated with different wavelengths of UV light. They used the state-of-the-art laser facilities within the Warwick Centre for Ultrafast Spectroscopy to take images of the molecule at extremely high speeds, to observe what happens to the light’s energy when it’s absorbed in the molecule in the very early stages (millionths of millionths of a second). Other techniques were also used to establish longer term (many hours) properties of diethyl sinapate, such as endocrine disruption activity and antioxidant potential.

Professor Vasilios Stavros from the University of Warwick, Department of Chemistry, who was part of the research team, explains: “A really good sunscreen absorbs light and converts it to harmless heat. A bad sunscreen is one that absorbs light and then, for example, breaks down potentially inducing other chemistry that you don’t want. Diethyl sinapate generates lots of heat, and that’s really crucial.”

When irradiated the molecule absorbs light and goes into an excited state but that energy then has to be disposed of somehow. The team of researchers observed that it does a kind of molecular ‘dance’ a mere 10 picoseconds (ten millionths of a millionth of a second) long: a twist in a similar fashion to the filigranas and floreos hand movements of flamenco dancers. That causes it to come back to its original ground state and convert that energy into vibrational energy, or heat.

It is this ‘flamenco dance’ that gives the molecule its long-lasting qualities. When the scientists bombarded the molecule with UVA light they found that it degraded only 3% over two hours, compared to the industry requirement of 30%.

Dr Michael Horbury, who was a Postgraduate Research Fellow at The University Warwick when he undertook this research (and now at the University of Leeds) adds: “We have shown that by studying the molecular dance on such a short time-scale, the information that you gain can have tremendous repercussions on how you design future sunscreens.
Emily Holt, a PhD student in the Department of Chemistry at the University of Warwick who was part of the research team, said: “The next step would be to test it on human skin, then to mix it with other ingredients that you find in a sunscreen to see how those affect its characteristics.”

Professor Florent Allais and Dr Louis Mouterde, URD Agro-Biotechnologies Industrielles at AgroParisTech (Pomacle, France) commented: “What we have developed together is a molecule based upon a UV photoprotective molecule found in the surface of leaves on a plant and refunctionalised it using greener synthetic procedures. Indeed, this molecule has excellent long-term properties while exhibiting low endocrine disruption and valuable antioxidant properties.”

Professor Laurent Blasco, Global Technical Manager (Skin Essentials) at Lubrizol and Honorary Professor at the University of Warwick commented: “In sunscreen formulations at the moment there is a lack of broad-spectrum protection from a single UV filter. Our collaboration has gone some way towards developing a next generation broad-spectrum UV filter inspired by nature. Our collaboration has also highlighted the importance of academia and industry working together towards a common goal.”

Professor Vasilios Stavros added, “Amidst escalating concerns about their impact on human toxicity (e.g. endocrine disruption) and ecotoxicity (e.g. coral bleaching), developing new UV filters is essential. We have demonstrated that a highly attractive avenue is ‘nature-inspired’ UV filters, which provide a front-line defence against skin cancer and premature skin aging.”

Here’s a link to and a citation for the paper,

Towards symmetry driven and nature inspired UV filter design by Michael D. Horbury, Emily L. Holt, Louis M. M. Mouterde, Patrick Balaguer, Juan Cebrián, Laurent Blasco, Florent Allais & Vasilios G. Stavros. Nature Communications volume 10, Article number: 4748 (2019) DOI: https://doi.org/10.1038/s41467-019-12719-z

This paper is open access.

Why the high hopes?

Briefly (the long story stretches over 10 years), the most recommended sunscreens today (2020) are ‘mineral-based’. This is painfully amusing because civil society groups (activists) such as Friends of the Earth (in particular the Australia chapter under Georgia Miller’s leadership) and Canada’s own ETC Group had campaigned against these same sunscreen when they were billed as being based on metal oxide nanoparticles such zinc oxide and/or titanium oxide. The ETC Group under Pat Roy Mooney’s leadership didn’t press the campaign after an initial push. As for Australia and Friend of the Earth, their anti-metallic oxide nanoparticle sunscreen campaign didn’t work out well as I noted in a February 9, 2012 posting and with a follow-up in an October 31, 2012 posting.

The only civil society group to give approval (very reluctantly) was the Environmental Working Group (EWG) as I noted in a July 9, 2009 posting. They had concerns about the fact that these ingredients are metallic but after a thorough of then available research, EWG gave the sunscreens a passing grade and noted, in their report, that they had more concerns about the use of oxybenzone in sunscreens. That latter concern has since been flagged by others (e.g., the state of Hawai’i) as noted in my July 6, 2018 posting.

So, rebranding metallic oxides as minerals has allowed the various civil society groups to support the very same sunscreens many of them were advocating against.

In the meantime, scientists continue work on developing plant-based sunscreens as an improvement to the ‘mineral-based’ sunscreens used now.

Shipwrecks being brought back to life with ‘smart nanotech’

The American Chemical Society (ACS) is holding its 256th meeting from August 19 – 22, 2018 in Boston, Massachusetts, US. This August 21, 2018 news item on Nanowerk announces a ‘shipwreck’ presentation at the meeting,

Thousands of shipwrecks litter the seafloor all over the world, preserved in sediments and cold water. But when one of these ships is brought up from the depths, the wood quickly starts deteriorating. Today, scientists report a new way to use “smart” nanocomposites to conserve a 16th-century British warship, the Mary Rose, and its artifacts. The new approach could help preserve other salvaged ships by eliminating harmful acids without damaging the wooden structures themselves.

An August 21, 2018 ACS press release (also on EurekAlert), which originated the news item, delves further into the research and scientists’ after hours (?) activities,

“This project began over a glass of wine with Eleanor Schofield, Ph.D., who is head of conservation at the Mary Rose Trust,” recalls Serena Corr, Ph.D., the project’s principal investigator. “She was working on techniques to preserve the wood hull and assorted artifacts and needed a way to direct the treatment into the wood. We had been working with functional magnetic nanomaterials for applications in imaging, and we thought we might be able to apply this technology to the Mary Rose.”

The Mary Rose sank in 1545 off the south coast of England and remained under the seabed until she was salvaged in 1982, along with over 19,000 artifacts and pieces of timber. About 40 percent of the original structure survived. The ship and its artifacts give unique insights into Tudor seafaring and what it was like to live during that period. A state-of-the-art museum in Portsmouth, England, displays the ship’s hull and artifacts. A video about the ship and its artifacts can be viewed here.

While buried in the seabed, sulfur-reducing marine bacteria migrated into the wood of the Mary Rose and produced hydrogen sulfide. This gas reacted with iron ions from corroded fixtures like cannons to form iron sulfides. Although stable in low-oxygen environments, sulfur rapidly oxidizes in regular air in the presence of iron to form destructive acids. Corr’s goal was to avoid acid production by removing the free iron ions.

Once raised from the seabed, the ship was sprayed with cold water, which stopped it from drying out and prevented further microbial activity. The conservation team then sprayed the hull with different types of polyethylene glycol (PEG), a common polymer with a wide range of applications, to replace the water in the cellular structure of the wood and strengthen its outer layer.

Corr and her postdoctoral fellow Esther Rani Aluri, Ph.D., and Ph.D. candidate Enrique Sanchez at the University of Glasgow are devising a new family of tiny magnetic nanoparticles to aid in this process, in collaboration with Schofield and Rachel O’Reilly, Ph.D., at the University of Warwick. In their initial step, the team, led by Schofield, used synchrotron techniques to probe the nature of the sulfur species before turning the PEG sprays off, and then periodically as the ship dried. This was the first real-time experiment to closely examine  the evolution of oxidized sulfur and iron species. This accomplishment has informed efforts to design new targeted treatments for the removal of these harmful species from the Mary Rose wood.

The next step will be to use a nanocomposite based on core magnetic iron oxide nanoparticles that include agents on their surfaces that can remove the ions. The nanoparticles can be directly applied to the porous wood structure and guided to particular areas of the wood using external magnetic fields, a technique previously demonstrated for drug delivery. The nanocomposite will be encompassed in a heat-responsive polymer that protects the nanoparticles and provides a way to safely deliver them to and from the wood surface. A major advantage of this approach is that it allows for the complete removal of free iron and sulfate ions from the wood, and these nanocomposites can be tuned by tweaking their surfaces.

With this understanding, Corr notes, “Conservators will have, for the first time, a state-of-the-art quantitative and restorative method for the safe and rapid treatment of wooden artifacts. We plan to then transfer this technology to other materials recovered from the Mary Rose, such as textiles and leather.”

The researchers acknowledge funding from the Mary Rose Trust and the Leverhulme Trust.

There is a video about the Mary Rose produced by Agence France Presse (AFP) and published on Youtube in May 2013,

Here’s the text from AFP Mary Rose entry on Youtube,

The relics from the Mary Rose, the flagship of England’s navy when it sank in 1545 as a heartbroken king Henry VIII watched from the shore, have finally been reunited with the famous wreck in a new museum offering a view of life in Tudor times. Duration: 02:35

One more thing: Canadian shipwrecks

We don’t have a ‘Henry VIII’ story or ‘smart nano and shipwrecks’ story but we do have a federal agency devoted to underwater archaeology, Parks Canada Underwater Archaeology webpage,

Underwater archaeology deals with archaeological sites found below the surface of oceans, rivers, and lakes and on the foreshore. In addition to shipwrecks, underwater archaeologists study submerged aboriginal sites such as fish weirs and middens; remains of historic structures such as wharves, canal locks, and marine railways; sunken aircraft; and other submerged cultural heritage resources.

Underwater archaeology shares the same methodology and principles as archaeology carried out on land sites. All archaeology involves the careful study of artefacts, structures and features to reconstruct and explain the lives of people in the past. However, because it is carried out in a more challenging environment, underwater archaeological fieldwork is more complex than land archaeology.

Specialized techniques and equipment are required to work productively underwater. Staying warm during long dives is a constant concern, so underwater archaeologists often use masks that cover their entire faces, dry suits worn over layers of warm clothing, or in cases where the water is extremely cold, such as the excavation in Red Bay (Labrador), wet suits supplied with a flow of hot water. Underwater communication systems are used to talk to people on the surface or to other divers. Removing sediments covering underwater sites requires the controlled use of specially designed equipment such as suction airlifts and small dredges. Recording information underwater presents its own challenges. Special underwater paper is used for notes and drawings, while photo and video cameras are placed in waterproof housings.

Underwater archaeological fieldwork includes remote-sensing surveys using geophysical techniques, diving surveys to locate and map sites, site monitoring, and excavation. The success of an underwater archaeological project rests on accurate documentation of all aspects of the process. Meticulous mapping and recording are particularly essential when excavation is required, as artefacts and other physical evidence are permanently removed from their original contexts. Archaeologists aim to be able to reconstruct the entire site from the records they generate during fieldwork.

Underwater archeology with Marc-André Bernier

Current position:00:00:00

Total time:00:02:27

There’s also a podcast interview with Marc-André Bernier where he discusses an important Canadian shipwreck, from the Library and Archives Canada, Underwater Canada: Investigating Shipwrecks webpage (podcast length 27:25), here’s the transcript for those who prefer reading,

Shipwrecks have stirred up interest in Canada’s maritime heritage for many decades. 2014 marks the 100th anniversary of the sinking of the Empress of Ireland, one of Canada’s worst maritime disasters.

In this episode, Marc-André Bernier, Chief of Parks Canada’s Underwater Archaeology Service, joins us to discuss shipwrecks, their importance in Canadian history, and how LAC plays an important role in researching, discovering and investigating them.

Podcast Transcript

Underwater Canada: Investigating Shipwrecks

Jessica Ouvrard: Welcome to “Discover Library and Archives Canada: Your History, Your Documentary Heritage.” I’m your host, Jessica Ouvrard. Join us as we showcase the treasures from our vaults; guide you through our many services; and introduce you to the people who acquire, safeguard and make known Canada’s documentary heritage.

Canada has a rich maritime history filled with many tragedies, from small boats [lost] in the Great Lakes, to the sinking of the Empress of Ireland in the St. Lawrence River, to Sir John Franklin’s doomed expeditions in the Arctic. The shipwrecks capture our imaginations and evoke images of tragedy, heroism, mystery and discovery. 2014 also marks the 100th anniversary of the sinking of the Empress of Ireland.

Marc-André Bernier, Chief of Parks Canada’s Underwater Archaeology Service, is joining us to discuss shipwrecks and their significance in Canada’s history, and LAC’s important role in the research, discovery and investigation of these shipwrecks.

Hello, Marc-André Bernier. Thank you for coming today.

Marc-André Bernier: My pleasure. Hello to you.

JO: For those who don’t know much about underwater archaeology, can you explain what it is and the risks and challenges that it presents?

MAB: I’ll start with the challenges rather than the risks, because there are obviously risks, but we try to minimize them. Diving is inherently risky. But I’ll start with the challenges because they are, to a certain extent, what characterize underwater archaeology.

We face a series of challenges that are more complicated, that make our work much more complicated than terrestrial archaeology. We work on water and underwater, and our working conditions are dictated by what happens outside, by nature. We can’t work every day on the water, especially if our work involves the sea or the ocean, for example. And when we work underwater, we have to deal with constraints in terms of time and sometimes visibility. That means that we have to be extremely well organized. Preparation is crucial. Logistics are crucial.

In terms of preparation, we need to properly prepare our research using archives and so on, but we also have to be prepared in terms of knowing what’s going on in the field. We need to know the environmental conditions and diving conditions, even when we can’t dive. Increasingly, the work involves heading into deeper areas that can only be reached by robots, by remotely operated equipment. So we have to be able to adapt.

We have to be very precise and very organized because sometimes we have only a few minutes to access a site that will tell us many historical secrets. So we have to come very well prepared.

And when we dive, we’re working in a foreign environment. We have to be good divers, yes, but we also have to have access to tools that will give us access to information. We have to take into account currents, darkness, and so on. The work is really very challenging. But with the rapid development of new technologies in recent years, we have access to more and more tools. We do basically the same work as archaeologists on land. However, the work is done in a completely different environment.

JO: A bit hostile in fact.

MAB: A bit hostile, but with sites, objects and information that are not accessible elsewhere. So there’s an opportunity to learn about history in a different way, and in some cases on a much larger scale.

JO: With all the maritime traffic in Canada, there must have been many accidents. Can you talk about them and give us an idea of the number?

MAB: People don’t realize that we’re a maritime country. We are a country that has evolved and developed around water. This was true even before the Europeans arrived. The First Nations often travelled by water. That travel increased or developed differently, if you will, when the Europeans arrived.

The St. Lawrence River, for example, and the Atlantic provinces were the point of entry and the route. We refer to different waterways, such as the Ottawa and Richelieu rivers. They constituted the route. So, there was heavy traffic, which meant many accidents. We’re talking about probably tens of thousands of shipwrecks if we include the Great Lakes and all the coasts of Canada. Since Canada has the longest coastline in the world, there is potential for shipwrecks. Only a small number of those shipwrecks have been found, but some are very significant and extremely impressive as well.

JO: Are there also many military ships, or is it more…?

MAB: That’s another thing that people don’t realize. There have been many military confrontations in Canadian waters, dating back to the New France era, or when Phips (Sir William Phips) arrived at Quebec City in 1690 and laid siege to the city. He arrived by ship and lost ships when he returned. During the Conquest, there were naval confrontations in Louisbourg, Nova Scotia; in Chaleur Bay; and even at Quebec City. Then, in the War of 1812, the Great Lakes were an extremely important maritime theatre of war in terms of naval battles. There are a number of examples in the Richelieu River.

Then we have the Second World War, with ships and German submarines. We all know the stories of the submarines that came inside the Gulf. So there are many military shipwrecks, from the New France era onward.

JO: What were the most significant shipwrecks in Canada? Have all the shipwrecks been found or…?

MAB: No. There are still shipwrecks that remain to be found. These days at Parks Canada, we’ve been looking for two of the shipwrecks that are considered among the most significant in the country: the HMS Erebus and the HMS Terror, Sir John Franklin’s ships lost in the Arctic. Franklin left England in 1845 to find the Northwest Passage, and he was never heard from again. Those are examples of significant shipwrecks that haven’t been found.

However, significance is always relative. A shipwreck may be very significant, especially if there is loss of life. It’s a tragic event that is deeply affecting. There are many shipwrecks that may not be seen as having national historic significance. However, at the local level, they are tragic stories that have very deep significance and that have profoundly affected an area.

That being said, there are ships that bear witness to memorable moments in the history of our country. Among the national historic sites of shipwrecks are, if we go back, the oldest shipwrecks: the Basque wrecks at Red Bay, Labrador, where whales were hunted in the 16th century. It’s even a UNESCO world heritage site. Then, from the New France era, there’s the Corossol from 1693 and the Phips wrecks from 1690. These are very significant shipwrecks.

Also of great significance are the Louisbourg shipwrecks, the battle site, the Battle of the Restigouche historic site, as well as shipwrecks such as the Hamilton and Scourge from the War of 1812. For all practical purposes, those shipwrecks are intact at the bottom of Lake Ontario. And the Franklin shipwrecks-even if they still haven’t been found-have been declared of national historic significance.

So there’s a wide range of shipwrecks that are significant, but there are thousands and thousands of shipwrecks that have significance. A shipwreck may also be of recreational significance. Some shipwrecks may be a little less historically significant, but for divers, they are exceptional sites for appreciating history and for having direct contact with history. That significance matters.

JO: Yes, they have a bit of a magical side.

MAB: They have a very magical side. When we dive shipwrecks, we travel through history. They give us direct access to our past.

JO: Yes. I imagine that finding a shipwreck is a bit like finding a needle in a haystack?

MAB: It can sometimes be a needle in a haystack, but often it’s by chance. Divers will sometimes stumble upon remains, and it leads to the discovery of a shipwreck. But usually, when we’re looking for a shipwreck, we have to start at the beginning and go to the source. We have to begin with the archives. We have to start by doing research, trying to find every small clue because searching in water over a large area is very difficult and complicated. We face logistical and environmental obstacles in our working conditions. It’s also expensive. We need to use ships and small boats.

There are different ways to find shipwrecks. At one extreme is a method that is technologically very simple. We dive and systematically search an area, if it’s not too deep. At the other extreme, we use the most sophisticated equipment. Today we have what we call robotic research vehicles. It is as sophisticated as launching the device, which is a bit like a self-guided torpedo. We launch it and recover it a few hours later. It carries out a sonar sweep of the bottom along a pre-programmed path. Between the two, we have a range of methods.

Basically, we have to properly define the boundaries of the area. It’s detective work. We have to try to recreate the events and define our search area, then use the proper equipment. The side-scan sonar gives us an image, and magnetometers detect metal. We have to decide which of the tools we’ll use. If we don’t do the research beforehand, we’ll lose a great deal of time.

JO: Have you used the LAC collections in your research, and what types of documents have you found?

MAB: Yes, as often as possible. We try to use the off-site archives, but it’s important to have access to the sources. Our research always starts with the archives. As for the types of documents, I mentioned the Basque documents that were collected through Library and Archives Canada. I’ve personally used colonial archives a lot. For the Corossol sinking in 1693, I remember looking at documents and correspondence that talked about the French recovery from the shipwreck the year after 1693, and the entire Phips epic.

At LAC, there’s a copy of the paintings of Creswell [Samuel Gurney Cresswell], who was an illustrator, painter, and also a lieutenant, in charge of doing illustrations during the HMS Investigator’s journey through the Arctic. So there’s a wide variety of documents, and sometimes we are surprised by the personal correspondence, which gives us details that official documents can’t provide.

JO: How do these documents help you in your research?

MAB: The archival records are always surprising. They help us in every respect. You have to see archaeology as detective work. Every detail is significant. It can be the change in topographical names on old maps that refer to events. There are many “Wreck Points” or “Pointe à la barque,” “Anse à la barque,” and so on. They refer to events. People named places after events. So we can always be surprised by bits of information that seem trivial at first.

It ranges from information on the sites and on the events that led to a shipwreck, to what happened after the sinking and what happened overall. What we want is not only to understand an event, but also to understand the event in the larger context of history, such as the history of navigation. Sometimes, the records provide that broader information.

It ranges from the research information to the analysis afterward: what we have, what we found, what it means and what it says about our history. That’s where the records offer limitless possibilities. We always have surprises. That’s why we enjoy coming to the archives, because we never know what we’ll discover.

JO: Yes, it’s always great to open a box.

MAB: It’s like Christmas. It’s like Christmas when we start delving into archival records, and it’s a sort of prelude to what happens in archaeology. When we reach a site, we’re always excited by what the site has to offer. But we have to be prepared to understand it. That’s why preparation using archives is extremely important to our work.

JO: In terms of LAC sources, do you often look at historical maps? Do you look at the different ones, because we have quite a large collection…

MAB: Quite exceptional, yes.

JO: … from the beginning until now?

MAB: Yes. They provide a lot of information, and we use them, like all sources, as much as possible. We look for different things on the maps. Obviously, we look for places that may show shipwreck locations. These maps may also show the navigation corridors or charts. The old charts show anchorages and routes. They help us recreate navigation habits, which helps us understand the navigation and maritime mindset of the era and gives us clues as to where the ships went and where they were lost.

These maps give us that type of information. They also give us information on the topography and the names of places that have changed over the years. Take the example of the Corossol in the Sept-Îles bay. One of the islands in that bay is called Corossol. For years, people looked for the French ship, the Corossol, near that island. However, Manowin Island was also called Corossol at that time and its name changed. So in the old maps, we traced the origin, and the ship lies much closer to that island. Those are some of the clues.

We also have magnificent maps. One in particular comes to mind. It was created in the 19th century on the Îles-de-la-Madeleine by an insurance company agent who made a wreck map of all the shipwrecks that he knew of. To us, that’s like candy. It’s one of the opportunities that maps provide. Maps are magnificent even if we don’t find clues. Just to admire them-they’re absolutely magnificent.

JO: From a historical point of view, why is it important to study shipwrecks?

MAB: Shipwrecks are in fact a microcosm. They represent a small world. During the time of the voyage, there was a world of its own inside the ship. That in itself is interesting. How did people live on board? What were they carrying? These are clues. The advantage of a shipwreck is that it’s like a Polaroid, a fixed image of a specific point in time. When we study a city such as Quebec City that has been continuously occupied, sometimes it’s difficult to see the separation between eras, or even between events. A shipwreck shows a specific time and specific place.

JO: And it’s frozen in time.

MAB: And it’s frozen in time. So here’s an image, in 1740, what did we have? Of course, we find objects made in other eras that were still in use in that time period. But it really gives us a fixed image, a capsule. We often have an image of a time capsule. It’s very useful, because it’s very rare to have these mini Pompeiis, and we have them underwater. It’s absolutely fascinating and interesting. It’s one of the contributions of underwater archaeology.

The other thing is that we don’t necessarily find the same type of material underwater as on land. The preservation conditions are completely different. On land, we find a great deal of metal. Iron stays fairly well preserved. But there’s not much organic material, unless the environment is extremely humid or extremely dry. Underwater, organic materials are very well preserved, especially if the sedimentation is fairly quick. I remember finding cartouches from 1690 that still had paper around them. So the preservation conditions are absolutely exceptional.

That’s why it’s important. The shipwrecks give us unique information that complements what we find on land, but they also offer something that can’t be found elsewhere.

JO: I imagine that there are preservation problems once it’s…

MAB: And that’s the other challenge.

JO: Yes, certainly.

MAB: If an object is brought up, we have to be ready to take action because it starts to degrade the moment we move it…

JO: It comes into contact with oxygen.

MAB: … Yes, but even when we move it, we expose it to a new corrosion, a new degradation. If we bring it to the surface right away, the process accelerates very quickly. We have to keep the object damp. We always have to be ready to take action. For example, if the water heats up too fast, micro-organisms may develop that accelerate the degradation. We then have to be ready to start preservation treatments, which can take years depending on the object. It’s an enormous responsibility and we have to be ready to handle it, if not, we destroy…

JO: … the heritage.

MAB: … what we are trying to save, and that’s to everyone’s detriment.

JO: Why do you think that people are so fascinated by archaeology, and more specifically by shipwrecks?

MAB: That’s also a paradox. We say that people aren’t interested in history. I am firmly convinced that people enjoy history and are interested in it. It must be well narrated, but people are interested in history. There’s already an interest in our past and in our links with the past. If people feel directly affected by the past, they’ll be fascinated by it. If we add on top of that the element of discovery, and archaeology is discovery, and all the myths surrounding artefact hunters…

JO: … treasure hunters.

MAB: … treasures, and so on. It’s an image that people have. Yes, we hunt treasure, but historical treasure. That image applies even more strongly to shipwrecks. There’s always that myth of the Spanish galleon filled with gold. Everyone thinks that all shipwrecks contain a treasure. That being said, there’s a fascination with discovery and with the past, and add on top of that the notion of the bottom of the sea: it’s the final frontier, where we can be surprised by what we discover. Since these discoveries are often remarkably well preserved, people are absolutely fascinated.

We grow up with stories of pirates, shipwrecks and lost ships. These are powerful images. A shipwreck is an image that captures the imagination. But a shipwreck, when we dive a shipwreck, we have direct contact with the past. People are fascinated by that.

JO: Are shipwreck sites accessible to divers?

MAB: Shipwreck sites are very accessible to divers. For us, it’s a basic principle. We want people to be able to visit these sites. Very rarely do we limit access to a site. We do, for example, in Louisbourg, Nova Scotia. The site is accessible, but with a guide. The site must be visited with a guide because the wrecks are unique and very fragile.

However, the basic principle is that, as I was saying, we should try to allow people to savour and absorb the spirit of the site. The best way is to visit the site. So there are sites that are accessible, and we try to make them accessible. We not only make them accessible, but we also promote them. We’re developing tools to provide information to people.

It’s also important to raise awareness. We have the opportunity and privilege to visit the sites. We have to ensure that our children and grandchildren have the same opportunity. So we have to protect and respect [the sites]. In that spirit, the sites have to be accessible because these experiences are absolutely incredible. With technology, we can now make them accessible not only to divers but also virtually, which is interesting and stimulating. Nowadays there are opportunities to make all these wonders available to as many people as possible, even if they don’t have the chance to dive.

JO: How long has Parks Canada been involved in underwater archaeology?

MAB: 2014 marks the 50th anniversary of the first dives at Fort Lennox in 1964 by Sean Gilmore and Walter Zacharchuk. That’s where it began. We’re going back there in August of this year, to the birthplace of underwater archaeology at Parks Canada.

We’re one of the oldest teams in the world, if we can say that. The first time an archaeologist dived a site was in 1960, so we were there basically at the beginning. Parks Canada joined the adventure very early on and it continues to be a part of it to this day. I believe that we’ve studied 225 sites across Canada, in the three oceans, the Great Lakes, rivers, truly across the entire country. We have a wealth of experience, and we’ll celebrate that this year by returning to Fort Lennox where it all began.

JO: Congratulations!

MAB: Thank you very much.

JO: 2014 marks the 100th anniversary of the sinking of the Empress of Ireland. What can you tell us about this maritime accident?

MAB: The story of the Empress begins on May 28, 1914. The Empress of Ireland left Quebec City for England with first, second and third class passengers on board. The Empress left Quebec in the late afternoon, with more than 1,400 passengers and crew on board. The ship headed down the St. Lawrence to Pointe au Père, a pilot station, because pilots were needed to navigate the St. Lawrence, given the reefs and hazards.

The pilot left the Empress at the Pointe au Père pilot station, and the ship resumed her journey. At the same time, the Storstad, a cargo ship, was heading in the opposite direction. In the fog, the two ships collided. The Storstad rammed the Empress of Ireland, creating a hole that immediately filled with water.

At that moment, it was after 1:30 a.m., so almost 2:00 a.m. It was night and foggy. The ship sank within 14 minutes, with a loss of 1,012 lives. Over 400 people survived, but over 1,000 people [died]. Many survivors were pulled from the water either by the ship that collided with the Empress or by other ships that were immediately dispatched.

JO: 14 minutes…

MAB: … In 14 minutes, the ship sank. The water rushed in and the ship sank extremely fast, leaving very little opportunity for people, especially those deeper inside the ship, to save themselves.

JO: So a disaster.

MAB: The greatest maritime tragedy in the history of the country.

JO: What’s your most unforgettable experience at an underwater archaeology site?

MAB :I’ve been doing this job for 24 years now, and I can tell you that I have had extraordinary experiences! There are two that stand out.

One was a Second World War plane in Longue-Pointe-de-Mingan that sank after takeoff. Five of the nine crew members drowned in the plane. In 2009, the plane was found intact at a depth of 40 metres. We knew that five of the crew members were still inside. What was absolutely fascinating, apart from the sense of contact and the very touching story, was that we had the opportunity, chance and privilege to have people who were on the beach when the event occurred, who saw the accident and who saw the soldiers board right beforehand. They told us how it happened and they are a direct link. They are part of the history and they experienced that history.

That was an absolutely incredible human experience. We worked with the American forces to recover the remains of the soldiers. Seeing people who had witnessed the event and who could participate 70 years later was a very powerful moment. Diving the wreck of that plane was truly a journey through time.

The other experience was with the HMS Investigator in the Arctic. That’s the ship that was credited with discovering the Northwest Passage. Actually, the crew found it, since the ship remained trapped in the ice and the crew continued on foot and were saved by another ship. The ship is practically intact up to the upper deck in ten metres of water. When you go down there, the area is completely isolated. The crew spent two winters there. On land we can see the remains of the equipment that they left on the ground. Three graves are also visible. So we can absorb the fact that they were in this environment, which was completely hostile, for two years, with the hope of being rescued.

And the ship: we then dive this amazing exploration machine that’s still upright, with its iron-clad prow to break the ice. It’s an icebreaker from the 1850s. We dive on the deck, with the debris left by the ice, the pieces of the ship completely sheared off by the ice. But underneath that is a complete ship, and on the inside, everything that the people left on board.

I often say that it’s like a time travel machine. We are transported and we can absorb the spirit of the site. That’s what I believe is important, and what we at Parks [Canada] try to impart, the spirit of the site. There was a historic moment, but it occurred at a site. That site must be seen and experienced for maximum appreciation. That’s part of the essence of the historic event and the site. On that site, we truly felt it.

JO: Thank you very much for coming to speak with us today. We greatly appreciate your knowledge of underwater Canada. Thank you.

MAB: Thank you very much.

JO: To learn more about shipwrecks, visit our website Shipwreck Investigations at lac-bac.gc.ca/sos/shipwrecks or read our articles on shipwrecks on thediscoverblog.com [I found other subjects but not shipwrecks in my admittedly brief search of the blog].

Thank you for joining us. I’m your host, Jessica Ouvrard, and you’ve been listening to “Discover Library and Archives Canada-where Canadian history, literature and culture await you.” A special thanks to our guest today, Marc-André Bernier.

A couple of comments. (1) It seems that neither Mr. Bernier nor his team have ever dived on the West Coast or west of Ottawa for that matter. (2) Given Bernier’s comments about oxygen and the degradation of artefacts once exposed to the air, I imagine there’s a fair of amount of excitement and interest in Corr’s work on ‘smart nanotech’ for shipwrecks.

Gold’s origin in the universe due to cosmic collision

An hypothesis for gold’s origins was first mentioned here in a May 26, 2016 posting,

The link between this research and my side project on gold nanoparticles is a bit tenuous but this work on the origins for gold and other precious metals being found in the stars is so fascinating and I’m determined to find a connection.

An artist's impression of two neutron stars colliding. (Credit: Dana Berry / Skyworks Digital, Inc.) Courtesy: Kavli Foundation

An artist’s impression of two neutron stars colliding. (Credit: Dana Berry / Skyworks Digital, Inc.) Courtesy: Kavli Foundation

From a May 19, 2016 news item on phys.org,

The origin of many of the most precious elements on the periodic table, such as gold, silver and platinum, has perplexed scientists for more than six decades. Now a recent study has an answer, evocatively conveyed in the faint starlight from a distant dwarf galaxy.

In a roundtable discussion, published today [May 19, 2016?], The Kavli Foundation spoke to two of the researchers behind the discovery about why the source of these heavy elements, collectively called “r-process” elements, has been so hard to crack.

From the Spring 2016 Kavli Foundation webpage hosting the  “Galactic ‘Gold Mine’ Explains the Origin of Nature’s Heaviest Elements” Roundtable ,

Astronomers studying a galaxy called Reticulum II have just discovered that its stars contain whopping amounts of these metals—collectively known as “r-process” elements (See “What is the R-Process?”). Of the 10 dwarf galaxies that have been similarly studied so far, only Reticulum II bears such strong chemical signatures. The finding suggests some unusual event took place billions of years ago that created ample amounts of heavy elements and then strew them throughout the galaxy’s reservoir of gas and dust. This r-process-enriched material then went on to form Reticulum II’s standout stars.

Based on the new study, from a team of researchers at the Kavli Institute at the Massachusetts Institute of Technology, the unusual event in Reticulum II was likely the collision of two, ultra-dense objects called neutron stars. Scientists have hypothesized for decades that these collisions could serve as a primary source for r-process elements, yet the idea had lacked solid observational evidence. Now armed with this information, scientists can further hope to retrace the histories of galaxies based on the contents of their stars, in effect conducting “stellar archeology.”

Researchers have confirmed the hypothesis according to an Oct. 16, 2017 news item on phys.org,

Gold’s origin in the Universe has finally been confirmed, after a gravitational wave source was seen and heard for the first time ever by an international collaboration of researchers, with astronomers at the University of Warwick playing a leading role.

Members of Warwick’s Astronomy and Astrophysics Group, Professor Andrew Levan, Dr Joe Lyman, Dr Sam Oates and Dr Danny Steeghs, led observations which captured the light of two colliding neutron stars, shortly after being detected through gravitational waves – perhaps the most eagerly anticipated phenomenon in modern astronomy.

Marina Koren’s Oct. 16, 2017 article for The Atlantic presents a richly evocative view (Note: Links have been removed),

Some 130 million years ago, in another galaxy, two neutron stars spiraled closer and closer together until they smashed into each other in spectacular fashion. The violent collision produced gravitational waves, cosmic ripples powerful enough to stretch and squeeze the fabric of the universe. There was a brief flash of light a million trillion times as bright as the sun, and then a hot cloud of radioactive debris. The afterglow hung for several days, shifting from bright blue to dull red as the ejected material cooled in the emptiness of space.

Astronomers detected the aftermath of the merger on Earth on August 17. For the first time, they could see the source of universe-warping forces Albert Einstein predicted a century ago. Unlike with black-hole collisions, they had visible proof, and it looked like a bright jewel in the night sky.

But the merger of two neutron stars is more than fireworks. It’s a factory.

Using infrared telescopes, astronomers studied the spectra—the chemical composition of cosmic objects—of the collision and found that the plume ejected by the merger contained a host of newly formed heavy chemical elements, including gold, silver, platinum, and others. Scientists estimate the amount of cosmic bling totals about 10,000 Earth-masses of heavy elements.

I’m not sure exactly what this image signifies but it did accompany Koren’s article so presumably it’s a representation of colliding neutron stars,

NSF / LIGO / Sonoma State University /A. Simonnet. Downloaded from: https://www.theatlantic.com/science/archive/2017/10/the-making-of-cosmic-bling/543030/

An Oct. 16, 2017 University of Warwick press release (also on EurekAlert), which originated the news item on phys.org, provides more detail,

Huge amounts of gold, platinum, uranium and other heavy elements were created in the collision of these compact stellar remnants, and were pumped out into the universe – unlocking the mystery of how gold on wedding rings and jewellery is originally formed.

The collision produced as much gold as the mass of the Earth. [emphasis mine]

This discovery has also confirmed conclusively that short gamma-ray bursts are directly caused by the merging of two neutron stars.

The neutron stars were very dense – as heavy as our Sun yet only 10 kilometres across – and they collided with each other 130 million years ago, when dinosaurs roamed the Earth, in a relatively old galaxy that was no longer forming many stars.

They drew towards each other over millions of light years, and revolved around each other increasingly quickly as they got closer – eventually spinning around each other five hundred times per second.

Their merging sent ripples through the fabric of space and time – and these ripples are the elusive gravitational waves spotted by the astronomers.

The gravitational waves were detected by the Advanced Laser Interferometer Gravitational-Wave Observatory (Adv-LIGO) on 17 August this year [2017], with a short duration gamma-ray burst detected by the Fermi satellite just two seconds later.

This led to a flurry of observations as night fell in Chile, with a first report of a new source from the Swope 1m telescope.

Longstanding collaborators Professor Levan and Professor Nial Tanvir (from the University of Leicester) used the facilities of the European Southern Observatory to pinpoint the source in infrared light.

Professor Levan’s team was the first one to get observations of this new source with the Hubble Space Telescope. It comes from a galaxy called NGC 4993, 130 million light years away.

Andrew Levan, Professor in the Astronomy & Astrophysics group at the University of Warwick, commented: “Once we saw the data, we realised we had caught a new kind of astrophysical object. This ushers in the era of multi-messenger astronomy, it is like being able to see and hear for the first time.”

Dr Joe Lyman, who was observing at the European Southern Observatory at the time was the first to alert the community that the source was unlike any seen before.

He commented: “The exquisite observations obtained in a few days showed we were observing a kilonova, an object whose light is powered by extreme nuclear reactions. This tells us that the heavy elements, like the gold or platinum in jewellery are the cinders, forged in the billion degree remnants of a merging neutron star.”

Dr Samantha Oates added: “This discovery has answered three questions that astronomers have been puzzling for decades: what happens when neutron stars merge? What causes the short duration gamma-ray bursts? Where are the heavy elements, like gold, made? In the space of about a week all three of these mysteries were solved.”

Dr Danny Steeghs said: “This is a new chapter in astrophysics. We hope that in the next few years we will detect many more events like this. Indeed, in Warwick we have just finished building a telescope designed to do just this job, and we expect it to pinpoint these sources in this new era of multi-messenger astronomy”.

Congratulations to all of the researchers involved in this work!

Many, many research teams were  involved. Here’s a sampling of their news releases which focus on their areas of research,

University of the Witwatersrand (South Africa)

https://www.eurekalert.org/pub_releases/2017-10/uotw-wti101717.php

Weizmann Institute of Science (Israel)

https://www.eurekalert.org/pub_releases/2017-10/wios-cns101717.php

Carnegie Institution for Science (US)

https://www.eurekalert.org/pub_releases/2017-10/cifs-dns101217.php

Northwestern University (US)

https://www.eurekalert.org/pub_releases/2017-10/nu-adc101617.php

National Radio Astronomy Observatory (US)

https://www.eurekalert.org/pub_releases/2017-10/nrao-ru101317.php

Max-Planck-Gesellschaft (Germany)

https://www.eurekalert.org/pub_releases/2017-10/m-gwf101817.php

Penn State (Pennsylvania State University; US)

https://www.eurekalert.org/pub_releases/2017-10/ps-stl101617.php

University of California – Davis

https://www.eurekalert.org/pub_releases/2017-10/uoc–cns101717.php

The American Association for the Advancement of Science’s (AAAS) magazine, Science, has published seven papers on this research. Here’s an Oct. 16, 2017 AAAS news release with an overview of the papers,

https://www.eurekalert.org/pub_releases/2017-10/aaft-btf101617.php

I’m sure there are more news releases out there and that there will be many more papers published in many journals, so if this interests, I encourage you to keep looking.

Two final pieces I’d like to draw your attention to: one answers basic questions and another focuses on how artists knew what to draw when neutron stars collide.

Keith A Spencer’s Oct. 18, 2017 piece on salon.com answers a lot of basic questions for those of us who don’t have a background in astronomy. Here are a couple of examples,

What is a neutron star?

Okay, you know how atoms have protons, neutrons, and electrons in them? And you know how protons are positively charged, and electrons are negatively charged, and neutrons are neutral?

Yeah, I remember that from watching Bill Nye as a kid.

Totally. Anyway, have you ever wondered why the negatively-charged electrons and the positively-charged protons don’t just merge into each other and form a neutral neutron? I mean, they’re sitting there in the atom’s nucleus pretty close to each other. Like, if you had two magnets that close, they’d stick together immediately.

I guess now that you mention it, yeah, it is weird.

Well, it’s because there’s another force deep in the atom that’s preventing them from merging.

It’s really really strong.

The only way to overcome this force is to have a huge amount of matter in a really hot, dense space — basically shove them into each other until they give up and stick together and become a neutron. This happens in very large stars that have been around for a while — the core collapses, and in the aftermath, the electrons in the star are so close to the protons, and under so much pressure, that they suddenly merge. There’s a big explosion and the outer material of the star is sloughed off.

Okay, so you’re saying under a lot of pressure and in certain conditions, some stars collapse and become big balls of neutrons?

Pretty much, yeah.

So why do the neutrons just stick around in a huge ball? Aren’t they neutral? What’s keeping them together? 

Gravity, mostly. But also the strong nuclear force, that aforementioned weird strong force. This isn’t something you’d encounter on a macroscopic scale — the strong force only really works at the type of distances typified by particles in atomic nuclei. And it’s different, fundamentally, than the electromagnetic force, which is what makes magnets attract and repel and what makes your hair stick up when you rub a balloon on it.

So these neutrons in a big ball are bound by gravity, but also sticking together by virtue of the strong nuclear force. 

So basically, the new ball of neutrons is really small, at least, compared to how heavy it is. That’s because the neutrons are all clumped together as if this neutron star is one giant atomic nucleus — which it kinda is. It’s like a giant atom made only of neutrons. If our sun were a neutron star, it would be less than 20 miles wide. It would also not be something you would ever want to get near.

Got it. That means two giant balls of neutrons that weighed like, more than our sun and were only ten-ish miles wide, suddenly smashed into each other, and in the aftermath created a black hole, and we are just now detecting it on Earth?

Exactly. Pretty weird, no?

Spencer does a good job of gradually taking you through increasingly complex explanations.

For those with artistic interests, Neel V. Patel tries to answer a question about how artists knew what draw when neutron stars collided in his Oct. 18, 2017 piece for Slate.com,

All of these things make this discovery easy to marvel at and somewhat impossible to picture. Luckily, artists have taken up the task of imagining it for us, which you’ve likely seen if you’ve already stumbled on coverage of the discovery. Two bright, furious spheres of light and gas spiraling quickly into one another, resulting in a massive swell of lit-up matter along with light and gravitational waves rippling off speedily in all directions, towards parts unknown. These illustrations aren’t just alluring interpretations of a rare phenomenon; they are, to some extent, the translation of raw data and numbers into a tangible visual that gives scientists and nonscientists alike some way of grasping what just happened. But are these visualizations realistic? Is this what it actually looked like? No one has any idea. Which is what makes the scientific illustrators’ work all the more fascinating.

“My goal is to represent what the scientists found,” says Aurore Simmonet, a scientific illustrator based at Sonoma State University in Rohnert Park, California. Even though she said she doesn’t have a rigorous science background (she certainly didn’t know what a kilonova was before being tasked to illustrate one), she also doesn’t believe that type of experience is an absolute necessity. More critical, she says, is for the artist to have an interest in the subject matter and in learning new things, as well as a capacity to speak directly to scientists about their work.

Illustrators like Simmonet usually start off work on an illustration by asking the scientist what’s the biggest takeaway a viewer should grasp when looking at a visual. Unfortunately, this latest discovery yielded a multitude of papers emphasizing different conclusions and highlights. With so many scientific angles, there’s a stark challenge in trying to cram every important thing into a single drawing.

Clearly, however, the illustrations needed to center around the kilonova. Simmonet loves colors, so she began by discussing with the researchers what kind of color scheme would work best. The smash of two neutron stars lends itself well to deep, vibrant hues. Simmonet and Robin Dienel at the Carnegie Institution for Science elected to use a wide array of colors and drew bright cracking to show pressure forming at the merging. Others, like Luis Calcada at the European Southern Observatory, limited the color scheme in favor of emphasizing the bright moment of collision and the signal waves created by the kilonova.

Animators have even more freedom to show the event, since they have much more than a single frame to play with. The Conceptual Image Lab at NASA’s [US National Aeronautics and Space Administration] Goddard Space Flight Center created a short video about the new findings, and lead animator Brian Monroe says the video he and his colleagues designed shows off the evolution of the entire process: the rising action, climax, and resolution of the kilonova event.

The illustrators try to adhere to what the likely physics of the event entailed, soliciting feedback from the scientists to make sure they’re getting it right. The swirling of gas, the direction of ejected matter upon impact, the reflection of light, the proportions of the objects—all of these things are deliberately framed such that they make scientific sense. …

Do take a look at Patel’s piece, if for no other reason than to see all of the images he has embedded there. You may recognize Aurore Simmonet’s name from the credit line in the second image I have embedded here.

Weirdly fascinating account of malaria-carrying mosquitoes and insecticide-treated bed nets

Researchers at the Liverpool School of Tropical Medicine (LSTM) have tracked mosquitoes to observe how they interact with insecticide-laden nets. From a Sept. 1, 2015 LSTM press release (also on EurekAlert),

LSTM vector biologists Dr Philip McCall and Ms Josie Parker worked with optical engineers Prof David Towers, Dr Natalia Angarita and Dr Catherine Towers from the University of Warwick’s School of Engineering to develop infrared video tracking technology that follows individual mosquitoes in flight as they try to reach a human sleeper inside a bed net. This system allowed the scientists to measure, define and characterise in fine detail, the behavioural events and sequences of the main African malaria vector, Anopheles gambiae, as it interacts with the net. Funded as part of the €12M AvecNet research consortium, the team’s initial results are published today in the journal Nature Scientific Reports.

Dr Philip McCall, senior author on the paper, said: “Essentially, the results demonstrated that an LLIN [Long-lasting insecticidal bed net] functions as a highly efficient, fast-acting, human-baited insecticidal trap. LLINs do not repel mosquitoes – they deliver insecticide very rapidly after the briefest contact: LLIN contact of less than 1 minute per mosquito during the first ten minutes can reduce mosquito activity such that after thirty minutes, virtually no mosquitoes are still flying. Surprisingly, mosquitoes were able to detect nets of any kind while still in flight, allowing them to decelerate before they ‘collided’ with the net surface.”

The use of this innovative approach to mosquito behaviour has provided unprecedented insight into the mode of action of our most important tool for preventing malaria transmission, under conditions that are as close to natural as possible. The findings potentially could influence many aspects of mosquito control, ranging from how we test mosquito populations for insecticide resistance to the design of a next generation of LLINs. An MRC Confidence in Concept grant has funded the team to use the tracking system to explore a number of novel LLIN designs, already patented as an outcome from the current research.

The tracking system also has been deployed in a rural Tanzania, results of which will be reported shortly. The team recently was awarded £0.9M support from the Medical Research Council (MRC) for the next stage of this project, where they will use a larger three-dimensional system to track mosquitoes throughout the entire domestic environment, in experimental houses in Tanzania.

Dr McCall continued: “preliminary results in field tests indicate that these laboratory findings are consistent with behaviour of wild mosquito populations which is very encouraging. We are at the early stages of this research, but we hope that our findings, and the use of this cutting edge technology, can contribute to the development of new and advanced vector control tools that will continue to save lives in endemic countries throughout the world.”

The fascinating part follows the link to and citation for the paper,

Infrared video tracking of Anopheles gambiae at insecticide-treated bed nets reveals rapid decisive impact after brief localised net contact by Josephine E.A. Parker, Natalia Angarita-Jaimes, Mayumi Abe, Catherine E. Towers, David Towers, & Philip J. McCall. Scientific Reports 5, Article number: 13392 (2015) doi:10.1038/srep13392 Published online: 01 September 2015

This open access paper provides an explanation for why this work was undertaken,

Delivering the ‘next generation’ of LLINs or similar tools will require a thorough understanding of how LLINs function, yet remarkably little is known of the mode of action or of precisely how mosquitoes behave at the LLIN interface. Recent studies using ‘sticky-nets’ reported that host-seeking female Anopheles spp. landed preferentially on the top surface of bed nets7,8 but that lethal capture method recorded only a single landing event and no other behaviours before or after. Although clustering at the net roof is likely to be a response to an attractant ‘plume’ rising from the human beneath [emphasis mine], this too remains speculative because knowledge of mosquito flight behaviour prior to blood-feeding and of the identity and location of the key attractants that mediate the host-seeking response is limited9,10,11,12. Importantly, how insecticide treatments influence that response is unclear. Some studies reported that insecticide residues repelled mosquitoes prior to contact13,14, which would reduce or eliminate the chance of mosquitoes receiving an effective dose and potentially divert them to unprotected hosts15. Others found no evidence for such repellency16,17,18,19 indicating that LLINs attract and impact on mosquitoes by direct contact.

A further complication is the existence of what is termed ‘contact-irritancy’ or ‘excito-repellency’ [emphasis miine], whereby brief exposure to an insecticide can result in mosquitoes exhibiting avoidance behaviour, potentially before a lethal dose has been delivered13,20. Remarkably, some basic details are missing: e.g. the minimum duration of LLIN contact necessary to deliver an effective dosage is not known. Despite these phenomena being recognised for decades20,21,22, when and how they occur and their relative importance in selecting for insecticide resistance have never been fully elucidated.

Consequently, behavioural resistance [emphasis mine] to insecticides remains poorly understood and rarely reported in mosquitoes, though the risk of vector populations switching blood-feeding times, locations or host preferences in order to avoid LLINs is recognized and closely monitored today23,24,25. However, additional but less apparent or detectable behavioural changes also might exist, potentially conferring partial or complete insecticide resistance (e.g. changes in sensitivity to repellents, attractants, or modified flight or resting behaviours). In the absence of definitions or quantifications of the basic behavioural events likely to be affected26,27, these changes cannot be investigated, let alone monitored.

I am fascinated by the ‘attractant plume’, ‘excito-repellency’, and the (new to me) notion that mosquitoes can exhibit behavioural resistance.

Does the universe have a heartbeat?

It may be a bit fanciful to suggest the universe has a heartbeat but if University of Warwick (UK) researchers can state that dying stars have ‘irregular heartbeats’ then why can’t the universe have a heartbeat of sorts? Getting back to the University of Warwick, their August 26, 2015 press release (also on EurekAlert) has this to say,

Some dying stars suffer from ‘irregular heartbeats’, research led by astronomers at the University of Warwick has discovered.

The research confirms rapid brightening events in otherwise normal pulsating white dwarfs, which are stars in the final stage of their life cycles.

In addition to the regular rhythm from pulsations they expected on the white dwarf PG1149+057, which cause the star to get a few percent brighter and fainter every few minutes, the researchers also observed something completely unexpected every few days: arrhythmic, massive outbursts, which broke the star’s regular pulse and significantly heated up its surface for many hours.

The discovery was made possible by using the planet-hunting spacecraft Kepler, which stares unblinkingly at a small patch of sky, uninterrupted by clouds or sunrises.

Led by Dr JJ Hermes of the University of Warwick’s Astrophysics Group, the astronomers targeted the Kepler spacecraft on a specific star in the constellation Virgo, PG1149+057, which is roughly 120 light years from Earth.

Dr Hermes explains:

“We have essentially found rogue waves in a pulsating star, akin to ‘irregular heartbeats’. These were truly a surprise to see: we have been watching pulsating white dwarfs for more than 50 years now from the ground, and only by being able to stare uninterrupted for months from space have we been able to catch these events.”

The star with the irregular beat, PG1149+057, is a pulsating white dwarf, which is the burnt-out core of an evolved star, an extremely dense star which is almost entirely made up of carbon and oxygen. Our Sun will eventually become a white dwarf in more than six billion years, after it runs out of its nuclear fuel.

White dwarfs have been known to pulsate for decades, and some are exceptional clocks, with pulsations that have kept nearly perfect time for more than 40 years. Pulsations are believed to be a naturally occurring stage when a white dwarf reaches the right temperature to generate a mix of partially ionized hydrogen atoms at its surface.

That mix of excited atoms can store up and then release energy, causing the star to resonate with pulsations characteristically every few minutes. Astronomers can use the regular periods of these pulsations just like seismologists use earthquakes on Earth, to see below the surface of the star into its exotic interior. This was why astronomers targeted PG1149+057 with Kepler, hoping to learn more about its dense core. In the process, they caught a new glimpse at these unexpected outbursts.

“These are highly energetic events, which can raise the star’s overall brightness by more than 15% and its overall temperature by more than 750 degrees in a matter of an hour,” said Dr Hermes. “For context, the Sun will only increase in overall brightness by about 1% over the next 100 million years.”

Interestingly, this is not the only white dwarf to show an irregular pulse. Recently, the Kepler spacecraft witnessed the first example of these strange outbursts while studying another white dwarf, KIC 4552982, which was observed from space for more than 2.5 years.

There is a narrow range of surface temperatures where pulsations can be excited in white dwarfs, and so far irregularities have only been seen in the coolest of those that pulsate. Thus, these irregular outbursts may not be just an oddity; they have the potential to change the way astronomers understand how pulsations, the regular heartbeats, ultimately cease in white dwarfs.

“The theory of stellar pulsations has long failed to explain why pulsations in white dwarfs stop at the temperature we observe them to,” argues Keaton Bell of the University of Texas at Austin, who analysed the first pulsating white dwarf to show an irregular heartbeat, KIC 4552982. “That both stars exhibiting this new outburst phenomenon are right at the temperature where pulsations shut down suggests that the outbursts could be the key to revealing the missing physics in our pulsation theory.”

Astronomers are still trying to settle on an explanation for these never-before-seen outbursts. Given the similarity between the first two stars to show this behaviour, they suspect it might have to do with how the pulsation waves interact with themselves, perhaps via a resonance.

“Ultimately, this may be a new type of nonlinear behaviour that is triggered when the amplitude of a pulsation passes a certain threshold, perhaps similar to rogue waves on the open seas here on Earth, which are massive, spontaneous waves that can be many times larger than average surface waves,” said Dr Hermes. “Still, this is a fresh discovery from observations, and there may be more to these irregular stellar heartbeats than we can imagine yet.”

Here’s a link to and a citation for the paper,

A Second Case of Outbursts in a Pulsating White Dwarf Observed by Kepler by J. J. Hermes, M. H. Montgomery, Keaton J. Bell, P. Chote, B. T. Gänsicke, Steven D. Kawaler, J. C. Clemens, Bart H. Dunlap, D. E. Winget, and D. J. Armstrong.
2015 ApJ 810 L5 (The Astrophysical Journal Letters Volume 810 Number 1). doi:10.1088/2041-8205/810/1/L5
Published 24 August 2015.

© 2015. The American Astronomical Society. All rights reserved.

This paper is behind a paywall but there is an earlier open access version available at arXiv.org,

A second case of outbursts in a pulsating white dwarf observed by Kepler by J. J. Hermes, M. H. Montgomery, Keaton J. Bell, P. Chote, B. T. Gaensicke, Steven D. Kawaler, J. C. Clemens, B. H. Dunlap, D. E. Winget, D. J. Armstrong.  arXiv.org > astro-ph > arXiv:1507.06319

In an attempt to find some live heart beats to illustrate this piece, I found this video from Wake Forest University’s body-on-a-chip program,

The video was released in an April 14, 2015 article by Joe Bargmann for Popular Mechanics,

A groundbreaking program has converted human skin cells into a network of functioning heart cells, and also fused them with lab-grown liver cells using a specialized 3D printer. Researchers at the Wake Forest Baptist Medical Center’s Institute for Regenerative Medicine provided Popular Mechanics with both still and moving images of the cells for a fascinating first look.

“The heart organoid beats because it contains specialized cardiac cells and because those cells are receiving the correct environmental cues,” says Ivy Mead, a Wake Forest graduate student and member of the research team. “We give them a special medium and keep them at the same temperature as the human body, and that makes them beat. We can also stimulate the miniature organ with electrical or chemical cues to alter the beating patterns. Also, when we grow them in three-dimensions it allows for them to interact with each other more easily, as they would in the human body.”

If you’re interested in body-on-a-chip projects, I have several stories here (suggestion: use body-on-a-chip as your search term in the blog search engine) and I encourage you to read Bargmann’s story in its entirety (the video no longer seems to be embedded there).

One final comment, there seems to be some interest in relating large systems to smaller ones. For example, humans and other animals along with white dwarf stars have heartbeats (as in this story) and patterns in a gold nanoparticle of 133 atoms resemble the Milky Way (my April 14, 2015 posting titled: Nature’s patterns reflected in gold nanoparticles).

Nanocrystallometry points the way to control of motion in the nano-world

A May 28, 2014 news item on Azonano describes a new technique that could lead to controlling the growth of metal oxide crystals,

Published in the journal Nature Communications and developed at the University of Warwick, the method, called Nanocrystallometry, allows for the creation of precise components for use in nanotechnology.

Professor Peter Sadler from the University’s [University of Warwick] Department of Chemistry commented that “The breakthrough with Nanocrystallometry is that it actually allows us to observe and directly control the nano-world in motion”.

A May ??, 2014 University of Warwick news release, which originated the news item provides more details about the technique (Note: A link has been removed),

Using a doped-graphene matrix to slow down and then trap atoms of the precious metal osmium the researchers were able to control and quantify the growth of metal-crystals. When the trapped atoms come into contact with further osmium atoms they bind together, eventually growing into 3D metal-crystals.

“Tailoring nanoscopic objects is of enormous importance for the production of the materials of the future”, says Dr Nicholas Barry from the University’s Department of Chemistry. “Until now the formation of metal nanocrystals, which are essential to those future materials, could not be controlled with precision at the level of individual atoms, under mild and accessible conditions.”

Prof. Sadler says: “Nanocrystallometry’s significance is that it has made it possible to grow with precision metal-crystals which can be as small as only 0.00000015cm, or 15 ångström, wide. If a nanodevice requires a million osmium atoms then from 1 gram of osmium we can make about 400 thousand devices for every person on this earth. Compared to existing methods of crystal growth Nanocrystallometry offers a significant improvement in the economic and efficient manufacture of precision nanoscopic objects.”

The researchers argue that the new method possesses a range of potential uses. “We envision the use Nanocrystallometry to build precise, atomic-level electronic circuits and new nano-information storage devices. The method also has significant potential for use in the biosensing of drugs, DNA and gases as well for creating unique nano-patterns on surfaces for security labelling and sealing confidential documents. Nanocrystallometry is also an innovative method for producing new metal nano-alloys, and many combinations can be envisaged. They may have very unusual and as yet unexplored properties”, commented Dr Barry.

Here’s a link to and a citation for the research paper,

Fabrication of crystals from single metal atoms by Nicolas P. E. Barry, Anaïs Pitto-Barry, Ana M. Sanchez, Andrew P. Dove, Richard J. Procter, Joan J. Soldevila-Barreda, Nigel Kirby, Ian Hands-Portman, Corinne J. Smith, Rachel K. O’Reilly, Richard Beanland, & Peter J. Sadler. Nature Communications 5, Article number: 3851 doi:10.1038/ncomms4851 Published 27 May 2014

This is an open access paper.

Phytoremediation, clearing pollutants from industrial lands, could also be called phyto-mining

The University of Edinburgh (along with the Universities of Warwick and Birmingham, Newcastle University and Cranfield University) according to its Mar. 4, 2013 news release on EurekAlert is involved in a phytoremediation project,

Common garden plants are to be used to clean polluted land, with the extracted poisons being used to produce car parts and aid medical research.

Scientists will use plants such as alyssum, pteridaceae and a type of mustard called sinapi to soak up metals from land previously occupied by factories, mines and landfill sites.

Dangerous levels of metals such as arsenic and platinum, which can lurk in the ground and can cause harm to people and animals, will be extracted using a natural process known as phytoremediation.

A Mar. 4, 2013 news item on the BBC News Edinburgh, Fife and East Scotland site offers more details about the project and the technology,

A team of researchers from the Universities of Edinburgh, Warwick, Birmingham, Newcastle and Cranfield has developed a way of extracting the chemicals through a process called phytoremediation, and are testing its effectiveness.

Once the plants have drawn contaminated material out of the soil, they will be harvested and processed in a bio-refinery.

A specially designed bacteria will be added to the waste to transform the toxic metal ions into metallic nanoparticles.

The team said these tiny particles could then be used to develop cancer treatments, and could also be used to make catalytic converters for cars.

Dr Louise Horsfall, of Edinburgh’s University’s school of biological sciences, said: “Land is a finite resource. As the world’s population grows along with the associated demand for food and shelter, we believe that it is worth decontaminating land to unlock vast areas for better food security and housing.

“I hope to use synthetic biology to enable bacteria to produce high value nanoparticles and thereby help make land decontamination financially viable.”

The research team said the land where phytoremediation was used would also be cleared of chemicals, meaning it could be reused for new building projects.

In my Sept. 28, 2012 posting I featured an international collaboration between universities in the UK, US, Canada, and New Zealand in a ‘phyto-mining’ project bearing some resemblance to this newly announced project. In that project, announced in Fall 2012, scientists were studying how they might remove platinum for reuse from plants near the tailings of mines.

I do have one other posting about phytoremediation. I featured a previously published piece by Joe Martin in a two-part series on the topic plant (phyto) and nano soil remediation. The March 30, 2012 posting is part one, which focuses on the role of plants in soil remediation.

Phyto-mining and environmental remediation flower in the United Kingdom

Researchers on a £3 million research programme called “Cleaning Land for Wealth” (CL4W) are confident they’ll be able to use flowers and plants to clean soil of poisonous materials (environmental remediation) and to recover platinum (phyto-mining). From the Nov. 21, 2012 news item on Nanowerk,

A consortium of researchers led by WMG (Warwick Manufacturing Group) at the University of Warwick are to embark on a £3 million research programme called “Cleaning Land for Wealth” (CL4W), that will use a common class of flower to restore poisoned soils while at the same time producing perfectly sized and shaped nano sized platinum and arsenic nanoparticles for use in catalytic convertors, cancer treatments and a range of other applications.

The Nov. 20, 2012 University of Warwick news release, which originated the news item, describes both how CL4W came together and how it produced an unintended project benefit,

A “Sandpit” exercise organised by the Engineering and Physical Sciences Research Council (EPSRC) allowed researchers from WMG (Warwick Manufacturing group) at the University of Warwick, Newcastle University, The University of Birmingham, Cranfield University and the University of Edinburgh to come together and share technologies and skills to come up with an innovative multidisciplinary research project that could help solve major technological and environmental challenges.

The researchers pooled their knowledge of how to use plants and bacteria to soak up particular elements and chemicals and how to subsequently harvest, process and collect that material. They have devised an approach to demonstrate the feasibility in which they are confident that they can use common classes of flower and plants (such as Alyssum), to remove poisonous chemicals such as arsenic and platinum from polluted land and water courses potentially allowing that land to be reclaimed and reused.

That in itself would be a significant achievement, but as the sandpit progressed the researchers found that jointly they had the knowledge to achieve much more than just cleaning up the land.

As lead researcher on the project Professor Kerry Kirwan from WMG at the University of Warwick explained:

“The processes we are developing will not only remove poisons such as arsenic and platinum from contaminated land and water courses, we are also confident that we can develop suitable biology and biorefining processes (or biofactories as we are calling them) that can tailor the shapes and sizes of the metallic nanoparticles they will make. This would give manufacturers of catalytic convertors, developers of cancer treatments and other applicable technologies exactly the right shape, size and functionality they need without subsequent refinement. We are also expecting to recover other high value materials such as fine chemicals, pharmaceuticals, anti-oxidants etc. from the crops during the same biorefining process.”

I last mentioned phyto-mining in my Sept. 26, 2012 post with regard to an international project being led by researchers at the University of York (UK).  The biorefining processes (biofactories) mentioned by Kirwan takes the idea of recovering platinum, etc. one step beyond phyto-mining recovery.

Here’s a picture of the flower (Alyssum) mentioned in the news release,

Alyssum montanum photographed by myself in 1988, Unterfranken, Germany [http://en.wikipedia.org/wiki/Alyssum]

From the Wikipedia essay (Note: I have removed links],

Alyssum is a genus of about 100–170 species of flowering plants in the family Brassicaceae, native to Europe, Asia, and northern Africa, with the highest species diversity in the Mediterranean region. The genus comprises annual and perennial herbaceous plants or (rarely) small shrubs, growing to 10–100 cm tall, with oblong-oval leaves and yellow or white flowers (pink to purple in a few species).