October 1, 2018 | David F. Coppedge

Geophysics Not Rock Solid Science

With observation, instruments and models, you would think geophysics is hard science.

Plate Tectonics May Have Been Active on Earth Since the Very Beginning (University of Tennessee at Knoxville). For years, geophysicists have claimed that plate tectonics began billions of years after planet Earth formed. Not so, say these revisionists at U Tenn:

A new study suggests that plate tectonics—a scientific theory that divides the earth into large chunks of crust that move slowly over hot viscous mantle rock—could have been active from the planet’s very beginning. The new findings defy previous beliefs that tectonic plates were developed over the course of billions of years.

Astrobiologists may get excited about this revision to become a big factor in discussions about habitable planets.

Plate tectonics set up the conditions for life,” said Nick Dygert, assistant professor of petrology and geochemistry in UT’s Department of Earth and Planetary Sciences and coauthor of the study. “The more we know about ancient plate tectonics, the better we can understand how Earth got to be the way it is now.

The geophysicists are also revising beliefs of how Earth got its Helium-3/Neon-22 ratio. Giant impacts couldn’t do it, they say, so the ratio must have come about by mantle recycling (plate tectonics).

The new belief will undoubtedly become textbook orthodoxy till some future geophysicists change it again.

Gaia 2.0 (Science). When James Lovelock first came out with the Gaia hypothesis (the idea that earth and its life actively support each other), the majority of scientists considered it a nutty idea. After all, wasn’t the notion named after the Mother Earth goddess of the Greeks, who gave birth to the Titans through an incestual relationship with her father Uranus? Bad metaphor for science! Now, according to Timothy M. Lenton and Bruno Latour, “Gaia 2.0” is becoming respectable. At least Science (AAAS) gave it good coverage. The main reason seems to be that politically correct scientists can now bang the climate drum, warning humans again about how they are messing things up.

According to Lovelock and Margulis’s Gaia hypothesis, living things are part of a planetary-scale self-regulating system that has maintained habitable conditions for the past 3.5 billion years. Gaia has operated without foresight or planning on the part of organisms, but the evolution of humans and their technology are changing that. Earth has now entered a new epoch called the Anthropocene, and humans are beginning to become aware of the global consequences of their actions. As a result, deliberate self-regulation—from personal action to global geoengineering schemes—is either happening or imminently possible. Making such conscious choices to operate within Gaia constitutes a fundamental new state of Gaia, which we call Gaia 2.0. By emphasizing the agency of life-forms and their ability to set goals, Gaia 2.0 may be an effective framework for fostering global sustainability.

Let’s get this straight: Gaia 1.0 operated “without foresight or planning,” but humans are supposed to use intelligent design by making conscious choices? Is this for moral reasons, in penance for “the global consequences of their actions”? We’re supposed to set goals? Are humans not organisms that evolved without foresight?

The origins of the High Plains landscape (ETH Zurich, via Phys.org). Texans, listen up: your flat land may look dull and uninteresting, but it has a claim to fame:

There is nowhere else in the world quite like the High Plains. There are, of course, gigantic alluvial plains in South America as well, and in the part of the Himalayas located in India. “But the High Plains have been inactive for nearly five million years, whereas the other large alluvial fans are still in the process of formation,” says the researcher.

It is also the largest aquifer in North America (the Ogallala aquifer), measuring 450,000 square kilometers, making it good for farmland. The plains are dotted with ephemeral lakes that benefit migrating birds.

The High Plains are in a process of transition, these geologists say. “It will take five or ten million years until the High Plains have completely eroded.” But why? Earlier, they called it a “preserved ancient landscape.” Do they really know what’s going on? Can inferences about unseen tens of millions of years be made about a land only observed by scientists for around 200 years?

Update 10/02/18: Another article shows rethinking in geophysics, this time concerning something believed for over 100 years. Science Daily announced, “Researchers challenge our assumptions on the effects of planetary rotation: Coriolis effect can influence eddies in wakes as small as 10 meters.” An oceanography professor who co-authored the paper said, “We have discovered some major — and largely overlooked — phenomena in fundamental fluid dynamics that pertain to the way the Earth’s rotation influences various geophysical flows.”

Real science is a lot more interesting than the Myth of Progress, because humans are more interesting than rocks. Humans are like the Blind Men with the Elephant. It’s fun to watch them get things wrong over and over, seeing parts of things for short periods of time, and pretending to have “understanding.” The pursuit of understanding is a worthy goal; don’t misconstrue the statement as cynical. But like the pursuit of happiness, one rarely seems to catch it. Taking the blindfolds off helps.


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