Hutton’s Solution and “Deep Time”

“No vestige of a beginning…

No prospect of an end.”

The Age of EnlightenmentLate 18th centuryTremendous advances in science, politics, philosophy, economics, etc.Thomas Jefferson and Benjamin Franklin

American figures in the Enlightenment

James Hutton

A “gentleman farmer”Associate of James Watt and other members of the “Oyster Club”The Scottish Enlightenment – centered in Edinburgh (Edinboro)

Hutton and DeismHutton was a DeistDeism held that one could gain greater understanding of God by understanding nature – his creationThe “Denudation Dilemma - a theological conundrum

Denudation DilemmaRock and soil are essential to lifeRock is the foundation for where we liveSoil is the foundation of agriculture – sustains lifeTo the Deists, this was evidence of God’s beneficence

Denudation DilemmaRocks decay at Earth’s surface – weathering

Soil is washed away from farmlands – erosion

Weathering and erosion indicate destruction of the landMartin Luther predicted that the world would end as a result of erosion

The DilemmaHow can one reconcile God’s beneficence with the destruction of the land, which is essential for life?

Hutton’s ObservationsProcesses of weathering and erosion are slowMany rocks visible on the land are made up of the products of weathering and erosionThese rocks are Sedimentary Rocks

Sediments accumulate in the ocean, so these rocks originally formed in the ocean

The RiddleHow can rocks that formed below sea level be found on land?

More of Hutton’s ObservationsNot all rocks form by accumulation of sedimentSome rocks are made of crystalsThese rocks show signs of having formed at very high temperatures from molten materialThese are Igneous Rocks

Arthur’s Seat and Salisbury Crags

Hutton’s SolutionIgneous rocks provide evidence for heat within the EarthHeat is capable of work (Watt’s influence)Heat within the Earth lifts rocks from the sea and creates new landThe dilemma is solved because as erosion destroys land, heat uplifts new landConcept of the Rock Cycle

Implications of Hutton’s SolutionEarth processes are slowGreat changes can be accomplished with great amounts of timeEvidence of great expanses of time recorded by the rocksConclusion: the Earth must be extremely old

Evidence for Deep Time – Hutton’s Unconformity

An old EarthRecycling of Earth materialsEvidence for earlier episodes of recycling“No vestige of a beginning… no prospect of an end.”

Hutton’s “Theory of the Earth” - 1785

Playfair’s Commentary“The mind seemed to grow giddy looking so far into the abyss of time…”

What’s so remarkable about Hutton’s Ideas?

Contrary to prevailing views of the timeBased on observation – what he sawHutton drew inferences from his observationsInferences are hypotheses

Hypotheses are testable

This is an application of the scientific method to study of the Earth

Science and the Scientific MethodScience – a way of knowing

ObjectiveBased on observation

Scientific Method – a rational way of verifying what is “known”Nothing is absolutely “true” in science. All ideas are subject to rejection as they are tested

Science and the Scientific MethodProposed explanations are hypothesesHypotheses are tested by

ExperimentationPrediction and verificationFurther observation

Well-tested hypotheses may be elevated to the status of theoryWell-tested theories may eventually become natural laws or simply laws