This is the fifth of five blog posts for British Science Week in which we address who we are, what we do and some of the challenges we face in using science to help understand, manage and conserve heritage.
Today’s challenge is resilience. Resilience is a term for how well something can respond to a difficulty and return to normal. Although many heritage sites and objects require protection and conservation from further damage, others are able to deal with whatever is thrown at them. This makes them resilient. Although many heritage buildings and sites have survived well and been resilient for many decades or centuries, some face new threats due a changing climate, air pollution and increasing visitor numbers. The goal of heritage conservation is to manage the change of objects and sites to make them more resilient – slowing down deterioration so that their values can be shared with future generations. If conservation goes wrong, heritage sites and objects can become less resilient. But doing nothing is usually not an option. The challenge for scientists and conservators is how best to manage change and improve the resilience of fragile, valued objects and sites.
The graph above shows some different responses to this challenge using two axes. The horizontal axis depicts how much change is allowed (on the left-hand side the word ‘conservation’ implies very little change, whereas the word ‘adaptation’ on the right-hand side implies a lot of change. The vertical axis depicts what the end goal is – from ‘restoration’ at the bottom, which implies returning something to its former condition, to ‘renovation’ at the top, which implies creating something new but still valued. All these approaches can increase or decrease the resilience of heritage, depending on how they’re done. There is no right answer to what the best approach is – it depends on the characteristics of the specific object or site, what the people who value it want, and what is most possible. Although in OxRBL we are scientists and not practicing conservators, we have to think about these issues. Many of our projects focus on testing whether a conservation strategy will be successful in managing change and increasing the resilience of a particular site or object. But we also need to think about what people want the site or object to look like.
Conserving 1000-year-old walls: Martin at the Tower of London
Doctoral student in OxRBL
Martin studied architecture at the University of Bath and building conservation at the Potsdam University of Applied Science before spending several years in practice.
He now works on how best to conserve fragile Reigate Stone walls at the Tower of London.
Martin is really lucky to be carrying out research at the Tower of London in collaboration with Historic Royal Palaces (the site manager). The medieval Reigate Stone at the Tower of London is often quite fragile, and decades of work has gone into trying various conservation methods to slow down the decay and increase its resilience. Most have only been partly successful at best. Martin’s project aims to explore new conservation approaches that might be more flexible and forward-looking while still conserving the important heritage values of the Tower.
This is the fourth of five blog posts for British Science Week in which we address who we are, what we do and some of the challenges we face in using science to help understand, manage and conserve heritage.
Today’s challenge is value. By definition, heritage objects and sites are things of great value to the people who identify them as part of their cultural heritage. The more valued an object or site, the less likely scientists are able to touch it, take samples or interfere with it in any way. This poses a real challenge for scientists who are used to collecting samples from objects to find out more about them. For example, geologists usually use hammers to chip off parts of a cliff face to identify what the rocks are – this would be completely unacceptable at somewhere like Stonehenge, where taking even the tiniest of samples is challenging and requires high-level permission. Luckily, there are several ways we can study valuable things without damaging them as we illustrate below.
At the top of the triangle we can, in some cases, get permission to take very small samples from heritage objects and sites. Even very tiny flakes of a deteriorating surface can be used to identify what is causing the deterioration. But such small samples can usually only be analysed with high-tech, expensive scientific equipment in specialised labs. These can only tell us certain things about the heritage site or building we are interested in as a whole. In the middle of the triangle are non-contact methods that we can use on heritage objects or sites to diagnose problems or monitor change over time. These non-contact methods are usually relatively inexpensive and easy to use but give less precise and accurate information than the high-tech sample-based methods. Access to the heritage object or site can a limiting factor for this type of research. At the bottom of the triangle are some of the most commonly used approaches, involving replica or analogue samples. Essentially, this means making our own objects that are as similar to the real heritage object as possible. As you can imagine, there are lots of challenges to making realistic replicas of many heritage objects (especially very large, complex and old ones!).
Studying without touching: Scott and his wet walls
Dr Scott Orr
Lecturer in Heritage Data Science, University College London and Honorary Research Associate, OxRBL.
Scott studied chemical and environmental engineering at the University of Toronto.
He works on climatic impacts on heritage buildings.
Scott is interested in why walls in historic buildings get wet and what damage that wetness can cause to the buildings, their contents and inhabitants. Faced with the challenge of not being able to drill holes into historic walls, Scott has worked with many non-destructive testing methods which can be used to ‘see inside walls’ without damaging them at all. One of his preferred methods is a hand-held system that measures microwave reflections by simply placing a sensor on the surface. This allows him to investigate how wet walls are at different depths.
Making minerals: Kathryn and museum collections
Doctoral student in OxRBL
Kathryn did an undergraduate degree in conservation science at Cardiff University.
She now studies the deterioration and conservation of mineral collections in association with the National Museum of Wales.
To cope with the challenge of not being able to take samples of valuable minerals stored in museums, Kathryn has decided to ‘grow her own’. Using the right chemicals under controlled conditions, it is possible to grow crystals of some minerals that look much like the ones on display in museums. The benefits of ‘growing your own’ are that you can make many replicas and then carry out many experiments on them. But how realistic are these ‘home grown’ minerals to the valuable ones on display (which might have been collected years ago from faraway places)?
This is the third of five blog posts for British Science Week in which we address who we are, what we do and some of the challenges we face in using science to help understand, manage and conserve heritage.
Today’s challenge is innovation. All scientific researchers aim to do something innovative, whether that’s by making some hugely important discovery or by developing a new way of making observations (or perhaps combining the two). Often when you are actually in the lab, in the field, or staring into your computer, it feels as though you are a long way from doing anything innovative at all. It’s easy to get disheartened. In OxRBL, we have found the illustration below a useful way of picturing the sources of innovation and how they are interrelated within the ‘cycle of innovation’.
Innovation can come from the scientific techniques we deploy (on the left-hand side of the diagram) or from the challenges that a heritage site or object might throw at us (on the right-hand side of the diagram). The black arrows illustrate the ways in which such innovations inform conventional approaches and which can often lead to new developments, adaptations and further innovations. Different sciences fit in different places on the diagram. For example, much engineering is challenge-led, while many parts of ‘pure’ sciences – like chemistry and physics – are technique-led. The science we do for heritage is really in the middle of the diagram.
Technique-led innovation: Dáire in the lab with lasers
Doctoral student in OxRBL
She studied chemistry in Oxford as an undergraduate and now works with OxRBL and the Ritchie Group in the Physical and Theoretical Chemistry Lab.
Dáire’s research is firmly based on technological innovation. She is currently developing a new instrument based on laser absorption spectroscopy to measure water and pollutant gases coming in and out of limestone. This instrument should provide a novel and accurate way of monitoring how some of the key agents of deterioration interact with the surfaces of heritage buildings. Dáire will spend most of her time in the lab, but we hope that one day she will be able to apply her technique to a number of different heritage challenges.
Challenge-led innovation: Richard and the mechanical foot
Doctoral student in OxRBL
Richard studied archaeology and landscape studies at the University of Worcester and historic conservation at Birmingham. He ran his own business before coming to Oxford.
Richard’s research aims to develop a ‘best practice’ method to test whether conservation treatments on crumbling historic sandstone surfaces have been successful. His challenge has been to find the best techniques available that can be used in the field or in the lab. He is particularly interested in the impact of visitors walking on vulnerable surfaces. Thanks to a chance conversation at a party, he found a company that tests footwear (Satra) who have been able to run some experiments for him using their Pedatron tester – a challenge-led, novel application of a technique usually deployed to assess the lifespan of walking boots.
This is the second of five blog posts for British Science Week in which we address who we are, what we do and some of the challenges we face in using science to help understand, manage and conserve heritage.
Today’s challenge is uniqueness. Every heritage object or site is unique and has its own particular history, characteristics and meanings for the people who value it. For example, the rock-hewn churches at Lalibela in Ethiopia that Blen Taye Gemeda studies vary hugely in architectural style, size and location. This causes some challenges for scientists who are used to developing general explanations and theories that might apply everywhere else. Sciences such as physics are based on numerous laws like the laws of thermodynamics or the law of gravity. But how can general scientific theories be applied to address the problems facing unique heritage objects or sites? As shown below, we visualise the situation as a spectrum with general scientific theories at one end and unique heritage sites at the other. Both learn from each other in different ways, and good scientific research with excellent practical applications can be carried out at many points along the spectrum.
Confronting uniqueness: Blen Taye Gemeda
Blen Taye Gemeda
Doctoral student in OxRBL
She trained in architecture, urban planning, archaeology and conservation in Ethiopia, Portugal and Italy.
She now works at Lalibela in Ethiopia and in OxRBL’s lab.
Blen’s research aims to better understand the deterioration of the amazing rock-hewn churches at Lalibela to help conserve them for current and future worshippers who use the site. While each church is distinctive, Blen’s fieldwork on monitoring the environmental conditions at different churches is helping her understand what causes the deterioration and why some churches are experiencing more serious problems than others. Her research sits towards the ‘unique heritage site’ end of the spectrum. She has made several visits to Lalibela and collected a vast array of data there.
Modelling environmental interactions: Jenny and her cellular automata
Doctoral student in OxRBL
She studied geography as an undergraduate in Oxford and then carried out an internship at the University of Adelaide, Australia, focusing on water quality monitoring.
She now works on modelling the deterioration of earthen heritage sites in NW China.
Jenny’s research sits towards the ‘general science theory’ end of the spectrum. She spends a lot of time on her computer, developing, testing and running a model which simulates the interactions between sand, wind, vegetation and earthen heritage sites. In the desert environments Jenny works on plant growth is highly influenced by wind-blown sand and, in turn, plants affect sand transport by wind. Plants growing in front of walls can protect them from wind and sand. Using her model (ViSTA-HD), Jenny is able to run lots of simulations that allow her to test various hypotheses about whether plants could help conserve earthen heritage sites such as Suoyang in NW China. Although she has visited Suoyang and done some fieldwork there, the bulk of her work is model-based.
This is the first of five blog posts for British Science Week in which we address who we are, what we do and some of the challenges we face in using science to help understand, manage and conserve heritage.
Today’s challenge is complexity. Heritage is complex and diverse. There are many different types of heritage, and they are facing a huge range of different threats and risks. For heritage to be conserved for future generations, a very wide range of scientific expertise needs to be deployed. In the circle below, we have tried to give a representative picture of the types of sciences needed. They are colour coded in a wheel from the blues of ‘pure’ sciences, the purples of more applied sciences, the reds of social sciences, oranges of more practical subjects, and the green of philosophy. Are these all science?
Some of the ‘sciences’ in the diagram may look very different to what we conventionally think of as science, but they all contribute to solving the problems facing heritage in today’s world. Indeed, the German term ‘Wissenschaft’ is, we think, a useful way of summarising all the different types/kinds of knowledge needed to help conserve heritage. Wissenschaft is often translated as ‘science’, but it’s a broader and more nuanced concept which includes scientific and non-scientific inquiry under the heading of ‘systematic research’.
Coping with complexity: Katrin at Pompeii
Dr Katrin Wilhelm,
Conservation and Heritage Scientist in OxRBL
She used to be a stone mason and is now an expert on the use of non-destructive, field-based methods to diagnose stone deterioration.
She works at many heritage sites, including the Roman ruins of Pompeii, Italy.
One of the OxRBL researchers, Dr Katrin Wilhelm, has worked on the conservation history of Pompeii. To understand the different materials used in the conservation of wall paintings at Pompeii and their long-term performance, she has had to consult historical records, use advanced microscopic techniques developed for geology and materials science, work with archaeologists and talk to microbiologists. No one field of science can provide all the answers, and anyone working on heritage has to be prepared to collaborate with others and step out of their comfort zone.
We are a group of scientists from diverse backgrounds who work at the University of Oxford in the Oxford Resilient Buildings and Landscapes Lab (OxRBL). For British Science Week we are posting a series of 5 blog posts to explain who we are, what we do and why, and how we use science to help conserve heritage. The ideas for these blog posts came out of some discussions in our weekly lab group meetings and illustrate the challenges we find applying science to heritage conservation.
But before we start… some introductions are needed.
What IS heritage? And why does it need conserving?
Heritage can be defined as anything that we value beyond everyday use and want to pass on to future generations. It’s much more than old buildings and archaeological sites (although these are important too!). Heritage can be both tangible (things we can see and touch such as pottery, shells or murals) and intangible (things we experience such as music and dance). Heritage can be cultural or natural, or a bit of both. Cultural heritage includes objects, buildings and sites created by humans, whereas natural heritage is made up of plants, animals and the physical environment. Heritage can be movable or immovable – things we can collect and put on display somewhere (like artworks) or things that we have to go and visit where they have been created (like mountains). What things do you value and would like to pass on to future generations so that they can enjoy them too?
Heritage needs conserving because there are many threats to all types of heritage – such as climate change, wars, economic and social change, as well as natural processes of decay. The more value we put on heritage, the harder we are prepared to work to conserve it.
Who are OxRBL?
Currently, there are 19 of us in OxRBL ranging in age from 22 to 60, including students, researchers, and three Honorary Research Associates who contribute to our research but who also have jobs elsewhere (in industry or at other universities or research organisations). We come from many different parts of the world – UK, Germany, France, Canada, USA, China, Japan, Ethiopia, and Syria. We have done many different undergraduate degrees including geography, conservation science, chemistry, architecture, geology, art history and archaeology. We come from a diverse range of cultural and religious backgrounds, some of us have caring responsibilities, and some of us have had difficult journeys to get to Oxford. OxRBL is very gender-balanced and we are proud of our LGBTQ+ members. We enjoy challenging stereotypes of what scientists should look like and what scientists should do.
Follow us on twitter Follow @oxrbl
Ammar Azzouz – works for Arup, producing a video on Domicide: the destruction of home.
Blen Taye Gemeda – Doctoral student researching rock-hewn churches, Lalibela, Ethipioa
Dáire Browne – Doctoral student researching laser spectroscopy methods for heritage
Heather Viles – Professor of Biogeomorphology and Heritage Conservation (@Geodiverse)
Hong Zhang – Research Technician in charge of OxRBL’s lab and field equipment
Jenny Richards – Doctoral student researching environmental impacts on earthen heritage
Katherine Jang – Doctoral student researching the impacts of moss growing on old walls
Kathryn Royce – Doctoral student researching mineral collections in museums
Katrin Wilhelm – Researcher working on sandstone conservation and other projects
Kenta Sayama – Masters student assisting research on Reigate Stone, Tower of London
Lucie Fusade – works for Rose of Jericho, developed the Use Lime Mortar app
Martin Coombes – Researcher working on biodiversity and heritage conservation
Martin Michette – Doctoral student researching Reigate Stone, Tower of London
Richard Grove – Doctoral student researching sandstone conservation
Sam Woor – Doctoral student researching the history of alluvial fans in Oman
Scott Orr – Lecturer in Heritage Data Science, University College London
Shanlong Yang – works for Dunhuang Academy, China on heritage conservation
Tim Baxter – Doctoral student researching marine life on historic walls
Yinghong Wang – Doctoral student researching sandstone grottoes in NW China
During the British Science Week (6 – 15th March 2020) our lab will be publishing blog posts to introduce ourselves and some core ideas and challenges science tackles in the field of cultural built heritage.