50 Years ago

'The neutrino' — While careful reasoning from experimental evidence gathered about all terms in the beta-decay process... may support the inference that a neutrino exists, its reality can only be demonstrated conclusively by a direct observation of the neutrino itself...Such an experiment is made possible by the availability of high beta-decay rates of fission fragments in multi-megawatt reactors and advances in detection techniques. An estimate of the neutrino flux available from large reactors shows that a few protons should undergo reaction in 50 litres of water placed near the reactor...The complete detector consisted of a 'club sandwich' arrangement employing two target tanks between three detector tanks... located deep underground near one of the Savannah River Plant production reactors of the United States Energy Commission...After running for 1,371 hr., including both reactor-up and reactor-down time...a signal dependent upon reactor-power, 2.88 ± 0.22 counts/hr. in agreement with the predicted cross-section (6 × 10−44 cm2.) was measured...

Frederick Reines and Clyde L. Cowan, jun.

From Nature 1 September 1956

100 Years ago

'Thermodynamic reasoning' — In the address delivered by Principal Griffiths at York... I read: “Prof. Armstrong remarks that it is unfair to 'cloak the inquiry by restricting it to thermodynamic reasoning'...He adds that such a course may satisfy the physicist but 'is repulsive to the chemist'.”

This statement shows a strange misapprehension of my position...At present, progress is not a little hampered by the fact that chemists and physicists cannot wander through the museums of nature in complete sympathy with one another...a confusion of language has arisen which keeps us apart: we must both strive to speak a simpler language.

From Nature 30 August 1906