1Drake MC 2Great Filter 3Aestivation 4IMBH Mass 5BZ Power 6Compute Limits Summary
Six-stage workflow · Fermi Paradox → MTH compute argument · all client-side

The Fermi / MTH Crossover

Where is everyone? This workflow runs the complete chain — from how many civilisations the Drake equation predicts, through where the Great Filter sits, through whether aestivation or the MTH is the better strategy, to the concrete compute budget of an ergosphere civilisation in ω Cen.

⚠ Theoretical (Fermi/Filter) 🔬 Established (BZ, Landauer) ✦ Speculative (MTH)
No backend · No tracking · State in URL hash · v1.0 · 2026-06-01
01
Sandberg-Drexler-Ord (2018) — Drake equation as a distribution
Drake Monte Carlo — prior on N
How many communicating civilisations does the universe likely contain?

The Drake equation gives a distribution over N, not a point estimate. Under log-uniform priors — the standard scale-uncertain prior when you don't know the order of magnitude — P(N < 1 in the Milky Way) ≈ 30–55% (Sandberg et al. 2018). Set the biology factor (f_l × f_i combined) and communicating lifetime L; the astrophysics factors are bundled at ~1/yr.

Inputs
10⁻¹⁰
1,000 yr
Stage 1 outputs
Median log₁₀(N)
Median N
P(N < 1 in MW)
P(alone in obs. universe)
Passes to Stage 2: median N =
02
Hanson (1998) — where does survival probability collapse?
Great Filter Localizer
Where on the chain from life to civilisation does survival collapse?

If N is small (Stage 1), nearly all the survival probability must collapse somewhere on the chain. Given that we exist, the question is whether the hard step is behind us (abiogenesis, eukaryogenesis — we got lucky and the future is open) or ahead of us (AI, warfare, climate — we haven't passed it yet).

Inputs (N implied from Stage 1)
Implied log₁₀(N) from Stage 1
10⁻¹⁰
10⁻²
10⁻¹
Stage 2 outputs
Total P(dead → interstellar)
Filter passed (behind us)
Filter remaining (ahead)
Implied planets needed
Passes to Stage 3: filter-ahead fraction = · if large, aestivation vs. MTH becomes urgent
03
Sandberg et al. 2017 / Bennett et al. 2019 — wait or act?
Aestivation vs. IMBH Ergosphere
If civilisations survive, should they wait for the CMB to cool or act now?

If the filter is mostly behind us (Stage 2), advanced civilisations exist. Should they aestivate — hibernate until the CMB cools, gaining up to 10³⁰× more compute per joule? Or should they act now via an IMBH ergosphere, which already provides exceptional compute with no waiting? The Sandberg gain and the IMBH ops/sec are computed in parallel here for direct comparison. N from Stage 1 contextualises how many civilisations face this choice.

Inputs
Filter-ahead from Stage 2
10¹¹ yr
1.00 (irreversible)
Stage 3 outputs
T_CMB after ΔtK
Sandberg ops gain factor
Bennett verdict
Strategy comparison
Proceeds to MTH path (Stages 4–6): quantify the IMBH ergosphere alternative
04
Observational constraint window
IMBH Mass — the MTH substrate
Pick an allowed mass for ωCen's IMBH

The MTH ergosphere compute argument requires a real IMBH. The allowed window for ω Cen's candidate spans 8,200–70,000 M☉. This mass determines the BZ power (Stage 5) and the Schwarzschild radius for time dilation.

Input
30,000 M☉
Stage 4 outputs
Mass MM☉
Schwarzschild radius r_sAU
Passes to Stage 5: M =
05
Blandford-Znajek mechanism
BZ Power Output
Extract ergosphere power via magnetic field coupling

With mass fixed from Stage 4, spin and magnetic field determine the BZ jet power. This is the energy source the MTH civilisation exploits instead of waiting.

Inputs (M fixed from Stage 4)
M from Stage 4
a* = 0.900
10⁶ T
Stage 5 outputs
P_BZW
Kardashev level K
vs. Sandberg gain (act now)
Passes to Stage 6: P_BZ =
06
Bekenstein-Landauer-Lloyd limits
Ergosphere Compute Rate
Maximum ops/sec from BZ power under physical limits

The Landauer limit converts BZ power to ops/sec at operating temperature T. This is the quantitative endpoint of the MTH argument: how much computation can the ergosphere civilisation perform per second?

Inputs (P_BZ from Stage 5)
P_BZ from Stage 5
2.73 K
Stage 6 outputs — MTH endpoint
Landauer ops/sec
Lloyd ops/sec
vs. Earth silicon
Aestivation gain needed to match
✓ Fermi / MTH Crossover — Full Summary
Median N (Milky Way)
civilisations
Filter-ahead fraction
log probability
Sandberg aestivation gain
× more ops per joule
BZ power (IMBH)
watts
MTH ops/sec (Landauer)
ops/s
vs. Earth silicon
× advantage