Photo of the Mathematical Bridge in Cambridge, England

Weekly Gem #149 Let’s cross that bridge since we’ve come to it

Published 2/3/2018

Location:  This hidden gem is a bridge over the River Cam (a Cam bridge), located in Queens College, University of Cambridge, Cambridge, England (see the Clue Me! Map). 

It is a rather famous bridge, and the subject of many tall tales. Did you know, it was built by none other than Isaac Newton right after the apple fell on his head? Astoundingly, he didn’t use nails, bolts, or any other fasteners, because after he discovered gravity, it became clear that careful positioning of the wooden beams would suffice to hold everything in place. That’s the tall tale anyway ... the 'minor' flaws were that Newton had died before the bridge was built, no apple fell on his melon, gravity has always existed, and fasteners were most definitely used! For what it’s worth, Newton did attend the University of Cambridge.

Although the bridge is held together by more than just gravity, its nickname (the “Mathematical Bridge”) is well deserved. The designers used something called ‘tangent and radial trussing.’ Note how the beams are mostly horizontal, forming what looks like an arch, but with every beam being perfectly straight. Here’s the weird part. If you stand on the bridge, your weight isn’t pressing ‘downward’, but is redirected entirely along the length of the beams. In that way, every beam is being pulled or pushed lengthwise so that the strength of the wood is utilized to its fullest, and no beam is being bent.

I tried to do the math, but instead “punted!”


Here's the hidden gem entry from our Clue Me! map.


If you tell a story here you'll probably go off on some tangent.


Wooden Bridge a.k.a. Mathematical Bridge

Why It's Interesting

This bridge looks like it is an arched bridge, but there are no arches present! It is made only from straight timbers. And just so you know: Although Isaac Newton is an alumnus of the University of Cambridge, he had nothing to do with the construction of this or the original version of this bridge.

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