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On a recent hike to the nearest cove of the lake, I photographed a pair of white pelicans swimming about and hunting for fish. White pelicans don't breed in Missouri, but they pass through in the spring on their way to their breeding grounds in the northern US and Canada, and again in the fall as they move to their wintering grounds in the southern US and Mexico. They often take a resting break from their migration, and we sometimes see hundreds of them at a time. White pelicans are one of the largest birds seen in Missouri, weighing up to twenty pounds. Astoundingly, their wings stretch nine feet from wingtip to wingtip. In the spring, as breeding time approaches, adults grow a vertical flat plate on the top of their bill (look closely at the two birds in the first photo, and the second photo shows the plate more clearly). They use these plates for courtship and in conflicts to establish their territories. Interestingly, after the eggs are laid, the adults lose these plates. So, the pelicans we see migrating south in the fall do not have these plates. A very strange bird is the pelican. His beak can hold more than his belly can. He can hold in his beak Enough food for a week. And I'm damned if I know how the hell he can.   Photo credit: White pelicans - Stan C. Smith
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Often touted as an impossible conundrum, this question is actually easier to answer than you might think. The answer is, quite clearly, the egg. We simply need to go back in time to examine things. The first eggs with waterproof shells that could be laid on land appeared about 312 million years ago. Most biologists agree that domestic chickens came from a tropical bird that still exists today in the forests of Southeast Asia, called the red junglefowl (Gallus gallus). Humans began domesticating red junglefowls about 10,000 years ago, eventually creating a new bird subspecies (Gallus gallus domesticus… aka the chicken). As you know, humans eventually spread domestic chickens around the world. So, in one respect, eggs obviously predated chickens by hundreds of millions of years. But this is an oversimplification of the question. Let’s consider the very first chicken—the very first individual that had the genetic characteristics that made it a new subspecies. Well, genetic variation comes about through a process called mutation. This is true whether we’re talking about life forms that live wild, or those that humans breed for certain desirable characteristics. The genetic variation comes from the same phenomenon—mutations. These mutations cause new physical traits, and these traits are selected, either by the forces of nature (natural selection) or by humans (artificial selection). Sometimes the mutations cause changes that are significant enough that the new individual is considered a new subspecies or even a new species (this usually occurs incrementally over time, but sometimes it can happen relatively quickly). Anyway, long ago, there was a time when a male red junglefowl mated with a female red junglefowl, and a mutation occurred in the process of the male’s sperm cell fertilizing the female’s egg cell. The mutation resulted in the very first bird that could be considered a chicken (Gallus gallus domesticus). This fertilized egg formed a chicken egg, with the embryo developing inside the egg. The very first chicken hatched out of that egg. So… the first chicken egg came before the first chicken. Mystery solved, right? But wait! If you think about it, that very first chicken came from an egg that developed inside a female red junglefowl. That means the egg was a red junglefowl egg. And the first chicken egg didn’t exist until that first chicken grew up and laid her own chicken egg. Which means the chicken came before the egg! Now I’m just confused.  I recently shared images of some hooded mergansers, showing the striking differences between the drakes and the hens. Another species I saw a few weeks ago (most of them have moved on north by now) is the common goldeneye. The first photo is a drake, the second photo shows a drake and a hen. Common goldeneyes are diving ducks, which means they dive all the way underwater to search for food. They are primarily predators, eating small fish and aquatic invertebrates like crayfish. They also eat plant material, but plants make up less than 25% of their diet. It's fun watching them feed because they synchronize their dives... the group (sometimes up to twenty) will disappear underwater all at once, which I suppose helps confuse the prey animals, making them easier to catch. They stay underwater for as long as a minute, then they all pop back up to the surface. Like the hooded merganser (and the wood duck), common goldeneyes nest in cavities in trees. They breed in northern Canada and Alaska. I also included a couple photos of a drake mallard that was feeding close to the shore. Mallards are dabbling ducks, rather than diving ducks. Instead of diving all the way under, they just tip their body and submerge their head in shallow water to feed on plants and seeds (though they also eat small animals to get more protein during the breeding season). There you go... another dose of quacky facts.     Photo credit: Goldeneyes and mallard - Stan C. Smith A few days ago, I was walking along the shore of the lake cove about a half mile from our house when I came upon a stone half buried in the mud. Seeing it had an unusually smooth shape, I pulled it out. This is what I found.   I'm not a serious collector of stone artifacts, and I honestly don't know much about them, so I sent photos to my son Ryan, who posted them to a Missouri artifacts Facebook group. Based on its shape and large size, the consensus seemed to be that it is likely an adze. Or possible an axe. Both of these are tools that were often used for woodcutting (and cutting many other things). For shaping canoes, tool handles, and anything else made of wood. Also used for digging. So, what's the difference between an adze and an axe? They have similar uses, but an adze has the blade positioned perpendicular (at a 90° angle) to the length of the handle (see the tool on the right below in the third photo). An axe, on the other hand, has the blade positioned parallel the handle (the tool on the left). If my artifact is an axe or adze, maybe it was positioned on the handle in such a way that both sharp ends could be used... one end with a flat, chisel-like tip, the other end with a more rounded tip. A dual-use tool. It's also possible this artifact is a spear tip. But most spear tips have a sharper point than this, which is why the consensus was a woodworking tool. How old is it? That's a much harder question to answer. Some of the oldest artifacts in Missouri are from the Clovis culture. The Clovis people were nomadic hunter-gatherers that were in the area of Missouri from about 13,000 years ago (maybe more) to about 10,000 ago. Their stone points are distinct in shape, different from the one I found. So, I can assume it was likely made in the last 10,000 years. But my limited knowledge ends here. I simply don't know. Still, I find it fascinating to imagine the person who made this tool. What was he (or she) like? What kinds of animals did this person see that are now long extinct? Did this person stand in the exact spot where I was standing when I found the artifact? Did the person think about love and joy and beauty? I wish I knew.  I recently hiked to the nearest cove of the lake to photograph wildlife. Several hooded mergansers were there, swimming about and diving underwater to hunt. In my opinion, hooded mergansers are among our most beautiful ducks. This first photo is a drake (a male) I saw:  Mergansers are mainly fish eaters, and they dive underwater to catch small fish, crayfish, and other aquatic animals with their long, narrow bill, which has sharp serrations to grip their prey. Hooded mergansers nest in cavities in trees rather than on the ground like many other ducks do. Only one day after hatching, all 7 to 15 of the tiny ducklings leap from the cavity all the way to the forest floor. Then the mother merganser leads them to the nearest body of water. In order for this to work, all the eggs must hatch on the same day. So, the mother waits until she has laid all of her eggs before she starts incubating them. This results in synchronous hatching. Like many ducks, hooded mergansers have extreme sexual dimorphism—the males and females look very different. In this photo, you can see the differences between two females and one male. Cool, huh?  Photo credits: Hooded mergansers - Stan C. Smith I took a walk a few days ago hoping to get good photos of the two squirrel species that live here, the gray squirrel and the fox squirrel (we also have flying squirrels, but they are nocturnal and extremely shy, so we've only seen one in all the years we've lived in Missouri). At first glance, gray squirrels and fox squirrels look similar, but they differ in color, size, and preferred habitat. Fox squirrels are orangish in color and they weigh, on average, almost twice as much as gray squirrels. Fox squirrels prefer to live near forest edges, whereas gray squirrels prefer to be deep within the forest. To illustrate that, our house is surrounded by forest, so we see at least twenty gray squirrels for every one fox squirrel. To find a fox squirrel on my hike, I had to go to the lake shore a half mile away, where the forest opens up to a wide grassy shoreline. Fox squirrels love to look for food at this forest edge. Here is a typical gray squirrel:  And here is the only fox squirrel I saw that day (notice the orange color):  Awesome Fact: Gray Squirrel Migration I saw a social media post where someone mentioned that their grandfather told them stories about massive gray squirrel migrations in the eastern half of the United States, with huge swarms of millions of squirrels on the move. I was extremely skeptical of this because I have never seen more than a few squirrels together, and I certainly haven't seen masses of them crossing highways or swimming rivers. So, I dug into this, and guess what—it's real. At least it used to happen. In 1811, Charles Joseph Labrobe wrote about a vast squirrel migration in Ohio: “A countless multitude of squirrels, obeying some great and universal impulse, which none can know but the Spirit that gave them being, left their reckless and gambolling life, and their ancient places of retreat in the north, and were seen pressing forward by tens of thousands in a deep and sober phalanx to the South...” In Wisconsin in 1842, a gray squirrel migration lasted four weeks and involved nearly a half billion squirrels. Thousands of squirrels were even seen swimming all the way across the Mississippi River. Similar events were documented throughout the 1800s, and the last really massive squirrel migration was in 1968. What's up with that? Here's an explanation. Throughout history, some years had bumper crops of acorns and other food, resulting in a drastic increase of the squirrel population. Then, if the next year saw a big decline in nut production, millions of squirrels had to either starve or leave to find greener pastures (or nuttier forests). So, why doesn't it happen anymore? Because the eastern half of the US no longer has vast regions of unbroken forest. The forests are now fragmented, and squirrel density is much lower than it used to be. I'm afraid we'll probably never have an opportunity to see it, but how cool would it be to witness millions of squirrels on the move?  Photo Credits: - Fox squirrel and gray squirrel - Stan C. Smith - Migrating squirrels - Midjourney 6.1 Time travel is one of the most frequent themes in science fiction. In fact, I’ve written a number of novels involving time travel. People love to imagine what it would be like to travel back or forward in time. So, is time travel really possible? Let’s consider the past first. I hate to say this, but currently there are few physics concepts that indicate traveling into the past will ever be possible. Well, there are some, but they are theoretical, with little hope of becoming practical things we can create and control. One example is to create a time curve—if a person follows the path, they would eventually find themselves back where they started. This was first shown to be mathematically possible in 1949, and many times since then. But there’s no evidence such a phenomenon actually exists anywhere in the universe. A few other scenarios have been proposed. There’s a wild idea involving two cosmic strings moving past each other in opposite directions, thus creating a time curve looping around the strings. Another idea is wormholes, in which space-time can fold like a piece of paper. These sound great, but they are mathematical in nature and have not been observed to exist. The barriers to creating and controlling them are overwhelming, to say the least. So… time travel into the past is probably not within our reach. Time travel to the future, on the other hand, is definitely possible. Yay! Technically, we are already traveling into the future at one hour per hour. But you knew that already. How can we travel into the future faster than one hour per hour? It’s simple—all we have to do is move through space very fast. According to Einstein’s Special Relativity theory, if you move through space at a really high speed (relative to other objects), time goes slower for you than for the people you left behind. This is called time dilation, and it’s an observable fact. It’s the reason the clocks on GPS satellites disagree with the clocks on Earth by seven millionths of a second for every day they are in orbit. Sergei Krikalev (a Russian cosmonaut) spent 803 days, 9 hours, 39 minutes orbiting our planet at 17,500 miles per hour. So, he traveled into his own future by 0.02 seconds. The closer you get to the speed of light, the faster your time travel. Let’s say a 10-year-old boy leaves Earth in a spaceship traveling at 99.5% the speed of light, then returns to Earth after five years have passed on the spaceship. The boy would be 15 years old, but his classmates would now be 60 years old. From the boy’s perspective, only five years passed, but fifty years passed on Earth. This is real time travel into the future. The problem is, the faster an object travels, not only does time pass faster, but the object also increases in mass (Special Relativity again), which means more fuel is needed to accelerate the object. At the speed of light, the object’s mass becomes infinite, which is why no physical object can travel the speed of light. With our current technology, we cannot accelerate any object to 99.5% the speed of light (or any velocity even close to that). So, while time travel into the future is certainly possible, it isn’t easy or practical. But that doesn't stop me from thinking about time travel frequently.  Photo Credits: - Time Travel image - Midjourney 6.1 A few months ago, before all the leaves fell from the trees and this ridiculously cold weather moved in, Trish and I were sitting on the deck, looking at the stars. I decided to take a few photos of the night sky with my iPhone, using night mode. The photos came out better than I expected (see the first photo). What I like about this photo is that you can clearly see a portion of our galaxy, the Milky Way. It's the whitish blur from the lower left to the upper right. And of course all the closer stars dotting the sky are also part of the Milky Way galaxy (the orange blobs on the bottom and left are trees). Nothing brings out our sense of awe more than staring up at the vastness of space, right? Here's a bit more information about the galaxy we inhabit. First, you may know galaxies are huge clusters of stars, bound together by gravity. According to current models, galaxies formed in the early stages of the universe, following the Big Bang. Our Milky Way is called a spiral galaxy because the stars are rotating around a dense center, forming spiral arms that look a bit like a pinwheel. The galaxies we've observed contain, on average, about 100 million stars each. BUT, this is just an average, and the variation is huge. Some dwarf galaxies contain less than a thousand stars, and some supergiant galaxies can contain a hundred trillion stars. Uh, this number makes my head spin. It's beyond comprehension. Our Milky Way galaxy has at least a thousand times more stars than the average, containing somewhere between 100 and 400 billion stars. Our sun (sometimes called Sol or Helios) is, of course, one of them. Let's consider the dimensions of the Milky Way. A light year is the distance light travels in one year in the vacuum of space: 186,000 miles per second, or about 300,000 km per second. Light is pretty freaking fast, so a light year is pretty freaking far. Like many galaxies, the Milky Way is shaped kind of like a disc. The disc is about 87,000 light years across. However, from top to bottom, it is only about 1,000 light years deep. And we (meaning Earth and the rest of our solar system) are about 27,000 light years out from the galaxy's center. One last tidbit of info to blow your mind. Our galaxy is obviously unimaginably large. However, scientists estimate there are between 200 billion and 2 trillion galaxies within the observable universe. Oh... in case you're wondering, the observable universe is a sphere with Earth at the center, and it includes everything we can see. In other words, every object close enough to us that light from the object has had time to reach Earth since the original expansion of the universe. This is not limited by our technology or telescopes, it is limited by the speed of light. Undoubtedly, there is much beyond the observable universe that we cannot see, simply because the light has not yet reached us. Just for kicks, the second image is a set of photos, taken by the Hubble telescope, of a few of the gazillion other galaxies out there in space.   Photo Credits: - Night sky - Stan C. Smith - Collection of galaxy photos - NASA, ESA, ADAM G. RIESS (STSCI, JHU), Public domain, via Wikimedia Commons First, in case you don't know, scorpions belong in an order of arachnids (spiders and kin), with 2,500 species around the world, on every continent except Antarctica. Scorpions have been around for 435 million years. They mostly live in desert regions, but some are adapted to other environments, including the striped bark scorpion that lives here in Missouri. The first photo is a striped bark scorpion I found under a rock near our home. The second photo is another striped bark scorpion, this one under a blacklight, which emits ultraviolet light. Scorpions glow a vibrant blue color in UV light, which can come from an artificial blacklight or from natural moonlight. But how? And why? Let's figure this out. Interestingly, each time a scorpion sheds its exoskeleton, the scorpion doesn't glow like this until the new exoskeleton hardens. There is a biofluorescent chemical in the exoskeleton that glows, but that chemical doesn't appear there until the shell hardens (which takes about 90 minutes). The chemical could be a by-product of the hardening process, or it could be secreted soon after the shell hardens. We don't know for sure. Anyway, the bioflourescent chemical absorbs UV light, then re-emits it as visible blue light. That's the how. Now let's consider the why. Well, no one is really sure why scorpions glow in UV light. One idea is that it helps scorpions find each other. Another idea is that it might confuse their prey, making it easier for them to hunt. A particularly intriguing idea (my favorite) is that the bioluminescent material makes the scorpion's entire body a kind of eye, to help the animal avoid sunlight. In general, scorpions avoid sunlight and moonlight (which is sunlight reflected off the moon). Scorpions are nocturnal, and they are much less active on moonlit nights. If the scorpion's body detects very much UV light (and therefore glows), this tells the scorpion to stay underground instead of hunting.   Photo Credits: - Striped Bark Scorpion (daylight) - Stan C. Smith - Striped Bark Scorpion (blacklight) - DepositPhotos Caution: Mind-bending concepts ahead... Perhaps you’ve heard of light sails (or solar sails). These are huge parachute-like sails that can be expanded in space to allow the pressure from light emitted from the sun to propel a spacecraft. The first spacecraft to demonstrate that this actually works was the Japanese craft IKAROS in 2010. Think about how odd this seems—light emitted by the sun can actually push something. This must mean that light must weigh something, right? Well, first it’s important to understand the difference between weight and mass. MASS is the total amount of matter, or stuff, an object contains. WEIGHT is the force of gravity on an object. I typically weigh 190 pounds (86 kg). On Earth, my weight and my mass are the same—190 pounds. But, if I go to the moon, where there is less gravity, my weight and mass are no longer the same. My mass is still 190 pounds, but my weight is only 32 pounds. On Mars, my mass is still 190 pounds, but I weigh 72 pounds. Remember, mass is how much stuff there is in an object, so mass does not change in situations with different gravity. Weight does change. Light is made up of photons, and photons do not have mass. So, a simple answer to this question is NO… light does not have mass, and therefore it does not have weight. But things aren’t that simple. Light actually has momentum (if you’re wondering how something without mass can have momentum, that’s beyond my ability to explain… it has to do with the fact that light also has energy… light is kind of weird). Anyway, light does indeed have momentum, and it can exert pressure on a surface. This is why light sails work. This is why, when I stand in direct sunlight, I weigh slightly more than when I stand in the shade. The sunlight from above pushes me downward with a slight amount of force. On a sunny day, the city of Chicago weighs 140 kilograms more than at night, simply because sunlight is pushing down on it. Here’s a tidbit that blows my mind: If you captured all the sunlight falling on Chicago in any moment and put that sunlight in a box that has perfect mirrors on the inner walls—mirrors that reflect 100% of the light so that the photons are continually reflected back and forth in the box, the box would then weigh 140 kg more than it did before. And in space, where the box has mass but no weight, more force would be required to accelerate the box. So, this seems like light has mass, right? Not exactly. Because it is the energy and momentum of the light that causes this to happen. Instead of saying the light in the box has mass, it is more accurate to say the light in the box contributes to the total mass of the box. What a weird and wonderful universe we live in! (this is a conceptual image of a spaceship with a solar sail)  Photo Credits: - Ship with solar sail - Midjourney v. 6.1 |
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