How Apples Get Their Shape

Physicists say a universal theory that describes everything from light reflecting in tea cups to black holes can explain why apples have a dip at the top. View in browser

Image credits: ND700/Shutterstock How Apples Get Their Shape Physicists say a universal theory that describes everything from light reflecting in tea cups to black holes can explain why apples have a dip at the top. Jessica Orwig, Contributor October 19, 2021                                                                                                                                                                                    (Inside Science) -- Next time you're about to bite into an apple, slice it open first and inspect its cross-section. If you look in the right spot, you'll observe that the stem cavity -- where the surface dips down to meet the stem -- is so sharply sloped it nearly becomes a vertical line. Here the curvature, the local change in slope, is what mathematicians would call "singular." Singularities show up in a large range of physical systems, from light reflecting in tea cups to black holes that warp space-time. And it turns out, the theory developed for analyzing singularities can also be applied to describe how an apple gets its stem cavity. Mathematicians and physicists have been using singularity theory for decades, said Thomas Michaels, a biophysicist at University College London. Michaels was co-lead author on a paper published this October in Nature Physics that is the first to mathematically model the apple cavity's shape -- what they refer to as the apple "cusp" in the study... Read more Copyright 2021 American Institute of Physics. Inside Science syndicates its articles, columns, blogs and videos to news organizations. To initiate syndication, or request permission to republish our content (on a one-time or continuing basis), please contact Inside Science at insidescience@aip.org. News organizations seeking permission to republish Inside Science content must fully credit Inside Science as the original source of the content, include the author byline, and republish the original, unaltered form (excluding content titles, headlines, or sub-headlines). The reprint format can be seen here. Copyright conditions and usage terms are subject to change at any time without consent or any type of prior notice. To unsubscribe from all future mailings from Inside Science please click here. To manage your email subscriptions please click here.

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