William Lawrence Bragg Sir William Lawrence Bragg CH OBE MC FRS ( 31 March 1890 – 1 July 1971 ) was an Australian - born British physicist and X - ray crystallographer , discoverer ( 1912 ) of the Bragg law of X - ray diffraction , which is basic for the determination of crystal structure . He was joint winner ( with his father , Sir William Bragg ) of the Nobel Prize for Physics in 1915 : " " For their services in the analysis of crystal structure by means of X - ray " " an important step in the development of X - ray crystallography . He was knighted in 1941 . To date , Lawrence Bragg is the youngest Nobel Laureate , having received the award at the age of 25 . He was the director of the Cavendish Laboratory , Cambridge , when the epochal discovery of the structure of DNA was reported by James D . Watson and Francis Crick in February 1953 . Biography . Early years . Bragg was born in North Adelaide , South Australia . He showed an early interest in science and mathematics . His father , William Henry Bragg , was Elder Professor of Mathematics and Physics at the University of Adelaide . Shortly after starting school aged 5 , William Lawrence Bragg fell from his tricycle and broke his arm . His father , who had read about Röntgen ' s experiments in Europe and was performing his own experiments , used the newly discovered X - rays and his experimental equipment to examine the broken arm . This is the first recorded surgical use of X - rays in Australia . Bragg was a very able student . After beginning his studies at St Peter ' s College , Adelaide in 1904 he went to the University of Adelaide at age 14 to study mathematics , chemistry and physics , graduating in 1908 . In the same year his father accepted the Cavendish chair of physics at the University of Leeds , and brought the family back to England . Bragg entered Trinity College , Cambridge in the autumn of 1909 and received a major scholarship in mathematics , despite taking the exam while in bed with pneumonia . After initially excelling in mathematics , he transferred to the physics course in the later years of his studies , and graduated with first class honours in 1911 . In 1914 Bragg was elected to a Fellowship at Trinity College – a Fellowship at a Cambridge college involves the submission and defence of a thesis . Career . Work on X - ray crystallography . Bragg is most famous for his law on the diffraction of X - rays by crystals . Bragg ' s law makes it possible to calculate the positions of the atoms within a crystal from the way in which an X - ray beam is diffracted by the crystal lattice . He made this discovery in 1912 , during his first year as a research student in Cambridge . He discussed his ideas with his father , who developed the X - ray spectrometer in Leeds . This tool allowed many different types of crystals to be analysed . Work on sound ranging . Bragg ' s research work was interrupted by both World War I and World War II . During both wars he worked on sound ranging methods for locating enemy guns . In this work he was aided by William Sansome Tucker , Harold Roper Robinson and Henry Harold Hemming . For his work during WWI he was awarded the Military Cross and appointed Officer of the Order of the British Empire . He was also Mentioned in Despatches on 16 June 1916 , 4 January 1917 and 7 July 1919 . On 2 September 1915 his brother was killed during the Gallipoli Campaign . Shortly afterwards , William Lawrence Bragg received the news that he had been awarded the Nobel Prize in Physics , aged 25 , making him the youngest ever winner of a Nobel Prize . Between the wars , from 1919 to 1937 , he worked at the Victoria University of Manchester as Langworthy Professor of Physics . After World War II , he returned to Cambridge , splitting the Cavendish Laboratory into research groups . He believed that " the ideal research unit is one of six to twelve scientists and a few assistants " . Work on proteins . In 1948 he became interested in the structure of proteins and was partly responsible for creating a group that used physics to solve biological problems . He played a part in the 1953 discovery of the structure of DNA , in that he provided support to Francis Crick and James D . Watson who worked under his aegis at the Cavendish . Bragg ' s original announcement of the discovery of the structure of DNA was made at a Solvay conference on proteins in Belgium on 8 April 1953 , but went unreported by the press . He then gave a talk at Guys Hospital Medical School in London on Thursday 14 May 1953 , which resulted in an article by Ritchie Calder in The News Chronicle of London on Friday 15 May 1953 , entitled " Why You Are You . Nearer Secret of Life . " Bragg was gratified to see that the X - ray method that he developed forty years before was at the heart of this profound insight to the nature of life itself . At the same time at the Cavendish , Max Perutz was also doing his Nobel Prize winning work on the structure of haemoglobin . Bragg subsequently successfully lobbied for , and nominated , Crick , Watson and Maurice Wilkins for the 1962 Nobel Prize in Physiology or Medicine ; Wilkins ' share recognised the contribution made by researchers ( using X - ray crystallography ) at King ' s College London to the determination of the structure of DNA . Among those researchers was Rosalind Franklin , whose " photograph 51 " showed that DNA was a double helix , not a triple helix as Linus Pauling had proposed . Franklin died before the prize ( which only goes to living people ) was awarded . The crystal structure of hen egg white lysozyme , which was solved by D C Phillips et al . in 1965 under the directorship of Lawrence Bragg at the Royal Institution , London , led to the discovery of the formula _ 1 helix . The lysozyme structure was determined from crystals of hen egg white lysozyme chloride , which belong to the tetragonal space group Pformula _ 2formula _ 32 with the unit cell dimensions a = b = 79 . 1 Å , c = 37 . 9 Å and have one lysozyme molecule in the asymmetric unit . The existence of the formula _ 1 helix , as opposed to Pauling ' s alpha helix , was predicted by W L Bragg , J C Kendrew & M F Perutz in 1950 . Apparently , many workers failed to mention the discovery of the formula _ 1 helix , and failed to acknowledge the part it plays in the lysozyme structure . Pauling never acknowledged that at least part of the above mentioned 1950 paper made sense . Unlike myoglobin , in which nearly 80 per cent of the amino - acid residues are in the alpha - helix conformation , in the lysozyme protein the alpha - helix content is only about 40 per cent of the amino - acid residues in four main stretches . The formula _ 1 helix is an earlier proposal for the structure of polypeptides made by Bragg W L , Kendrew J C & Perutz M F in 1950 . It is based on the crystallographic idea of an integral number of residues per turn of the helix . In this conformation , every third peptide is hydrogen - bonded back to the first peptide , thus forming a ring containing ten atoms . Lectures . In 1931 , 1934 and 1961 Bragg was invited to deliver the Royal Institution Christmas Lecture on " The Universe of Light " , " Electricity " and " Electricity " . Personal life . He married Alice Hopkinson in 1921 ; she was a cousin of Bragg ' s friend Rudolph Cecil Hopkinson , killed in WWI . They had four children , Stephen Lawrence ( born 1923 ) , David William ( born 1926 ) , Margaret Alice , born 1931 , ( who married Mark Heath ) and Patience Mary , born 1935 . Bragg ' s hobbies included painting , literature and a lifelong interest in gardening . When he moved to London , he missed having a garden and so worked as a part - time gardener , unrecognised by his employer , until a guest at the house expressed surprise at seeing him there . He died at a hospital near his home at Waldringfield , Ipswich , Suffolk . He was buried in Trinity College , Cambridge ; his son David is buried in the Parish of the Ascension Burial Ground in Cambridge , where Bragg ' s friend Rudolph Cecil Hopkinson is also buried . Honours and awards . He was elected an FRS in 1921 — " a qualification that makes other ones irrelevant " . He was knighted by King George VI in the 1941 New Year Honours , and received both the Copley Medal and the Royal Medal of the Royal Society . Although Hunter , in his book on Bragg " Light is a Messenger " , argued that he was more a crystallographer than a physicist , Bragg ' s lifelong activity showed otherwise — he was more of a physicist than anything else . Thus , from 1939 to 1943 , he served as President of the Institute of Physics , London . In the 1967 New Year Honours he was appointed Companion of Honour by Queen Elizabeth II . Since 1992 , the Australian Institute of Physics has awarded the Bragg Gold Medal for Excellence in Physics to commemorate Sir Lawrence Bragg ( in front on the medal ) and his father , Sir William Bragg , for the best PhD thesis by a student at an Australian university . Quotations . “ The gift of expression is important to them as scientists ; the best research is wasted when it is extremely difficult to discover what it is all about . . . It is even more important when scientists are called upon to play their part in the world of affairs , as is happening to an increasing extent . ” " The important thing in science is not so much to obtain new facts as to discover new ways of thinking about them . "