Physics, Earth & Space
Intelligent Design and Planetary Timing
Yesterday I considered the matter of timing as evidence of design. Michael Denton’s book The Miracle of Man pulls together an astounding collection of requirements for complex life that are fulfilled ideally on Earth. Some of these, like plate tectonics, have a timing component; one paper calculates the onset of plate tectonics at 700 million years ago out of the planet’s consensus lifetime of 4.5 billion years. Another temporal factor is a magnetic field, which according to measurements over 160 years, is decreasing in strength. Even if its polarity reverses from time to time and is generated by an internal dynamo as most geophysicists believe, the second law of thermodynamics guarantees that it must lose energy to heat and eventually weaken. Indeed, some of the other moons and planets (like Mars) appear to have lost their magnetic fields. Without the protection of a magnetic field, our atmosphere and life itself would be severely threatened.
All in the Timing
Some of the “coincidences” discussed by Denton, like the nature of water, rely on laws of nature and do not have temporal dimensions, but others might. Earth’s atmospheric density and composition, ozone layer, hydrologic cycle, and availability of key minerals at the surface are satisfactory now, but when did they first become optimal? How long can they persist? When was the Earth ready to open shop, and how long can life on Earth take these perfections for granted?
Dynamical perturbations to Earth’s orbit could also affect habitability. Some scientists calculate cyclical changes in eccentricity, obliquity, and precession that could have affected past climate (NASA). A sufficiently extreme perturbation could render Earth inhospitable, as apparently has affected some exoplanets observed to have wildly eccentric orbits, likely due to a gravitational disturbance from a nearby gas giant. Astrophysicists also tell us that many stars go through periods of extreme flare activity, which could destroy Earth’s atmosphere and life. And eventually, they say, our star will balloon outward as a red giant and burn up the Earth. They assure us that we have several billions of years before that happens, but it does point out that our “continuously habitable zone” is a temporary blessing.
Our Solar System
A bizarre twist on the moon’s origin appeared this month from NASA. According to computer simulations at the Ames Research Center, researchers posit that the moon could have formed by a collision in a matter of hours! The collision theory has been the leading contender for the moon’s origin for years, but to consider the moon forming that fast should raise eyebrows. They say the lucky collision occurred billions of years ago. It already seemed like special pleading to expect a lucky strike from just the right sized impactor, with just the right composition, coming in at just the right angle and velocity to create our unique moon. But to have it occur on one lucky day exactly long enough before human beings appeared on the Earth observing perfect solar eclipses — now there’s a screenplay that’s hard to swallow.
I remember in 2008 asking a well-known planetary scientist about his attempt to extend the lifetime of Saturn’s rings. He admitted to me that his motivation was philosophical. If the rings were as young as some other scientists were deducing from Cassini data, it would imply that humans live at a special time when the beautiful rings are visible. That conclusion made him feel uncomfortable and motivated his attempt to extend the lifetime of the rings by proposing that they were denser than believed at the time. Unfortunately, later measurements in 2016 disconfirmed his proposal (JPL). But even if his proposal had been confirmed, Cassini witnessed ephemeral rings such as the E-ring (formed by Enceladus) and the F and G rings, as well as other short-lived phenomena like ring rain, propellers, and shepherd moon perturbations that could not persist for billions of years. These temporary phenomena have given planetary scientists a wealth of opportunities to learn about the dynamics and composition of ring particles.
The Case of Enceladus
Enceladus is an especially fascinating case. Nearly 100 geysers of water ice are currently jetting out of its south pole at supersonic speed, creating the vast E-ring between Mimas and Titan. The particles are subjected to enormous forces from Saturn and its magnetic field. If the geysers stopped, the E-ring would dissipate within a few tens of years. So why do they exist now when scientists can watch the dynamic changes in the geysers and the E-ring? Enceladus is not alone in this regard. Jupiter has thin “gossamer” rings composed of smoke-size particles. Both Uranus and Neptune also have sparse rings. Planetary rings are temporary phenomena that humans are privileged to observe and learn from at a time they can use telescopes and launch spacecraft to observe them. While the temporal brevity of these phenomena does not in itself prove design, it adds to the number of solar system coincidences that seem to be fortuitously timed for scientific discovery.
Tomorrow, “Intelligent Design and Cosmic Fine-Tuning.”