On Broad Street, behind the famous stone heads on pillars
opposite Blackwell's bookshop, is the Museum of the
History of Science.
This was the old Ashmolean Museum, built to house the
collection of Elias Ashmole and opened in 1683. Elias had by somewhat
underhand means come into the possession of the "natural
curiosities" of John Tradescant the younger. His father, John
Tradescant the elder, was head gardener to Charles I and
had travelled the known world collecting
plants and unusual objects of interest.
The Tradescant curiosities formed the core of Ashmole's collection.
In addition to displaying
objects, the old Ashmolean was the first
scientific institution in England, containing a library, a chemical
laboratory, and a dissecting room. Lectures were also given.
The Museum of the History of Science draws together many of the
strands of Oxford science that we have encountered on our walk.
You can see the original penicillin apparatus, a print commemorating
James Sadler and a medallion struck in his honour, a portrait of Sir Henry
Savile, Hooke's drawings of fleas as observed by him under a microscope,
a Victorian replica of the Hooke-Boyle air pump and a small
component part of the original, a portrait of Halley,
and a colourful painting of a dodo.
The museum also houses early chemical apparatus, watches and clocks,
medical instruments, and
the finest collection of European and Islamic astrolabes in
the world. These were medieval instruments used for making
astronomical measurements. The only complete spherical astrolabe
known to have survived is in the museum's collection.
Henry Mosely, the atomic physicist, lived and worked in Oxford before the First World War. Moseley was the first to determine the atomic numbers of some elements in a series of brilliant experiments. He was killed at Gallipolli in 1915 and is pictured above holding some of his apparatus.
In the first three lines on the blackboard,
Einstein derives an expression for D, the coefficient of expansion of the
universe, in terms of rho, the density of matter in the universe.
The last four lines give numerical values for the expansion D, the density
rho, the radius P, and the age t of the universe.
LJ
denotes Licht-Jahr, or light-year, and J denotes Jahr,
or year. A value for the age of the universe of 10 (or
100) billion years compares with the modern-day estimate of around 15
billion years.
In the basement of the Museum is the blackboard used
by Albert Einstein in the second of three Rhodes Memorial Lectures
on the theory of relativity he delivered at Rhodes House, Oxford, in May 1931.
These lectures were given at an exciting time in physics.
The application of new solutions of Einstein's field equations to the
actual universe became possible by Edwin Hubble's discovery in 1929
that shifts towards the red of the spectral lines emitted by distant
galaxies (the so-called "red shifts") were directly proportional to
their distance from the observer. This discovery
was generally taken to indicate the expansion of the universe
as a whole. The relation between this expansion and the mean density
of the universe formed the subject of the second of Einstein's lectures,
delivered on 16 May 1931.
