astronomy

‘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://hsm.ox.ac.uk/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.

Building time machines

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The Museum is famous for its collection of astrolabes, the largest and most significant in the world and particularly strong in Islamic instruments. An astrolabe is a brilliant astronomical device used, very roughly speaking, for timekeeping. But as researcher Taha Yasin Arslan explains, timekeeping in the medieval Muslim world involved many different things…

by Taha Yasin Arslan

Perhaps the most fundamental definition of timekeeping is the reading of the position of the Sun or stars. But in the medieval Muslim world it had a much broader meaning. Knowledge of timekeeping or ilm al-mīqāt covered the finding of instantaneous time; the times of the five daily prayers; the direction of Mecca; as well as making instruments and writing manuals for observational devices. People who worked on timekeeping were called muwaqqīt or mīqātī, which means ‘timekeeper’.

Arabic tables for timekeeping

Arabic tables for timekeeping

Timekeeping in the medieval Muslim world started in Baghdad in the 9th century, but it was the Mamluk-era (1250-1517 CE) astronomers who lived in Egypt, Syria and Palestine who were the real deal. They studied all branches of astronomy but specialised in timekeeping. They prepared tables and invented practical instruments for observation and calculations. In fact, they were excellent instrument makers who made some of the best astrolabes, astrolabe quadrants and sundials in the history of astronomy. Several of these instruments are here in the Museum’s collections.

I am particularly interested in how these instruments were made and used, and how the meticulous and complex tables were drawn up. The astrolabes have many parts, markings and scales and are not easy to understand at first glance. So I have decided to study timekeeping in detail; and the more I studied it the clearer it became that these tables aren’t so hard to understand after all. In fact, the astronomers prepared the tables for timekeeping so that the less initiated would be able to find the time without making extensive observations or calculations.

The same idea was applied to instruments. Astronomers made the instruments user-friendly, even for beginners. Once you learn basic and simple principles, you would know how to use any astrolabe or any other similar instrument.

Replica of Ibn al-Sarraj's Universal Astrolabe by Taha

Replica of Ibn al-Sarraj’s Universal Astrolabe by Taha Yasin Arslan

Preparing tables and making instruments demands an extensive knowledge of spherical trigonometry and astronomy, but using them doesn’t. As a student of the history of astronomy, the best way for me to understand how they work has been to prepare the tables and construct the instruments myself. So, that’s what I did.

First, I have learned the formulas for the markings (altitude, azimuth, hour-lines…) on the instruments. Then I drew various instruments on the computer. Finally, I was ready to make the instruments. With my brother’s help for the 3D modelling, and the pursuit of at least five different artisans for every instrument, I have managed to make my own devices. Some are replicas of medieval instruments, but some are my own adaptations in the same tradition.

When you take an instrument made with your own hands, understanding how it works becomes so easy and it feels amazing. When you appreciate how hard it is to make an instrument, even in these modern times, it’s a wonder how people a thousand years ago managed to make the beautiful objects that you can see in the Museum now.

Building time machines like this is a noble and beautiful endeavour indeed!

Replica of Bayezid Astrolabe

Replica of Bayezid Astrolabe by Taha Yasin Arslan