One of the most common sounds in the modern world is the beep. From microwaves and cellphones to computers and backing-up trucks, this high-pitched alert pings us from every direction. But how is it ...

One of the most common sounds in the modern world is the beep. From microwaves and cellphones to computers and backing-up trucks, this high-pitched alert pings us from every direction. But how is it ...

This is the eighth in an exclusive series of 50 articles, one published each day until July 20, exploring the 50th anniversary of the first-ever Moon landing. You can check out 50 Days to the Moon ...