 As a geologist, I've had a lot of surprises in the field, but I never expected that a field excursion to a remote corner of Tibet would lead me to a new appreciation for the biblical story of Noah's Flood. But there in the headwaters of the Brahmaputra River, we discovered evidence for how a wall of ice and mud descended the flanks of a 25,000-foot-high peak to block the river, and this glacial dam backed up an enormous lake on the edge of the Tibetan Plateau. And as you might imagine, ice does not make for a very good dam, and when the dam failed as it inevitably would have, it set a wall of water surging down the biggest, deepest gorge on Earth. When I told this story about our discovery to a local farmer's wife, an interpreter related her reply. Yes, she knew all about our big ancient flood, and she even pointed to a point high on the valley wall, where three boats apparently had been stranded. It turns out that the Lamas of the local temple had told her about how Guru Rinpoche, the guy who brought Buddhism to Tibet, had fought the demon at the lake, defeated it to drain its waters and reveal the fertile valley bottom that her village now farmed. Did Tibetan villagers really have an oral tradition of our ancient flood? Well, I was intrigued, and this got me interested in looking into the origin of other flood stories from around the world. As a geologist, like most geologists, I considered such stories fairy tales, enrooted in superstition. But as I started to look into other flood stories, I started to realize that an awful lot of areas that had geological evidence for really big ancient floods also had deep cultural traditions of flood stories. And for example, if you look at tsunami-prone coasts, there's traditional stories of large floods that rose from the sea, from Chile all the way up to Alaska and on Pacific Islands from Hawaii right on across to South Pacific Islands and Southeast Asia. And at the end of the last Ice Age, when all the glaciers melted off the poles, and sea level rose enough that the Mediterranean overtopped the Bosporus to spill into what's now the Black Sea and inundate a fertile valley right next door to the Mesopotamian roots of the biblical flood story. I was astonished. Could science really be playing catch-up to folklore? Well, as I looked further into the story of Noah's flood, I was in for another surprise. It turns out that science and religion have not always squared off in polarized conflict. Indeed, some of the first geologists framed their view of the world, and indeed, their interpretation of their data through the story of Noah's flood. You might even say that Noah's flood served as the first geological theory. Steno, the Catholic bishop that is widely revered as the grandfather of geology, developed his foundational principles for how to read the rock record, that the oldest rocks in a stratigraphic pile, a pile of sedimentary rocks, are found at the bottom, the youngest ones are found at the top. He then interpreted his field observations by invoking Noah's flood. Steno's thinking was greatly influenced both by his deep personal religious faith and also by the long-standing tradition in Christian theology that we could learn things from studying the natural world through the application of reason, what we now call science. It turns out Steno was not alone. He was not unusual. He was more the norm than an exception. Most early geologists were also clergy, and they were perfectly comfortable wearing both hats. And as they applied Steno's principles to unraveling the geological story of Northern Europe and Europe, they discovered that the rock record told a story that was far more involved and complex than laid out in the biblical stories of the creation and Noah's flood. Their thinking was basically involved in how you could look at the world through the lens of religion and science and that there was not inherent conflict between the two. Indeed, the first professor of geology at Oxford, William Buckland, argued in his inaugural address at Oxford about that the biblical flood story was backed up by the geologic record. Indeed, what else he argued could explain the large out-of-place boulders that you could find laying all around Northern Europe. It turns out that as he studied the geologic record over the next several decades, he found increasingly conflicting evidence and finally decided that there was no geologic signature of Noah's flood. And indeed, by the late 19th century, geologists had laid to rest the idea of a global flood. Theological and scientific opinions converged on the realization that rocks that make up our world tell a very longer and more elaborate story than laid out in Genesis. Fast forward now to the 21st century and public opinion polls consistently indicate that about 40% of the American public believes creationist ideas that fly in the face of geological evidence. Ideas like the world is less than 10,000 years old and that people and dinosaurs live together in harmony in the days before a world-wrecking flood. Well, I was even more surprised to realize that creationism, modern creationism, is one of the most recently evolved forms of Christianity. Not even the original fundamentalists of the early 20th century did not believe the discredited idea of a global flood. I wonder how many of today's creationists know this. Well, why is all this important today and relevant? Well, we have always and always will interpret the world around us through what we believe and what we can see for ourselves to be true, the filter of faith and the lens of reason. Now, it's for Noah's flood, we know it was not a global flood, but it could have been a local flood or regional flood. It might have been the flooding of the Black Sea. It could have been a catastrophic Mesopotamian flood. I don't think it actually really matters. But if we look at the history of thinking about Noah's flood, it reveals the power and value of an open mind and how both reason and faith shape the evolution of science and religion. And I can't help but think that portraying a fundamental conflict between science and religion is particularly dangerous today now that we really need new creative solutions to basic social and environmental problems if we're gonna maintain civilization on this rock in space. And I'm pretty sure that if you think you know everything, you will never learn anything. Thank you very much. Thank you.