Tim Urban says the black hole era lasts so long you would need 1.4 billion observable universes packed with timeline ribbon to measure it

There is big, there is cosmic, and then there is Tim Urban turning the end of the universe into the world’s most upsetting Hobby Lobby project. On Modern Wisdom, Urban said the black hole era lasts so long that, if every centimeter of ribbon represented a billion years, you would need 1.4 billion observable universes packed solid with ribbon to reach the end of it.

This is the kind of sentence that makes your brain briefly show the spinning beach ball. It also explains why Urban is good at what he does. The Wait But Why house style is not just making complicated things simpler. It is making scale feel rude. A trillion years is a number. A universe stuffed to the rafters with ribbon is an accusation.

I was just writing about the black hole era. Do you know what that is?

The universe ends, then keeps going. Annoyingly.

Urban is writing what he cheerfully described as a book about everything, from the Big Bang to the end of the universe, which is a very normal project if your resting state is a 40,000-word blog post. His trip into cosmology brought him to the far future, after the star era, after the last new stars are born, after the universe has stopped being photogenic.

the last stars will be born around 100 trillion years from now and then like 20 trillion years later, the last stars are gone and we’re in the degenerate era and there’s just nothing except for little white dwarfs and then that ends and all that’s left is black holes.

The claim here is not that Urban discovered a new cosmic calendar. This is standard far-future stuff, the sort of thing cosmologists discuss when they are apparently trying to ruin sleep for everyone else. If the universe keeps expanding and no surprise physics shows up to save the party, stars burn out, remnants cool, and black holes dominate for a grotesquely long stretch before evaporating by Hawking radiation.

The official numbers are useless in the way only honest numbers can be useless. Urban cited 10 to the 106 years. Written out as 10^106, it looks clean, almost polite. It is not polite. It is a number so far beyond ordinary comprehension that saying it out loud has the same emotional value as saying, “many.”

It’s 10 to the 106 years. Okay. So what how do you what does that mean? How do you put that into context?

The ribbon math is silly. That is why it works.

Urban’s answer was to invent a physical timeline. Big Bang to today, at one centimeter per billion years, would be about 13 centimeters. Cute. Put it on a desk. The black hole era, by contrast, breaks the desk, the room, the planet, and then the observable universe, which is generally a sign that your metaphor has become sentient and is trying to leave.

No. No, you’d have to pack the entire observable universe to the brim with ribbon and that would get you nowhere close. You’d have to have packs and the final number I came to is 1.4 billion observable universes with this this ribbon to have by the end of the last universe to get to the end of the ribbon that’s the end of the black hole era.

Is the 1.4 billion figure the thing to tattoo on your arm? No. The far future depends on live assumptions about black hole size, proton decay, dark energy, and whether our current physics survives contact with eternity. But as a teaching device, it is excellent. It does what the best pop science analogies do, not by shrinking reality into something manageable, but by letting reality humiliate the analogy.

This is also why Urban’s riff hit harder than the episode’s many other excellent detours, including Japanese handjob economics, South Korean hair-loss policy, and whether Kesha should have foreseen the P. Diddy line aging like gas-station sushi. Those are jokes with sociology attached. The black hole ribbon is a joke with vertigo attached.

Tim Ferriss pushed the thought even further, bringing up the idea that advanced alien civilizations might hibernate through hotter cosmic eras and wake up when computation is colder and cheaper. This is the fun version of the Fermi paradox, if your definition of fun includes imagining that the reason we haven’t met aliens is that the serious civilizations all hit snooze for a few hundred billion years.

The real claim is emotional, not numerical

Urban’s best move is admitting that this stuff bothers him. Too many science communicators cosplay as calm ambassadors from Planet Rational. Urban lets the mask slip. He is not just explaining deep time. He is being personally inconvenienced by it.

That makes the whole riff more credible, not less. The sane response to 10^106 years is not serenity. It is lying awake beside your spouse, trying to explain that you are tired because the universe will spend almost all of its existence as a dead, cold accounting error.

So I get upset about this. This is the kind of thing that when I think about then I’m like in bed and I literally can’t sleep and I’m tossing and turning and the next day my wife is like why are you so tired?