Honoring Petrov Day on the EA Forum: 2021

Petrov Day

Today we celebrate not destroying the world. We do so today because 38 years ago, Stanislav Petrov made a decision that averted tremendous calamity. It’s possible that an all-out nuclear exchange between the US and USSR would not have actually destroyed the world, but there are few things with an equal chance of doing so.

As a Lieutenant Colonel of the Soviet Army, Petrov manned the system built to detect whether the US government had fired nuclear weapons on Russia. On September 26th, 1983, the system reported five incoming missiles. Petrov’s job was to report this as an attack to his superiors, who would launch a retaliative nuclear response. But instead, contrary to the evidence the systems were giving him, he called it in as a false alarm, for he did not wish to instigate nuclear armageddon.

For more information, see: 1983 Soviet nuclear false alarm incident

Petrov is not alone in having made decisions that averted destruction — presidents, generals, commanders of nuclear submarines, and similar also made brave and fortunate calls — but Petrov’s story is salient, so today we celebrate him and all those who chose equally well.

As the world progresses, it’s likely that many more people will face decisions like Petrov’s. Let’s hope they’ll make good decisions! And if we expect to face decisions ourselves, let us resolve to decide wisely!

Mutually Assured Destruction (??)

The Petrov Day tradition is to celebrate Petrov’s decisions and also to practice not destroying things, even when it’s tempting.

In both 2019 and 2020, LessWrong placed a large red button on the frontpage and distributed “launch codes” to a few hundred “trustworthy” people. A launch would bring down the frontpage for the duration of Petrov Day, denying hundreds to thousands of people access to LessWrong. In 2019, all was fine. In 2020… let’s just say some bad decisions were made.

And yet, having a button on your own page that brings down your own site doesn’t make much sense! Why would you have nukes pointed at yourself? It’s also not very analogous to the cold war nuclear scenario between major world powers.

For those reasons, in 2021, LessWrong is teaming up with the Forum to play a game of mutual destruction. Two buttons, two sets of codes, and two sets of hopefully trustworthy users.

(The button will appear on the homepage on Sunday morning, 8 AM PST.)

If LessWrong chose any launch code recipients they couldn’t trust, the EA Forum will go down, and vice versa. One of the sites going down means that people are blocked from accessing important resources: the destruction of significant real value. What’s more, it will damage trust between the two sites (“I guess your most trusted users couldn’t be trusted to not take down our site”) and also for each site itself (“I guess the admins couldn’t find a hundred people who could be trusted”).

For exact rules of the game, see the final section below.

Last year, it emerged that there was ambiguity about how serious the Petrov Day exercise was. I’ll be clear as I can via text: there is real value on the line here, and this is a real trust-building exercise that was not undertaken lightly by either LessWrong or the Forum. Both sites have chosen recipients who we hope will understand this.

How Do I Celebrate?

If you were one of the two hundred people to receive launch codes for LessWrong or the Forum, celebrate by doing nothing!

Other ways of celebrating:

  • You can discuss Petrov Day and threats to humanity with your friends.

  • You can hold a quiet, dignified ceremony with candles and the beautiful booklets created by Jim Babcock.

  • And you can also play on hard mode: “During said ceremony, unveil a large red button. If anybody presses the button, the ceremony is over. Go home. Do not speak.”

    • This has been a common practice at Petrov Day celebrations in Oxford, Boston, Berkeley, New York, and in other rationalist communities. It is often done with pairs of celebrations, each with a button that can end the other.

Rules of the Exercise

The following email was sent last night to 100 users from the EA Forum. 100 LessWrong users received a similar message.


I invite you to participate in an exercise to determine whether the EA Forum can find 100 users it can trust with a genuinely high-stakes decision.

This year, we’re joining LessWrong in celebrating Petrov Day — a holiday where we celebrate the non-destruction of the world, and practice not destroying it ourselves.

To prove the goodwill and trust between the two sites, each site is sending “nuclear launch codes” to 100 users we think we can trust. I chose you personally to receive this message.

(For more on why we’ve done this, see this post.)

If you enter your launch codes into the launch console on the Forum’s homepage, they will cause LessWrong’s homepage to go down for the duration of Petrov Day. For the rest of the day, thousands of people will have a hard time using the site; some posts and comments will likely go unwritten. And I’ll have failed in my mission to find 100 people I could trust not to take down our friendly compatriots.

Your code is personalized; if someone enters it, we’ll know whose code took down the site.

This is your code: [CODE]

LessWrong and the Forum both have second-strike capability that will last for one hour after one of the sites is taken down. If the Forum’s homepage disappears, please consider very carefully whether or not you think it is correct to retaliate.

I hope you’ll help us all keep LessWrong safe, and that they’ll do the same for us.

Yours truly,
Aaron Gertler and the EA Forum team

To all, I wish you a safe and stable Petrov Day.

Here is the mirror of this post on LessWrong. You may wish to view it for the discussion there.