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Creationism News

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Title: Creationism News


1
Creationism News January 2013 ????? 2013?1?
  • Dedicated to David Coppedge who sacrificed his
    career as the Head Systems Administrator for the
    Cassini Spacecraft in JPL to honor the Creator
    of the Universe. He also spent literally
    thousands of hours to make his excellent
    websites.
  • The contents of this presentation were taken from
    David Coppedges website http//crev.info. Pray
    for the Lords guidance and help in his excellent
    websites.
  • Pastor Chui
  • http//ChristCenterGospel.org
  • ckchui1_at_yahoo.com

5/25/2015
1
2
Is Science a Special Interest Group for One
Party? ??????????????
  • A commentator in the worlds leading science
    journal advised that science needs to work harder
    at becoming bipartisan.
  • Daniel Sarewitz, whose pointed commentaries are
    often critical of science as it is compared to
    how it should be, wrote a disturbing World View
    column in Nature (Jan 3 issue)  disturbing, that
    is, for American Democrats.  He accused both
    individual scientists and scientific institutions
    of neglecting Republicans and conservatives,
    appearing to overwhelmingly support the
    Democratic Party.

5/25/2015
2
3
Is Science a Special Interest Group for One
Party? ??????????????
  • Science must be seen to bridge the political
    divide
  • Scientists in the United States are often
    perceived as a Democratic interest group. For
    sciences sake this has to change, argues Daniel
    Sarewitz.
  • To prevent science from continuing its worrying
    slide towards politicization, heres a New Years
    resolution for scientists, especially in the
    United States gain the confidence of people and
    politicians across the political spectrum by
    demonstrating that science is bipartisan.

5/25/2015
3
4
Is Science a Special Interest Group for One
Party? ??????????????
  • Sarewitz discussed how key spokespersons for
    science are often very partisan, simply assuming
    that the Democratic Party is their friend, and
    the Republican Party the enemy.
  • That President Barack Obama chose to mention
    technology, discovery and innovation in his
    passionate victory speech in November shows just
    how strongly science has come, over the past
    decade or so, to be a part of the identity of one
    political party, the Democrats, in the United
    States. The highest-profile voices in the
    scientific community have avidly pursued this
    embrace. For the third presidential election in a
    row, dozens of Nobel prizewinners in physics,
    chemistry and medicine signed a letter endorsing
    the Democratic candidate.

5/25/2015
4
5
Is Science a Special Interest Group for One
Party? ??????????????
  • He tallied the record and found that Of the 43
    (out of 68) signatories on record as having made
    past political donations, only five had ever
    contributed to a Republican candidate, and none
    did so in the last election cycle.  Thats not
    right.  Nobel laureates are citizens with
    political preferences, he said, and should not
    treat science like a political football.  If the
    laureates are speaking on behalf of science, then
    science is revealing itself, like the unions, the
    civil service, environmentalists and tort
    lawyers, to be a Democratic interest, not a
    democratic one.  Ouch!

5/25/2015
5
6
Is Science a Special Interest Group for One
Party? ??????????????
  • Sarewitz went on to describe how historically,
    science has prospered under both parties.  The
    claim that Republicans are anti-science is a
    staple of Democratic political rhetoric, but
    bipartisan support among politicians for national
    investment in science, especially basic research,
    is still strong, he said, providing some
    statistics.

5/25/2015
6
7
Is Science a Special Interest Group for One
Party? ??????????????
  • He voiced a theory about why Republicans get a
    bad rap they typically oppose social science,
    not so much science per se.  Thats because
    they believe social science tilts towards
    liberal political agendas.  Compounding the
    trouble is that social science is invading more
    and more scientific initiatives As scientists
    seek to provide policy-relevant knowledge on
    complex, interdisciplinary problems ranging from
    fisheries depletion and carbon emissions to
    obesity and natural hazards, the boundary between
    the natural and the social sciences has blurred
    more than many scientists want to acknowledge. 
    When leading scientists enthusiastically align
    themselves with the Democratic Party, its no
    wonder that conservatives are suspicious that
    all science is social science when it comes to
    contentious issues such as climate change,
    natural-resource management and policies around
    reproduction.

5/25/2015
7
8
Is Science a Special Interest Group for One
Party? ??????????????
  • One-party science is dangerous for science and
    for the nation, he warned.  A healthy national
    scientific enterprise needs to be bipartisan. 
    Sarewitz rebuked the scientific community about
    this in no uncertain terms
  • The US scientific community must decide if it
    wants to be a Democratic interest group or if it
    wants to reassert its value as an independent
    national asset. If scientists want to claim that
    their recommendations are independent of their
    political beliefs, they ought to be able to show
    that those recommendations have the support of
    scientists with conflicting beliefs.
  • Bipartisan science, by contrast, would benefit
    science and the nation.  Politicians would find
    it more difficult to attack science endorsed by
    avowedly bipartisan groups of scientists, and
    more difficult to justify their policy
    preferences by scientific claims that were
    contradicted by bipartisan panels.

5/25/2015
8
9
Is Science a Special Interest Group for One
Party? ??????????????
  • Sarewitz ended with an unfortunate analogy,
    comparing his advice to bridge the divide with
    Republicans with the historic attempts of
    scientists during the Cold War to bridge the
    divide with Russian scientists.  By implication,
    this might suggest the Republicans are like the
    Russian Reds (even though red is the current
    color of the Republican Party), when in fact
    communism is more aligned with far left ideology.

5/25/2015
9
10
Is Science a Special Interest Group for One
Party? ??????????????
  • Other than that, this article is important, not
    only for its good advice, but for reinforcing
    what CEH has alleged for a long time that
    scientists and academics are (to an overwhelming
    degree) willing agents of the liberals, leftists,
    and the Democratic Party (see9/07/2012, 8/22/2012,
     7/06/2012, 8/07/2011, 10/14/2010, 7/05/2010, 9/28
    /2008, or search on Democrats in the search
    bar).  Notice these same people are predominantly
    Darwinist, too.   Unless parity is achieved,
    scientists and their institutions have lost
    credibility to claim science is an independent
    national asset providing value to all Americans.

5/25/2015
10
11
Is Science a Special Interest Group for One
Party? ??????????????
  • One can detect a faint undertone that Sarewitz is
    more concerned about loss of funding than about
    political balance.  In the current period of
    dire fiscal stress, one way to undermine this
    stable funding and bipartisan support would be to
    convince Republicans, who control the House of
    Representatives, that science is a Democratic
    special interest, he worried.

5/25/2015
11
12
Is Science a Special Interest Group for One
Party? ??????????????
  • Well, guess what Sarewitz left out of his
    equation.  When does scientific funding go up? 
    In a booming economy!  Republicans should be seen
    as the greatest friends of science, because they
    strongly support growth of the private sector by
    reducing taxes and regulations.  When business
    thrives because entrepreneurs are not punished
    with stifling taxes and interference, the economy
    surges, and government becomes one of the key
    beneficiaries.  More growth means more jobs. 
    More jobs means more taxpayers.  It doesnt take
    high tax rates to increase revenues it takes a
    growing and expanding pool of successful
    businesses and the jobs they create.  A strong
    economy (the Republican model) is the very boost
    science needs.  Thats when revenues are strong,
    lifting all ships, including science funding.

5/25/2015
12
13
Is Science a Special Interest Group for One
Party? ??????????????
  • The redistributionist path we are on under the
    current administration, though, will damage
    science along with the rest of the private
    sector, because all ships will founder on the
    rocks.  President Obama is intent on fairness,
    by which he means taking from the wealthy and
    handing it out to the poor.  This doesnt spread
    the wealth around (remember that phrase from his
    conversation with Joe the Plumber) it spreads
    the misery around.  It reduces incentive to take
    risks.  The economy falters, joblessness rises. 
    The President cannot be blind to the fact that
    taking all the money from the wealthiest
    Americans would only run the government for a few
    days or weeks.  He knows that increasing taxes on
    capital gains does not increase revenues.  But he
    is stuck on fairness regardless everyone
    should be equally miserable, including scientists.

5/25/2015
13
14
Is Science a Special Interest Group for One
Party? ??????????????
  • The Democrats own this economy now.  As the debt
    skyrockets into unprecedented trillions (more
    than incurred by all previous presidents
    combined), scientists are getting hurt along with
    every other American.  The value of the currency
    drops as inflation threatens to rise.  Everything
    becomes more costly.  Scientists will have to
    argue for the smallest cuts rather than
    affordable increases, with the spectre of
    complete economic collapse looming on the horizon
    a time when all scientific funding by the
    government would be a fools luxury, last on the
    priority list.  The economic crisis America
    faces, along with many of the worlds democratic
    nations bent on equality of outcome instead of
    equality of opportunity, is being exacerbated
    by liberal policies.  Scientists who align with
    the Democratic Party have a death wish they love
    what is destroying them.  Instead of pampering
    the goose that lays the golden egg, they slay it
    in greed.

5/25/2015
14
15
Is Science a Special Interest Group for One
Party? ??????????????
  • As for hoping that scientists will heed
    Sarewitzs advice to become more bipartisan  
    thats funny, its so unlikely.  If anything
    happens at all, it will be a scheme to appear
    more bipartisan without any substantive change
    (for example of phony engagement, see this
    article on ENV).  It could take a generation or
    longer to get real bipartisanship.  Will the
    country last that long?

5/25/2015
15
16
Whats Up with Alley Oop? ??????????
  • Here are some recent stories about human
    evolution.  Some might deserve to be in the
    comics.
  • 1.  Lucy walked up right into the trees 
    Nathaniel Dominy thinks Lucys ankle bones dont
    rule out the possibility she was a tree-climber. 
    By studying the Twa tribe in Uganda, whose
    members routinely climb trees looking for honey,
    Dominy and colleagues found the fossil evidence
    of Australopithecus afarensis ambiguous.  Thats
    because the muscle and tendon changes associated
    with habitual tree climbing dont
    fossilize.  PhysOrg posted a video clip
    explaining the problem.  Dominys work was
    published in an open-access paper in PNAS, where
    the abstract states,

5/25/2015
16
17
Whats Up with Alley Oop? ??????????
  • Paleoanthropologists have long arguedoften
    contentiouslyabout the climbing abilities of
    early hominins and whether a foot adapted to
    terrestrial bipedalism constrained regular access
    to trees. However, some modern humans climb tall
    trees routinely in pursuit of honey, fruit, and
    game, often without the aid of tools or support
    systems Here we show that Twa huntergatherers
    use extraordinary ankle dorsiflexion (gt45)
    during climbing, similar to the degree observed
    in wild chimpanzees. Our results imply that
    derived aspects of the hominin ankle associated
    with bipedalism remain compatible with vertical
    climbing and arboreal resource acquisition. Our
    findings challenge the persistent
    arborealterrestrial dichotomy that has informed
    behavioral reconstructions of fossil hominins and
    highlight the value of using modern humans as
    models for inferring the limits of hominin
    arboreality.

5/25/2015
17
18
Whats Up with Alley Oop? ??????????
  • Not so fast, PhysOrg put it.  Claiming that
    Lucy didnt climb trees may be a rush to
    judgment in light of new evidence in the paper.
  • 2.  Clothes make the Peking Man  The Homo
    erectus specimens collectively dubbed Peking Man
    apparently exhibited another human trait they
    were fastidious about fashion.  Reporter Owen
    Jarus said in Live Science,
  • Peking Man, a human ancestor who lived in China
    between roughly 200,000 and 750,000 years ago,
    was a wood-working, fire-using, spear-hafting
    hominid who, mysteriously, liked to drill holes
    into objects for unknown reasons.
  • And, yes, these hominids, a form of Homo
    erectus, appear to have been quite meticulous
    about their clothing, using stone tools to soften
    and depress animal hides.

5/25/2015
18
19
Whats Up with Alley Oop? ??????????
  • Jarus pointed out that these people made spears
    like Heidelberg Man, but theyre not sure if they
    learned the skill independently or at the same
    time.  As for the drilling of holes, just because
    living humans cant figure out why they did it
    doesnt mean the cave dwellers didnt have good
    reasons.  They apparently made tools for their
    fashion industry.  If they are depressing the
    hides, if they are softening hides, they can use
    the hides for their clothes, something no
    sophisticated hominids would dare live without. 
    Alley Oop wore clothes, we remember from the
    cartoons, but since the hides didnt fossilize
    with the skulls, we cant really know how chic
    Mrs. Oop looked.

5/25/2015
19
20
Whats Up with Alley Oop? ??????????
  • 3.  Climate makes the man  If you can believe a
    headline on PhysOrg, we are what we are because
    the weather was what it was.  Fluctuating
    environment may have driven human evolution, it
    reads A series of rapid environmental
    changes in East Africa roughly 2 million
    years ago may be responsible for driving human
    evolution, according to researchers at Penn State
    and Rutgers University.  How did they come up
    with this notion?  By looking at leaves in an
    ancient lake.  Presuming the dates of those
    leaves tell a climate story, and presuming they
    match epochal periods of human evolution, they
    placed cause with effect.  But if anthropogenic
    climate change is a big modern debate, perhaps
    the hominids caused the climate change, not the
    other way around.

5/25/2015
20
21
Whats Up with Alley Oop? ??????????
  • It seems this idea could be testable.  See if
    people in the polar regions are regrowing fur. 
    Without asking questions like this, the
    researchers convinced themselves that they had
    found natural forcing mechanisms to drive
    hominid evolution toward scholarship.  They
    didnt explain why other species didnt
    simultaneously learn abstract language and
    philosophy.

5/25/2015
21
22
Whats Up with Alley Oop? ??????????
  • 4.  Out of Out of Africa theories  A new find
    musses up common ideas about humans emerging out
    of Africa.  Pamela Willoughby has found evidence
    of continuous habitation at two sites in Tanzania
    between 200,000 years ago and the present. 
    According to PhysOrg, this may lead to a
    rethinking of how, when and from where our
    ancestors left Africa. Many paleoanthropologists
    believe a genetic bottleneck after the Ice Age
    shows there was a migration into Europe at around
    50,000 to 60,000 years ago, but Willoughbys
    evidence includes the whole period before and
    after the bottleneck all the way to the
    present.  She explained why this represents an
    upset

5/25/2015
22
23
Whats Up with Alley Oop? ??????????
  • It was only about 20 years ago that people
    recognized that modern Homo sapiens actually had
    an African ancestry, and everyone was focused on
    looking at early Homo sapiens in Europe who
    appeared around 40,000 years ago, she said. But
    we now know that as far as back as around 200,000
    years ago, Africa was inhabited by people who
    were already physically exactly like us today or
    really close to being the same as us. All of a
    sudden, its not Europe in this time period
    thats really important, its Africa.

5/25/2015
23
24
Whats Up with Alley Oop? ??????????
  • What were hominids identical to us doing for
    200,000 years against the inexorable forces of
    evolution?  Didnt they read the bumper stickers,
    Evolve or perish?  Willoughbys upset is just
    the latest upset until the next upset.

5/25/2015
24
25
Whats Up with Alley Oop? ??????????
  • 5.  Annus horribilis, a new endangered species 
    Latin speakers will know that Annus
    horribilis means terrible year, not a Linnaean
    classification name.  But according to Science
    Magazine (Dec. 21), it was a terrible year
    for Homo sapiens var. anthropologist  a recent
    entry in the endangered species list.  A lot of
    anthropology graduates cant find work.  There
    just arent that many jobs labeled
    anthropologist, so graduates are evolving into
    subspecies that adapt their image to a changing
    environment.  With multiculturalism a buzzword in
    certain quarters, anthropologists can advertise
    themselves as ones able to research human life,
    history, and culture, and apply that knowledge to
    current issues such as diversity in the
    world.  The article did not describe the plight
    of a minor subspecies of the clade,
    paleoanthropologists.

5/25/2015
25
26
Whats Up with Alley Oop? ??????????
  • None of these stories really matter, because
    paleoanthropology is a field where every year or
    two they announce, Everything you know is
    wrong.  Since there are infinitely more wrong
    ideas than correct ones, changes to this pattern
    are unlikely when the blind lead the blind.  We
    offer paleoanthropology stories less as
    scientific discovery as much as funny pages.

5/25/2015
26
27
Happy New Biomimetics Year ????????
  • The variety of design applications coming from
    the imitation of natural solutions continues to
    be astonishing.
  • Hope for sensitive teeth  When is it time to see
    the dentist?  At 230 (tooth hurty).  If you have
    sensitive teeth like 3 out of 4 people, there may
    be a biomimetic solution coming.  Sensitivity
    occurs when dentin at the gum line erodes,
    leaving nerves exposed to hot, cold, sweet or
    sour signals.  PhysOrg and Science Daily, echoing
    a press release from the American Chemical
    Society, announced a way to rebuild enamel and
    dentin, taking a clue from mussels.  Mussels
    build a waterproof adhesive to secure themselves
    to the rocks.  Taking inspiration from nature,
    a team reasoned that it could help keep minerals
    in contact with dentin long enough for the
    rebuilding process to occur.  They have invented
    a gooey substance that allows the dentin and
    enamel to grow together (see picture
    on PhysOrg).  This solution would be far better
    than the current band-aid treatment of brushing
    with special toothpaste that deadens the nerves. 
    Instead, the adhesive could allow the teeth to be
    reconstructed for good.

5/25/2015
27
28
Happy New Biomimetics Year ????????
  • Pearl of great price  The beauty of pearl and
    mother-of-pearl (nacre) goes beyond its
    attractiveness in jewelry.  The material is also
    desirable for its durability against cracks. 
    Biomimetics engineers would like to imitate the
    construction of similar materials, but
    understanding how the mollusk does it is a
    prerequisite.  It looks like imitation will be a
    way off in a PNAS paper, researchers described
    how they identified 80 shell matrix proteins,
    among which 66 are entirely unique.  Although
    they believed that shell-making was key to the
    evolutionary success of mollusks, they didnt
    describe how these unique proteins arose, each
    one being a highly improbable outcome for a blind
    evolutionary process (see online book).  The
    French team said,

5/25/2015
28
29
Happy New Biomimetics Year ????????
  • This is the only description of the whole
    biomineralization toolkit of the matrices that,
    at least in part, is thought to regulate the
    formation of the prismatic and nacreous shell
    layers in the pearl oysters. We unambiguously
    demonstrate that prisms and nacre are assembled
    from very different protein repertoires. This
    suggests that these layers do not derive from
    each other.

5/25/2015
29
30
Happy New Biomimetics Year ????????
  • Imitating rapid steroid synthesis  Researchers
    at Scripps Institute are achieving a feat that
    only nature could make on a large scale the
    synthesis of polyhydroxylated steroids.  These
    compounds. used in heart-failure medications and
    other drugs, have been notoriously problematic to
    synthesize in the laboratory, PhysOrg reported. 
    The work points the way to a scalable formation
    and modification of a variety of useful
    compounds that had been obtainable in significant
    quantities only from plants or animals.  They
    reduced the number of steps from 41 to 21, making
    natures feat still look superior.

5/25/2015
30
31
Happy New Biomimetics Year ????????
  • Bioinspired catalysts  Nature makes it look so
    easy.  Naturally occurring metalloenzymes have
    long been recognized as attractive catalysts for
    aerobic oxidations because they can operate under
    mild conditions with complete chemoselectivity, S
    cience Magazine said. Simulation of the function
    of these enzymes has led to the discovery of many
    biomimetic oxidation catalysts.  Martine
    Largeron and Maurice-Bernard Fleury described
    progress in this dynamic research field. 
    Researchers arent yet close to catching up with
    what living cells do every day

5/25/2015
31
32
Happy New Biomimetics Year ????????
  • Many challenges remain, including the development
    of biomimetic catalytic systems that operate
    effectively at room temperature with ambient
    air rather than pure molecular oxygen. The
    development of recyclable heterogeneous
    nanocluster catalysts that contain biocompatible
    rather than rare and precious metals would also
    be welcome. From a more general
    viewpoint, mimicking the function of amine
    oxidase enzymes would provide environmentally
    friendly organic synthesis because air is the
    cheaper and less polluting stoichiometric oxidant.

5/25/2015
32
33
Happy New Biomimetics Year ????????
  • Mitochondria-inspired fuel cells  Inspired by
    how cellular organelles like mitochondria and
    chloroplasts harvest sunlight so efficiently,
    researchers at the University of Reading have
    built nanowire networks with vastly increased
    surface area that can reside on plastic
    substrates, promising fuel cells and other
    products that are more efficient, cheaper,
    lightweight, and environmentally
    friendly.  PhysOrg headlined this, Nanomaterial
    inspired by nature paves way for greener
    energy.  If you dont mind the goofy music, a
    video clip shows the manufacturing process.

5/25/2015
33
34
Happy New Biomimetics Year ????????
  • Living buildings  Imagine buildings of the
    future hosting lichens and mosses that can absorb
    excess C02.  Thats becoming an option,
    reported Science Daily, with a drawing of a
    building with a vegetated facade making the
    most of the sunlight.  The new material, designed
    at a university in Barcelona, Spain,
    offers environmental, thermal and aesthetic
    advantages over other similar construction
    solutions.  It also improves the thermal comfort
    of people inside.  The innovative feature of
    this new (vertical multilayer) concrete is that
    it acts as a natural biological support for the
    growth and development of certain biological
    organisms, to be specific, certain families of
    microalgae, fungi, lichens and mosses.  The
    layered structure captures rainwater for use by
    the organisms, and as they grow, the buildings
    will change in color over time.  The researchers
    see their patented concrete being used for
    renovating buildings, creating vertical gardens
    and designing architectures that blend into the
    landscape.

5/25/2015
34
35
Happy New Biomimetics Year ????????
  • Everyone can love biomimetics.  Many of the above
    are unique stories, not mentioned here before. 
    Faster, better, cheaper nature shows us the
    way.  Darwin-talk drops out of the discussion
    when the focus is on natural design we can use to
    improve our lives.

5/25/2015
35
36
Faint Young Sun Paradox Solution Criticized
????????????
  • A proposed solution for keeping the Earth warm
    when the sun was 25 cooler leaves other
    evolutionists doubtful.
  • The faint young sun paradox has been a worry
    for decades.  Theoretically, stars like our sun
    would have been 2030 cooler in their early
    years about the time when the Earth was
    preparing for life in evolutionary scenarios. 
    How did the Earths surface avoid becoming frozen
    solid, from which an escape to springtime was
    impossible?  Besides, records of the oldest
    crustal rocks show signs that oceans were liquid
    34 billion years ago in the evolutionary
    timeline.

5/25/2015
36
37
Faint Young Sun Paradox Solution Criticized
????????????
  • A new solution was proposed in the 4 Jan issue
    of Science Magazine by Robin Wordsworth and
    Raymond Pierrehumbert of the University of
    Chicago.  They propose that higher levels of
    nitrogen combined with 10 hydrogen would have
    increased collisional and rotational states in
    these gases.  That would produce global warming
    enough to keep the surface from freezing.  This
    new proposal adds to earlier hypotheses about
    other greenhouse gases that might have been
    present, such as methane or more carbon dioxide.

5/25/2015
37
38
Faint Young Sun Paradox Solution Criticized
????????????
  • But in the same issue of Science, James Kasting
    of Penn State threw cold water on the new
    proposal.  Hydrogen gas was unlikely to have
    existed once life evolved, because methanogens
    would have eaten it out of the atmosphere in
    short order.  In addition, Sara Reardon in New
    Scientist noted that fossil raindrop imprints,
    which are large and show free fall through a thin
    atmosphere, contradict the idea that nitrogen and
    hydrogen were abundant.  She also pointed out
    that volcanoes do not typically exude the amount
    of hydrogen needed in the new model.  And
    on Space.com, Charles Q. Choi said that Past
    research had suggested that the early Earth was
    not rich in hydrogen.  Even Wordsworth admitted,
    Hydrogen is such a rare gas in Earths
    atmosphere today that at first glance, it seems
    crazy that it could ever have played a role in
    warming the climate.

5/25/2015
38
39
Faint Young Sun Paradox Solution Criticized
????????????
  • While not overthrowing the new proposal, Kasting,
    Reardon and Choi suggested that the paradox will
    require further work to resolve.  Woodworth
    agreed Theres been lots of previous work on
    the faint young sun paradox, and were sure our
    study wont be the last word on the matter,
    Wordsworth added. Its of course
    quite possible that the early Earth was kept warm
    by a combination of effects.

5/25/2015
39
40
Faint Young Sun Paradox Solution Criticized
????????????
  • Nevertheless, the headlines in the popular media
    put the proposal in a positive light.  Because
    Titans atmosphere has more hydrogen than
    Earths, New Scientist titled its entry, Titan
    holds clue to faint young sun paradox.  This is
    misleading because the hydrogen does not
    contribute significantly to warming on Titan due
    to the low temperature, according to Kasting. 
    And Space.com promised but did not deliver on its
    headline, How Early Earth Kept Warm Despite
    Faint Sun.

5/25/2015
40
41
Faint Young Sun Paradox Solution Criticized
????????????
  • This is a classic case of special pleading. 
    Planetary evolutionists need a warm Earth to fit
    their old-age ideas of the sun and the planet,
    but the Earth has to maintain a stable
    temperature as the sun gets warmer and life
    evolves.  So they invent scenarios to walk that
    tightrope.  The Earth could have stayed
    warm if hydrogen made up 10 of the atmosphere
    and nitrogen was 23 times as dense as it is
    today.  This implausible ad hoc
    scenario could conceivably have increased surface
    temperatures by as much as 10 to 15C.  But then
    the hydrogen had to leak out, and the nitrogen
    become less dense, to match the increasing
    temperature of the sun over time.

5/25/2015
41
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Faint Young Sun Paradox Solution Criticized
????????????
  • Building on the house of cards, Kasting says it
    could have been caused by pressure broadening
    of CO2 and H2O lines with the higher nitrogen
    levels.  Climbing higher on the house of cards,
    he says the realization that H2 can warm
    terrestrial planet climates could be important
    for the prebiotic Earth, early Mars, and young
    Earth-like exoplanets.  Wowwe got from one
    implausible hypothesis to life all over the
    place!  Isnt evolution wonderful.  It explains
    everything.  (So does unbounded imagination.)

5/25/2015
42
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Faint Young Sun Paradox Solution Criticized
????????????
  • The faint young sun paradox is a
    self-contradiction within evolutionary theory. 
    It does not exist for creationists.  They know
    that God created Earth to be inhabited from the
    start, not that long ago.

5/25/2015
43
44
 A Brain Wouldnt Survive Star Travel ??????????
  • Dont take a star trek unless you want to arrive
    demented.
  • According to Science Daily, prolonged exposure to
    cosmic radiation accelerates the development of
    dementia, including Alzheimers Disease.  The
    headline says it Space Travel May Be Harmful to
    the Brain, Study Suggests Prolonged Cosmic
    Radiation Exposure Could Hasten Alzheimers. 
    The press release at the University of
    Rochester put it this way Houston, We Have
    Another Problem.

5/25/2015
44
45
 A Brain Wouldnt Survive Star Travel ??????????
  • A study published in PLoS ONE (open access) found
    that mice at Brookhaven National Lab exposed to
    radiation levels similar to those in space had
    accelerated levels of dementia.  This damage adds
    to the well-known cancer risks and potential for
    muscle atrophy for long trips in weightlessness.
    The new study shows that galactic cosmic rays not
    only have cardiovascular and musculoskeletal
    impacts they slowly destroy the brain.

5/25/2015
45
46
 A Brain Wouldnt Survive Star Travel ??????????
  • Why is galactic cosmic radiation so damaging? 
    Cant NASA guard against it?  The press release
    explains,
  • While space is full of radiation, the earths
    magnetic field generally protects the planet and
    people in low earth orbit from these
    particles. However, once astronauts leave orbit,
    they are exposed to constant shower of various
    radioactive particles. With appropriate warning,
    astronauts can be shielded from dangerous
    radiation associated with solar flares. But there
    are also other forms of cosmic radiation that,
    for all intents and purposes, cannot be
    effectively blocked.

5/25/2015
46
47
 A Brain Wouldnt Survive Star Travel ??????????
  • Thats because cosmic rays are so energetic
    shielding cannot stop them, or else it creates a
    shower of lower-energy particles that are also
    damaging. Heavy ion particles sent out from
    galaxies would be impossible to deflect One
    would have to essentially wrap a spacecraft in a
    six-foot block of lead or concrete, co-author M.
    Kerry OBanion said.  Try launching that out of
    Earth gravity.
  • There arent as many cosmic particles as those in
    the solar wind, but the damage they cause
    accumulates. Because this radiation exists in
    low levels, the longer an astronaut is in deep
    space, the greater the exposure.  At this rate,
    forget star travel the effects may be too harsh
    for astronauts on NASAs drawing-board proposals
    for a 3-year mission to Mars.

5/25/2015
47
48
 A Brain Wouldnt Survive Star Travel ??????????
  • Update 1/07/13  Science NOW reported on results
    from the Mars500 mission simulation, during which
    six practice crewmen lived in the confinement of
    a space capsule for 520 days the length of time
    for a Mars round trip.  In short, they became
    couch potatoes lethargic, bored, and
    unenthusiastic.  This is another reality that
    mission planners will have to take into account.

5/25/2015
48
49
 A Brain Wouldnt Survive Star Travel ??????????
  • This updates an entry from 9/23/2006, showing
    that the problem has not gone away with six more
    years of research.  The take-home lesson should
    be gratitude for the safety bubble we inhabit in
    the cosmic shooting gallery, allowing us to live,
    love, and enjoy the beauty of creation.  Safe
    within our bubble, Hollywood screenwriters can
    envision epic space voyages (acted out by actors
    in Earth-bound studios), and astronomers can
    search out the most distant galaxies and strive
    to understand the entire universe from a
    protected platform our Privileged Planet.

5/25/2015
49
50
 Wilt Thou? Not with Guards in the Chem
Lab ???????????????
  • Plants avoid wilting with pairs of guard cells
    performing chemical wizardry.
  • Leaves are peppered with oval pores called
    stomata (singular, stoma).  Surrounding these
    pores are guard cells that control the rate of
    moisture escape and carbon dioxide intake.  Under
    dry conditions, the guard cells relax and close
    the pores when moisture is plentiful, they
    stiffen, opening the pore.  But how do they do
    it?  How do they know its dry, and what causes
    them to open the gates?

5/25/2015
50
51
 Wilt Thou? Not with Guards in the Chem
Lab ???????????????
  • A new paper in Current Biology found something
    interesting the guard cells know how to make
    abscisic acid (ABA) from scratch.  ABA is
    required to close the stoma.  Its remarkable
    that no one really figured this out till now,
    especially since Francis Darwin (Charless son),
    way back in 1898, observed stomata closing when
    the relative humidity (rh) drops.  That
    observation was relatively simple however, our
    understanding of the signaling pathway
    responsible for coupling changes in rh to
    alterations in stomatal aperture is
    fragmentary.  Heres what Bauer et al., a team
    of 14 mostly in Germany, found out by stressing
    plants with dry air and watching the genes that
    responded

5/25/2015
51
52
 Wilt Thou? Not with Guards in the Chem
Lab ???????????????
  • The results presented here highlight the primacy
    of abscisic acid (ABA) in the stomatal response
    to drying air. We show that guard cells possess
    the entire ABA biosynthesis pathway and that it
    appears upregulated by positive feedback
    by ABA. When wild-type Arabidopsis and the
    ABA-deficient mutant aba3-1 were exposed to
    reductions in rh, the aba3-1 mutant wilted,
    whereas the wild-type did not. However,
    when aba3-1 plants, in which ABA synthesis had
    been specifically rescued in guard cells, were
    challenged with dry air, they did not wilt. These
    data indicate that guard cell-autonomous ABA synth
    esis is required for and is sufficient for
    stomatal closure in response to low rh. Guard
    cell-autonomous ABA synthesis allows the plant to
    tailor leaf gas exchange exquisitely to suit the
    prevailing environmental conditions.

5/25/2015
52
53
 Wilt Thou? Not with Guards in the Chem
Lab ???????????????
  • The team found 588 genes whose expression
    profiles changed when exposed to dry air.  Of
    those, 131 belong to the class of guard
    cell-enriched genes, they said.  But thats not
    all Within the pool of guard cell-expressed
    genes, 1,550 appeared sensitive to ABA, with
    1,080 being upregulated and 470 being
    downregulated.  Within the cluster of robust
    ABA-induced genes, they found candidate genes
    that respond to humidity.

5/25/2015
53
54
 Wilt Thou? Not with Guards in the Chem
Lab ???????????????
  • One of the most striking features of their
    observations was that guard cells contain all the
    genes necessary to synthesize abscisic acid. 
    Thats not as easy as it looks.  In their
    Figure 2A, they list 8 intermediate steps
    required to go from Beta-carotene to ABA, the
    first five steps taking place in the plastids of
    the guard cells, the last three in the cytosol.

5/25/2015
54
55
 Wilt Thou? Not with Guards in the Chem
Lab ???????????????
  • Our results suggest that guard cells express the
    entire repertoire of ABA biosynthesis genes and
    that the abundance of their transcripts increases
    after exposure to ABA. This latter result
    suggests the existence of a positive feedback
    loop.

5/25/2015
55
56
 Wilt Thou? Not with Guards in the Chem
Lab ???????????????
  • They further found that ABA is essential for
    stomal closure.  Without it, leaves wilted.  The
    leaves could be rescued, though, by turning on
    the ABA-expressing genes.  In their final
    discussion you can sense their excitement at
    elucidating this elegant system

5/25/2015
56
57
 Wilt Thou? Not with Guards in the Chem
Lab ???????????????
  • Understanding how stomata respond to changes in
    atmospheric rh has been a key challenge since the
    phenomenon was first described by Francis
    Darwin. Our work and data from Okamoto et al.
    reveal a significant role for ABA in the stomatal
    response to both reduced and elevated rh. We also
    show that stomata are capable of responding to a
    reduction in rh in a cell-autonomous way, and
    this is mediated through the highly localized
    production of ABA.

5/25/2015
57
58
 Wilt Thou? Not with Guards in the Chem
Lab ???????????????
  • Guard cell-autonomous ABA synthesis not
    only allows an individual stoma to respond to
    changes in leaf hydration but also permits it to
    respond to changes in atmospheric rh and other
    stresses that use ABA as a signal. This in
    turn presents the plant with the possibility of
    exquisitely tuning leaf gas exchange to highly
    local environmental conditions. Furthermore,
    because our transcriptomic data are suggestive of
    a positive ABA-mediated feedback
    on ABA production, the possibilities for tightly
    controlled self-regulation at a highly local
    level over gas exchange are apparent. Our data
    add a new level of complexity to the overall
    understanding of how plants couple photosynthesis
    and water loss to changes in their environment.

5/25/2015
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59
 Wilt Thou? Not with Guards in the Chem
Lab ???????????????
  • The authors made no comment on how this new
    level of complexity arose by natural selection.
  • The plant hormone ABA is also known as
    (2Z,4E)-5-(1S)-1-hydroxy-2,6,6-trimethyl-4-oxocy
    clohex-2-en-1-yl-3-methylpenta-2,4-dienoic
    acid.  It has 15 carbons and 3 rings its
    formula is C15H20O4.  According to Wikipedia,
    the C15 backbone of ABA is formed after cleavage
    of C40 carotenoids in MEP. Zeaxanthin is the
    first committed ABA precursor a series of
    enzyme-catalyzed epoxidations and isomerizations
    via violaxanthin, and final cleavage of the
    C40 carotenoid by a dioxygenation reaction yields
    the proximal ABA precursor, xanthoxin, which is
    then further oxidized to ABA.  Abscisic acid,
    produced throughout the plant, is also involved
    in seed maturation, fruit ripening, leaf fall,
    photosynthesis rate, and salt stress.  It can
    move rapidly throughout the plant in the xylem
    vessels.

5/25/2015
59
60
 Wilt Thou? Not with Guards in the Chem
Lab ???????????????
  • Wonderful discovery good experimental work by
    this team from Germany.  If you want to know,
    heres the recipe the guard cell has to know to
    cook up ABA (these things have to be synthesized
    in order)  first, in the plastid, (1)
    beta-carotene, (2) zeazanthin, (3)
    antheraxanthin, (4) violaxanthin, (5) neoxanthin,
    (6) 9-cis violaxanthin then, in the cytosol, (7)
    xanthoxin, (8) abscisic aldehyde, and finally (9)
    abscisic acid (ABA).  Thats the ABA
    Biosynthesis Pathway involving at least 29 genes.

5/25/2015
60
61
 Wilt Thou? Not with Guards in the Chem
Lab ???????????????
  • If old Frankie D. had known this earlier, he
    might have told Pop Charlie, Hey dad, we have a
    problem.  This natural selection thing doesnt
    look like it can cut it with guard cells. 
    Theyre a LOT more complicated than we thought. 
    Maybe you should stop making like a phylogenetic
    tree, and leaf.

5/25/2015
61
62
 Uranium-Lead Dating Fraught With Discordance ?
- ?????????
  • Behind the confidence of uranium-lead dates hides
    worry about numbers that dont match up.
  • Uranium-lead (U-Pb) dating is a staple of the
    billions-of-years claims about igneous and
    metamorphic rocks and meteorites giving rise to
    the consensus age of the solar system at 4.55
    billion years.  The technique has been refined
    over the last century, but discordances
    (mismatches) remain.  Thats because there are
    two isotopically distinct yet chemically
    identical decay chains, F. Corfu described in
    the Geological Society of America Bulletin this
    month the 235U to 207Pb pathway, and the 238U
    to 206Pb pathway.  (The ratios of the
    products,207Pb/206Pb, can also be measured.) 
    These twin decay systems, running at different
    speeds, allow an immediate verification of
    the validity of their ages, which must be
    concordant to be considered valid, although under
    favorable circumstances, discordant data can
    be extrapolated to the correct age.  Since
    uranium is often locked in tightly-bound minerals
    called zircons, from which parent and daughter
    product are locked in, the method is thought by
    modern geologists to provide a reliable clock.

5/25/2015
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63
 Uranium-Lead Dating Fraught With Discordance ?
- ?????????
  • In A century of U-Pb geochronology The long
    quest towards concordance, Corfu, a geologist at
    the University of Oslo, described geologists
    frustration at persistent discordance between the
    two methods.  The discordances are small around
    1 or less.  Still, he finds it troubling that
    there should be any discordance if the same
    physical processes are operating for the same
    amount of time.  At the beginning of the article,
    he quoted T. E. Krogh Only one answer is the
    right one, and only that one is good enough.

5/25/2015
63
64
 Uranium-Lead Dating Fraught With Discordance ?
- ?????????
  • The progress in developments of the U-Pb method
    is both a history of technical discoveries and
    advances, as well as a history of a long struggle
    toward concordance, toward an understanding of
    the causes of discordance, and toward ways to
    eliminate it. Despite the enormous
    progress achieved in this field, the problems of
    U-Pb discordance have not yet been completely
    resolved and will be one of the main hurdles to
    overcome in the future.

5/25/2015
64
65
 Uranium-Lead Dating Fraught With Discordance ?
- ?????????
  • The paper is technical, so detailed evaluation of
    the contents should be left to geophysicists. 
    The following quotes give a sense of the kinds of
    problems Corfu discussed, and their
    implications.  Alert readers will want to watch
    for instances of card stacking, circular
    reasoning, extrapolation and sidestepping. 
  • Philosophers of science will want to watch for
    data manipulation, unargued interpretation and
    possible self-deception.

5/25/2015
65
66
 Uranium-Lead Dating Fraught With Discordance ?
- ?????????
  • Now, 60 yr later, we see two contrasting trends,
    two philosophies one that continues the battle
    to eliminate discordance, but also a second one
    that bypasses the problem and solves the Gordian
    knot by essentially eliminating the concept,
    declaring U-Pb systems concordant by
    definition (see section Administrative
    Concordancy).
  • By 1956 There was a gradually growing
    consensus that the dominant cause of discordance
    was loss of Pb, and different attempts were
    made to rationalize the effect and extract
    reliable ages.

5/25/2015
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67
 Uranium-Lead Dating Fraught With Discordance ?
- ?????????
  • While intellectually stimulating, these models
    and discussions could not provide unique and
    fully reliable solutions, and the problems of
    discordant U-Pb data remained a challenge.

5/25/2015
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68
 Uranium-Lead Dating Fraught With Discordance ?
- ?????????
  • The rebound from these rather discouraging early
    phases in the development of U-Pb can be credited
    largely to the work and imagination of Leon
    Silver, at Caltech in Pasadena. He realized that
    the weak point in the analytical procedure was
    the absence of a suitable approach in selecting
    samples from which data could be successfully
    systematized and interpreted (Silver, 1963a,
    1963b, p. 281). He understood that zircon
    populations in rocks can be extremely variable in
    terms of composition, crystallinity, and other
    parameters. He experimented in separating
    fractions according to size and magnetic
    variability, and his measurements of the U-Pb
    ratios of the different fractions revealed
    extreme variation in the degree of discordance,
    which correlated with U content and degree of
    radioactivity. The U-Pb results defined collinear
    arrays for which intercepts could be
    interpreted in terms of primary crystallization
    and secondary Pb loss (Silver, 1963a, 1963b
    Silver and Deutsch, 1963).

5/25/2015
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69
 Uranium-Lead Dating Fraught With Discordance ?
- ?????????
  • Silvers developments set up analytical
    approaches that were to become standard
    procedures in the following two decades. Given
    that discordance was next to unavoidable in most
    samples, the strategy became that of maximizing
    the spread in order to establish more robust
    discordia lines and increase the reliability of
    their intercept ages. A major hurdle, however,
    remained the immense analytical effort needed to
    produce individual analyses from zircon fractions
    of 100500 mg (Silver and Deutsch, 1963),
    which severely limited the utility of the method.

5/25/2015
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70
 Uranium-Lead Dating Fraught With Discordance ?
- ?????????
  • The change of focus by Tom Krogh, then at the
    Carnegie Institution of Washington, to U-Pb
    geochronology from his previous involvement with
    Rb-Sr dating (Kamo et al., 2011) represents
    the next major step in the evolution of the
    method, and the one that really enabled the more
    widespread application and testing of the
    principles and analytical approaches defined by
    Leon Silvers work. Although this flurry of
    activities and new applications helped to solve
    many geological questions, many of the studies
    involving zircon had to rely on extrapolating the
    age from discordant arrays, which in complex
    cases had detrimental effects on the precision
    and accuracy of the ages.

5/25/2015
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71
 Uranium-Lead Dating Fraught With Discordance ?
- ?????????
  • Since model solutions to discordance did not work
    very well, and since extrapolating the ages from
    discordant arrays could be problematic in all
    those cases that had undergone a Pb evolution
    involving more than just two stages, Tom Krogh
    concluded that the only reliable strategy had to
    be that of finding, isolating, and analyzing
    concordant domains of zircon.
  • Because altered domains are easily soluble and
    could be separated from the unaltered zircon by
    partial dissolution, several workers experimented
    with partial dissolution techniques. The results,
    however, were not encouraging because the
    technique introduced secondary effects,
    fractionating U from Pb in the remaining parts of
    the zircons (e.g., Pidgeon and Hopgood, 1975
    Todt and Büsch, 1981 Turek et al., 1982).

5/25/2015
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 Uranium-Lead Dating Fraught With Discordance ?
- ?????????
  • Krogh (1982a) chose instead a different track.
    To avoid the side effects of the chemical
    attacks, he opted to remove the outside of the
    grains, or of fragments of grains, by spinning
    them around in a steel chamber with a jet of
    compressed air (air abrasion method). His tests
    showed that, in many cases, the technique could
    indeed strip most of the discordant zircon
    matter In general, to achieve the best results,
    these methods had to be combined with careful
    inspection and selection of the grains under a
    binocular microscope, and in specific cases with
    imaging (cf. Corfu et al., 2003). From here,
    Corfu discusses other method refinements and
    cross-correlation techniques leading up to the
    ion microprobe.

5/25/2015
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73
 Uranium-Lead Dating Fraught With Discordance ?
- ?????????
  • When compared to ID-TIMS isotope
    dilutionthermal ionization mass spectrometry,
    the main disadvantage of the ion probe was
    a considerable decrease in precision, and
    hence loss of temporal resolution. This stemmed
    mainly from the much smaller amount of material
    available for measurement. Another critical step
    was the determination of the U-Pb ratios, which
    in SIMS secondary ionization mass
    spectrometry must be calibrated against the
    corresponding ratios of an external standard, in
    contrast to ID-TIMS, where the ratios are
    obtained by mixing a tracer of known composition
    with the sample. Because the sputtering of U and
    Pb is controlled to some degree by the
    composition and/or structure of the sample
    (McLaren et al., 1994), discrepancies can arise
    between sample and standard when they have quite
    distinct basic properties. The anomalous
    behavior is evident in some zircons very rich in
    U, such as the cases reported by Harrison et al.
    (1987) and Wiedenbeck (1995). This potential
    problem is now largely recognized in the SIMS
    community, and modern analytical protocols are
    generally concerned with proper matching of the
    reference zircons.

5/25/2015
73
74
 Uranium-Lead Dating Fraught With Discordance ?
- ?????????
  • The latest addition to the arsenal of U-Pb dating
    methods is the laser ablationinductively coupled
    plasmamass spectrometry (LA-ICP-MS) technique.
    The first experiments with U-Pb dating
    by LA-ICP-MS were done in the early 1990s (Fryer
    et al., 1993), and from there the technique
    rapidly improved. In less than a decade, many
    laboratories worldwide had adopted it,
    contributing to many improvements and
    refinements. The method is attractive mainly
    because of the high throughput capability, which
    makes it ideal for the study of large
    populations, such as in detrital zircon studies.
    The main initial challenges for LA-ICP-MS were ach
    ieving control of the analytical
    fractionation between U and Pb, and correcting
    for common Pb.

5/25/2015
74
75
 Uranium-Lead Dating Fraught With Discordance ?
- ?????????
  • In my experience, it is generally difficult to
    apply the chemical abrasion method to U-rich
    and metamict grains because they dissolve too
    easily, even in cases where the grains, though
    rich in U, are free of alteration and yield
    concordant data when treated with air abrasion
    (e.g., Svensen et al., 2012).
  • The Pb-Pb method is a special branch of U-Pb
    geochronology, but it has been used mostly to
    pursue a different type of problem, namely,
    employing the Pb composition of U-poor or U-free
    minerals and rocks to study the genesis of rocks
    rather than to date them. Occasionally, however,
    the two tracks overlap and complement each other.

5/25/2015
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76
 Uranium-Lead Dating Fraught With Discordance ?
- ?????????
  • One of the most prominent applications of Pb
    isotopic analysis to dating was that of Patterson
    (1956), who determined the first
    (essentially) correct age of 4.55 Ga for
    meteorites and, by extension, the planet Earth.
  • THE ROAD TOWARD CONCORDANCE
  • A UTOPIAN GOAL?

5/25/2015
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77
 Uranium-Lead Dating Fraught With Discordance ?
- ?????????
  • At present, U-Pb dating is the method of
    choice in many studies of magmatic systems,
    metamorphism, and provenance. Thousands of
    studies have examined the behavior of the decay
    system, the behavior of U-Pb in different
    minerals, and the response in different
    geological settings.  The preoccupation with
    discordance, which laid a cloud of skepticism
    over the initial enthusiasm, has been largely
    dispersed by the subsequent developments. Today,
    we have reasonably good control of the behavior
    of U-Pb systems. Yet, do we really understand
    discordance do we really know how to navigate
    around it?  Although the basic definition of
    concordance is clear-cut, as soon as the
    analytical error is considered, the term becomes
    somewhat fuzzy, occasionally progressing into
    extreme fogginess.

5/25/2015
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 Uranium-Lead Dating Fraught With Discordance ?
- ?????????
  • However, even the use of the better matching
    decay constant does not always succeed in
    bringing data sets into concordance.
  • Another factor that can affect the degree of
    discordance is the U isotopic composition.
  • A second set of causes that has been widely
    discussed, and convincingly proven in some cases,
    is related to initial disequilibrium in the decay
    chains from U to Pb.

5/25/2015
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79
 Uranium-Lead Dating Fraught With Discordance ?
- ?????????
  • A related phenomenon is the excess of 231Pa
    protactinium, which produces an excess of 207Pb
    (Fig. 2A-I). The phenomenon has been demonstrated
    convincingly in two cases (Parrish and Noble,
    2003 Anczkiewicz et al., 2001) where the effect
    is very strong, but it has been discussed as
    a possible cause in many other cases where the
    discordance toward too high 207Pb/235U ratios for
    uniform 206Pb/238U is distinct, but not extreme.

5/25/2015
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80
 Uranium-Lead Dating Fraught With Discordance ?
- ?????????
  • In practice, subtle disequilibrium effects can be
    difficult to distinguish from effects caused by
    other factors, such as small amounts
    of inheritance of xenocrystic material, Pb loss,
    incorrect common Pb corrections, or simply
    analytical biases from improper blank
    corrections, fractionation, and instrumental
    nonlinearities.
  • More severely discordant data will generally have
    been produced by either Pb loss or mixing.

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  • By contrast, Pb loss by recrystallization and/or r
    edistribution oflead means that there may not be
    any parts of a mineral left with preserved
    close-system relationships and thus that
    are capable of providing concordant ages.
  • SOME MODERN DILEMMAS
  • The main difficulty in interpreting such U-Pb
    data is in identifying correctly the reasons for
    the specific distribution of discrete data
    patterns.

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  • One critical question affecting modern
    studies done with chemical abrasion ID-TIMS is
    whether Pb loss effects can be completely
    eliminated by the chemical abrasion procedure.
    Some examples show that this assumption is not
    always valid (Schoene et al., 2010a). A similar
    uncertainty, but in the opposite direction, is
    introduced by the difficulty of
    evaluating whether some slightly too old grains
    might indicate the presence of antecrysts or
    traces of xenocrystic material.

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  • Finally, the not always easily controllable role
    of disequilibrium in 230Th, 231Pa, and 222Rn,
    discussed previously, can further complicate the
    interpretation of high-resolution data.
  • Ultimately, the overriding criterion for the
    validity of an interpretation is the mutual
    coherence of the data, their consistency with the
    various properties of the analyzed zircons, the
    consistency with coexisting minerals, and
    the consistency within the geological framework.

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  • A somewhat related dilemma, which becomes more
    acute in interpreting Paleozoic and older U-Pb
    data sets, concerns the interpretation of data
    that are nearly, but not fully, concordant
    (Fig. 2A-III). One common solution is to
    extrapol
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