Ben Goertz

Exploring the Drake Equation

There’s a beautiful scene in Five Billion Years of Solitude that I keep returning to where the author is touring Frake Drake’s greenhouses filled with orchids:

He opened the door to the nearest one, and the hum of ventilation fans and a blast of humid, loamy air flowed out over the grass. Stepping inside, he let out a peaceful sigh. Like the other two greenhouses alongside it, this one was filled with orchids.


Drake turned to what he said was his current favorite, a single orange bloom with three angular petals that tapered to sharp, blood-red points. They looked like fangs. 'This one's a hybrid of two different genuses [... ] No one's seen one like this before, with this red. It wasn't blooming yesterday. Some of these only blossom one day out of the year, and the next day they're gone. You're lucky to be here right now – the flowers aren't long for this world.' He touched the petals with reverence.


I told Drake his orchids made me think of L, a technological civilizations longevity, the greatest uncertainty in his equation. If it was too low, our galaxy could give birth to millions, even billions, of civilizations over its eons-long life, but each one, isolated on a lonely planet, would wither and fall unseen with no chance for cross-pollination. If L was high, then in-bloom civilizations could linger and eventually intermingle, hybridizing their cultures across the light-years. Stability could set in; some would perhaps gain a sort of immortality.

Drake smiled and nodded. The similarity had not escaped his notice.

The book has many other fantastic moments but this scene has lodged that L, longevity, in my mind as something worth thinking deeply about. Essays from The Clock of the Long Now pair well with this.

Drake Equation

N = RfpneflfifcL

It’s hard to understand exactly what the range of possible values in the Drake Equation (above) produce, so I made a small explorable version to play with below. Each of the underlined values is interactive and draggable like a slider.

How I Made This

I used idyll-embed and a simple inline script. The tiny scale of this explorable reminds me of being back in high school tinkering around on the internet. Puttering aimlessly, except here I’ve found a question I want to think more about.