Why the end of the world is inevitable

US astronomer and planetary scientist, Carl Sagan, gave a lecture in Glasgow in 1985 in which he stated, ‘‘by far most of the species of life that have ever existed are now extinct. Extinction is the rule. Survival is the exception.’’

Comforting stuff. Sagan was enthusiastic about finding extraterrestrial life. I don’t share his optimism. We’ve been searching for decades and found nothing.

Frank Drake, an American astrophysicist, developed a theory that although the possibility of life evolving was intensely tiny on any specific planet, given the nearly infinite number of planets, intelligent life must exist.

The Fermi paradox confronts the problem that if advanced life is so likely, why can’t we find any evidence for it?

One thought is that the development of complex organic life, is highly improbable. Life does not guarantee the evolution of intelligent life capable of developing Wordle or sending electric cars into orbit.

But Drake has another answer: advanced life inevitability self-destructs.

Sagan speculated in 1966 that the short timeframe between developing radio waves and nuclear weapons could be responsible for the lack of spacehopping aliens. This theory became known as the Great Filter, which is a perfect answer to the Fermi paradox.

How likely is this?

In 2011, Stephen Pinker’s book, The Better Angels of our Nature, looked at the long-term decline of violence over the past millennium, crediting it to the development of the nation state and their monopoly on violence, the moderating influence of commerce, the rise in the power and influence of women, modern communications and the increasing adoption of reason. He points to the Long Peace, the post-World War II period of relative harmony, as evidence.

This argument was aggressively rebutted by Nassim Nicholas Taleb in his book The Black Swan, in which he asserts that humans are not very good at estimating or predicting outsized negative events.

Taleb estimated the time between conflicts killing more than 10 million people is, on average, 136 years so the decades since the last conflagration is too short for meaningful conclusions.

I am on the side of Taleb in this debate, but I would go further. I believe that the evidence points to us selfdestructing.

After the end of the Napoleonic Wars in 1815 there was a pause in the size and severity of global conflicts until 1914. We have enjoyed merely 77 years since the fall of Berlin in May 1945 and the absence of large-scale military conflicts is often credited to the existence of nuclear weapons. To adhere to this belief is to pretend the 1961 Cuban Missile Crisis did not exist and the 1983 nuclear nearmiss can be ignored, and to overlook the fact Nixon considered dropping nukes on Hanoi.

And these are what we know about. There will be others, and right now Vladimir Putin is openly sabre-rattling with his thermonuclear toys. He is probably bluffing. Probably. Just as the claim that alien life must exist, so too must we accept that each year the risk of an unconstrained nuclear exchange is greater than zero, and that given enough years we will eventually hit the jackpot.

There seems to be a near miss once every two decades, and once a nuclear war starts there is a non-trivial risk of an exponential reaction. Humanity might not end, but civilization would.

But this is to demonstrate a failure of imagination. The spread of technology and democratisation of science has allowed even backwater states like North Korea to develop nukes, and in the coming centuries isn’t it conceivable that teenagers will be able to cobble them together in their parents’ basements?

The ability of intelligent life to discover things that can eliminate intelligent life seems obvious to me. You cannot control knowledge nor eliminate the lone actor who would willingly end all life.

It may take a millennium from here, but I think we understand both the march of science and the malevolence of a small minority of humanity to appreciate the inevitability of our destruction.

As we look to the heavens I fear that we are the only creatures in the universe to comprehend its enormity. We are the inevitable creation of the possibilities created by its vastness, destined to discover its secrets and use the power of that discovery to condemn ourselves to oblivion.

Now. What’s for lunch?

Right now Vladimir Putin is openly sabrerattling with his thermonuclear toys. He is probably bluffing. Probably.