Why the US standard railway gauge is 4 feet, 8.5 inches.

This is a good story but it is not true. See snopes: http://www.snopes.com/history/american/gauge.asp.

Also see here for more clarification: http://www.straightdope.com/columns/read/2538/was-standard-r...

This is an old and a goodie, but it's not entirely accurate.

1435 mm for the metric people. ;-)

ok, seriously? What makes this HN worthy?