Just a reminder that Earth is almost empty of humans, contrary to what many people think
7.3 Billion People, One Building
March 3, 2015 By Tim Urban
After a year and a half of writing Wait But Why posts, I’ve noticed a theme: humans seem to come up a lot.
Sometimes we talk about where humans came from or where we might be going or how we’re all related; other times we look at how we interact and communicate and form relationships. We’ve talked about rich humans and famous humans and baby humans and dead humans and humans from all over the world. We’ve explored what it means to be a human, what it means to be a good human, and whether we’re all alone in the universe. And we’ve spent a lot of time trying to figure out what really matters most in this one, short human life.
But somehow, we made it through all of that discussion without ever asking the most important question of all about humans—
How big a building would you need to fit them all in it?
It’s a question that’s tantalized almost no one through the ages, and today we’re gonna tackle it hard.
But before we ask all 7.3 billion humans to stop what they’re doing so I can arrange and bunch them together at my whim, let’s discuss the number 7.3 billion.
The first thing to note is that when I did a post on population density in August of 2013, the number I kept referring to was 7.1 billion. The world population has grown by 194,000,000, or almost 3%, since then.
Second, 7.3 billion people is a lot of people. If each living human were represented by a dry grain of rice, the rice would fill a cube-shaped box with a side of 6.1 meters, 1 or about 20 feet—around the size of a two-story house.
That’s a lot of rice grains.
And how about 7.3 billion grains of sand? Well according to this delightful chart, “sand” can mean a lot of things. 7.3 billion “very coarse” grains (about 2mm in diameter) would fill a large cubic room with a height of 4m (13ft). 7.3 billion medium-size grains (.25mm in diameter) would fill a medium, 46cm high (1.5ft) cardboard box. And 7.3 billion of the finest, .0625mm sand grains (any smaller and it wouldn’t be sand anymore—it would be silt) would take up about 1,700 cubic centimeters of space, almost but not quite filling a 2-liter soda bottle. |
