ever taken. And in 1992, this became the very first image

ever uploaded to the web. But how many photographs have we all taken,

altogether throughout all of history? Well, 1000memories investigated this very

question. They took a look at the number of digital cameras

currently in use, typical usage of a digital camera, as well as the amount of analog film

and film-developing supplies used by the industry ever since the 19th century.

Tabulated altogether, they estimated that we have taken 3.5 trillion photographs, 4

billion of which were taken this year alone. We are snapping more photographs than ever

before, because of the proliferation of easy-to-use, affordable digital cameras.

In fact, we take 4 times more pictures per day than we did 10 years ago.

Or think of it this way. Today, every 2 minutes, humanity takes more

pictures than we took altogether in the entire 1800s.

Of course, the 1800s were a long time ago. But if we take every year from the invention

of photography until today, 10% of all of those images, a tenth of every still image

recorded of our world, was taken in the last 12 months.

That's a lot. But even crazier is the fact that a fifth

of these images, 20% of them, all wind up in the same place - Facebook.

Facebook is huge. But to put it in perspective, you Vsaucers

are huge. If all of us got together in one place and

claimed independence, we would become the 152nd largest country on Earth.

Right between Guinea-Bissau and Trinidad and Tobago.

But Facebook, with is 1 billion users, would be the 3rd largest country on Earth.

To take a quick, dark detour, of those 1 billion people on Facebook, it's estimated that 30

million of them are now dead. And in 100 years, it's estimated that half

a billion of the people on Facebook will be deceased.

Facebook stories offers a really neat tool, where you click on a country and then see

what other countries most of their Facebook friends live in.

It's fun to see what countries are most connected to which others, but this whole thing brings

up the question of degrees of separation. If you were to take 2 random people on Earth,

how many friend of a friend of a friend of a friends would you need to connect those

2 people? Well, in the real world, it's a little difficult

to figure out, because we don't know who's friends with who and there are a lot of people.

But, luckily, mathematics has come to our rescue.

Watts and Strogatz showed that you could calculate the average path between any 2 random people

quite easily. In this equation, the "N" stands for the total

number of people in the population. And "K" stands for the number of friends each

person has. If we assume that each person has, say, 30

friends and we assume that 10% of our population is too young to have actual friends, it turns

out that you can connect any two people on Earth with only 6.6 connections.

Theoretically. Of course, in the real world, we don't all

have the same number of friends, we don't all have 30 friends and isolated groups make

the average much, much higher. Of course, there are non-real world places,

where these connections are easier to follow. For instance, Facebook.

Last year, Facebook's data team released two papers, showing that amongst all Facebook

users at the time, the average distance between any two random users was only 4.74 friends.

Twitter is even tighter. It's been shown that any two random users

of Twitter are connected by only 4.67 friends, though some studies have shown it to be as

low as 3.5. Numbers like that can make impersonal crowd

seem quite intimate. But one of my favorite things about crowds

is how smart they are. Wisdom of the Crowds is a fascinating phenomenon,

where the collective knowledge or guesses or estimations of a big group of people, when

averaged, are better than one individual person working alone.

A good example of this is trying to guess how many jellybeans are in a jar.

Some people will overestimate, while others will underestimate, but collectively, each

member cancels out the errors of the other and the group average estimation winds up

being smarter than the sum of its parts. The BBC's demonstration of this is fantastic,

I've linked it down in the description, it's worth watching.

They had 160 people guess the number of jellybeans in a jar.

The guesses ranged from a few hundred to tens of thousands, but the average of all 160 guesses

was 4,515, only 5 beans away from the exact answer.

It's amazing to think that in a large enough group, the errors and shortcomings of everyone

else, no matter how annoying they are individually, actually can balance and correct our own shortcomings.

It feels good, though a little bit strange to think that in a group, it's possible for

nobody to be correct, but for everybody to be right.

And as always,

thanks for watching.