It’s not a new fear. Humans love predicting the end of things. Plagues, asteroids, nuclear war. Physical threats. Visible indicators.
But some researchers are ignoring the hardware.
They are looking at the numbers. Pure probability. One specific data point: how many people have already lived. It is the doomsday argument. And it suggests our clock is ticking.
Imagine two drums.
One holds 100 tickets. The other holds a billion. Both are numbered sequentially. You are blindfolded. You reach into one drum. You pull out ticket #14.
Which drum was it?
Probably the one with 100 tickets. If it were the billion-ticket drum, the odds of picking a low number are astronomically slim. You would expect something like 437 million. Not 14.
Now swap tickets for humans.
You are roughly the 117-billionth human ever born. Is this number a statistical anomaly? Are we standing at the dawn of a trillion-person galactic empire? Or are we average? Somewhere in the middle of the line.
If you assume you are random, average, the math gets uncomfortable.
The middle of the line
Picture every human who has lived or will live, standing in a line. Chronologically. First homo sapiens to the last.
Quarter of the people are in the first 25% of that line. A quarter are in the final 25%. The rest? Half are in the middle.
We have no proof that we are special. That we live in a miraculous early chapter. The rational assumption? We are random. A random point in the human story.
There is a 50% chance we fall into that middle 50%.
If 117 billion people came before us, they likely represent somewhere between the first 25th percentile and the 75th percentile of all humans ever. That means total human population numbers between 156 billion and nearly 500 billion.
Current birth rate: 132 million per year.
Do the division.
There is a 50% probability that the last human is born within 295 years. An 80% probability within roughly 8,000 years.
“These projections might seem like plenty of time”
It sounds long. It is actually short. Especially when compared to our history. And bad for anyone wanting a Star Trek future. And that assumes a linear birth rate. Exponential growth? The timeline shrinks faster.
The Berlin Wall proof
Is this just abstract nonsense?
Maybe. But it has a track record.
In 1969, astrophysicist J.R. Gott visited the Berlin Wall. It had stood for eight years. How much longer would it last? He made one assumption. His visit wasn’t special. It was a random point in the wall’s timeline.
50% chance the visit happened in the middle half of the wall’s existence.
Math suggested the wall had been up for between 25% and 75% of its total life. Prediction? The wall would fall between 2.7 and 24 years later.
It fell in 1989. Twenty years later. Spot on.
He tried it with Broadway shows. 1993. 44 shows. He predicted their end dates. 37 had closed by 2001. All fit his predicted windows. Gott is a big proponent. He builds on work by Brandon Carter.
It works because it leans on the Copernican principle. Earth isn’t the center. We aren’t special. We are probably just typical observers. Average. Somewhere in the middle.
The objections
It makes you uneasy.
Which is good. It means the math is doing something.
Critics argue it’s a sleight of hand. But nobody can agree on where the trick happens.
- The reference class problem: Why humans only? What about Neanderthals? Aliens? Future cyborgs? Broaden the definition of “who” and the expiration date pushes far away. The argument feels too dependent on arbitrary boxes.
- The caveman objection: If a prehistoric human used this logic, they’d guess our lineage lasts another century. They’d be wrong by thousands of years. Why trust math that fails in hindsight?
- Self-indication: A universe with trillions of beings has more slots for consciousness. You are more likely to be born in the big universe than the small one. Existence itself might favor longevity.
- No causality: Asteroids kill people. Nuclear war kills people. Being the 117-billionth person doesn’t. Birth rank has no physical mechanism for apocalypse. It’s a number, not a bomb.
Proponents have answers for every point. The debate gets technical. Intense.
Maybe that is the point.
It’s less about when we die and more about where we think we stand. What does our existence actually prove? Where do probabilistic arguments break down? It forces us to question the assumptions we don’t think about.
It remains unresolved. And arguably, it should stay that way. The not-knowing keeps us sharp. Even if the clock is running.
