FUTURES NATURE|Vol 436|25 August 2005

MAXO signals

A new and unfortunate solution to the Fermi paradox.

Charles Stross

SIR  In the three years since the publica tion and confirmation of the first micro wave artefact of xenobiological origin (MAXO), and the subsequent detection of similar signals, interdisciplinary teams have invested substantial effort in object frequency analysis, parsing, symbolic encoding and signal processing. The

excitement generated by the availability of such close evidence of extraterrestrial intelligence proximity.

has been enormous. However, after the We have formu initial, easily decoded symbolic represenlated an explana tational map was analysed, the semantics tory hypothesis that of the linguistic payload were found to cultural variables unfa be refractory.

A total of 21 confirmed MAXO signals have been received to date. These super ficially similar signals originate from planetary systems within a range of 11 par secs, median 9.9 parsecs1. It has been spec ulated that the observed growth of the MAXO horizon at 0.5 c can be explained as a response to one or more of: the deploy ment of AN/FPS-50 and related ballistic missile warning radars in the early 1960s1, television broadcasts11

GHz microwave leakage from ovens2, and optical detection of atmospheric nuclear tests3. All MAXO signals to this date share the common logic header. The payload data are multiply redundant, packetized and exhibit both simple checksums and message-level cryptographic hashing. The ratio of header to payload content varies between 1:1 and 2,644:1 (the latter perhaps indicating a truncated payload1). Some preliminary syntax analysis delivered promising results4 but seems to have foundered on high-level semantics. It has been hypothesized that the transforma tional grammars used in the MAXO pay loads are variable, implying dialectization of the common core synthetic language4.

The new-found ubiquity of MAXO

signals makes the Fermi paradox  now nearly 70 years old  even more pressing.

Posed by Enrico Fermi, the paradox can be paraphrased thus: if the Universe has many technologically advanced civiliza tions, why have none of them directly visited us? The urgency with which orga nizations such as ESA and NASDA are

now evaluating proposals for fast interstel lar probes, in conjunction with the exis tence of the MAXO signals, renders the non-appearance of aliens incomprehensi ble, especially given the apparent presence of numerous technological civilizations in miliar to the majority of researchers may account both for the semantic ambiguity of the MAXO payloads, and the non-appearance of aliens. This hypothesis was tested (as described below) and resulted in a plausible translation, on the basis of which we would like to recommend a complete, permanent ban on further attempts to decode or respond to MAXOs.

Our investigation resulted in MAXO payload data being made available to the Serious Fraud Office (SFO) in Nigeria. Bayesian analysis of payload symbol sequences and sequence matching against the extensive database maintained by the SFO has made it possible to produce a tentative transcription of Signal 1142/98 (ref. 1), the ninth MAXO hit confirmed by the IAU. Signal 1142/98 was selected because of its unusually low headerto-content ratio and good redundancy. Further bayesian matching against other MAXO samples indicates a high degree of congruence. Far from being incomprehensibly alien, the MAXO payloads seem to be dismaFUTURES NATURE|Vol 436|25 August 2005

MAXO signals

A new and unfortunate solution to the Fermi paradox.

Charles Stross

SIR  In the three years since the publica tion and confirmation of the first micro wave artefact of xenobiological origin (MAXO), and the subsequent detection of similar signals, interdisciplinary teams have invested substantial effort in object frequency analysis, parsing, symbolic encoding and signal processing. The

excitement generated by the availability of such close evidence of extraterrestrial intelligence proximity.

has been enormous. However, after the We have formu initial, easily decoded symbolic represenlated an explana tational map was analysed, the semantics tory hypothesis that of the linguistic payload were found to cultural variables unfa be refractory.

A total of 21 confirmed MAXO signals have been received to date. These super ficially similar signals originate from planetary systems within a range of 11 par secs, median 9.9 parsecs1. It has been spec ulated that the observed growth of the MAXO horizon at 0.5 c can be explained as a response to one or more of: the deploy ment of AN/FPS-50 and related ballistic missile warning radars in the early 1960s1, television broadcasts11

GHz microwave leakage from ovens2, and optical detection of atmospheric nuclear tests3. All MAXO signals to this date share the common logic header. The payload data are multiply redundant, packetized and exhibit both simple checksums and message-level cryptographic hashing. The ratio of header to payload content varies between 1:1 and 2,644:1 (the latter perhaps indicating a truncated payload1). Some preliminary syntax analysis delivered promising results4 but seems to have foundered on high-level semantics. It has been hypothesized that the transforma tional grammars used in the MAXO pay loads are variable, implying dialectization of the common core synthetic language4.

The new-found ubiquity of MAXO

signals makes the Fermi paradox  now nearly 70 years old  even more pressing.

Posed by Enrico Fermi, the paradox can be paraphrased thus: if the Universe has many technologically advanced civiliza tions, why have none of them directly visited us? The urgency with which orga nizations such as ESA and NASDA are

now evaluating proposals for fast interstel lar probes, in conjunction with the exis tence of the MAXO signals, renders the non-appearance of aliens incomprehensi ble, especially given the apparent presence of numerous technological civilizations in miliar to the majority of researchers may account both for the semantic ambiguity of the MAXO payloads, and the non-appearance of aliens. This hypothesis was tested (as described below) and resulted in a plausible translation, on the basis of which we would like to recommend a complete, permanent ban on further attempts to decode or respond to MAXOs.

Our investigation resulted in MAXO payload data being made available to the Serious Fraud Office (SFO) in Nigeria. Bayesian analysis of payload symbol sequences and sequence matching against the extensive database maintained by the SFO has made it possible to produce a tentative transcription of Signal 1142/98 (ref. 1), the ninth MAXO hit confirmed by the IAU. Signal 1142/98 was selected because of its unusually low headerto-content ratio and good redundancy. Further bayesian matching against other MAXO samples indicates a high degree of congruence. Far from being incomprehensibly alien, the MAXO payloads seem to be disma