A recursive tweet that links to itself

That tweet above doesn't look very remarkable, but what it's doing is super weird and fun — it is retweeting a link to itself.

How was this possible? Through a bunch of very clever detective work by Oisín Moran. He knew that Twitter issues a unique URL for every tweet, which ends with a 19-digit ID number — i.e. one of my recent tweets is "https://twitter.com/pomeranian99/status/1334026979838980096".

So, Moran realized, if — while you were composing a tweet — you could predict which unique ID number Twitter would assign to that very tweet, you could put an URL in your tweet that would link to the tweet itself. Recursive tweeting!

He wrote a long, entertaining post describing how he figured it out — it involved some smart analysis of the IDs, running scripts that would create guesses. And le voila

Moran points out that using this technique, one could, in theory, perform some apparent time-travel …

One other weird idea would be to tweet lots of IDs with timestamps from a good bit in the future—maybe a month or a year from now—and see the reactions when people realise they were quote-tweeted a year before they actually sent the tweet! Heck, why limit ourselves to such short-termism? There's enough room in these timestamps for almost 70 years of milliseconds. This means we could actually quote-tweet someone before they've even been born! Now that would be something.