|
I haven’t ridden very many horses, and I’ve never owned a horse. But… if I could ride a domesticated zebra, I might consider becoming a cowboy. In fact, in the second book of my Peregrine Outpost series, a leader of the bad guys rides a zebra, which gives him a certain lofty status among his tribe members. Seriously, how cool would it be to ride a zebra? The only place I wouldn’t ride my zebra would be on the plains of the Serengeti. Because riding one there would be like offering the lions a double-layer snack. So, why haven’t people domesticated zebras? Humans originated in the land of zebras—it’s not like our ancestors didn’t have plenty of time to make this goal a priority. Zebra-riding seems like a no-brainer, so why didn’t they do it? As it turns out, plenty of people have tried. In fact, the 2005 movie Racing Stripes, one of those talking-animal movies, is about a zebra that wants to be a racehorse. But even in this movie, the producers had to use a horse (in zebra makeup) for the actual riding and racing scenes. Why? Horses, donkeys, and zebras all came from a common ancestor that lived millions of years ago in North America and Europe. As you probably know, the ones in North America went extinct about 10,000 years ago (there aren’t really any wild horses in North America today, just feral horses that escaped from herds of domestic horses brought over from Europe). Donkeys and zebras are more closely related to each other than to horses. Horses were domesticated in western Eurasia, and they were first kept as food animals, then eventually people figured out they could ride them. Thusly, they became an important element of the development of human civilization. Horses, donkeys, and zebras were all preyed upon by large predators, but zebras lived amidst a wide variety of the world’s most impressive predators. To survive, they evolved to be particularly alert, to flee at any sign of danger, and—perhaps most importantly—to fight desperately when captured. I’ve seen videos in which zebras kick pursuing lions, breaking the lions’ jaws (a lion with a broken jaw will soon starve). Also, zebras bite viciously when they feel threatened. In 2013, a zebra at the National Zoo in Washington DC attacked and repeatedly bit a zoo keeper, sending the keeper to the hospital for surgery. Zebras also have a strong “ducking reflex” to escape attack, making it difficult to lasso them. Basically, zebras are just not people friendly. In order for an animal species to be a good candidate for domestication, the animal should be naturally fond of humans, and it helps if the animal has a desire for a comfortable life and is easy to work with and tend. Horses, yes. Zebras, nope. Okay, remember above when I said I would not ride my theoretical zebra across the Serengeti? I wasn’t kidding. It’s likely that thousands of generations of early humans avoided even trying to domesticate zebras, knowing that zebras were basically lion fodder. This, and the zebra’s belligerent behavior, explain why zebras have never been domesticated, and why I’ll never be a zebra-riding cowboy. 
0 Comments
On Tuesday night, at the designated time (9:35 PM), Trish talked me into going outside to observe the supermoon. I sighed, thinking about how comfortable I already was, but I grabbed my camera and out we went. Glad I did. A bonus was seeing a partial lunar eclipse at the same time. I got some nice photos. What the heck is a supermoon, anyway? It's another word for harvest moon, which is a full moon when the moon is closer to Earth than usual. Technically, an astronomer would tell you this is when the moon is within 90% of perigee (which is the moon's closest approach to Earth in its orbit). Typically, the distance between Earth and the moon averages about 239,000 miles. On Tuesday night, it was at about 222,000 miles. The traditional name harvest moon refers to the fact that it usually happens in the early fall, when many crops are almost ready for harvesting. Okay, so what is a lunar eclipse? This is when the moon enters Earth's shadow. If you think about it, a lunar eclipse can only happen when the moon is full. Why? Because the moon is full only when Earth is directly between the sun and the moon. In other words, when you look up at the moon, the sun has to be directly behind your line of sight in order to fully illuminate the moon as you look at it. If the sun is not directly behind your line of sight, you see only a portion (a sliver) of the moon. And on Tuesday, we were treated to a harvest moon AND a partial lunar eclipse at the same time. This is why it looks like there is a bite out of the top of the moon in my photo. That's Earth's shadow.  Yeah, I know 3D printers aren’t from the future, but some kinds of technology make me wonder sometimes. Recently, when visiting our daughter Katie, her husband Michael showed me how his 3D printer works. It was the first time I had actually seen one operate. 3D printers have been around for a while, and I suppose they aren’t as astounding as some of the new AI technologies, or even newer cell phones for that matter. But still… they print anything you can imagine as a three-dimensional object. That’s Star Trek territory, maybe even The Jetsons! How do they actually work? Well, first you have to have on your computer a digital 3D model of an object. A 3D model includes all the spatial information, such as height, width, and the precise measurements of every portion of the object. Every contour, every surface, every projection, everything. 3D models are actually quite common, as almost all products are modeled in 3D before companies produce them. Also, most animated movies and shows are now just 3D characters, 3D objects, and 3D backgrounds. A 3D model can be made from several photos (or drawings) of something, as long as the photos show all the sides of the object. Next, you use software to convert your 3D model into an STL (stereolithography) file. This maps the object’s entire surface as a series of triangles. The STL file is then used by software that creates really thin slices of the model, from the bottom of the object to the top. The 3D printer then lays down a thin layer of material for each of the slices, building the object from the bottom up. Basically, it’s kind of like an inkjet printer, but instead of laying down one thin one-dimensional line of ink at a time to create a 2D image, it lays down a heated layer of resin one 2D slice at a time, piling the slices on top of each other. The resin is heated just before being squirted on top of the previous slice, and it quickly cools, then the printer scans the layer with UV light, which cures it. I recently watched a video about huge 3D printers that print houses by laying down one thin layer of concrete at a time. Some of the most impressive 3D printers actually use metal instead of resin, using an electron beam to melt metal powder into each layer. These machines can quickly make things like replacement metal machine parts, surgical implants, and anything else you can think of. Imagine this futuristic scenario: a large ship is out at sea (or, better yet, out in space) for a long time. It is not feasible to store every possible spare replacement part aboard the ship. The parts would take up too much space. But the 3D files for every imaginable part could be available on a ship computer, along with a 3D printer to print any replacement part that is needed (especially if the faulty part can be used for raw material to make the new part) . Like I said... this is Star Trek territory.  This is the time of the year when giant horseflies are everywhere, looking for a blood meal. Seriously, these puppies are over an inch long, quite large for a fly. The males are nice, docile eaters of pollen and nectar from flowers, but the females are demons from the apocalypse. You think I'm exaggerating? Then you haven't been chomped by an inch-long female horsefly. It hurts, and here's why: Mosquitoes drill a nice clean hole in your skin, then drink your blood through a straw—not very painful. Horseflies (and the smaller deer flies, for that matter) have mouthparts that act like a pair of serrated knives. They slide these back and forth, making a gash in your skin so they can slurp up the blood that comes out. They have anticoagulants in their saliva, which keeps the blood flowing. On humans, though, the knife-sawing business is so painful that we usually curse, then swat at the fly while doing an awkward horsefly dance. Therefore, the fly doesn't have a chance to get much of a blood meal, so it continues buzzing around, hoping for another opportunity for a knife attack. Now here's the real reason why I'm talking about horseflies today. Trish and I have noticed, as we drive our vehicles down the one-mile gravel road from our house to the nearest paved road, numerous horseflies attack our cars, chasing us and slamming into our windows and hoods, even when we are going twenty miles per hour. We got to wondering, why do horseflies do this, especially once they try to bite the car and presumably realize it will not provide any blood? As it turns out, horseflies are irresistibly drawn to large, dark, moving objects (an evolutionary advantage for a critter that feeds on mammals). But it's more than that. Horseflies are attracted to polarized light when searching for animals to bite and for water (where they lay their eggs). Sunlight reflected off a car, particularly a dark-colored car, is polarized. When the car is moving, these factors together drive the horseflies crazy, and they will follow a car for miles as if possessed. Horseflies are awesome, but they're also vicious.  My Bridgers series is a sci-fi series of novels in which our heroes try to save humanity by "bridging" as many people as possible to alternate versions of Earth. Let's examine this basic science idea of the Bridgers series, the rather mind-bending concept of infinite parallel universes. While there are certainly cosmologists who are skeptical of the concept, it is important to point out that multiple parallel universes is not an idea scientists simply came up with using their imaginations. Instead, the concept is a mathematical consequence of our current theories in physics, particularly quantum mechanics and string theory. What this means, essentially, is that even those physicists who are skeptical of the idea must examine it as a real possibility (even if they do so reluctantly). If we assume quantum mechanics and string theory are not completely wrong, then it is important for scientists to examine all of the mathematical consequences of those theories. Even if those consequences (such as parallel universes) seem strange to us. There are at least five important scientific theories that suggest the existence of multiple universes. For example, the theory of quantum mechanics suggests the possibility of "daughter universes" (this is my favorite). Quantum mechanics describes things in terms of probabilities rather than definite outcomes. The mathematics of quantum mechanics suggest that every possible outcome of every situation actually occurs—in its own separate universe. Everything is made up of tiny particles, and what this "daughter universes" concept boils down to is that there could be infinite parallel universes, each of them differing by the position of only one particle. The concept boggles the mind. We may never know for sure if infinite universes are real, but the concept certainly makes for a fun story.  |
Stan's Cogitations
Everyone needs a creative outlet. That's why I write. Archives
April 2025
|
RSS Feed