Readers will recall that last year, we were looking at science writer Matt Williams’s analysis of the various reasons that we do not see extraterrestrials except at the movies. (See the links below.) Last time out in November, we looked at the Transcension Hypothesis: The extraterrestrial intelligences exist—but after a Singularity, they became virtual intelligences, exploring inner space at an undetectably small scale. Williams has reported since then on some additional hypotheses so this week we look at a more conventional approach — the “Ocean Worlds” Hypothesis, that icy planets may have interior oceans that harbor life:

To illustrate, there’s the search for life that is going on right now in the Solar System, which is almost entirely focused on Mars. But past the Frost Line, the theoretical boundary in the Solar System beyond which volatiles can exist in solid form, there are icy moons that might harbor life in their interiors.

Matt Williams, “Beyond “Fermi’s Paradox” XIII: What is the “Ocean Worlds” Hypothesis?” at Universe Today

Jupiter’s moon, Europa, is an example:

Other moons of Jupiter like Callisto and Ganymede are also thought to have interior oceans, as is Saturn’s Enceladus and some of Uranus’s moons.

As Williams points out, Alan Stern, Principle Investigator of the NASA New Horizons mission to explore outer planets, thinks that ocean moons/planets might be a solution to the Fermi Paradox (if extraterrestrial intelligences exist, where are they?):

Central to Stern’s presentation was the hypothesis that the great majority of planets in our galaxy that have given rise to life and civilizations are interior ocean worlds. Due to their icy crusts, these civilizations would be unable to communicate with other planets using methods we might recognize (like radio transmitters). But seeing as how these civilians would be aquatic, it’s unlikely they would rely on technologies similar to our own.

Matt Williams, “Beyond “Fermi’s Paradox” XIII: What is the “Ocean Worlds” Hypothesis?” at Universe Today

Williams concludes, “In the end, it could be that intelligent life is not rare at all, but that it’s simply unable to communicate with us.” Indeed, it’s not just us. They may not be able to know of or communicate with any other intelligent entity anywhere.

But then a curious consequence follows — the idea that Earth is unique returns with a vengeance:

In terms of drawbacks, the Ocean Worlds hypothesis raises the all-important Copernican Principle (aka. Cosmological Principle). If most life in the Universe is to be found inside icy planets and moons, then planet Earth, terrestrial life, and humanity are atypical and are in a unique and advantageous position to observe the cosmos – which is consistent with the Anthropic Principle.

What’s more, it implies an imperative or even a duty for humanity to seek out life if it wants to make contact. Otherwise, the Fermi Paradox will endure because other life forms are unable to contact us. But if in so doing, we run the risk of contaminating and destroying any life we find, are we not better off letting it endure? All good questions, and one which help to frame the ethical questions that searching for extraterrestrial life raises.

Matt Williams, “Beyond “Fermi’s Paradox” XIII: What is the “Ocean Worlds” Hypothesis?” at Universe Today

A mission to Europa is a long way off just now. But it’s a curious fact that, if the Ocean Worlds hypothesis is correct, Earth is not, after all, Carl Sagan’s pale blue dot (“Our planet is a lonely speck in the great enveloping cosmic dark.”). It is in fact the privileged planet, whether we like it or not:

You may also enjoy these accounts of why we do not see the aliens:

1.Are the Aliens We Never Find Obeying Star Trek’s Prime Directive? The Directive is, don’t interfere in the evolution of alien societies, even if you have good intentions. Assuming the aliens exist, perhaps it’s just as well, on the whole, if they do want to leave us alone. They could want to “fix” us instead…

2.How can we be sure we are not just an ET’s simulation? A number of books and films are based on the idea. Should we believe it? We make a faith-based decision that logic and evidence together are reasonable guides to what is true. Logical possibility alone does not make an idea true.

3.Did the smart machines destroy the aliens who invented them? That’s the Berserker hypothesis. A smart deadly weapon could well decide to do without its inventor and, lacking moral guidance, destroy everything in sight. Extinction of a highly advanced civilization by its own lethal technology may be more likely than extinction by natural disaster. They could control nature.

4.Researchers: The aliens exist but they are sleeping… And we wake them at our peril. The Aestivation hypothesis is that immensely powerful aliens are waiting in a digitized form for the universe to cool down from the heat their computers emit.

5.Maybe there are just very few aliens out there… The Rare Earth hypothesis offers science-based reasons that life in the universe is rare. Even if life is rare in the universe, Earth may be uniquely suited to space exploration, as the Privileged Planet hypothesis suggests.

6.Does science fiction hint that we are actually doomed? That’s the implication of an influential theory as to why we never see extraterrestrials. Depending how we read the Kardashev scale, civilizations disappear somewhere between where we are now and the advanced state needed for intergalactic travel.

7.Space aliens could in fact be watching us. Using the methods we use to spot exoplanets. But if they are technologically advanced, wouldn’t they be here by now? The Hart-Tipler conjecture (they don’t exist) is, of course, very unpopular in sci-fi. But let’s confront it, if only to move on to more promising speculations.

8.Is the brief window for finding ET closing? According to some scenarios, we could be past our best-before date for contacting aliens. Of course, here we are assuming a law of nature as to how long civilizations last. Can someone state that law? How is it derived?

9.What if we don’t see aliens because they have not evolved yet? On this view, not only did we emerge during a favorable time in the universe’s history but we could end up suppressing them. The Firstborn hypothesis (we achieved intelligence before extraterrestrials) lines up with the view that humans are unique but sees that status as temporary.

10.The aliens exist—but evolved into virtual reality at a nanoscale. That’s the Transcension Hypothesis, the latest in our series on science fiction hypotheses as to why we don’t see extraterrestrials.
On this view, after a Singularity the ETs become virtual intelligences, exploring inner space at an undetectably small scale.