Bitcoin's Last Clock: Block Time Reveals Humanity's End

The silent ledger and what we actually measured

Imagine a handful of curious investigators turning up on a quiet Earth and booting up the only clock that kept ticking: a global ledger left behind by its creators. We treated the blockchain like an archaeological record — only headers and the coinbase transaction were preserved — and read what those little digital fossils could tell us.

Key findings, boiled down: the chain had about 86,000 blocks between the present and the last “normal” era. Coinbase outputs matched the programmed subsidy, which is nerd-speak for “no meaningful fees were being paid.” Block arrivals had slowed way down — not minutes, but hours. Over long stretches the average spacing clustered around 60–70 minutes, with a long-run mean near 65 minutes.

Do the math and you get a handy timestamp: 86,000 blocks × ~65 minutes per block translates to roughly 10.6 years of unattended writing. In plain language: machines kept minting blocks for a decade or so after people stopped sending payments.

One of the neat emergent patterns was the appearance of terraces — flat-ish plateaus of near-constant block interval separated by sudden downward steps. That’s a direct consequence of how difficulty adjusts: retargets happen every 2,016 blocks and the allowed change per epoch is capped, so when total hashing power collapses you don’t get a smooth slowdown — you get a staircase.

For example, if remaining miners represented about 1% of previous power, an epoch could stretch to roughly 16–17 hours per block, turning those 2,016 blocks into roughly 3.8 years on that plateau. If power fell further to ~0.1%, the same epoch could last around 167 hours per block, i.e., decades for a single retarget span. Those are rounded, back-of-envelope numbers, but they match what the headers showed in some regions.

What the chain whispers about power, place, and the end of routine

Beyond timestamps and cadence, the pattern of block times contained geography vibes. Repeated clusters of timestamps aligned to local solar noon suggested pockets of still-active miners sitting in particular longitude bands. Seasonal swings in the cadence hinted at latitude — solar seasons change energy availability, especially when the surviving grid mix included solar, hydro, or other local sources.

Timestamps slowly drifted once accurate human clocks were gone. The median-time-past (MTP) rule limited how wildly timestamps could be faked, but it didn’t stop regional groups of machines from marching their own clocks forward in a coherent way. When connectivity was intermittent you could see the fingerprints of partitions: competing tips sprouted, then reconciled when a satellite link or a microwave hop returned, leaving only the winning branch in the canonical chain.

Some other juicy forensic bits lingered in the coinbase strings and version/nonces: pool labels and software/hardware fingerprints stuck around because no one was there to change defaults. That meant you could, with some confidence, link blocks to persistent device families and operators long after transactions dried up.

Essentially the ledger answered three simple requirements: at least one power source that kept some miners running, a way for a few blocks to propagate occasionally, and the protocol mechanics that bottled all that behavior into timestamps and difficulty adjustments. From headers and coinbase data alone, you can reconstruct approximately when human-led activity ended, how quickly energy faded, and how networks fragment — a surprisingly detailed obituary written in bits and block intervals.

So yes, if you like bleak poetry: unattended machines kept writing time for years. If you like cold math: difficulty rules and epoch lengths turn a drop in hashing power into a readable timeline. Either way, the chain becomes the last clock standing — stubborn, noisy, and oddly informative.