Cryptoterrestrial Hypothesis (Lomas et al., 2024)
A 2024 academic preprint argues that UAP phenomena might be explained by a non-human intelligence that shares Earth with us — hidden in oceans, underground, or in a 'next-door' way — and that this deserves serious consideration.
The Cryptoterrestrial Hypothesis (CTH) is the name given by Tim Lomas, Brendan Case, and Michael Paul Masters to a 2024 paper arguing that UAP/non-human intelligence (NHI) reports should be evaluated against a fourth working hypothesis alongside the usual three (mundane misidentification, secret human tech, ETH — extraterrestrial). That fourth: a terrestrial NHI that has either always been here or has been here long enough that Earth is its origin, not some other star system.
The paper, hosted on the Harvard Human Flourishing Program’s preprint repository, sketches four sub-hypotheses for what such a population could be:
- A surviving terrestrial hominid offshoot (think: an unbroken cryptid lineage)
- A previous Earth civilization that went underground (deep-history collapse → subterranean continuity)
- Non-human Earth intelligences of unfamiliar form (radically alien octopod-class minds, or something stranger)
- Cryptids / “magical” beings whose ontology is just different from ours
The paper is careful: it doesn’t claim any of these are true. It argues that none have been adequately ruled out and that scientific dismissal has been epistemically lazy. The thing to read for, if you want to feel the academic register: the paper is written like a normal hypothesis paper. That tone is the news.
Worldbuilding payoff. CTH absorbs almost all of Tier 3 cleanly: - USOs → cryptoterrestrials live in deep ocean - Dulce-class lore → underground habitations - Operation Highjump → Antarctica encounters - Skinwalker Ranch → portal site between worlds
This is the hypothesis I’d anchor a serious fiction project around, because it grants Tier-1 plausibility without committing to “rocketships from Zeta Reticuli.”
Sources
Methodology assessments software-engineering rigor turned on the claim
The cryptoterrestrial hypothesis (CTH) as a contract:
hypothesis: at least one non-human intelligence is *Earth-resident* (not extraterrestrial,
not extradimensional, not entirely psychological)
preconditions (must hold to evaluate):
- some UAP / NHI reports are not adequately explained by mundane causes
- the explanation-space includes Earth-resident as a coherent option
(no a priori "only off-planet" reasoning)
postconditions (if true, expect):
- geographic clustering of long-tail reports in Earth-resident habitable spaces
(deep ocean, deep underground, remote wilderness)
- persistent indigenous traditions referring to local non-human peoples
that map to UAP-class reports (folklore as ethnography)
- the entities, if real, exhibit understanding of *Earth* (geology, biology,
weather) inconsistent with a recently-arrived alien
invariants (would break CTH):
- the entities consistently demonstrate technology/biology inconsistent with
plausible terrestrial evolution or buried-civilization timescales
- the entities have *no* connection to Earth-historical narrative or geography
current state: pre-conditions met (the unexplained residual exists; the explanation-
space is now formally open as of the 2024 Lomas paper). Post-conditions partially met
(USOs, indigenous traditions). Invariants neither confirmed nor refuted yet.
What would constitute evidence FOR CTH?
CTH true
│
┌──────────────┼──────────────┐
▼ ▼ ▼
geographic biological artifact
clustering contact recovery
│ │ │
USOs + credible unambiguous
Skinwalker + witness corpus non-mundane
deep-mountain of repeated material
sites same-place with Earth
encounters isotopic ratio
Falsification: a single artifact with isotope ratios matching an off-Earth body (meteorite-like) would refute CTH (would imply ETH instead). Conversely, a single artifact matching deep-Earth isotopic ratios would be the strongest single confirmation.