Michael Faraday

(September 22, 1791 - August 25, 1867

• Einstein believed that physical science contained two couples of equal magnitude: Galileo Galilei and Isaac Newton; Michael Faraday and James Clerk Maxwell.
• Faraday was a late-bloomer compared to most significant science discoverers.

1. At 40 he discovered how to obtain electric currents from magnetic

fields.

2. 54, he discovered how light may be affected by magnetism and he

formulated ideas on the nature of an electric force – the foundations

for relativity.

3. 69, he had ideas on the nature of electricity and gravity.

• As a child he ran errands for a bookseller – in those days they would rent out newspapers. During his time here an artist customer taught him how to draw – this would become useful in his science life.
• When he was 14 he became a bookbinder. He read many books and partook in his own makeshift experiments. One day a Mr. Dance took him to Professor Humphrey Davy’s lectures. After the lecture he wrote out his lecture and bound it up. He sent it to Davy with a letter requesting a job. Both are preserved at the Royal Institute.
• He became Davy’s assistant and educated himself. Together they went on an 18 month trip around Europe. He was treated like crap but met several of the leading scientists of the day. It was also a great education for him.
• In 1824 he became a member of the Royal Society at the age of 30.
• In 1825 he became the director of the laboratory.
• He started the Christmas lectures to revitalise the state of the Royal Institution. His more popular series: ‘The history of the Candle’. [All lectures are preserved].
• In 1825 he discovered Benzene, an aromatic carbon compound. Later he became a Professor of Chemistry at the Royal Institute.
• Because of Oerted’s Occurrence (current moving compass needle) Faraday believed that the vice versa was possible (magnetism inducing an electric current. This problem took him 10 years to master.
• He introduced many terms: ion, electrode, cathode, and anode.
• In 1821 Faraday made his first electric motor. He then found that he could induce a current in a wire by wrapping it around a magnet. He would later create the generator and transformer.
• Faraday didn’t believe in accumulating wealth because of his Christian faith. He did some private work for industry which brought in a bit of coin, but shunned it for most of his life. After much wrangling he finally agreed to accept a pension from the government.
• To honour his accomplishments, a unit of electricity was named after him. The "farad" measures capacitance, an amount of electrical charge.
• Faraday’s journal is preserved at the Royal Institute.

Werner Heisenberg (December 5^th, 1901–)

• Werner came from a family of middle-class craftsmen. Father was a lecturer (then lecturer) and secondary school teacher.
• His uncle Karl was a rich factory owner in New York (uniform buttons). He would become invaluable to Werner after WWII.
• Werner could play a mean piano, loved practicing it all his life.
• Since a child he was keen on mathematics. He worked hard on finding the proof for Fermat’s Last Theorem, failed and gave it up.
• To the Heisenbergs, class, social standing and cultural recognition meant a great deal. This would also continue on with Werner.
• In 1927, at the age of 26, Werner became a professor of physics at Leipzig.
• He was always against the Nazis increasing control over his professional career and the choices he made. He disliked the spies in the lectures etc.
• Although he never actually joined the Third Reich, he did go on to hold several scientific positions throughout the party without ever really complaining. However his love of country deemed it impossible for him to desert Germany.
• Werner and Neils Bohr (especially Neils Bohr) helped several Jewish scientist to flee Germany and the occupied territories – Bloch; Gerhard Herzberg etc.
• In 1932 he was awarded the Nobel Prize for Physics. However, at this same time he refused to participate in a national rally for the National Socialist Teachers League (who supported Germany’s withdrawal from the League Of Nations and supported the Nazis). He informed physicist Johannes Stark, the rally’s organizer, of his decision. The Nazis Youth League were angered. It also created a nemesis in Johannes Stark throughout the Nazis reign.
• There was a slight controversy in the awarding of the Nobel Prize to him as the Nobel committee deems Werner the father of Quantum Mechanics – over Born, Shrodinger and Dirac. Werner later expresses his uneasiness in the award.
• Ongoing public struggle between Starkes and Werner, this also led to a problem with the SS in general. Werner tried to maintain his independence without rocking the boat.
• Werner Heisenberg predicted absorption of neutrons by U-238 would reach equilibrium at such a high temperature as to generate electricity etc. He did NOT think to increase the amount of material used therefore requiring a higher absorption of neutrons through the control – otherwise a chain reaction would spiral. One of Werner’s flaws that prevented Germany ever developing the atomic bomb in time.
• In September ’41 Werner realized his path to making the atomic bomb. Also in this month the famous meeting of Werner and Niels Bohr took place in Copenhagen. It is still shrouded in mystery but it caused a lot of distress to Bohr.
• Heisenberg, in a letter to a friend, stated that ‘we could very well bring upon ourselves a ‘last day’ or something closely related to it.

[a lot more to come on Heisenberg’s life]

General Atomic Bomb development history

• Rutherford had caused the first transmutation in 1899 by bombarding nitrogen with alpha particles (helium nucleus – 2 protons and 2 neutrons). This created an oxygen isotope O-17
• Rutherford was convinced that a ‘neutron’ existed. James Chadwick spent years running tests. He will later find the neutron theory to be true.
• Neils Bohr’s discovery of quantum levels for electrons revolutionises quantum mechanics and paves the way for Heisenberg, Dirac etc.
• Meitner and Otto Frisch showed how fission occurred by using Niels Bohr’s liquid drop model of heavy nuclei. They told Bohr.
• In 1939 Bohr took it to America and worked on the theory of nuclear fissionwith John Wheeler in Princeton.
• A Paris-based nuclear research team (under Frederick Joliot, confirmed more neutrons were produced than absorbed; thus sparking a chain reaction.
• Pegram and Fermi alerted US Navy of the possible uses of fission. They were ignored.
• After war broke out Einstein wrote his famed letter to Roosevelt (on the insistence of Leo Szilard, with whom Einstein had patented a design for a magnetic pump refrigerator (it was taken on by German company AEG, who built the prototype, but it was too noisy and they dropped it).
• Frisch and Peierls (German refugee scientists in the UK) told the British Government about the Nazis plan for an atomic bomb.
• By mid 1940, two nuclear fission projects were well underway on either side of the ocean. They later merged (French and US teams) to form the Manhattan Project.
• Two Gottingen professors informed the Reich Education Ministry about this.
• The Reich controlled the largest supply of uranium ore in Czechoslovakia.
• Bohr realised that the two isotopes – U-235 and U-238 – is easily split by slow neutrons. However, U-235 is extremely rare.
• Plutonium was the artificial element used in the ‘Fat Man’ atomic bomb, dropped on Nagasaki in ’45.

Lise Meitner (1878-1968)

• From a well to do family. Father was doctor, mother a pianist.
• In 1901 Meitner was one of only four women admitted to the university of Vienna.
• In 1906 she was awarded a Ph.D in physics. She worked as a lab assistant for Professor Ludwig Boltzman.
• Meitner joined Han on radioactivity and was grudgingly allowed to work in the labs as long as she did not venture into the chemistry labs. This barrier for women was soon brought down and she was ablr to walk freely through the labs.
• In 1918 Meitner had isolated a new element. Together (Meitner and Hahn) published their results. Name of element: protactinium.
• In 1909 Meitner attended an Einstein lecture about special relativity and E-mc2.
• Hahn and Meitner attended a lecture by Ida Noddack (’34) about how bombardment of the nucleus by neutrons can split the atom. This inspired them to change the direction of their research.
• Meitner was exiled from Germany due to the Nazis situation – which wasn’t helped by Hahn’s refusal to vouch for her.
• From Sweden she advised Hahn to hit U238 for a Radium decay product.
• On December 19, 1939 Hahn told her that the resulting isotopes from the bombardment weren’t Radium… but Barium.
• Walking in the snow with her cousin Otto Frisch (also a physicist working at Neils Bohr’s labs, she realised that the atom was splitting into Barium and Crypton gas with energy of 200eV being released. She came round to this conclusion by recalling Einstein’s lecture and utilising E=mc2. The calculation proved to be true.
• In 1944 Otto Hahn won the Nobel Prize for this work in fission – a term also coined by Meitner.
• Meitner was invited to join the Manhattan Project but turned it down for moral reasons stating: ‘I hope they will not succeed in making an atomic bomb, but I fear they will.’
• Her desk for fission experiments is erroneously labelled as Otto Hahn’s.
• [more to be done on her life and work]

Tez Asfaw