It's complicated.

The concluding sentence of Gavyn Davies' overview (registration required), published in the FT on Friday, of Herndon, Ash, and Pollin's recently published critique of Reinhart and Rogoff's 2010 paper:

The moral of this story is that it is an illusion to expect that the complicated relationship between public debt and GDP growth will always and everywhere be the same.

The tin can 200 years after its first patenting, from BBC News Magazine.

Instructions from Fortnum and Mason's 1849 catalogue on how to open cans.
From http://www.bbc.co.uk/news/magazine-21689069:

So committed were these bright minds to the technology of food preservation that they gave little thought to making a device to open their new invention, so for decades a hammer and chisel, a bayonet or a rock had to do the job.

...

The first tin opener was designed in the 1860s, but it didn't become a staple of household drawers until a second serrated wheel was added in 1925.