Visiting the Cavendish Museum

Year 13 2013 trip to the Cavendish Museum

The year 13 students are preparing to give one of our year 9 classes a lesson on the history of the atom so to help them we visited the Cavendish Museum to see some of the apparatus used by famous scientists in the field of Particle Physics.

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http://www-outreach.phy.cam.ac.uk/cav_museum/

We were lucky to be shown around by Elizabeth Bateman who had recently graduated with a degree in Natural Sciences specialising in Physics from Cambridge University.

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http://www-outreach.phy.cam.ac.uk/camphys/

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The above picture shows Lizzie giving Pameer and Wing Chung a map to where the various exhibits can be found.

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The above picture is of a bust of the great man James Clerk Maxwell.

http://en.wikipedia.org/wiki/James_Clerk_Maxwell

The picture below left shows Maxwell’s desk which he used at the Cavendish Laboratory on Free School Lane.

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On the desk is a framed copy of a letter found in the desk. The letter was sent in 1871 and invites Maxwell to become the Professor of Experimental Physics at Cambridge.

The picture above right shows some of the students seeing if Maxwell had left anything in his desk. They found a rather old rubber band.

The main reason for the students going to the museum was to learn more about J.J. Thomson and the discovery of the electron, Rutherford and the discovery of the nucleus and Chadwick and the discovery of the neutron.

http://en.wikipedia.org/wiki/J._J._Thomson

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Sir Joseph John “J. J.” Thomson, OM, FRS (18 December 1856 – 30 August 1940) was a British physicist. In 1897, Thomson showed that cathode rays were composed of a previously unknown negatively charged particle, and thus is credited with the discovery and identification of the electron.

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Thomson’s illustration of the Crookes tube by which he observed the deflection of cathode rays by an electric field (and later measured their mass to charge ratio). Cathode rays were emitted from the cathode C, passed through slits A (the anode) and B (grounded), then through the electric field generated between plates D and E, finally impacting the surface at the far end.

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The above pictures show a copy of the apparatus used by J. J. Thomson to discover the electron.

Ernest Rutherford was the fourth Cavendish Professor. He had become famous, along with Geiger and Marsden, for discovering the nucleus of the atom whilst at Manchester University.

http://en.wikipedia.org/wiki/Ernest_Rutherford

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Ernest Rutherford, 1st Baron Rutherford of Nelson, OM FRS (30 August 1871 – 19 October 1937) was a New Zealand-born physicist who became known as the father of nuclear physics.

Along with Hans Geiger and Ernest Marsden in 1909, he carried out the Geiger–Marsden experiment, which demonstrated the nuclear nature of atoms. Rutherford was inspired to ask Geiger and Marsden in this experiment to look for alpha particles with very high deflection angles, of a type not expected from any theory of matter at that time. Such deflections, though rare, were found, and proved to be a smooth but high-order function of the deflection angle. It was Rutherford’s interpretation of this data that led him to formulate the Rutherford model of the atom in 1911 – that a very small charged nucleus, containing much of the atom’s mass, was orbited by low-mass electrons.

http://en.wikipedia.org/wiki/Hans_Geiger

http://en.wikipedia.org/wiki/Ernest_Marsden

http://en.wikipedia.org/wiki/Geiger%E2%80%93Marsden_experiment

http://en.wikipedia.org/wiki/James_Chadwick

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Sir James Chadwick CH FRS (20 October 1891 – 24 July 1974) was an English physicist who was awarded the 1935 Nobel Prize in physics for his discovery of the neutron in 1932. He devised a simple apparatus that consisted of a cylinder containing a polonium source and beryllium target. The resulting radiation could then be directed a material such as paraffin wax and the particles displaced, which were protons, would go into a small ionisation chamber where they could be detected with an oscilloscope.

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The above picture shows some of the students looking at the exhibits.

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Alfie and Pameer looking at a diffusion cloud chamber. Pameer was photographing it.

http://en.wikipedia.org/wiki/Cloud_chamber

The cloud chamber, also known as the Wilson chamber, is a particle detector used for detecting ionizing radiation.

Cloud chamber with visible tracks from ionizing radiation (short, thick: α-particles; long, thin: β-particles).

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The above picture shows Wing Chung, Aslam, Pameer, Alfie and Matthew standing beside the bust of James Clerk Maxwell.

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The above picture shows the students standing with Lizzie by Maxwell’s desk.

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