Celsius – a life and death by degrees with Ian Hembrow with Bristol Humanists

Best-known for the 100-point ‘centi-grade’ temperature scale that bears his name, Anders Celsius was a scientist of astonishing breadth. From the Northern Lights to air pressure and sea levels, he unravelled the mysteries of many of nature’s greatest phenomena during his short life. His mind, methods and manners contain powerful lessons for how humans live in the 21st century and beyond – if we’re inclined and willing to listen.

Ian Hembrow’s book Celsius: a life and death by degrees is the first full-length English language biography of this world-changing Swedish scientist. Longlisted for the 2025 Wolfson History Prize, it tracks not just Celsius’ life and times, but also the author’s journey to uncover his story. Ian travelled to the Arctic Circle, down mines and up cathedral towers to follow in his subject’s footsteps. This is a thought-provoking opportunity to learn more about the modest, little-known man with the well-known name, his links with Humanism and how his science continues to shape all of our lives almost three centuries after his death. Anders Celsius (1701-1744) was an enlightenment genius and a mercurial thinker who ran out of time, but his discoveries, philosophy and personality still point a hopeful way forward.

Ian Hembrow is a Bristol-based author and Humanist celebrant, who has written widely including for The Guardian, New Statesman and the Oldie. His previous books, Making Medicines Safe & Rare Events are on global medicines safety.

Reviews of Celsius
‘This is a beautifully written masterwork of science biography, covering the life and times of the great Swedish astronomer Anders Celsius. Ian Hembrow provides a gripping narrative that details his search for a man who was very much embedded in his city and landscape…’ Sarah Covington, Professor of History, Biography and Memoir, City University of New York
‘……a carefully researched and entertaining life of an Enlightenment astronomer, scientist and explorer who gave his name to the Celsius temperature scale…. a fascinating pen-portrait of the times and of this remarkable man.’ – Dr Julian Mayes, Former Vice-President, Royal Meteorological Society

Everyone is welcome. The event is free to members of Bristol Humanists. Non-members are asked to pay £5/£2 (concessions)