Doubling

You start with one in 1876.

Double every 4.5 years, and by the end of 1880, you’ve got two. By the end of the year 1900, you’re up to 32.

Just keep doubling.

By the time of the 1929 stock market crash, you're at 2048. Let’s just call it 2000 to make the math easier. By the time of Alan Turing’s visit to the US in WW II, you now have 16,000.

Doubling is powerful, but we’ve got a long way to go.

By the time Star Trek is on the air and The Beatles are recording Paperback Writer in 1966, enough doublings have happened so that you break a milestone: one million. By 1970, that has become 2 million, which turns into 8 million by 1980, and eventually 64 million by 1993.

You don’t reach your first billion until 2011, but it’s a relative blink of an eye to get to 8 billion today.

The one thing we started with is the first telephone connection, briefly established by Alexander Graham Bell and his assistant, Thomas Watson.

One connection didn’t neatly double every 4.5 years as I’ve laid out here, but on average, that’s the pace of growth in telephone subscriptions since then. Today, there are about 9.7 billion telephone subscriptions worldwide.