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  • Writer's pictureDale DeBakcsy

Beatrice Tinsley, the Birth of Galaxies, and the Ever-Expanding Universe

Dr Beatrice Tinsley lived on our resolutely turning planet for only four decades, but in that time she gifted us a vision of the cosmos as dynamic and expanding even in those places it appears most placidly serene. She plucked galaxies from the pantheon of static celestial objects and showed us, through a rigorous combination of chemistry, mathematics, physics, and state of the art machine computation, how these creatures are likely born, how they age and interact with one another, and what their fate will ultimately be. She was the passionate nerve-centre of the world’s cosmological efforts, connecting everyone to everyone through the medium of her encyclopedic memory for facts and people, and when she was gone, there was simply nobody to fill the void. We had Tinsley, and then we did not, and astronomy was long in recovering from the transition.

The career of Beatrice Muriel Hill (1941–1981) spanned fourteen short years, from 1967 to 1981, but so intense was her passion for astronomy, so keen her basic need to work and discover, that she managed to forge the towering reputation of an elder scientific statesman in that brief span. There are people who take time to slowly develop their gifts and become the scientist they were meant to be, and others who explode out of the gate, shouting their skill from the first moment they turn their brain to the tangles and wonders of the world, and Tinsley was decidedly the latter. She tried everything, and succeeded at whatever she tried. She was a classical violinist who played chamber and orchestral music, a prize winner in Latin and French, and a lover of mathematics who sat in the back of the class just so she wouldn't be distracted while she taught herself more advanced mathematics than her classes could provide for her hungry brain.

The daughter of a ex-military man and aspiring priest who moved the family from England to New Zealand when Beatrice was very young in pursuit of a parish, her skills shone in every school she attended, culminating in her college work at Canterbury University in Christchurch. At the physics department there, she threw herself into learning how to use the new computer systems to perform complicated calculations, a skill that would prove useful when she turned it upon the massive problems of galactic evolution later. And she fell in love, with a physics student named Brian Tinsley, who she married some months before her twenty-first birthday.

Together, they relocated to Texas, where Brian had an attractive offer from the Southwest Center for Advanced Studies in Dallas to carry out his work in spectroscopy, while she was allowed to transfer her scholarship there to carry on study. Soon after arriving in 1963, however, she decided upon the University of Texas in Austin for her PhD work, flying out to Austin every Tuesday morning and returning by bus every Friday afternoon to spend the weekends at home with Brian. It was a punishing schedule but worth it to finally be free of the sense of academic stagnation that she felt in Dallas, where she was often treated as more of a faculty wife than a scientist in her own regard.

Her PhD thesis dealt with the evolution of galaxies, and proved to be the start of a revolution in that field. In the face of an academic community which held that galaxies could be treated as fixed objects in the night sky because they did not effectively change their composition or luminosity over time, Tinsley argued that galaxies were in fact dynamic objects, the colours of which could not necessarily be directly tied to their age, and the luminosity of which fades distinctly over time, meaning that any attempt to use them as ‘standard candles’ is doomed unless the astronomer applies crucial correcting factors to their computations.

It was one of those theses that announce to the academic world the arrival of a new force, and demonstrated already the hallmarks for which Tinsley would come to be known – a deep familiarity with the existing literature, and a fundamental ability to find and evaluate factors that influence astronomical events that others had not previously taken into account. It was the ship that should have launched a startling new career, but it was very nearly both introductory volley and swan song, as in 1968 the Tinsleys, unable to conceive a child of their own, took the step of adopting, followed a couple years later by the adoption of a second child. Beatrice decided to stay at home to be with the children while Brian’s work took him around the world for the standard academic fare of seminars, colloquia, and consultations.

Over the next five years, she gradually returned to her research in astronomy, but it wasn't until 1973 that she was fully engaged in her life’s work again, meaning that the scant fourteen years she had as a professional was effectively more like a positively shudderingly brief nine. She was made aware of the fact that Austin would most likely never give her a tenured position or resources commensurate with her research needs, and so she went hunting for a new university where she could realise the full scope of her intellectual vision. That university, it turned out, was Yale, but choosing it came at a great cost.

Beatrice and Brian had agreed to begin divorce proceedings in 1973, but that left the question of what was to become of the children. When Beatrice decided to move to Yale, the question became that much more keenly pressing. To bring the children with her would be to uproot them from their home, friends, and school, but to leave them behind would mean only the barest of contact with them sporadically as vacations might allow. After some trial runs, she satisfied herself that the children could do well without her daily presence, and made the difficult decision to leave them in Brian’s care as she headed for Yale, and her destiny.

She arrived there in 1974, and the next six years saw her as the beating heart of a new community seeking to understand the universe through a complicated combination of physics, chemistry, mathematics, computer modeling, and thermodynamics. The astronomy community, which had been so inspired by her PhD work, rushed to consult her, sending her papers for critique, and inviting her to conferences the world over. She took responsibility for the shepherding of graduate students, and made sure that they connected with experienced astronomers whose work aligned with their interests. She collaborated with observatories and her colleagues to produce dozens of papers which considered the impact of galactic collisions on the evolution of galaxies, the luminosities of galaxies in their infancy and demise, the existence and pace of universal expansion, the evolving chemical composition of galaxies as their component stars synthesised new elements (including FORTRAN programs that modeled 12 billion years of galactic development), and encyclopedic evaluation and criticism of the reigning galactic models.

She was the person you talked to if you had a notion about galaxies and the evolving universe and wanted to know what obscure but crucial chemical or physical interaction your model might be leaving out. Mentor, researcher, and colleague, her frantic pace and iron work ethic astounded those who collaborated with her, and given the four decades of mature mental labour that ought to have been her due, who knows what visions of the cosmos she might have provided us.

It was not, however, to be. In February of 1977 she wrote her father to let him know that the doctors had determined that a lump on her leg was due to skin cancer. Throughout the next four years, she would experience bouts of seeming complete recovery, and pushed herself to work until the end, but in spite of several operations the cancer eventually spread to her vital organs. When the cancer eventually invaded her brain, she lost the use of her right hand but, determined not to surrender to circumstance, she taught herself how to write with her left in order to continue her correspondence. Her last letter to her father, written in large blocky print, said simply at its end, ‘I think of you a whole lot, not only on Birthdays, and wish you strength and happiness in the coming days. I honestly don't think the length of life is important. Very much love, from Beatrice,’ next to which she drew a small picture of a beetle, which had been her nickname as a child.

At her funeral, one of her poems, written when she knew her death was immanent, was read aloud:

Let me be like Bach, creating fugues,

Till suddenly the pen will move no more.

Let all my themes within – of ancient light,

Of origins, and change and human worth-

Let all their melodies still intertwine,

Evolve and merge with ever growing unity,

Ever without fading,

Ever without a final chord...

Till suddenly my mind can hear no more.


Edward Hill, Beatrice’s father, wrote a memoir of her life after her passing, My Daughter Beatrice: A Personal Memoir of Dr Beatrice Tinsley, Astronomer (1986) which gives wonderful glimpses of her early years, though the later years are primarily given over to less compelling accounts of her travels and meetings. There is however an introductory appreciation of her life, and an obituary by her colleagues that lay out her more scientific accomplishments, so all in all it's a fine book to have.

If you'd like to read more about women astronomers like this one, check out my History of Women in Astronomy and Space Exploration, which you can order from Amazon, or from Pen and Sword US or UK.


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