Each week, I devote part of my Sunday to reading. I tend to accumulate a lot of saved links on Facebook during the week, and I like to try to keep up with what fellow writers are posting here on WordPress. At the end of my reading day, I like to put up a post to draw my readers’ attention to a few articles I found to be of particular interest.
Here’s what I enjoyed this week:
by Julia Demarines, Astrobiology Magazine
Two and a half million years ago, a supernova resulted in a significant depletion of Earth’s ozone layer, potentially altering the course of evolution on our planet. In this fascinating article published on Phys.org, Julia Demarines discusses the potential impact of supernovae on life on Earth.
The potential impact of supernovae on life is well-known to science. Caused by the rapid collapse of a supermassive star (think type A or O blue supergiant), supernova explosions are vital to the health of our galaxy, resulting in the expulsion of raw materials that eventually seed nebulae, feeding stellar nurseries. However, such events also result in a powerful wave of cosmic rays: massive amounts of ionizing radiation. Ionizing radiation, the same form of radiation produced my nuclear reactors and weapons, is harmful to most forms of life, and a supernova can sterilize nearby planets.
But how would such an event effect planets further away? Say, our planet, which was between 50-100 parsecs (163-362 light years) away from the supernovae mentioned in the article? To find out, Washburn University astrophysicist Brian Thomas modeled the propagation of cosmic rays through Earth’s atmosphere, based on geological data from nearby supernovae (in the cosmic sense) that occurred 2.5 and 8 million years ago.
This is important work, not only for understanding our past, but also planning for the future. Several stars with the potential to go supernova lie close enough to Earth to impact our climate and biosphere, most notably Betelgeuse, Antares, and Spica. Fortunately, Dr. Thomas’s models suggested a far lest apocalyptic impact than most would assume. A variety of factors would lead to a staggered exposure, with high-energy particles and low-energy particles affecting Earth at different points. What’s more, while some species would be negatively affected by the radiation, others (like wheat and soybeans, both vitally important staples) would actually benefit from the increased exposure. Perhaps most importantly, humans would only be mildly affected (a slight increase in skin cancer), and plankton, responsible for most of our planet’s oxygen production, would be largely unaffected.
by Carolyn Gramling, Science News
Dinosaurs: they’re everyone’s favorite extinct species. Appearing in everything from toys to books to movies, while serving as the primary draw of every natural history museum, the well-known primary species of dinosaur are easily the most recognizable and captivating creatures we’ve gleaned from our planet’s fossil record.
For most, the word “dinosaur” immediately conjures up images of massive, towering reptiles, with long necks and tails, once the undisputed masters of our planet. Yet before the dinosaurs rose to prominence in the Jurassic period, they began as small, furtive creatures darting around at the feet of the massive archosaurs that dominated the preceding Triassic. And the more fossil species we discover from that earlier, formative period in their evolution, the more we find ourselves asking the question: just what, exactly, makes a dinosaur a dinosaur?
As Gramling discusses in this fascinating article, while paleontologists previously used a list of about six easily-identified features (called “characters”) that made a dinosaur a dinosaur, recent discoveries have caused the lines between dinosaurs and other, earlier reptiles, to blur. Throughout the Triassic, various reptile species existed which exhibited some, but not all, of the traits most closely associated with dinosaurs. These species, generally grouped together as “dinosauromorphs”, present a problem: when did these creatures stop being dinosaur-like and start being true dinosaurs?
In many ways, these recent discoveries have done for dinosaur evolution what many other discoveries have done for various other species, including our own. It’s a common question throughout paleontology. When did primates stop being apes and become hominids? When did amphibious ungulates start being whales? It could be that as with those other species, the dinosaurs did not evolve abruptly; there may never be one species we can point to and say “There – that’s the first dinosaur”. Rather, various reptiles throughout the Triassic may have slowly evolved the various traits that made the dinosaurs so successful, ultimately yielding the creatures that ruled Earth for over 100 million years.
by Kate Keller, Smithsonian.com
In this fascinating and lighthearted article from Smithsonian, Kate Keller discusses the long-standing tradition of fruitcakes served at royal weddings in the UK.
The tradition of serving elaborate fruitcakes at royal weddings dates back to the Middle Ages in England. While often the butt of derisive holiday jokes today, during the Middle Ages fruitcakes were the very peak of culinary luxury. As they included fruit (notably candied cherries and raisins), exotic spices, alcohol, and copious amounts of sugar, fruitcakes were comprised of the most expensive baking ingredients available at the time. Hence, serving large, elaborately decorated fruitcakes was an expression of wealth and prestige.
Today, of course, we live in different times. Sugar is viewed as more of a public health threat than a luxury, fresh fruit from across the world is available at every grocery store, and the “exotic” spices used in medieval fruitcakes can be found in most anyone’s kitchen. As such, the serving of fruitcakes at royal weddings has gone from being a symbol of wealth and stature to, as one well-regarded English baker put it, “sort of a cruel joke”. Fruitcakes are notoriously rich and dense, with one infamous royal cake proving so impenetrable it had to be cut with a saw. It probably doesn’t help that royal cakes have traditionally been ornately decorated with royal icing: a confection composed primarily of sugar paste and egg whites, the consistency of which has been likened to that of candle wax.
Thus, the tradition has been on its way out for some time. Recently, the royal family offered at auction several samples of previous royal fruitcakes, all shockingly well-preserved, some dating back as far as 1973. At the 2011 wedding of Kate Middleton and Prince William, the bride and groom requested that the traditional fruitcake be accompanied by a more modest (and edible) dark chocolate cake.
This year, the tradition finally broke with the wedding of Prince Harry to American actress Meghan Markle. The bride and groom eschewed the typical fruitcake for a more subdued lemon and elderflower cake made by Claire Ptak, owner of Violet Bakery in London.
Knowledge is power. Take time out to read a bit every day. It’s your window into the world around you. – MK