Why changing the date on your iPhone to 1/1/1970 bricks your phone

Have you heard about this weird iPhone bug? If you set your iPhone's clock to January 1, 1970, the phone bricks itself on restart. This means you can't use it or change the date back until you effectively run the battery out completely. How somebody found this out is beyond me, but there's a somewhat reasonable explanation for it. It deals with the UNIX Epoch Time and how modern 64-bit devices store date and time. Somewhere in the iPhone's software code, there's a bug (as of this post, they haven't found it yet) that basically makes the phone think the date is suddenly 20 times longer than the expected lifespan of the universe. Tom Scott explains further -- quite fascinating.