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Showing posts from March, 2021

What does a city weigh?

  By Allison Kubo Hutchison Noah Friedlander , San Francisco from the Marin Headlands in March 2019 , CC BY-SA 4.0  As you walk the pavement of your city, the buildings rising around you, the impact of a city on the landscape is clear. It changes the skyline and the view. But how does it change the ground below? Does the weight of a city bend the crust below? Thirty years from now it is estimated that 70% of Earth’s population will concentrate into high-density metropolitan regions most of which are coastal. It is evident that our human activities influence the air we breathe but how do the concrete structures influence the land below? Recent research published in the AGU Advances estimated the weight of the San Fransisco Bay region home to about 7.75 million people at 1.6x1012 kg. Author Tom Parsons of the US Geologic Survey calculated the weight by satellite-based building footprints across the Bay area then applied average values for the dead load, the weight of the building its

What’s a Hedgehog Got to Do with Condensed Matter Physics?

By: Hannah Pell Pictures are a helpful way to express abstract ideas. Whether through Gedanken experiment s like the famous Schroedinger’s Cat or Feynman diagrams (some of which have been described as " penguin diagrams "), physicists often draw on everyday language, sketches, and well, animals, to characterize complex scientific theories. You can take a quick visit to the Particle Zoo and see more examples for yourself. Hedgehogs have also entered the condensed matter physics vocabulary. Papers with titles such as “ Topological Transport of Deconfined Hedgehogs in Magnets ,” “ Finding Spin Hedgehogs in Chiral Crystals ,” and “ Magnetic hedgehog lattices in noncentrosymmetric metals ,” were published in Physical Review Letters last year. So you’re probably wondering (as was I): what does a small, pokey tiny, pokey animal have to do with condensed matter systems? The answer has to do with magnetism, thin films, and a very interesting particle called the skyrmion. Image Cr

The Solar Farm in My New Pennsylvania Backyard

  By: Hannah Pell I recently relocated from the bustling Washington, D.C. metro area back to my south-central Pennsylvania hometown. My new space is in a quiet, wooded area; outside my back window I see an expanse full of trees (“Pennsylvania” actually means “Penn’s Woods”) — and a small solar farm is nestled in between them. As the sun shines onto the panels, I can’t help but wonder: how much of the electricity powering my laptop is sourced from the sun? What’s the science behind it all, and where does solar fit within Pennsylvania’s diverse energy portfolio? Physics of solar cells and their efficiency The fundamental physics principle underlying solar cell technology is the photoelectric effect. Photons (light particles) can be thought of as discrete packets of energy. The energy of the electrons emitted when some form of radiation (such as light) strikes a material directly depends on the frequency of that incident radiation. Solar cells are designed using semiconducting mat

Abnormal Shrimp: An Apex Predator or Barely Chewing?

  By Allison Kubo Hutchison The same animal was once described by paleontologists as a shrimp, jellyfish, sea cucumber, and a sponge at different times during its study. Anomalocaris, Latin for “abnormal shrimp”, is a creature of exceeding strangeness to modern hominids; it is related to modern-day shrimp with a flat segmented body, faceted eyes on stalks, and two grabbing appendages which more closely resemble tentacles. Artistic Rendering of Anomalocaris magnabasis Species could grow up to a meter long, significantly larger than most other beasts in the Cambrian. It swam by undulating the segmented flaps along the sides of its body and its large faceted eyes offset from the body mass could peer around for prey. Despite its strange appearance, the scientist has often thought the ecological niche of the Anomalocaris can be likened to that of the majestic lion or humans ourselves. Nothing could take it on and all feared it. It was long thought that Anomalocaris was an apex predator

Damascus Steel: A Premier in Material Science and Nanoengineering

  By Allison Kubo Hutchison Reproduced Wootz Damascus blade showing both a ladder and rose pattern made by Alfred Pendray. Photo by JD Verhoeven, AH Pendray and WE Dauksh. Material science and nanoengineering are emerging fields promising to revolutionize the industry, medicine, and energy technologies. But our understanding of both is rooted in ancient knowledge. Would it surprise you to know that we had knowledge of and used nanoparticles as far back as 400 CE? Roman technologists were using gold-silver nanoparticles to make colored glass and the Mayans used indigo dyes stored in clay nanopores to make brilliant long-lasting pigments. One of the most impactful of these technologies was Damascus steel developed in 300 CE in the Middle East.   Although you may have seen the beautiful wavy patterns in kitchen knives, this is not ancient Damascus. The modern “Damascus steel” is formed by welding different pieces of steel together then folding it together. The technique to make true d

Hydrogen production and the future of fuel

  By: Hannah Pell “The most important car in 100 years.” Such is how James May, co-host of the British car show Top Gear, described the Honda Clarity during his test drive several years ago. “This is the future of motoring.” What is it about this car that seemed so revolutionary? It’s the fact that it’s not powered by an engine or a battery — but by a hydrogen fuel cell. Hydrogen technology has been getting a lot of coverage lately, and I wanted to know a bit more about the science behind it, as well as its role in the future of fuel. Hydrogen production   Hydrogen is the lightest element at #1 on the periodic table and the most abundant in the universe. Its chemical structure contains only one proton and one electron, making it highly reactive (flammable!) and therefore not freely found in nature. In order to get hydrogen by itself, it must be extracted from naturally occurring compounds. There are several processes for producing hydrogen: steam methane reforming, gasifica

Ferreting out the Details of Reproductive Cloning

  By Allison Kubo Hutchison  Elizabeth Ann, the first cloned black-footed ferret taken on Jan 29,2021. U.S. Fish and Wildlife Service via AP. Although all births are special and joyous occasions, on December 10, 2020, researchers celebrated the birth of an extraordinary ferret kit. Elizabeth Ann, born from a domestic ferret surrogate, is not biologically related to her birth mother. She is a clone of the endangered black-footed ferret, a wild US-native species. The ferret she was cloned from died in 1988. Elizabeth Ann is the first US-native endangered species to be cloned. The black-footed ferret was thought completely extinct due to habitat loss until a small colony was discovered in 1981. Conservationists engaged in a captive breeding program to preserve the species but only seven females were able to reproduce meaning that 40 years later all the approximately 1,000 remaining black-footed ferrets have a limited gene pool. The lack of genetic diversity leaves the population susc

UW-La Crosse professor creates ‘My Nuclear Life’ podcast, exploring the intersection of nuclear science and society

  Nuclear science first penetrated American consciousness with the building of the atomic bomb. It has become both a beneficial and destructive force that influences many aspects of human life from energy, to the environment, to medicine. Yet this field of study —that peers into the atomic nuclei — is something people generally don’t teach or talk too much about. University of Wisconsin-La Crosse (UWL) Physics Professor Shelly Lesher is working to change that. Lesher launched a new podcast, “My Nuclear Life,” in December that explores the intersection of nuclear science and society through interviews with historians, policymakers, and other experts. “I wanted to share my love for physics and the excitement of the field with the public, and I hope they become excited about physics too,” she says. Episodes of the podcast series cover topics such as: nuclear sanctions, the start of radium therapy to treat cancer, and the beginning of the environmental movement in the U.S. They don’t

How Bananas Make Radiation Ap-peel-ing

  By: Hannah Pell On March 7, 1995, Gary Mansfield, a health physicist at the Lawrence Livermore National Laboratory, sent out an email to members of the RadSafe nuclear safety mailing list. The subject line read: “Banana Equivalent Dose.” “Some time ago (when I almost had time to do such things), I calculated the [radiation] dose one receives from the average banana,” the email begins . Bananas contain the radionuclide K-40, a naturally occurring isotope of the element potassium (K). So, bananas are indeed radioactive, and Mansfield wanted to know how much radiation is in one “reference banana.” His rough calculation amounted to approximately .01 millirem. (Put another way, that's 1/100 of the average dose from a 3-hour airplane trip ). Mansfield continued: “Would love to go into more detail, but have to get back to our DEADLY Human Radiation Experiments (i.e., eating bananas).” Mansfield could have just as well replaced ‘bananas’ with potatoes, red kidney beans, broccoli,