How physics get done not what you might expect

[Naty1]

How physics gets done...not what you might expect

ahoy geeks! I came across a couple of funny stories I thought worth sharing...So if you have any, add them on...

Stephen Hawking; Sixty years in a Nutshell, Chapter 6, The future of Theoretical Physics and Cosmology, Celebrating Stephen HAwkings 60th Birthday, Cambdirdge University Press, 2003

I arrived in Cambridge in October 1962 as a graduate student…. I felt that elementary particles at that time was too like botany. The Cambridge school held that there was no underlying field theory. Instead everything would be determined by unitarity, that is probability conservation, and certain patterns in scattering….With hindsight it seems amazing that it was thought this approach would work, but I remember the scorn that was poured on the first attempts at unified theories of the weak nuclear forces…

Unlike elementary particles there was a well defined theory, the general theory of relativity, but this was thought impossibly difficult. People were so pleased to find any solution of the field equations, they didn’t ask what physical significance, if any, it had. This was the old school of general relativity Feynman had encountered in Warsaw {same year} and he described in a letter to his wife: “I am not getting anything out of the meeting. I am learning nothing…few of the best men are working on it... The result is that there are hosts of dopes here [126] and it is not good for my blood pressure. Remind me not to come to any more gravity conferences.”

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http://en.wikipedia.org/wiki/Microwave_oven#Accidental_discovery

It was in 1945 that the specific heating effect of a high-power microwave beam was discovered, accidentally. Percy Spencer, an American self-taught engineer from Howland, Maine who worked at the time for Raytheon was working on an active radar set when he noticed that a Mr. Goodbar he had in his pocket started to melt — the radar had melted his chocolate bar with microwaves. The first food to be deliberately cooked with Spencer's microwave was popcorn, and the second was an egg, which exploded in the face of one of the experimenters.[6][7] To verify his finding, Spencer created a high density electromagnetic field by feeding microwave power from a magnetron into a metal box from which it had no way to escape. When food was placed in the box with the microwave energy, the temperature of the food rose rapidly.

On October 8, 1945,[8] Raytheon filed a United States patent application for Spencer's microwave cooking process

I wonder why the chocolate bar melted but he didn't??

 

[Jilang]

LOL, he may have just noticed a warm feeling!

 

[SteamKing]

Lower melting point for the chocolate. I'm sure if Mr. Spencer didn't have a chocolate bar in his pants, he probably would have left the magnetron on until he did melt.

 

[DrGreg]

I wonder why the chocolate bar melted but he didn't??

Chocolate melts at blood temperature. So chocolate in a pocket is almost at melting point and needs only a small amount of extra energy to melt.

Humans melt at a much higher temperature.

 

[Jilang]

LOL. Don't worry Naty, we don't all assume you know nothing about chocolate!

 

[Naty1]

LOL, he may have just noticed a warm feeling!

That is what I wondered...likely a lucky guy...

 

[russ_watters]

Humans are predominantly liquid: they don't melt, they boil.

 

[AlephZero]

It's well known (especailly you read Wikipedia) that Americans invented all modern technology, but the Brits got there first with the cavity magetron, in 1940. http://en.wikipedia.org/wiki/John_Randall_(physicist )

IN fact the USA tried to stop the Brits from using it in WWII, claiming for some reason that it didn't work. See "American opposition" in http://rsnr.royalsocietypublishing.org/content/58/3/283.full.pdf

And when the Germans found out about the British system from a crashed plane, they wrote a report claiming it was a copy of a Russian patent. (see link above).

But of course it is well known (in Russia) that Russians also invented all modern technology, from the steam engine onwards

I've heard anecdotes that the British military also used them for culinary purposes, though this was officially a military secret and I can't find a web reference anywhere.

 

[Enigman]

Chemistry and math:

How to discover the structure of organic compounds:

The ouroboros dream

The new understanding of benzene, and hence of all aromatic compounds, proved to be so important for both pure and applied chemistry after 1865 that in 1890 the German Chemical Society organized an elaborate appreciation in Kekulé's honor, celebrating the twenty-fifth anniversary of his first benzene paper. Here Kekulé spoke of the creation of the theory. He said that he had discovered the ring shape of the benzene molecule after having a reverie or day-dream of a snake seizing its own tail (this is a common ancient symbol known as the ouroboros).[7] This vision, he said, came to him after years of studying the nature of carbon-carbon bonds.
It is curious that a similar humorous depiction of benzene had appeared in 1886 in the Berichte der Durstigen Chemischen Gesellschaft (Journal of the Thirsty Chemical Society), a parody of the Berichte der Deutschen Chemischen Gesellschaft, only the parody had monkeys seizing each other in a circle, rather than snakes as in Kekulé's anecdote.
[..spoilsport cynical harping removed...E]
He told yet another anecdote in 1890, of a vision of dancing atoms and molecules that led to his theory of structure. This happened, he claimed, while he was riding on the upper deck of a horse-drawn omnibus in London. If true, this probably occurred in the late summer of 1855.

http://en.wikipedia.org/wiki/August_Kekulé#The_ouroboros_dream

Somebody asked von Neumann to solve the famous fly puzzle:
(edited)

Two bicyclists start twenty miles apart and head toward each other, each going at a steady rate of 10 mph. At the same time a fly that travels at a steady 15 mph starts from the front wheel of the southbound bicycle and flies to the front wheel of the northbound one, then turns around and flies to the front wheel of the southbound one again, and continues in this manner till he is crushed between the two front wheels. Question: what total distance did the fly cover?

*The slow way to find the answer is to calculate what distance the fly covers on the first, northbound, leg of the trip, then on the second, southbound, leg, then on the third, etc., etc., and, finally, to sum the infinite series so obtained.

*The quick way is to observe that the bicycles meet exactly one hour after their start, so that the fly had just an hour for his travels; the answer must therefore be 15 miles.

When the question was put to von Neumann, he solved it in an instant, and thereby disappointed the questioner: "Oh, you must have heard the trick before!" "What trick?" asked von Neumann, "All I did was sum the infinite series.

http://en.wikipedia.org/wiki/John_von_Neumann#Cognitive_abilities

 

[Naty1]

geeks, please, just calm down...please, 'stifle' yourselves! Some are beginning to remind me of the joker, Feynman.

Too many are taking my original question about 'melting' as would "Dr. Sheldon Cooper" [Jim Parsons] of the TV show, 'Big Bang Theory'...LITERALLY.

Further chocolate discussion, human melting and so forth, from this time forward risk being referred to as 'geeks', a mantle many find difficult to wear...So far in these forums, only perfect has admitted 'geek status' that I have seen. I have implied as much about myself but that's likely a bit of an exaggeration. I would consider that mantle,however, should I encounter 'Penny' [Kaley Cuoco] of the same TV show.

This a bit different than I recall reading: cavity magnetron...

IN fact the USA tried to stop the Brits from using it in WWII, claiming for some reason that it didn't work.

I seem to recall that the development of RADAR was considered so crucial to the war effort that documents and maybe an early model were shipped to the US by the British for parallel development in the US.

 

[Naty1]

Lecture by Stephen Hawking, same source as the first...
The future of Theoretical Physics and Cosmology, Celebrating Stephen Hawking 60th Birthday, Cambridge University Press, 2003

[Dennis Sciama was Hawking's advisor at Cambridge.]

"Sciama was very keen on Mach's principle: An object owes it's inertia to the influence of all other matter in the universe. He tried to get me to work on this but I felt his formulations...were not well defined. However, he introduced me to something a bit similar with regard to light, the so called Wheeler-Feynman [WF]electrodynamics. This said that electricity and magnetism were time symmetric. However, when one switched on a lamp, it was the influence of all other matter in the universe that caused lightwaves to travel outward from the lamp, rather than come in from infinity and end on the lamp.

"For WF to work, it was necessary that all the light traveling out from the lamp should be absorbed by other matter in the universe. This would happen in a steady state universe in which the density of matter would remain constant, but not in a Big Bang universe, where the desnity would go down. It was claimed that this was another proof, if proof were needed, that we live in a steady state universe. There was a conference on WF and the arrow of time in 1963. Feynman was so disgusted by the nonsense, that he refused to let his name appear on the proceedings. He was referred to as Mr X, but everyone knew who X was.

"I found that Hoyle and Narlikr had worked out WH electrodymanics in an expanding universe...Hoyle unveiled the theory...in 1964. I was at the lecture and, in the question period, I said that the influence of all the matter in a steady state universe would make his masses infinite. Hoye asked why I said that, and I replied I had calculated it.

Everyone thought I had done it in my head during the lecture, but in fact I was sharing an office with Narlikar and had seen a draft of the paper. Hoyle was furious. He was trying to set up his own institute and threatening to joing the brain drain to America if he didn't get the money. He thought I had been put up to it to sabotage his plans. However, he got his institute, and later gave me a job, so he didn't harbour a grudge against me."

 

[phinds]

...

But of course it is well known (in Russia) that Russians also invented all modern technology, from the steam engine onwards

Hm ... I think you have a limited view of this. From what I've heard, Russians invented fire, the wheel, metalworking, and everything since, with the exception of democracy which they have in recent years imported, but very unsuccessfully.

 

[Office_Shredder]

I seem to recall that the development of RADAR was considered so crucial to the war effort that documents and maybe an early model were shipped to the US by the British for parallel development in the US.

The US didn't invent radar, but they did invent the name which is equally important :tongue:

 

[Astronuc]

I wonder why the chocolate bar melted but he didn't??

I've been told by some who served in the Navy that some on watch would stand in front of the radar systems because the radar waves would warm them.