Big Questions in Time

Earth Time - Deep Time

Misha Velthuis

work@mishavelthuis.nl

Mon 17 Feb 2025

Today

Picking things up where we left them

Becoming one with the sediment

Brannen: "Only a handful of spots on earth will count themselves lucky enough to get covered in sediment and then subside into the earth, where they’ll remain shielded from erosion and endure the ages unmolested by plate tectonics. These are the fragments of our modern world that have even the slightest chance of leaving any trace in the rocks in the far, far future of geological time. It’s heartening to know that, though its prospects for short-term survival are grim, New Orleans—sitting as it does on the business end of a subsiding sedimentary basin—has perhaps the world’s greatest potential for long-term preservation. If, in 100 million years, a geologist from somewhere on the tree of life discovers the flattened strata of the Crescent City in the side of a canyon, I can think of worse ways to be represented in the fossil record than by this one data point about humanity."

Not so fast. Don't forget the AUC dorms.

We are in the middle of future sediment…

… on top of unknown mountains

My history with rocks

Marcia Bjornerod

Metaphors

Disciplines

Timefullness

Temporal illiteracy

The history of our temporal "awakening"

Three revolutions of self-perception

Heliocentricism

Less significant in space

"The first was when it realized that our earth was not the center of the universe, but only a speck in a world-system of a magnitude hardly conceivable"

Darwinism

Less significant in ‘animal world’

"The second was when biological research robbed man of his particular privilege of having been specially created and relegated him to a descent from the animal world."

Deep Time

Less significant in time

"What could be more comforting, what more convenient for human domination, than the traditional concept of a young earth, ruled by human will within days of its origin. How threatening, by contrast, the notion of an almost incomprehensible immensity, with human habitation restricted to a millimicrosecond at the very end!"

How did we get to
knowing how we got here?

Let's not mock. Or be arrogant. We would most likely have believed what they believed, if we were born in that time.

In the hope that the future won't mock us for what we currently believe to be true.

The beginning of everything

Burnet's history of the Earth

Thomas Burnet (1635-1715)

If you're looking for inspiration for your capstone title:

"The Sacred Theory of the Earth: Containing an Account of the Original of the Earth, and of all the General Changes which it hath already undergone, or is to undergo Till the Consummation of all Things."

Chaos. (4004 BC)
Matter settles in concentric rings: paradise (no seasons, people lived to 900 years)
The deluge (see boat of Noah)
Our world (1700)
The conflagration (all-consuming fire)
Matter settles again in concentric rings: Christ reigns for 1000 years
After 7000 years: Last battle between good and evil, final judgment, distribution over heaven and hell. Earth no longer needed. Becomes a start.

"There we leave [the earth]; having conducted it for the space of seven thousand years, through various changes from a dark chaos to a bright star"

Smooth surface = perfect conditions, that's why people grew so old.

Smoothness = perfect. Like the Netherlands.

The deluge

James Hutton

Deep time

James Hutton:

"We find no vestige of a beginning - no prospect of an end".

Deep time

John Playfair:

“The mind seemed to grow giddy by looking so far into the abyss of time”.

Conceptual tools of geology

The rock cycle

Plate tectonics

Relative dating

Relative dating with fossils

Connecting the discontinuous #1

Connecting the discontinuous #2

Putting it all together

From relative to absolute

Darwin

Kelvin

Absolute dating

From Lyle (see reference below):

Zircon minerals in igneous rock contain Uranium (U) that decays into Lead (Pb).

"The form of uranium with a mass number of 235 (235U) decays to form lead with a mass number of 207 (207Pb) with a half-life of 704 myr."

"In considering the theory behind radiometric dating it is worth reviewing the words of Holmes himself in that ground-breaking paper in 1911, explaining why he was analysing minerals that he knew contained uranium and lead:"

Such minerals may be regarded as storehouses of the various series of genetically connected radioactive elements. In them the parent element slowly disintegrates, while the ultimate products of the transformation gradually accumulate. The analysis of these minerals ought, then, in the first place, to disclose the nature of the ultimate product of each series; secondly a knowledge of the rate of formation of this product, and of the total quantity accumulated, gives the requisite data for calculation of the age of the mineral.

No pressure:

After graduation he had the opportunity to stay at Imperial College, working in Strutt’s laboratory on radiomet- ric dating problems, from where he published his first scientific paper at the precociously early age of 21 in 1911.

Lyle, P. (2015). Abyss of Time. Dunedin Academic Press Ltd.