Physicist Richard Feynman explains how a train stays on the tracks.

http://www.youtube.com/watch?v=y7h4OtFDnYE

by amichail • 17 years ago

48 7 17 years ago

arketyp• 17 years ago

Wow, neat. I'm not sure I should attribute all my amazement to Feynman, but it sure is lovely hearing that man explain things.

jhayes• 17 years ago

This clip (and the others posted by 'ChristopherJSykes') are from the BBC show "Fun to Imagine". Been a few months, but I remember the 'Magnets (and 'Why?' questions...)' segment being particularly worthwhile if you're looking for good bang-for-buck timewise.

Incidentally, the guy releasing this also directed it.

Also in case you prefer text: http://varatek.com/scott/feynman_problems.html

Luc• 17 years ago

So now all I need to do is figure out what determines the angle of the taper on the wheels...

pbhj• 17 years ago

The difference between the circumferences would have to be such that the train could round the sharpest bend on the track.

That should approximate to a maximum angular change (in direction of travel) per metre:

angle per metre = tan( 2 PI (R-r) / inner track gauge ) x 2 PI r

where R is the largest contact circumference of the wheel and r the smallest.

TrevorJ3• 17 years ago

What I don't get is how the train rounds a variety of curve radii. How do they control the part of the wheel that is riding the rail precisely enough to allow the train to turn at differing angles depending on the radius of the curve?

TrevorJ3• 17 years ago

Physicist Richard Feynman explains how a train stays on the tracks.

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