Page 30 - BBC History The Story of Science & Technology - 2017 UK

Ideas & Inventions / Objects

It wasn’t until the invention of the laser
in 1960 that 3D holography could develop

10 THE HOLOGRAM
½ The 3D image that
made a 15-year journey
10 ROSALIND FRANKLIN’S from half-realised
theory to practice
X-RAY PHOTOGRAPH
Impossible to pin down with a photograph,
This image, taken in a London laboratory in the early holograms flicker from one half-state
1950s, was crucial in unlocking the secrets of DNA of existence to another. Unlike almost
every other scientific invention, the theory
When the crystallographer Rosalind like Franklin, Watson knew that the underpinning holograms was thoroughly
Franklin (1920–58) produced the x-ray prominent X shape revealed a spiral, worked out long before the first one
photograph above in London in the and he realised later that two was created.
early 1950s, she carefully filed it away molecular strands must be inter- Dennis Gabor (1900–1971), a Hungarian
for future analysis. A firm believer in twined. Fully analysing the photo- Jew who had fled to Britain, developed the
following scientific protocol, she had graph involved careful measurements idea in 1947. Using standard laws of
been trained to carry out her research and long calculations. Both Watson optical physics, he suggested that the
methodically, and she was deter- and Crick soon rushed into print, 3D-appearance of an object might be
mined to complete her current set of claiming that by unravelling the recorded permanently, to be made visible
experiments before exploring any structure of complex molecules inside once again by shining the same type of
further possibilities, however genes, they had discovered the light as before. For years, holograms
tantalising they might seem. secrets of inheritance. Franklin died existed in a limbo state, envisaged
James Watson (1928–) was a very young, in 1958, but her contribution intellectually but unrealised in practice. It
different character. A young American to the understanding of DNA is now was only after lasers were invented in 1960
PhD student at Cambridge, he was fully recognised. that holography became feasible.
impulsive, ambitious and firmly
focused on his goal: to decipher the Patricia Fara is president of the British Society a
structure of DNA. Watson defied his Watson engaged for the History of Science
boss’s instructions to get on with his
own work, and instead engaged in in clandestine DISCOVER MORE
clandestine meetings with Francis
Crick (1916–2004) as they struggled meetings with BOOK
to solve science’s biggest puzzle. Science: A Four Thousand Year History
When Watson was shown Crick as they by Patricia Fara (OUP, 2009)
Franklin’s picture without her WEBSITE
knowledge, he immediately recog- struggled to For more information on key objects
nised its significance – “my mouth fell in the history of science, log on to the ALAMY/SCIENCE PHOTO LIBRARY
open and my pulse began to race,” he solve science’s website of the Whipple Museum of
reported in his bestselling book, The the History of Science: hps.cam.ac.uk/
Double Helix. Although not an expert biggest puzzle whipple/explore

30 The Story of Science & Technology