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Dark matter killed the dinosaurs, says a noted cosmologist
Harvard's theoretical physicist Lisa Randall links the extinction of the dinosaurs to the mysterious "dark matter".
What killed the dinosaurs is a classic science mystery whose prevailing current solution is that a giant asteroid crashed in the Yucatan Peninsula in Mexico about 66 million years ago. It caused all manner of calamities, from tsunamis and volcanic eruptions to blocking out the sky with debris for a few years, bringing about a cold darkness on Earth that proved to be the demise of the dinosaurs.
Physicist Lisa Randall, who teaches at Harvard University, doesn’t necessarily dispute this turn of events. But she thinks the celestial object that did the dinosaurs in was possibly sent on its way by dark matter - an enigmatic and theoretical material that scientists theorize makes up about 27% of the known universe. Randall’s book “Dark Matter and the Dinosaurs: The Astounding Interconnectedness of the Universe” lays out her case.
What Randall proposes is that a part of dark matter (perhaps 5%) can experience a force similar to electromagnetism, which she calls “dark light”. By interacting with dark light, this portion of dark matter could have formed an invisible disk that overlapped with the visible disk of spiral arms in the Milky Way galaxy. And what’s more - this dark disk , which is thin and extremely dense, interfered with the orbit of a comet on the outer reaches of our solar system, in an area known as the Oort Cloud. This resulted in the comet ultimately colliding with Earth, bringing to extinction to its dinosaurs.
Other scientists have generally reacted to this hypothesis with curiosity, especially considering Randall’s track record in the field, saying the idea may be credible but lacks supporting evidence. Randall thinks that we could eventually locate such a disk and that the catapulting of the comets happens with some regularity so we might be in for it once again at some point.
You can read Lisa Randall and Matthew Reece’s study on the subject of dark matter triggering comet impacts here, in Physical Review Letters.
For more, check out Lisa Randall’s talk upon the release of her book on dark matter and dinosaurs:
PER NASA: The Small Magellanic Cloud (SMC), at center, is the second-largest satellite galaxy orbiting our own. This image superimposes a photograph of the SMC with one half of a model of its dark matter (right of center). Lighter colors indicate greater density and show a strong concentration toward the galaxy's center. Ninety-five percent of the dark matter is contained within a circle tracing the outer edge of the model shown. In six years of data, Fermi finds no indication of gamma rays from the SMC's dark matter. Credits: Dark matter, R. Caputo et al. 2016; background, Axel Mellinger, Central Michigan University
"Deepfakes" and "cheap fakes" are becoming strikingly convincing — even ones generated on freely available apps.
- A writer named Magdalene Visaggio recently used FaceApp and Airbrush to generate convincing portraits of early U.S. presidents.
- "Deepfake" technology has improved drastically in recent years, and some countries are already experiencing how it can weaponized for political purposes.
- It's currently unknown whether it'll be possible to develop technology that can quickly and accurately determine whether a given video is real or fake.
The future of deepfakes<p>In 2018, Gabon's president Ali Bongo had been out of the country for months receiving medical treatment. After Bongo hadn't been seen in public for months, rumors began swirling about his condition. Some suggested Bongo might even be dead. In response, Bongo's administration released a video that seemed to show the president addressing the nation.</p><p>But the <a href="https://www.facebook.com/watch/?v=324528215059254" target="_blank">video</a> is strange, appearing choppy and blurry in parts. After political opponents declared the video to be a deepfake, Gabon's military attempted an unsuccessful coup. What's striking about the story is that, to this day, experts in the field of deepfakes can't conclusively verify whether the video was real. </p><p>The uncertainty and confusion generated by deepfakes poses a "global problem," according to a <a href="https://www.brookings.edu/research/is-seeing-still-believing-the-deepfake-challenge-to-truth-in-politics/#cancel" target="_blank">2020 report from The Brookings Institution</a>. In 2018, the U.S. Department of Defense released some of the first tools able to successfully detect deepfake videos. The problem, however, is that deepfake technology keeps improving, meaning forensic approaches may forever be one step behind the most sophisticated forms of deepfakes. </p><p>As the 2020 report noted, even if the private sector or governments create technology to identify deepfakes, they will:</p><p style="margin-left: 20px;">"...operate more slowly than the generation of these fakes, allowing false representations to dominate the media landscape for days or even weeks. "A lie can go halfway around the world before the truth can get its shoes on," warns David Doermann, the director of the Artificial Intelligence Institute at the University of Buffalo. And if defensive methods yield results short of certainty, as many will, technology companies will be hesitant to label the likely misrepresentations as fakes."</p>
Context is everything.
The COVID-19 pandemic has introduced a number of new behaviours into daily routines, like physical distancing, mask-wearing and hand sanitizing. Meanwhile, many old behaviours such as attending events, eating out and seeing friends have been put on hold.
A new study looks at how images of coffee's origins affect the perception of its premiumness and quality.
- Images can affect how people perceive the quality of a product.
- In a new study, researchers show using virtual reality that images of farms positively influence the subjects' experience of coffee.
- The results provide insights on the psychology and power of marketing.