Saturn and Unobserved Events
When is it rational to invoke unobservable events
to make a theory work? Here’s a test case at Saturn.
“A catastrophic event could have created Saturn’s rings while the dinosaurs were still roaming Earth.” Well, it could have, but did it?
At Space.com on 15 Sept 2022, reporter Keith Cooper cheerfully echoed the latest idea coming from planetary science wizards at their computers. “Saturn’s rings might have formed 100 million years ago when one of its icy moons was ripped apart by the planet’s gravity.” But does might make right?
Reporters’ imaginations launched into metaphorical wonderland. Theorists have even given a name to this unseen moon: Chrysalis, suggestive of an abiotic transformation that made Saturn the beautiful planet it is today, its shimmering rings shining like the colorful wings of a butterfly hatched from a caterpillar.
The catchy story was hatched by Jack Wisdom from MIT. He used computer models to investigate why Saturn has a 26.7° tilt—unexpected in planetary cosmogony. Fortunately for humans, Saturn’s tilt allows us to view the rings from Earth in all their glory.
Leah Crane runs with the metaphor at New Scientist on 15 Sept 2022:
If the extra moon was destroyed, the debris left behind could have later become Saturn’s rings, leading the researchers to name this wrecked moon Chrysalis after the form a caterpillar takes as it transforms into a butterfly. “The butterfly is long dormant in this chrysalis phase and then it unveils itself and flaps its wings,” says Wisdom. “Similarly, this was just a small moon made of ice and then the rings suddenly emerged when it was ripped apart.”
What is the justification for this supposition? Nobody saw Chrysalis. Nobody saw any moon rip apart. Nobody was present in the age of dinosaurs. We know dinosaurs from their bones, but are the rings of Saturn evidence of Chrysalis?
Press Leapfrogs Over the Evidence into Fantasy
Some are excited about Jack’s wisdom. He gets two explanations for the price of one: young rings and obliquity. Saturn’s young-looking rings have long been a puzzle to old-age views of Saturn (18 Jan 2019). They had to form long after Saturn’s formation, but how?
Before now, planetary scientists tried to explain Saturn’s tilt from interactions with Neptune. That explanation came under fire after observations from the Cassini mission. Jennifer Chu explains in a 15 Sept 2022 press release from MIT, where Jack Wisdom teaches planetary science.
In the early 2000s, scientists put forward the idea that Saturn’s tilted axis is a result of the planet being trapped in a resonance, or gravitational association, with Neptune. But observations taken by NASA’s Cassini spacecraft, which orbited Saturn from 2004 to 2017, put a new twist on the problem. Scientists found that Titan, Saturn’s largest satellite, was migrating away from Saturn at a faster clip than expected, at a rate of about 11 centimeters per year. Titan’s fast migration, and its gravitational pull, led scientists to conclude that the moon was likely responsible for tilting and keeping Saturn in resonance with Neptune.
The story became more twisted when Cassini measured Saturn’s moment of inertia. The measurement put Saturn outside of a resonance with Neptune, weakening that theory. What could be done to save the phenomena of Saturn’s obliquity and rings? Something must have happened to take Saturn out of resonance with Neptune, Wisdom speculated. He set to work with equations and computer models, and came up with his “pretty good story” about Chrysalis.
Sometime between 200 and 100 million years ago, Chrysalis entered a chaotic orbital zone, experienced a number of close encounters with Iapetus and Titan, and eventually came too close to Saturn, in a grazing encounter that ripped the satellite to bits, leaving a small fraction to circle the planet as a debris-strewn ring.
The loss of Chrysalis, they found, explains Saturn’s precession, and its present-day tilt, as well as the late formation of its rings.
Three explanations from one event! If an unseen object solves these problems, who can complain? Or is it like a ghost story to conjure up unobservable past entities to explain present-day realities?
Pressure for Unobservable Realities
Science Magazine went into more depth about this proposal. On the same day, Sept 15 (see collusion problem in science reporting, 7 Feb 2013), Maryame El Moutamid gave her write-up in Science a Kipling just-so story headline: “How Saturn got its tilt and its rings.” She qualified it with some hedging words in the subtitle: “The destruction of a hypothetical moon may help explain the origin of both.”
The angle between a planet’s equator and its orbit plane is known as its axial tilt or obliquity. As gas giants form from the disk made of gas and dust that swirls around the host star, the gas accretion process is expected to conserve the angular momentum and force the planet to spin perpendicular to its orbital plane. However, within our own Solar System, all gas giants, except for Jupiter, have a substantial nonzero tilt. This implies that something else must have happened to these planets after they formed that caused them to tilt.
The simplest explanation, though, is that the planets have always been that way, and the rings really are young. It was the need for conforming observable reality with favored theories of planet formation and deep time that motivated a search for unobservable causes.
To put their claims about Saturn’s tilt in more quantifiable terms, Wisdom et al. performed simulations that show the destruction of their hypothetical moon to be a low-probability event. They found that the mechanism for destabilizing the resonance is chaotic and can produce very different outcomes with small variations in the starting parameters. Out of their 390 simulated scenarios, only 17 produced results in which the satellite is disrupted close enough to Saturn to form the rings. This is compatible with the destruction of one of Saturn’s moons being a one-time event.
How satisfying is it to propose a very low-probability, one-time event to score three runs in the planetary science game? Is this like a National Enquirer headline? “UFO distracts pitcher, allows three on base to run home for the win. Naturalist Science League wins the world series!”
When Is Unobservable Reality Justified?
Scientists invoke unobservable realities frequently. Laypeople do, too, in common sense situations. We see wet ground and assume it rained, even when the sky above is clear. Archaeologists distinguish pottery from natural hardened clay. Scientists study volcanoes and infer unseen heat under the Earth. Here are some criteria for evaluating the credibility of unobservable entities in hypotheses rigged to explain observable phenomena:
- Is the proposed unobservable entity probable?
- Are similar entities or processes observed in other instances, or is it a one-time occurrence?
- Is the event being proposed in order to save a favored theory when there are other explanations available?
Another example to illustrate the criteria is the concept of “ghost lineages” in phylogeny (see Evolution News for explanation). When phylogenetic trees yield unexpected results, some evolutionists will invoke “ghost lineages” to fill in gaps. However, a paper by Tricou et al. in PLoS One on 14 Sept 2022 argues that “Ghost lineages can invalidate or even reverse findings regarding gene flow.” Now that horizontal gene flow (HGF) is seen to be pervasive in the genomes of many animals, tree-building has become much more complicated. Simple diagrams of presumed evolutionary ancestry must give way to the observed realities of hybridization, introgression and horizontal gene flow. After admitting that ghosts can change the interpretation of phylogenetic trees, the authors still favor them in the end: “we suggest that the results of gene flow-related methods should be interpreted with the signature of ghost lineages as the foremost hypothesis,” they conclude. But if we run the invocation of unobservable “ghost lineages” through the criteria above, how much of it is motivated by the urge to save evolutionary common ancestry from contrary evidence?
Critics might counter that creationists invoke unobservable events to maintain belief in Genesis. If we run Creation and the global Flood by the criteria listed above, though, we can see differences between their invocations of unobserved or one-time events and those of the secular materialists.
As for the Flood, known and observed floods can inform processes that imply a global flood. Historic floods like those at Mt St Helens that produced a 1/40 scale of the Grand Canyon in one day, and the floods that cut the Channeled Scablands in Washington through solid rock in mere days, and tsunamis that moved boulders far inland, can be compared with similar but larger phenomena around the world that creationists point to as evidence of a global flood. It’s just a matter of scale (see 10 Evidences at Grand Canyon for a Global Flood). The power of observed floods can be used to justify an inference to a much larger but unseen flood in the past. Plus, that Flood has narrative accounts handed down by eyewitnesses.
As for Creation, intelligence is a known cause. Intelligent causes that can create artistic and complex entities are observable realities all around us. Human-engineered systems that we saw coming into existence can be compared with observed entities that, though not seen coming into existence, are rationally inferred to be the work of intelligence (9 Sept 2022). This can also be a matter of scale. The functional elegance of molecular machines in bacteria (read quote about ATP synthase, 14 Sept 2022) makes intelligent causation the clear winner, especially when the chance emergence by natural causes of such is outrageously low (see online book).
The justification for using unobserved reality in scientific explanation is a vexed question in philosophy of science. Sometimes an unobservable entity can serve temporarily as a placeholder for inference, as was the proposal for a missing planet beyond Neptune that led to the discovery of Pluto, or today’s search for dark matter to save the Standard Model. Unobservable entities must be used sparingly and carefully in scientific explanations, though, and should be disclosed with integrity and transparency by scientists, who should employ them only as placeholders till more evidence comes in. Moreover, scientists need to be fair with alternative theories, including those outside the consensus paradigm.
Today’s scientific realists often go far beyond what can be rationally justified. It is regrettable that the Big Science Media are in cahoots with Big Science, regurgitating mythical entities like Chrysalis without adequate push-back or critical analysis.