Coin Flip Decides Material’s Fate

The connection to the St. Petersburg paradox is pretty tenuous.

All the paper seems to suggest is that strength of a fiber is proportional to log(length_fiber). But the St. Petersburg paradox doesn't just come from observing that the odds of getting log_2(n) heads in a row is 1/n. Instead, you're multiplying that quantity by an exponentially growing quantity and then taking an expectation (i.e. summing) and getting an unbounded sum. I don't see a clear analogy to that in material strength.

"A chain is only as strong as its weakest link"

And if you model a rope or fiber as multiple chains side-by-side (and on a molecular level they kinda-sorta are) then the longer the chain the more likely you end up with multiple parallel/concurrent defects.

It's an interesting finding in that few would ever intuit it but once told about it they'll say it's "obvious". At least that's what I thought!

> Materials typically contain lots of small imperfections, but it’s the rare, large defects that cause a material to fail.

Ok so.... we need to know more about the rare large defects! Unfortunately that's the last we hear about them in this paper.

So does this mean a space elevator is out?

For a moment I was excited, and thought Material Design would disappear if it came up tails.