Wednesday, 7 November 2018

Physics in the Early 20th Century



 

Modern ideas

What do you know about the following?
Radiation         Relativity         Quantum mechanics 

 

The vastness of the universe

Few people realize how much our picture of the universe has changed in 100 years. At the end of the 19th century, the universe was thought to contain only hundreds of thousands of stars arranged in no particularly interesting patterns. The most distance stars were thought to be about 100,000 light years away (meaning that it would take light 100,000 years to travel from Earth to such distant stars; 1 light-year is about 10 trillion kilometres or 6 trillion miles). Today, astronomers have observed objects that are about 10,000,000,000 [= ten billion] light years away. Furthermore, they have discovered that the universe contains many interesting structures. Amazingly, it was not until the 1920's that it was realized that galaxies exist. Galaxies are vast collections of stars grouped together in a relatively localized region of the universe. A typical galaxy contains 100,000,000,000 [=one hundred billion] stars and is 100,000 light years in size.

Some important physicists

What do you know about the following scientists? 
Neils Bohr       Werner Heisenberg    Erwin Schrodinger      Frederic Joliot-Curie
Enrico Fermi   H.G. Wells                   Leo Szilard                   Vannevar Bush
Thomas Kuhn

 

National Socialism and the scientists – two sides to every story

At the peak of atomic and nuclear physics, there was a rise in National Socialism. The Nazis drove out many German scientists, including Albert Einstein, Otto Hahn, Lise Meitner, and Fritz Strassmann due to “anti-intellectualism” according to McGee. This led to certain German and Jewish intellectuals fleeing into the arms of German enemies, bringing nuclear research to other countries such as the United States. Ultimately, these escaped researchers contributed to the development and research of atomic ware fare under the code name—the Manhattan Project.   

Breakthroughs 1912-1947

1915 – relativity          1916 – wormhole        1917 – cosmological constant           
1919 – proton discovered       1922 – primeval soup 1925- size of universe contended      
1926- uncertainty principle    1927- universe is expanding   1928-antimatter exists
1929 – galaxies moving away                        1932 – electrons / splitting the atom 
1934 – dark matter     1939 – nuclear fission

Wednesday, 10 October 2018

Nuremberg During World War II




Nuremberg is famous

·         For its Parade Ground where mass rallies were held 
·         Nuremberg laws
·         Bomb damage
·         Nuremberg trials
So, Nuremberg is famous for four reasons to do with the war. 




Not bombed so much? (But see picture) 

Nuremberg was not bombed much - the major reason the War Crimes trials were held there was that the city had not suffered much war damage, and the courthouse and adjacent were large and intact when the war ended, RAF Bomber Command targetted all major German cities in an attempt to kill as many German civilians as possible. USAAF targetted all railway junctions in Germany (including those in Nuremberg and Munich) so as to destroy the German transport infrastructure and thus damage their war effort.
 


Some facts about Nuremberg:

·         Mediaeval town
·         Town built inside a castle
·         Famous for toys 
·        Early centre of humanism, science, printing, and mechanical invention 


Wednesday, 22 August 2018

Hyperinflation


A tale of two rucksacks

There were two left when he got there.
“I’d like the two rucksacks in the window,” he told the assistant.
“That will be 20,000,000 marks,” said the young man.
What? They’d gone up that much in what – how long had he been – an hour?
“Very well,” said Ernst. “And what could you sell me for 100,000 marks?”
“Nothing really. You could try the stationers next door. Maybe a note book?”
That might be an idea. He could record their journey in it or try and work out his thoughts on this new life he wanted to take on. He handed the money over to the assistant.
“I’ll just go next door while you wrap those up,” he said. If he waited a moment longer the 100,000 mark wouldn’t even buy a piece of paper.     
(Extract from Clara's Story.)  

Things get worse


But as it went on, things got worse. Dentists and doctors stopped asking for currency, seeking payment in butter or eggs instead. Prices rose not just by the day, but by the hour — or even the minute. If you had your morning coffee in a café, and you preferred drinking two cups rather than one, it was cheaper to order both cups at the same time. See: https://inflationdata.com/articles/hyperinflation/

People collected their wages in suitcases.

One person, who left their suitcase unattended, found that a thief had stolen the suitcase but not the money.

One boy, who was sent to buy two bread buns, stopped to play football and by the time he got to the shop, the price had gone up, so he could only afford to buy one.

One father set out for Berlin to buy a pair of shoes. When he got there, he could only afford a cup of coffee and the bus fare home. See:
 

And wheelbarrows 

In 1920s’ Germany hyperinflation devalues the currency so much that a wheelbarrow filled with cash wasn’t enough to purchase a newspaper.