{"id":4254,"date":"2026-02-25T08:00:10","date_gmt":"2026-02-25T13:00:10","guid":{"rendered":"https:\/\/mathvoices.ams.org\/mathmedia\/?p=4254"},"modified":"2026-02-26T14:22:00","modified_gmt":"2026-02-26T19:22:00","slug":"math-digests-january-february-2026","status":"publish","type":"post","link":"https:\/\/mathvoices.ams.org\/mathmedia\/math-digests-january-february-2026\/","title":{"rendered":"Math Digests January &amp; February 2026"},"content":{"rendered":"<h2 style=\"text-align: left\">January &amp; February digests:<\/h2>\n<ul>\n<li style=\"list-style-type: none\">\n<ul>\n<li><a href=\"#1\">U.S. Navy mathematician behind GPS systems dies, from NPR<\/a><\/li>\n<li><a href=\"#2\">Probability in poker, in <i>Scientific American<\/i><\/a><\/li>\n<li><a href=\"#3\">Modeling earthquakes, on <i>Earth.com<\/i><\/a><\/li>\n<li><a href=\"#4\">How curvature does and doesn&#8217;t dictate shape, in <i>Quanta Magazine<\/i><\/a><\/li>\n<li><a href=\"#5\">Quantifying the savings from plug-in batteries, in <i>Canary Media<\/i><\/a><\/li>\n<\/ul>\n<\/li>\n<\/ul>\n<hr \/>\n<h3><a id=\"1\" href=\"https:\/\/www.npr.org\/2026\/01\/23\/nx-s1-5685027\/gladys-west-gps-mathematician\">Gladys West, mathematician whose work paved the way for GPS, dies at 95<\/a><\/h3>\n<p><em>NPR<\/em>, January 23, 2026<\/p>\n<p>Gladys West, a former mathematician with the U.S. Navy, died in January at age 95. West pioneered models of Earth\u2019s shape. Global positioning systems (GPS) still use her findings today. \u201cDespite the struggles of her childhood and the effects of racism on her career, West said she believes she accomplished all she could,\u201d <em>NPR<\/em>\u2019s Bill Chappell wrote in an obituary for West.<\/p>\n<p><strong>Classroom Activities:<\/strong><em> geometry, trigonometry, trilateralization <\/em><\/p>\n<ul>\n<li>(Mid-level) To determine a receiver\u2019s location, GPS calculates its distance to satellites orbiting Earth.\n<ul>\n<li>If a GPS satellite is 12,000 miles overhead and its signal moves at the speed of light (~186,000 miles\/second), calculate the signal\u2019s travel time.<\/li>\n<li>Calculate the distances between a receiver and each of three satellites (<strong>A<\/strong>, <strong>B<\/strong>, and <strong>C<\/strong>) if the signals travel for 71 milliseconds, 68 milliseconds, and 72 milliseconds respectively.<\/li>\n<li>GPS requires at least 3 satellites to determine a receiver\u2019s longitude, latitude, and altitude. Why do you think three satellites are necessary to provide enough information? (Hint: Think of position on Earth as $(x,y,z)$ coordinates.)<\/li>\n<\/ul>\n<\/li>\n<li>(Mid-level) Consider a simplified GPS that measures a receiver\u2019s location in two dimensions. Suppose <strong>Satellite 1 <\/strong>is positioned at the coordinates (0,0), <strong>Satellite 2<\/strong> is at coordinates (8,6), and <strong>Satellite 3 <\/strong>is at coordinates (13,4). Determine the coordinates of the following objects. If you are unable to determine the object\u2019s unique coordinates based on the information provided, explain why.\n<ul>\n<li>Object A is 5 units away from Satellite 1 and 5 units away from Satellite 2.<\/li>\n<li>Object B is equidistant from Satellites 1 and 3.<\/li>\n<li>Object C is 16 units away from Satellite 1, 6\u221a2 units away from Satellite 2, and 5 units from Satellite 3.<\/li>\n<li>Object D is equidistant from all three satellites.<\/li>\n<\/ul>\n<\/li>\n<\/ul>\n<p style=\"text-align: right\"><em>\u2014 Max Levy<\/em><\/p>\n<hr \/>\n<h3><a id=\"2\" href=\"https:\/\/www.scientificamerican.com\/article\/why-52-cards-is-the-perfect-number-for-poker-mathematically\/\">The Math behind a Perfect Poker Deck<\/a><\/h3>\n<p><em>Scientific American<\/em>, January 12, 2026<\/p>\n<p>To play poker successfully, it helps to understand probability. To win, players must find the best five-card hand they can, and hands that display rarer patterns are worth more. Calculating the odds is complicated\u2014but a recent preprint argues that the traditional 52-card deck actually simplifies those calculations. It\u2019s a happy coincidence, writes Emma Hasson: \u201cThe usual number of cards in a deck is purely historical.\u201d Perhaps mathematics had something to do with why the 52-card deck has lasted.<\/p>\n<p><strong>Classroom Activities: <\/strong><em>probability<\/em><\/p>\n<ul>\n<li>(High level) Read the article and answer the following questions.\n<ul>\n<li>Examine the graphic \u201cA Guide to Poker Hands.\u201d If you pull five cards from a four suit, 52-card deck, what is the probability of getting each type of hand? What is the probability that you get none of the hands listed?<\/li>\n<li>What is the probability that the best hand among five cards is a straight flush? A three of a kind? A high card?<\/li>\n<li>What is the \u201cshowdown probability\u201d? Why is it different from the probability of getting a particular hand?<\/li>\n<li>What is special about a 52-card deck, according to Williamson\u2019s preprint?<\/li>\n<li>(Bonus) Try <a href=\"https:\/\/www.scientificamerican.com\/game\/math-puzzle-winning-loser\/\"><em>Scientific American<\/em>\u2019s tie-in poker puzzle<\/a>.<\/li>\n<\/ul>\n<\/li>\n<li>(Mid-level) After calculating the probabilities above, play Texas Hold\u2019em in small groups. As you play, identify an odds calculation that would help your game. As homework, write down how you came up with your question, solve it, and explain how the answer would have affected the game.<\/li>\n<\/ul>\n<p style=\"text-align: right\"><em>\u2014Leila Sloman<\/em><\/p>\n<hr \/>\n<h3><a id=\"3\" href=\"https:\/\/www.earth.com\/news\/math-trick-speeds-up-seismic-calculations-for-earthquake-simulations\/\">Math trick speeds up seismic calculations to transform earthquake preparedness<\/a><\/h3>\n<p><em>Earth.com<\/em>, February 15, 2026<\/p>\n<p>Earthquake simulation is slow and expensive. Right now, accurate models require many rounds of computation. \u201cWhen a single run can take hours on a cluster, teams cannot afford the thousands of repeats they need,\u201d writes Raquel Brandao for <em>Earth.com<\/em>. But a recent study could change that. In this article, Brandao covers the study, which could reduce the computations need by a factor of 1,000.<\/p>\n<p><strong>Classroom Activities: <\/strong><em>Fourier transform, simulation<\/em><\/p>\n<ul>\n<li>(Mid-level) Read the first three sections of the article (\u201cSpeed meets shaking,\u201d \u201cNew models for earthquake simulations,\u201d and \u201cThe slow loop\u201d). Answer the following questions.\n<ul>\n<li>What is the goal of earthquake simulation?<\/li>\n<li>What difficulty is the new work addressing?<\/li>\n<li>Read <a href=\"https:\/\/www.usgs.gov\/faqs\/seismometers-seismographs-seismograms-whats-difference-how-do-they-work\">this explanation<\/a> of a seismogram. Describe what a seismogram is in your own words. Using an educated guess, describe how a seismogram can help scientists study earthquakes.<\/li>\n<\/ul>\n<\/li>\n<li>(Mid-level) A useful tool in seismology is the Fourier transform. <a href=\"https:\/\/kids.kiddle.co\/Fourier_transform\">Read about the Fourier transform here.<\/a> Why do you think it might be useful to apply the Fourier transform to a seismogram?<\/li>\n<li>(High level) <a href=\"https:\/\/www.khanacademy.org\/science\/electrical-engineering\/ee-signals\/ee-fourier-series\/v\/ee-fourier-series-intro\">This Khan Academy unit<\/a> explains how to calculate the Fourier transform of a periodic function (called a Fourier series). Watch the videos, and then find the Fourier series coefficients of the following functions.\n<ul>\n<li>$f(x) = \\sin(x) + \\cos(2x)$<\/li>\n<li>$f(x) = \\sin(x)^2$<\/li>\n<li>$f(x) = |\\cos(x)|$<\/li>\n<li>$f(x) = \\{ x \\}$, the fractional part of $x$<\/li>\n<\/ul>\n<\/li>\n<\/ul>\n<p style=\"text-align: right\"><em>\u2014Leila Sloman<\/em><\/p>\n<hr \/>\n<h3><a id=\"4\" href=\"https:\/\/www.quantamagazine.org\/two-twisty-shapes-resolve-a-centuries-old-topology-puzzle-20260120\/\">Two Twisty Shapes Resolve a Centuries-Old Topology Puzzle<\/a><\/h3>\n<p><em>Quanta Magazine<\/em>, January 20, 2026<\/p>\n<p>If you carve up a surface like a jigsaw puzzle, can you build a new shape out of the pieces? If you want the shape to be smooth and self-contained, then the answer is usually no\u2014the pieces of a sphere can only come together as a sphere; the pieces of a flat sheet can only form a flat sheet. \u201cA relatively small amount of local information about the surface is all you need to figure out its overall form. The part uniquely defines the whole,\u201d wrote Elise Cutts for <em>Quanta Magazine. <\/em>A new study has finally proven an exception thanks to a series of twisty shapes resembling rhinos.<\/p>\n<p><strong>Classroom Activities:<\/strong><em> topology, geometry<\/em><\/p>\n<ul>\n<li>(High level) Based on your reading and the first figure in article, explain the difference between extrinsic and intrinsic curvature. Then answer the following:\n<ul>\n<li>What is the mean curvature of a flat surface?<\/li>\n<li>What is the mean curvature of a cylinder where the largest curvature is 5?<\/li>\n<li>At a point where the largest curvature is 5 and the smallest curvature is 1, what does the surface look like?<\/li>\n<li>Where would there be two different mean curvatures on a donut shape (torus)?<\/li>\n<li>How do the intrinsic curvatures of the above shapes compare to each other? To the intrinsic curvature of a sphere?<\/li>\n<\/ul>\n<\/li>\n<li>(All levels) Draw a triangle on a flat piece of paper and measure its angles. They should sum to 180 degrees.\n<ul>\n<li>Roll another sheet of paper into a cylinder. With thumbtacks, identify three points to be the corners of a triangle. On a curved surface, a \u201cstraight\u201d path means the shortest path, so mark the edges of your triangle with string, stretching the string tight to ensure it traces out the shortest possible path among the corners. Sum the angles of the triangle. Unwrap the cylinder and repeat; do the triangle\u2019s edges change at all?<\/li>\n<li>Draw a triangle on a globe by moving directly south from the North Pole down to the equator, then moving east along the equator, then moving due north again. What is the sum of this triangle\u2019s three angles?<\/li>\n<\/ul>\n<\/li>\n<\/ul>\n<p style=\"text-align: right\"><em>\u2014Max Levy<\/em><\/p>\n<hr \/>\n<h3><a id=\"5\" href=\"https:\/\/www.canarymedia.com\/articles\/batteries\/brooklyn-bagel-shop-plug-in-batteries\">This Brooklyn bagel shop is saving money with plug-in batteries<\/a><\/h3>\n<p><em>Canary Media<\/em>, January 19, 2026<\/p>\n<p>An electricity startup called David Energy is giving large batteries away for free, claiming that it will financially benefit both their customers and them. \u201cWe\u2019re in the game of nickels and dimes,\u201d said the owner of a bagel shop. That shop uses one of David Energy\u2019s batteries to power their oven during times of peak demand. This <em>Canary <\/em>article explains how battery technology may improve economics for customers, electricity companies, and renewable energy.<\/p>\n<p><strong>Classroom Activities:<\/strong><em> financial math, energy costs, algebra<\/em><\/p>\n<ul>\n<li>(All levels) Black Seed Bagels is testing battery technology to reduce <strong>demand charges<\/strong>: extra costs levied by a power company when customers use a large amount of power within a short time. According to the article, Black Seed has 10 locations across New York City, and demand charges from peak electricity can represent up to 50% of a company\u2019s monthly utility bills.\n<ul>\n<li>If Black Seed&#8217;s average monthly electricity bill is $720 per location, and demand charges make up 40% of each bill, how much are they paying in demand charges each month at that location? How much are they paying in demand charges across all of their locations?<\/li>\n<li>The article mentions that every kilowatt reduced from peak hours saves about $50 over the course of one month. If three batteries at one location help reduce their rate of demand by 3.5 kilowatts, how much money would that location save per month in demand charges?<\/li>\n<li>Each of Black Seed&#8217;s three plug-in batteries has a capacity of 2.8 kilowatt-hours (kWh). If all three batteries are fully charged and then used during peak hours, how many total kilowatt-hours of stored energy can they provide across all 10 stores? If electricity costs $0.25 per kWh during peak hours, what is the dollar value of the electricity they can provide from stored battery power?<\/li>\n<li>Suppose the batteries cost David Energy $1,200 per location to provide and install. Based on the savings-per-battery you calculated above, how many months would it take for the total savings across all 10 locations to equal the total investment David Energy made in batteries for all locations?<\/li>\n<li>Currently, David Energy provides the batteries to customers for free. Based on these savings, could David Energy charge a $20 rental fee per battery in the future? Explain why or why not.<\/li>\n<\/ul>\n<\/li>\n<\/ul>\n<p style=\"text-align: right\"><em>\u2014Max Levy<\/em><\/p>\n<hr \/>\n<h3><strong>More math headlines from January &amp; February<\/strong><\/h3>\n<ul>\n<li><a href=\"https:\/\/www.popsci.com\/science\/catchy-song-math-symmetry\/\">Can\u2019t stop humming that tune? Thank math.<\/a><br \/>\n<em>Popular Science<\/em>, February 19, 2026<\/li>\n<li><a href=\"https:\/\/www.insidehighered.com\/news\/faculty-issues\/research\/2026\/02\/19\/mathematician-lifting-lid-trumps-attacks\">The Mathematician Lifting the Lid on Trump\u2019s \u2018Attacks\u2019<\/a><br \/>\n<em>Inside Higher Ed<\/em>, February 19, 2026<\/li>\n<li><a href=\"https:\/\/www.scientificamerican.com\/article\/this-mathematician-proved-the-random-walk-theorem-to-clear-his-name-as-a\/\">This mathematician proved a brilliant theorem to justify his social awkwardness<\/a><br \/>\n<em>Scientific American<\/em>, February 17, 2026<\/li>\n<li><a href=\"https:\/\/www.popularmechanics.com\/science\/a70381341\/open-math-problem-random-walks-solved\/\">Scientists Solve One of the Most Notorious Open Problems in Math<\/a><br \/>\n<em>Popular Mechanics<\/em>, February 16, 2026<\/li>\n<li><a href=\"https:\/\/www.the74million.org\/article\/split-times-speed-acceleration-what-the-olympics-can-teach-kids-about-math\/\">Split Times, Speed, Acceleration: What the Olympics Can Teach Kids About Math<\/a><br \/>\n<em>The 74<\/em>, February 9, 2026<\/li>\n<li><a href=\"https:\/\/www.nytimes.com\/2026\/02\/07\/science\/mathematics-ai-proof-hairer.html\">These Mathematicians Are Putting A.I. to the Test<\/a><br \/>\n<em>The New York Times<\/em>, February 7, 2026<\/li>\n<li><a href=\"https:\/\/www.express.co.uk\/celebrity-news\/2160853\/mathematician-deal-or-no-deal-hidden-method\">Mathematician shows exactly how to win Deal or No Deal with hidden method<\/a><br \/>\n<em>Express<\/em>, January 31, 2026<\/li>\n<li><a href=\"https:\/\/www.scientificamerican.com\/article\/how-math-can-reveal-lottery-fraud\/\">How math can reveal lottery fraud<\/a><br \/>\n<em>Scientific American<\/em>, January 24, 2026<\/li>\n<li><a href=\"https:\/\/www.newscientist.com\/article\/2510651-why-its-easy-to-be-misunderstood-when-talking-about-probability\/\">Why it\u2019s easy to be misunderstood when talking about probability<\/a><br \/>\n<em>New Scientist<\/em>, January 12, 2026<\/li>\n<li><a href=\"https:\/\/www.quantamagazine.org\/using-ai-mathematicians-find-hidden-glitches-in-fluid-equations-20260109\/\">Using AI, Mathematicians Find Hidden Glitches in Fluid Equations<\/a><br \/>\n<em>Quanta Magazine<\/em>, January 9, 2026<\/li>\n<li><a href=\"https:\/\/thefulcrum.us\/electoral-reforms\/ranked-choice-voting-study\">Why Mathematicians Love Ranked Choice Voting<\/a><br \/>\n<em>Fulcrum<\/em>, January 6, 2026<\/li>\n<li><a href=\"https:\/\/www.bbc.com\/audio\/play\/m002nv73\">Frosty Fractals<\/a><br \/>\nBBC <em>Curious Cases<\/em>, January 2, 2026<\/li>\n<\/ul>\n","protected":false},"excerpt":{"rendered":"<p>January &amp; February digests: U.S. Navy mathematician behind GPS systems dies, from NPR Probability in poker, in Scientific American Modeling earthquakes, on Earth.com How curvature does and doesn&#8217;t dictate shape, in Quanta Magazine Quantifying the savings from plug-in batteries, in Canary Media Gladys West, mathematician whose work paved the way<span class=\"more-link\"><a href=\"https:\/\/mathvoices.ams.org\/mathmedia\/math-digests-january-february-2026\/\">Read More &rarr;<\/a><\/span><\/p>\n","protected":false},"author":13,"featured_media":0,"comment_status":"closed","ping_status":"closed","sticky":false,"template":"","format":"standard","meta":{"advanced_seo_description":"","jetpack_seo_html_title":"","jetpack_seo_noindex":false,"jetpack_post_was_ever_published":false,"_jetpack_newsletter_access":"","_jetpack_dont_email_post_to_subs":false,"_jetpack_newsletter_tier_id":0,"_jetpack_memberships_contains_paywalled_content":false,"_jetpack_memberships_contains_paid_content":false,"footnotes":""},"categories":[2],"tags":[6,514,513,512,35,73,181,145,142,511],"class_list":["entry","author-leilasloman","post-4254","post","type-post","status-publish","format-standard","category-math-in-the-media-digests","tag-algebra","tag-energy-costs","tag-financial-math","tag-fourier-transform","tag-geometry","tag-probability","tag-simulation","tag-topology","tag-trigonometry","tag-trilateralization"],"jetpack_featured_media_url":"","jetpack_sharing_enabled":true,"jetpack_likes_enabled":true,"_links":{"self":[{"href":"https:\/\/mathvoices.ams.org\/mathmedia\/wp-json\/wp\/v2\/posts\/4254","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/mathvoices.ams.org\/mathmedia\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/mathvoices.ams.org\/mathmedia\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/mathvoices.ams.org\/mathmedia\/wp-json\/wp\/v2\/users\/13"}],"replies":[{"embeddable":true,"href":"https:\/\/mathvoices.ams.org\/mathmedia\/wp-json\/wp\/v2\/comments?post=4254"}],"version-history":[{"count":5,"href":"https:\/\/mathvoices.ams.org\/mathmedia\/wp-json\/wp\/v2\/posts\/4254\/revisions"}],"predecessor-version":[{"id":4259,"href":"https:\/\/mathvoices.ams.org\/mathmedia\/wp-json\/wp\/v2\/posts\/4254\/revisions\/4259"}],"wp:attachment":[{"href":"https:\/\/mathvoices.ams.org\/mathmedia\/wp-json\/wp\/v2\/media?parent=4254"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/mathvoices.ams.org\/mathmedia\/wp-json\/wp\/v2\/categories?post=4254"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/mathvoices.ams.org\/mathmedia\/wp-json\/wp\/v2\/tags?post=4254"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}