What if we are alone?

David Waltham

Why Am I So Gloomy?

• I have spent a decade researching the question “Is the Earth Special?”

• My conclusion: “Yes it is!”

Why Am I So Gloomy?

• 4 Billion Years of Good Weather– Solar Evolution– Biological Evolution– Geological Evolution– Earth-Moon-System Evolution

P = 1.0±0.5 %

P(M < m < M~ ) = 5±4 %

IntenseIce Ages

Why Am I So Gloomy?

• Each condition satisfied by a few percent of planets

• 5 conditions with a 10% chance of occurrence mean we’d need to observe ~100 000 planets to find one that satisfies them all

Why Am I So Gloomy?

• Each condition satisfied by a few percent of planets

• 5 conditions with a 10% chance of occurrence mean we’d need to observe ~100 000 planets to find one that satisfies them all

• 10 independent 1%-events, P=10-20

Why Am I So Gloomy?

• Each condition satisfied by a few percent of planets

• 5 conditions with a 10% chance of occurrence mean we’d need to observe ~100 000 planets to find one that satisfies them all

• 10 independent 1%-events, P=10-20

• Failure is a genuine possibility!

My Concerns

• There have been studies and discussions of the consequences for science and society of detection of life or intelligent life

• There appear to be no similar studies of the consequences of non-detection after, say, 50 years or 100 years or …

Ways Forward

• Investigations into the consequences finding ET have made progress by studying similar events in the past– The Spanish Conquest of Mexico– Orson Welles Broadcast of 1937– Great Moon Hoax of 1835

Ways Forward

The same could be done for non-discovery• The Great Disappointment of 1844 (The

Millerites who expected Christ’s Second Coming on Oct 22)

Ways Forward

The same could be done for non-discovery• The Great Disappointment of 1844 (The

Millerites who expected Christ’s Second Coming on Oct 22)

• Dorothy Martin’s followers of 1954 (End of the world predicted for dawn on Dec 21 with believers to be saved by flying saucers at midnight)

Ways Forward

The same could be done for non-discovery• The Great Disappointment of 1844 (The

Millerites who expected Christ’s Second Coming on Oct 22)

• Dorothy Martin’s followers of 1954 (End of the world predicted for dawn on Dec 21 with believers to be saved by flying saucers at midnight)

• Cold Fusion (1989)

Ways Forward

• Common Patterns From “Disappointments”– Attempts by Believers to Explain Failure Away– Extreme Persecution & Ridicule of Believers

Conclusions

• It’s possible that worlds which remain life-friendly over billions of years, are extraordinarily rare

• SETI and searches for exoplanet-biosignatures may produce no results after 50, 100, 200 … years

• Earlier “failures of prophesy” give clues to how society will react and it’s not pretty

• Let’s not allow our understandable enthusiasm to lead us into overselling the chances of success