# Feynman discusses what keeps trains on the tracks



## CHamilton (Apr 10, 2013)

A bit confusing to me, but I'm sure that our experts can improve the explanation.


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## xyzzy (Apr 10, 2013)

See here http://www.railway-technical.com/whl001.gif.


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## CHamilton (Apr 10, 2013)

Thanks, xyzzy, this is helpful for us visually-oriented types.


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## AmtrakBlue (Apr 10, 2013)

My teenage daughter asked me (either at NTD or on our trip) why the "flanges" weren't on both sides of the wheel. I tried, hopefully successfully, explaining the switches and how the flanges facilitate that.


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## leemell (Apr 10, 2013)

Improve a mechanical explanation from Richard Feynman? Really? This genius was a Caltech Professor of Physics, Nobel Prize winner and polymath extraordinaire. He would come over to JPL (Caltech operated) once or twice a year and give standing room only lectures in the main auditorium. In the 80's he gave a lecture on nanodevices --- nearly 20 years before they became real. He also provided the real cause of the Challenger failure and explained it very simply and clearly. I got to shake his hand once. A real honor.


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## TimePeace (Apr 10, 2013)

One of the most brilliant and most interesting scientists our country ever had. There are several very good biographies - my favorite was "Genius" by James Gleick.

His autobiography is called "Surely You're Joking, Mr. Feynman".

One thing I remember: whenever Feynman took a new job, or position, the first thing he'd do would be to go around to all the other scientists' offices when they were absent, and crack their safe open and leave some cryptic note. Apparently he was a skilled safecracker!

Leemell: what a treat to shake the man's hand! Good on ya.


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## leemell (Apr 10, 2013)

Maine Rider said:


> One of the most brilliant and most interesting scientists our country ever had. There are several very good biographies - my favorite was "Genius" by James Gleick.
> His autobiography is called "Surely You're Joking, Mr. Feynman".
> 
> One thing I remember: whenever Feynman took a new job, or position, the first thing he'd do would be to go around to all the other scientists' offices when they were absent, and crack their safe open and leave some cryptic note. Apparently he was a skilled safecracker!
> ...


He started on locks seriously  that when he was on the Manhattan Project. He drove security nuts, he picked the locks on every door and cabinet he found.


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## Anderson (Apr 11, 2013)

From what I recall from reading his biographies, Feynman's secret to that was apparently that most folks didn't change their combinations from the factory standard, and often the factory standard was the same from one safe to the next. So, he would go to a few basic combinations that would pop something like 3/4 of the locks he came across.


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## cirdan (Apr 11, 2013)

He was that rare combination of extraordinary intelligence with the ability to explain and connect to people.

My Dad met him on one occasion. An incredible man.


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## DET63 (Apr 17, 2013)

The rod connecting the two wheels is called an axle.

BART's wheels are "flat," i.e., not conical, at least according to the BART article at Wikipedia (though there don't appear to be any sources verifying that assertion).


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## cirdan (May 15, 2013)

DET63 said:


> The rod connecting the two wheels is called an axle.
> BART's wheels are "flat," i.e., not conical, at least according to the BART article at Wikipedia (though there don't appear to be any sources verifying that assertion).


I believe flat refers to a special type of conical.

The angle of conicity is determined by various trade-offs, and some systems will have flatter angles than others.


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