Himmeä nuori Aurinko -paradoksi

Laskelmien mukaan nuori Aurinko oli niin himmeä, ettei sen säteily olisi riittänyt pitämään vettä sulana maapallolla, mutta geologiset todisteet osoittavat, että sulaa vettä oli jo pari sataa miljoonaa vuotta maapallon syntymisen jälkeen. Tämän ongelman muotoili tähtitieteilijä ja tieteenkansantajuistaja Carl Sagan yhdessä George Mullenin kanssa vuonna 1972.

Kreationistit ovat luonnollisestikkin olleet kovin iloisia tästä paradoksista, ja pitäneet tätä todisteenaa sekä nuoresta aurinkokunnasta että elämän syntymisen mahdottomuudesta naturalistisen käsityksen mukaan ja myöskin tieteen kyvyyttömyytenä selittää asioita.

http://www.icr.org/article/429/

"If Earth were recently created and designed to have the kind of atmosphere that it has now and the Sun has not changed appreciably in luminosity, then the young faint Sun paradox has been resolved. While the early faint Sun paradox does not tell us that the Solar System is only thousands of years old, it does seem to rule out the age being billions of years."

http://www.answersingenesis.org/articles/tj/v15/n2/faint-sun

"So, the early faint Sun paradox is evidence that the Sun, and therefore the solar system, is young and consistent with the 6,000-year age of the solar system as recorded by Biblical chronology."

http://creation.com/young-sun-paradox

"Of course, creationists do not have a paradox with a faint young sun because the solar system is young. Moreover, the failed solutions to the paradox provide one more reason why the solar system is young."

Paradoksia on selvitelty tutkijoiden toimesta jo yli 40 vuotta ja nyt supertietoneella tehdyt mallinnukset todennäköisesti osoittavat jo aikaisemmin spekuloidut ratkaisut ongelmaan oikeiksi ja paradoksi saa mahdollisesti ratkaisunsa.

Mallinnuksen mukaan vulkaanisen toiminnan synnyttämät hiilidioksi- ja metaanikaasut tiettyinä pitoisuuksina, joita geologiset todisteet tukevat, riittivät pitämään veden sulana osassa maapalloa.

"Solving the "faint young sun paradox"—explaining how early Earth was warm and habitable for life beginning more than 3 billion years ago even though the sun was 20 percent dimmer than today—may not be as difficult as believed, says a new University of Colorado Boulder study."

"The simplest solution to the faint sun paradox, which duplicates Earth's present climate, involves maintaining roughly 20,000 parts per million of the greenhouse gas CO2 and 1,000 ppm of methane in the ancient atmosphere some 2.8 billion years ago, said Wolf. While that may seem like a lot compared to today's 400 ppm of CO2 in the atmosphere, geological studies of ancient soil samples support the idea that CO2 likely could have been that high during that time period. Methane is considered to be at least 20 times more powerful as a greenhouse gas than CO2 and could have played a significant role in warming the early Earth as well, said the CU researchers."

"Even if half of Earth's surface was below freezing back in the Archean and half was above freezing, it still would have constituted a habitable planet since at least 50 percent of the ocean would have remained open," said Wolf. "Most scientists have not considered that there might have been a middle ground for the climate of the Archean.

"The leap from one-dimensional to three-dimensional models is an important step," said Wolf. "Clouds and sea ice are critical factors in determining climate, but the one-dimensional models completely ignore them."

Has the faint young sun paradox finally been solved? "I don't want to be presumptuous here," said Wolf. "But we show that the paradox is definitely not as challenging as was believed over the past 40 years. While we can't say definitively what the atmosphere looked like back then without more geological evidence, it is certainly not a stretch at all with our model to get a warm early Earth that would have been hospitable to life."

"The Janus supercomputer has been a tremendous addition to the campus, and this early Earth climate modeling project would have impossible without it," said Toon. The researchers estimated the project required roughly 6,000 hours of supercomputer computation time, an effort equal to about 10 years on a home computer."

Varmoja ei siis edelleenkään voida olla, mutta uusi mallinnus osoittaa, ettei mitään kreationistien juhlimaa ongelmaa todellisuudessa ole. Eikö kreationisteilla soi kellot lainkaan, kun tiede selvittää yksi toisensa jälkeen teidän kreationismin tueksi mainostamia tieteen ongelmia?

http://phys.org/news/2013-07-early-earth-life.html