Common sense isn't good enough, we need sense in-common.

I had an interesting exchange on a recent post about the roles of the two professions and the development of “common sense.” This was between a geologist and an engineer, both experienced, but with very different educations and professional

My best college course was Regional Structural Synthesis (yes, better than field camp!). A small class of students each created cross sections of the Valley and Ridge Province of the Central Appalachians. They were based on detailed geologic maps, borehole records, gravity data, etc. They were also balanced, meaning that each layer was shortened the same amount, an arduous task in the days before portable computers. In the end, we all had cross sections that met all known constraints, and yet each was different. Each was a different, valid interpretation of the extensive geologic data that was on hand. I have carried this lesson with me throughout my career and it has served me very well. Understand what you don’t know!

In contrast, I understand that an engineer’s education is very different and necessarily so. They have bridges, dams, and tunnels to build and every one needs to be safe, efficient, and effective. This calls for a deep understanding of materials and methods, for rigorous analytical testing and for certainty of project execution. Errors can not only be expensive but deadly. It is important work and is not for dreamy minds.

Both professions are important, both are valid. And both need to understand this and work together in beneficial ways, to back up and expand their view. I have seen progress in this area within my own realm but resistance continues.

This morning I read a paper that touches on “common sense” and I thought it worth sharing:

“I’m very concerned with new young people who want to do geology, geophysics, and hydrology on the computer without learning geology, geophysics and hydrology fundamentals in the field. How can anyone do modeling on the computer out of school without learning common sense? I believe that common sense is a learned trait based, in part, on learning from our mistakes.” [1]

While I agree with this comment, my thought is that the two professions create differing common sense. One learned by the geologist, who is trained to understand what they don’t know, has a common sense about geologic variability and complexity that is grounded in field observation and measurement. The other learned by the civil engineer, who has a bridge to build, has a common sense based on site conditions, material properties, constructability, and public safety. They are both common sense, but not necessarily in-common sense.

[1] Robert E. Crowder, “‘In the Land of the Blind a One‐Eyed Man Is King,’” in Symposium on the Application of Geophysics to Engineering and Environmental Problems 2007 (Symposium on the Application of Geophysics to Engineering and Environmental Problems 2007, Environment and Engineering Geophysical Society, 2007), 332–43, https://doi.org/10.4133/1.2924686.

AI Bots are Joining Your Calls

You may or may not have noticed that you are losing control of your online conversations. 

See my piece in the 25Q3 issue of The Professional Geologist.

Danville’s magnetic history

A stone marker outside the Hendricks County Historical Museum is a monument to magnetism. The magnetic compass was a powerful invention. The mineral magnetite or “lodestone” was used to magnetize compass needles in China as early as 200 BC. Some say this technology was brought to the West by Marco Polo.

In the 1200s, the compass needle was thought to point to the north star. Around 1600, Sir William Gilbert noted that a splinter of magnetite hung from a thread took up a “generally north-south position” and suggested this was evidence that the Earth has an iron core and acts as a bar magnet.

While the “generally north-south” aspect of a compass was helpful, it was open to improvement. The magnetic compass was helpful for navigation because the previous technology, a sextant, required a visual siting of the sun or stars, preventing its use under overcast skies or on rough seas. Improvement was needed because the magnetic north pole isn’t located at the geographic north pole, and because the location of the magnetic north pole wanders over time.

To address these issues, the United States Coast and Geodetic Survey established a network of reference stations to be used by county surveyors. In 1908, a “Meridian Station” was established in Hendricks County. A monument was carved from Bedford Limestone and placed well away from any magnetic disturbances: “at the county poor farm, about 1 mile east of Danville.” It marked an 800-foot long true meridian where surveyors could calibrate their instruments.

The bearing of the meridian was referenced to the spire of the Christian Church in Danville. A surveyor could set up their instrument at the monument and know the spire was exactly 81 degrees 00.8 minutes west of the meridian. Their magnetic compass could be adjusted accordingly and then taken anywhere in the county to measure true north.

Trouble came around 1927 when the spire was demolished for the construction of a new church. There was also concern about magnetic influences from a power line and a tool house built nearby. In 1943, Mr. Stanley Shartle inspected the station and found it to be “in a most dangerous place” as the area by then was a parking lot for heavy trucks and road machinery. The monument showed “signs of having been abused, without being displaced however.”

In 1997, Mr. Shartle and Mr. Steve Maxwell of the County Engineering Department found the meridian stone had been knocked down and damaged. Mr. Shartle consulted with Mr. Bob Carroll of the Engineering Department and the two made the decision to move the monument to the Hendricks County Historical Museum where it now resides near the main entryway.

Today you can see the monument by navigating to the museum with the compass in your smartphone. It uses magnetic sensors on a microchip to give you an accurate bearing. Or you can follow your smartphone’s map app to “170 S. Washington Street.”

Great Scot! AIPG geotour of Scotland, May 2024

Sunlight accentuates the topographic expression of a swarm of small imbricated thrusts. Viewed from the Peach & Horn memorial at Loch Assynt, this region was at the heart of the Highlands controversy of Northwest Scotland.

Volcanoes and Climate Change

A colleague shared some claims made by Ian Rutherford Plimer. Claims made in big, bold red fonts make me suspicious, as does the absence of research offered up to support the claims.

NASA offers this, “Large-scale volcanic activity may last only a few days, but the massive outpouring of gases and ash can influence climate patterns for years.”

NASA also interpreted SAGE II satellite measurements to account for a decline in the globally averaged surface temperature in mid-1992 of about 1° degree F as a result of aerosols released during the 1991 Pinatubo eruption. It seems reasonable to me, based only on what I recall from climate projections, that 1°F (0.55 C) is significant.

But it's not clear how to compare that to the progress in CO2 cuts over the past 5 years. The accounting for the effects of carbon cuts in atmospheric cooling seems as perilous as accounting for future earnings in investment plans.