How many people have ever lived?

August 9, 2020

We are somewhere around the point in time/human history where there are/have been an estimated 110 billion humans in total since the beginning of humanity.

I cannot fathom that number. So let's try to grasp it for a moment.

Think firstly of yourself, your life, and all that has gone into it and all that will come of it. That represents the number one.

Now think of nine other people in life that you feel you could write a decent biography of. Think of everything that has ever happened to them, everything they've ever experienced, and everything that they have done or will do. Now we're at the number ten.

Now take the breadth and depth of this mental snapshot, encapsulate it somehow, hold it in your frame of mind, and multiply that times 11 billion.

Ok, well, we still don't grasp 11 billion mentally, so let's try this all again…

Let's think of some large population groups:

China is estimated to have a population of around 1,440,000,000 people. So it would take about 75 China's to represent the entirety of humanity across all time.

Is this difficult to comprehend still? Maybe you've never been to China and don't know much about it. Perhaps it's difficult to visualize the entire population of China. It's hard to picture the number of people in the world's largest country. So how about the world's largest city?

Tokyo is estimated to have about 38 million people living in it in 2020. So by that measure, we would need to take the entire population of Tokyo and multiply that by around 2900 times.

Still can't picture it? Me either, honestly.

Let's say I can only comprehend about 500 people's lives in depth. If I could grasp that image and multiply that by 220 million, then I could comprehend the entire population of humanity since its beginning.

But I can't.

Even if we tried to pare down these thought experiments to just the total number of humans alive today, we're still stuck trying to make sense of what 7.8 billion people looks like, feels like, lives like. For instance, if you wanted to meet every human alive today, then you would need to meet 300,000 people every day for the next 72 years (assuming that you have about that long to live). (Most people won't come close to meeting 300,000 people in their whole lifetime.)

Humans cannot fathom these numbers and picture these lives. (Our brains aren't powerful enough to envision and empathize with 110 billion other people.) Yet I'm still drawn to even that partial understanding. I want to try to picture it, even if I never may be able to grasp it. I want to dive deeper…

If it is already barely feasible to fathom the idea of 110 billion human lives — from birth to death, 110 billion times — then how much harder would it be to imagine how many times humans have ever experienced love, suffering, joy, or awe?

If everyone only ever experienced those things about 10 times in life, then we're estimating that humans have experienced those feelings somewhere around a trillion times. A trillion experiences of suffering. A trillion experiences of love.

But let's go further…

If we were to take the average lifespan of human throughout history and estimate it as low as possible (with the lowest average at 20 and the highest at 80), we might put humans at an average of a 30-40 year lifespan throughout history. In total, this would be between roughly 3.3–4.4 trillion years of human life experienced. That's ~1.2–1.6 quadrillion days or ~30–40 quadrillion hours or ~2 quintillion minutes.

Let's sit with this thought for a moment:

Collectively, humans have experienced around 4 trillion years of life on Earth — 4 trillion years of all kinds of life experiences. (Or 40 quadrillion hours.)

Whatever it is that you're experiencing in life right now, it's extremely likely that it has been experienced at least a billion times over by at least a billion other people in human history. And that's only assuming that whatever it is you're experiencing is experienced by 1 in every 100 human lifetimes. More than likely none of what we experience happens to less than 1 in 10 human lifetimes. In which case you can rightly assume that whatever you're experienced has already been experienced by 11 billion other humans. If most people experience whatever it is you're experiencing a few times in life, then in total it has been experienced a few hundred billion times throughout human history.

What's the worst experience you can imagine happening to you in life? I don't particularly like sitting around thinking of these things, but let's assume the worst experiences are sufferings in the forms of death of a loved one, heartbreak, disease, and violent crime (that needn't be written in detail here). Humanity has experienced these tragedies a few hundred billion times throughout history. They have occurred somewhere around 100 billion to 1 trillion times. That's awful.

But what about the best experiences? What's the best experience you can imagine experiencing in your life? Falling in love, getting married, having sex, having a child, experiencing beauty in some way, etc. All of these things have also been experienced a few hundred billion times over throughout human history. According to these numbers there have obviously been 110 billion births and thus 220 billion parents and thus 110 billion sexy times. More realistically, humans have had sex over 1 trillion to 600 trillion times. We can only assume some of that had to have involved the little thing we call love, whether between partners or parents and children or families overall. And as for other forms of beauty, let's consider the possibility that perhaps somewhere between 60–90 billion humans have ever created art and then shared that art with about 5 other people. That's somewhere around 3–4.5 trillion experiences of art and human expression. And these are modest estimates. I personally believe the numbers are much, much larger than this.

What are some of the best things that have ever happened amidst the ~3.3–4.4 trillion years of human experiences?
What are the best successes of human history? What are the best achievements and the greatest moments of progress?

Revolution, reformation, renaissance, invention, scientific breakthrough, health improvement, technological advancement, declarations, zeitgeist shifts…

Most of these things have been experienced by humans only within the past thousand or so years.

(Although you might argue that humanity has experienced revolutions, reformations, and zeitgeist shifts of varying degrees throughout its entire history. So let's say there have been somewhere between 200–500 revolutions in human history — perhaps once ever so many hundred years. Thus maybe ½ or ⅒ of all of humanity has ever experienced a revolution in this context, depending on how you look at it.)

In total there have been hundreds or thousands of scientific breakthroughs (depending on your definition) in math, physics, astronomy, biology, social sciences, engineering, medicine, etc. Same goes for noteworthy inventions, health improvements, and technological advancements.

Here again I'm thinking now of how the majority of those ~4 trillion years of human life have been spent… Sleeping, eating, caretaking, playing, loving, lovemaking, working, relaxing, …

Would you define humanity as the sum of experiencing 2–4 quadrillion meals, 10–20 quadrillion hours of sleep, 1–600 trillion copulations, 8–12 quadrillion hours of work, etc?

What's the best use of all that time? How would that time be best spent? If you could choose how 110 billion people would spend their total of 4.4 trillion years, what would have them do with their lives?