It was hard to miss the news at the beginning of February 2014: Bill Nye faced off in a debate on creationism vs. evolution against Ken Ham, who founded the biblically literalist Creation Museum in Kentucky. But while no one seems to have been convinced from their previous opinions by either debater (and some scientists feel that Nye’s willingness to engage Ham lends unfortunate credence to Ham’s position), the pursuit of dating materials from Earth’s earliest days continues. Scientists published a study February 23, 2014, finding that the oldest dated zircon crystal, originally found in Western Australia, to be 4.4 billion years old. If you are looking for a good research paper topic in geology or cosmology, consider looking at Earth’s oldest fragment.
Nye vs. Ham
“Is creation a viable model for origins?” That was the title of the debate sponsored by the Creation Museum. Ham invited Nye, a spokesperson for how teaching creation alongside (or in place of) evolution in schools undermines science education, to debate the possibilities of a 6,000 year-old Earth. More than 3 million people watched the live stream of the broadcast, in which Ham made a distinction between observational science, which Ham believes leads to technological advances, and historical science, which Ham feels is speculation that scientists use about the history of the world to prop up their theories. Nye, whose field of expertise is mechanical engineering rather than evolutionary theory, did his part to support current scientific understandings about the age of the earth, using data from radioisotopic and ice core studies.
While many science supporters believe that Nye won the debate handily, some still worry at the credibility the debate gives to creationism. “Would it be useful for a famous geologist to debate a flat-earther on the topic ‘Is the earth round’?” asked Professor Jerry A. Coyne of University of Chicago, quoted by Sudeshna Chowdhury of the Christian Science Monitor in “Bill Nye vs. Ken Ham: Who won?” posted February 5, 2014. “But I forgive him,” Coyne concluded of Nye, “for he did a credible job.”
West Australian Zircon crystal
A paper in Nature Geoscience had no concerns for the debate, rather focusing on the dating of a zircon crystal collected in Western Australia. Professor John Valley of the University of Wisconsin—Madison led a team in dating a zircon crystal they believed to be 4.4 billion years old, one of the oldest pieces of Earth. The team dated the tiny zircon crystal 13 years ago by analyzing the decay of uranium within the crystal’s structure. When the date was questioned by other scientists, Valley’s team used a technique called atom-probe tomography, which measures the lateral location of atoms, to confirm their original findings.
What does this mean? Well, it lends support to the idea that the Earth cooled off earlier than scientists previously thought. The first 600 million years of the Earth’s history is called the “Hadean Eon,” or the hell-like era, because Earth was thought to be super hot and untenable for life. “Evidence including this zircon suggests that within the first 100 million to 200 million years of its existence, our planet cooled enough to make crust,” summarized Elizabeth Landau in “4.4 billion-year-old crystal is oldest piece of earth” on CNNWorld, February 24, 2014. She continued, “Steam from the atmosphere condensed to make oceans.”
Landau also quoted Valley’s assessment of the find: “Once you know that there were oceans, it’s very reasonable that there would have been life that early,” he wrote.
This is not the first planetary zircon crystal that has been dated at 4.4 billion years old. Andrew Grant of Science News reported on a 4.4 billion year-old crystal from Mars, discovered by collectors after being purchased by a Moroccan gem dealer, in “Meteorite preserves chunks of Mars’ earliest crust: Rock could reveal what the Red Planet’s environment was like billions of years ago” on December 28, 2013. Grant described the technique geochemist Munir Humayun of Florida State University and his team used to date the zircon: “He and his team probed five zircons using a technique that measures how much of a particular uranium isotope has radioactively decayed into lead. Humayun and colleagues now report that the crystals yielded an age of 4.4 billion years, making the crystals a remnant of the very first Martian crust.”
Given dating techniques used by geochemists, how would you answer Ken Ham’s debate topic question? Tell us in the comments.