Post on 20-Jan-2016
Outline
Oreskes vs. Pollack
Geology
Steno
Hutton
Paleontology (Anning, Mantel, Owen)
Smith
Wegener
Oreskes vs. Pollack, again
Pollack
Pollack’s perspectives on uncertainty:• Uncertainty can never be fully eliminated• Decisions about the future must be made in
the face of uncertainty (or conversely, the absence of certainty- to not do so is to maintain status quo)
• Uncertainty is a strong stimulus for (and important ingredient of) creativity
Pollack
• How is scientific uncertainty different from everyday uncertainties we encounter?
• Despite these uncertainties, how can the knowledge that science produces still be credible and productive?
Pollack argues that “With a better understanding of scientific uncertainty, readers will be able to see through the clouds that sometimes obscure the value and relevance of science to societal issues. In the process of coming to understand uncertainty, they will become more self-confident in grasping what science can and cannot offer.” (p. 4)
Pollack vs. Oreskes
“Scientists are not free agents, historians and sociologists have argued, and the social context of their work not only delimits their options but may even determine the content of their knowledge. And if all knowledge is socially constructed, then objectivity is a chimera. This radical claim strikes at the heart of scientists’ beliefs about their enterprise.”
Geology
Laws, theories, and developments leading up to continental drift
Steno's LAW of superposition: layers of rock are arranged in a time sequence, with the oldest on the bottom and the youngest on the top, unless later processes disturb this arrangement.
Note that it is a scientific law because it DESCRIBES the relationship but does not try to explain why it exists.
Steno (Niels Stensen) 1638-1686Image source: Wikipedia.
So, I’m using a spatial pattern (one layeron top of each other), to determine a temporalrelationship (the bottom layer is older).
Image source: Wikipedia.
This is an important development
This is the:
SPACE-FOR-TIME SUBSTITUTION
Which is the sine qua non ("without which it could not be”) of natural history.
Image source: Wikipedia.
OLD
YOUNG
For the record, I also said that rocks were horizontalitylaid down and arelateral continuity
I also noticed that some layershave fossils and others do not, so I tried to use the stratigraphicrecord to distinguish different time periods in the Earth's history
Image source: Wikipedia.
Completely incomprehensiblewriting
Part of ScottishEnlightenment:John Playfair (math)Joseph Black (chemistry)Adam Smith (economist)David Hume (philosopher)
James Hutton (1726-1797)
The present is the key to the past. Image source: Wikimedia.
Siccar Point, Scotland
Image source: Wikimedia Commons, courtesy of Dave Souza.
Siccar Point, Scotland
"the mind seemed to grow giddy by looking so far into the abyss of time”Yes, I really said the “g” word.
Image source: Wikimedia Commons, courtesy of Dave Souza.
Image source: Wikimedia Commons.
The extremely eccentric Prof. William Buckland
Thomas Sopwith’s cartoon of William Buckland as a convert to the glacial theory ("Scratched by T. Sopwith"): “COSTUME of the GLACIERS.” Image source: University of Minnesota.
The unfortunate Mantells (Gideon & Mary Ann)
Image source: Wikipedia, US public domain. Image source: modified from Brooklyn College, CUNY.
Richard OwenImage source: Wikipedia, US Public Domain.
Portrait of Mary Anning with her dog Tray and the Golden Cap outcrop in the background, Natural History Museum, London. Image source: Wikipedia, US Public Domain.
Autograph letter concerning the discovery of plesiosaurus, from Mary Anning. Image source: Wikipedia, US Public Domain.
Othniel Charles Marsh
Edward Drinker Cope
Image source: Wikimedia Commons, US public domain.
Image source: Wikipedia, US public domain.
Image source: Wikipedia. Copyright Jim Ottaviani, but used in compliance with the fair use of 2-d non-free art.
Image source: USGS.
Diagram representing the stages of Geologic time as sections of a 24 hour day/clock. Image source: Wikimedia Commons, courtesy of James.mcd.nz.
William “Strata” Smith
Gloomy form Bust form
Image source: Wikipedia, US public domain. Image source: Wikipedia, courtesy of Ballista.
He noticed that:1) Each particular rock stratum could be identified by the fossils it contained; and 2) The same succession of fossil groups, from older to younger rocks,are found in many parts of England.
Those, in combination,are the rule of faunal succession.
So, he made a geologicalmap of England.(Implicit in this, is that the fossilrecord is a “one-way street”, recording changes of life inthe past.)
Theories that have the earth eroded
May all with safety be exploded
For of the Deluge we have data
Shells in plenty mark the strata
And though we know not yet awhile
What made them range, what made them pile,
Yet this one thing full well we know -
How to find them ordered so.
attributed to William Smith (1829)
World-wide knowledge of fossils, basic geological maps of all of the continents, and some geography will set the stage for a young German meteorologist to suggest an idea….
Alfred Lothar Wegener (1880-1930)
What’s withthe pipe, dude?
Image source: Wikipedia, US public domain.
Alfred W.
Hey, do you have PrinceAlbert in a can?
"Doesn't the east coast of South America fit exactly against the west coast of Africa, as if they had once been joined?”"This is an idea I'll have to pursue.”- letter to his future wife, December 1910
Image source: USGS.
Turns out, he wasn’t the first. Francis Bacon noticed this in the 1600s.
Been there, done that.
Remember that I’m also widelycredited with establishinginduction (akaempiricism) and theessay.
Image source: Wikipedia, US public domain.
In 1858, geographer Antonio Snider-Pellegrini made these two maps showing his version of how the American and African continents may once have fit together, then later separated.
But, no one likes looking at me.Image source: Wikimedia Commons, US public domain.
"A conviction of the fundamental soundness of the idea took root in my mind."
Alfred W.Well, let him out!
Why did he ask that question? Apparently, this is a case of pure intellectualism - he was just struck by the idea in the library.
Library (definition) - where academics “surfed” before the internet.
Image source: USGS.
Evidence for continental drift:1) The shapes of continents match2) The geological maps match (stratigraphy & others)3) The fossil match (paleontological)4) The rocks record features that indicate that ice was
present in the past (paleoclimatic)Yet, the current positions don’t match
A younger Alfred
A ghoulish Alfred
A colder Alfred
Image source: Wikipedia, US public domain.
Image source: Wikipedia, US public domain.
Wegener’s evidence
Putting together pieces of a puzzle
Dramatic re-enactment
This all lead to a theory…CONTINENTAL DRIFT
The continents have movedaround the globe over time.
They were all together about 250Million years ago (I’ll call it Pangea, meaning “all the Earth” in Greek)
There was a southern mega-continent (Gondwana) and a northern mega-continent(Laurasia).Image source: USGS.
Ja, good lookingmaps.
Forget the pipe, where’d you get the beanie?
I like theblack and white maps better.
For the record, continental drift was proposed one year earlier by American geologist Frank Taylor.
Wegener was credited for the theory, because his presentation was clear, comprehensive, and cogent and thus could not be ignored (which was the fate of
Frank’s).
My name is Frank, and I’m so obscure that there isn’t a
single picture of me anywhere that Google can find.
This theory led to a lot of gags…….
Is there uncertainty in the data?
Yes, there always is:
1) The fossil record is inevitably incomplete.2) The rock tie-points are non-unique (one could
come up with multiple arrangements).
Yet, there was never any serious doubt about any of the observations.
What makes a good scientific theory?
Scientific Theory - A hypothesis or group of hypotheses that: 1) Explains scientific observations; 2) Is tested with repeated experiments and observations and found always to work; and 3) Is accepted by the scientific community.
A good scientific theory:1) Logical consistency - parts of it don’t contradict other
parts 2) Agrees with the data.3) Suggests verifiable causes that explain and predict 4) Advanced comparisons (simplicity, tradeoff of
generality and specificity, distinction between non-fatal difficulties and fatal difficulties)
Image source: Wikipedia.
Is this a good theory?- Self consistent- Agreed with available data- Made specific, testable predictions- Had difficulties, but weren’t fatal ones
Do you think peopleknow that we startedour careers as German arcticmeterologists, Statler?
Ah, to be youngand freezing coldagain, Waldorf.
It lead to a whole lot of criticism.
"Utter, damned rot!” -W.B. Scott
"If we are to believe [this] hypothesis, we must forget everything we have learned in the last 70 years and start all over again” -American scientist
"Wegener's hypothesis in general is of the footloose type, in that it takes considerable liberty with our globe, and is less bound by restrictions or tied down by awkward, ugly facts than most of its rival theories." - Dr. Rollin T. Chamberlin, University of Chicago
I’ve seen better filmson laundry detergent.
This sounds likeour kind of criticism.
Image removed due to copyright: Statler and Waldorf Jim Henson puppets.
Implications1) The older concept of land bridges to explain fossil
distributions became less likely.2) The concept of a mobilistic Earth is brought
forward.3) It allowed scientist to start making predictions
about fossil distributions, geological structures, and earthquakes.
It placed an easily comprehensible, tremendously exciting structure of ideas upon a solid foundation. It released the continents from the Earth's core and transformed them into icebergs of gneiss [granite] on a sea of basalt. It let them float and drift, break apart and converge. Where they broke away, cracks, rifts, trenches remain; where they collided, ranges of folded mountains appear.