For 60 years we've assumed civilisations grow their energy use
exponentially at ~1%/yr. It's baked into most SETI and Fermi-paradox
reasoning.

I tested it against six decades of real global energy data.

It fails. Growth is linear, not exponential — and a linear fit pushes
"Type II" out to ~10^15 years, a hundred thousand times longer than
the Sun will live. Nobody reaches it.

So the fix isn't a better growth curve. It's a better variable: energy
per unit of computation, bounded below by the Landauer limit. And the
only continuously-measured, globally-aggregated record of computation
we have is Bitcoin's hashrate.

Full writeup + open-access preprint (arXiv, submitted to MNRAS Letters):

naddr1qvzq...

#Bitcoin #Landauer #SETI #Kardashev #desci #astronomy