Why Does Size Matter Not?

I’ve been home sick for a couple of days, and I’m feeding my son breakfast before getting him off to kindergarten and then collapsing on the couch. He loves it. He’s taking the opportunity to ask me questions (“how would you blow up a planet?”), and talk to me, and show off his progress reading.

“Dad,” he asks, “what did Yoda mean when he told Luke that size matters not when your ally is the Force?”

“Well, son,” I say, trying to use this as a teaching moment, “it’s all about how he lifted the X-wing. Did he use his muscles, and drag it out of the swamp?”

“No,” my son said.

“You’re right. He used the Force.” I leaned forward, just a little. “And he meant that, if you believe in yourself and believe you can succeed, you can do anything you want.”

He considered that, then last ones at me. “Dad?”

“Yes, son?”

“Would you rather fly an X-wing, or the Death Star?”

This is going to be a little different, isn’t it?

Yep. Believe it or not, this isn’t a science blog. It’s a blog dedicated to trying to answer my son’s questions. It’s just that, most of the time, he asks questions that I can answer with science.

Size matters not

This really isn’t one of those questions. I mean, sure. There are probably studies on confidence and how it generates success. But that’s not the point, not really.

My son is six. To him, the world is a huge, exciting place filled with wonder and possibility and excitement. And, thanks to him, I’m being reminded that the world is filled with wonder and possibility and excitement. So, as I see it, it’s my job to encourage him and teach him and help him take advantage of everything the world offers.

That starts with confidence.

See, I’m well aware that there are things that are by definition impossible. But I’m also aware that, all too often, we look at things that are merely difficult and declare them “impossible”. “I can’t get out of debt.” “My family can’t make it on one income.” “I’ll never get in shape.” “I’ll never be able to retire.” A million fears become a million reasons to never try.

I don’t want my son to learn that. Not from me, anyway. “Dad,” he’ll say, “I’m going to build a robot!” Or he’ll declare to me that he’s going to build a speeder bike, or a lightsaber, or buy a house next to us so we won’t get lonely, or that he’s going to fly. And it would be easy to accidentally crush his dreams, in the name of “teaching” him.  Instead, I try to respond with this: “Cool! That might be hard, though. How should we start?”

“So certain are you. Always with you it cannot be done. Hear you nothing that I say?”

For the record, we have never built a robot, or a speeder bike, or a lightsaber that works outside our imaginations. That’s mostly due to the fact that sticks and rocks and Legos and paper aren’t the optimal components for such things. But we’ve spent hours working on them, and chasing each other with them, and playing and learning.

My son’s got plenty of time to learn that some things may very well be actually impossible. Right now, though, he’s learning a more important lesson: if you fail, and you still want to do it, try doing it a different way.

“Size matters not, when your ally is the Force.” Sure, I can’t teach my son to move an X-wing with his mind. But I can teach him that it can be moved, and that he can use his mind to figure out the way. And I can teach him to try again, and try something different, if he doesn’t succeed. And to remember that you don’t fail unless you give up.

In the process, maybe I’ll learn it again for myself.

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What Are Crystals Made Of?

It’s summer, and my son and I are walking home from preschoool and he’s exploring the area and looking at everything. As he does, he stops at a smallish boulder that’s been left at the corner of a road by a landscaper. “Daddy!” he calls, “Look!” So I go and look. He’s pointing at a band of what I think is quartz, rippling through the stone. “What is that?”

“Those are crystals,” I tell him. “Like the ones we saw at the museum. Remember them?” We’d just recently been to the Cincinnati Natural History Museum, and one thing they had on display was a collection of different crystals and geodes.

“Oh,” he says, staring at the rock. “They’re pretty.”

“Yes,” I agree, “they are.”

“What are they made of?”

Uhm…

What is a crystal?

To begin with, let’s hit Merriam-Webster up. They define ‘crystal‘ as:

  1. quartz that is transparent or nearly so and that is either colorless or only slightly tinged
  2. something resembling crystal in transparency and colorlessness
  3. a body that is formed by the solidification of a chemical element, a compound, or a mixture and has a regularly repeating internal arrangement of its atoms and often external plane faces
  4. a clear colorless glass of superior quality; also : objects or ware of such glass
  5. the glass or transparent plastic cover over a watch or clock dial
  6. a crystalline material used in electronics as a frequency-determining element or for rectification

What is a Crystal, a page on University of California Berkeley’s College of Natural Resources site, says:

Something is crystalline if the atoms or ions that compose it are arranged in a regular way (i.e, a crystal has internal order due to the periodic arrangement of atoms in three dimensions).  Gems are described as amorphous if they are non-crystalline.

Crystals characterized by well developed crystal faces (external surfaces) are described as euhedral . Crystals do not always show well developed crystal faces seen on euhedral examples.

A crystal is built up by arranging atoms and groups of atoms in regular patterns, for example at the corners of a cube or rectangular prism.

The basic arrangement of atoms that describes the crystal structure is identified. This is termed the unit cell.

Crystals must be charge balanced.  This means that the amount of negative charge must be compensated by the same amount of positive charge.

 

So what are crystals made of?

Atoms.

More usefully, Crystal Structure of the elements says that the only elements that don’t form crystals are promethium, astatine, radon, francium, einsteinium, fermium, mendelevium, nobelium, lawrencium, rutherfordium, dubnium, seaborgium, bohriumhassium, meitnerium, darmstadtium, roentgenium, unubium, unutrium, unuquadium, ununpentium, ununhexium, ununseptium, and ununoctium. Of all of these, only radon is found naturally on Earth, and the idea that it has no crystal structure is contradicted by Elements Database which states it has a cubic crystal structure. So it’s quite possible that the others have them as well, and we just don’t know because they tend to fall apart before we can see what they do.

The most common crystals on Earth tend to be made out of the most common elements on Earth. Why? Because they’re available to make crystals. These elements are oxygen (O), silicon (Si), aluminum (Al), iron (Fe), calcium (Ca), sodium (Na), potassium (K), and magnesium (Mg) in the proportions seen below.

I’ll be honest here, and say that I expected carbon (C) to be much higher on that list. You know, what with it being so vital to every living thing we see. But no. Carbon is part of the 1.5% “other”, and makes up only 0.15% of the Earth’s crust. Go figure.

Most likely, the crystal that caught my son’s eye was either feldspar or quartz – the boulder was granite, after all, and granite is largely made up of those two crystals. Quartz is silicon dioxide (SiO2), it comes in a variety of colors depending on the impurities in the crystalline structure, and it ranges from transparent to opaque. Feldspar is actually a group of three related minerals (KAlSi3O8, NaAlSi3O8, and CaAl2Si3O8) which can resemble quartz. I’m certain a minerologist could figure out the difference, but I certainly couldn’t. Not from a purely visual inspection, anyway.

Why Do Birds Poop And Pee At The Same Time?

I don’t know if my son was watching a nature program, or if he’d been talking about this at school, or what. All I know is that, as we were walking into the condo one day, he suddenly stops and points. “Look dad! An owl!”

I stare along the side of the building, wondering which of the trees he’s talking about. Or is it perched on a balcony, maybe? “I… don’t see it,” I say.

“It’s right there!” he exclaims, pointing. “Oh, no. It’s a squirrel. Look, dad! A squirrel!”

“I don’t see it,” I tell him. “But my eyes aren’t as good as yours.”

He nods at that. “Dad?”

“Yes, son?”

“Why do birds poop and pee at the same time?”

…that is not what I thought he was going to ask.

Do they poop and pee at the same time?

This seems like the first place to start, because I’m not at all certain they do. I mean, sure. I’ve heard this before. But it wouldn’t be the first time I’ve found that “received wisdom” is wrong and that something I thought was true wasn’t true. However, in this case, it seems that received wisdom is correct.

This is going to be more than I wanted to know, isn’t it?

Hey, you’re the one reading this.

Pretty much all animals produce ammonia (NH3) during digestion. It’s a side effect of the breakdown of proteins, which all animals need whether they’re carnivores or herbivores. Ammonia is, however, toxic (doses of 350 mg/kg of weight can kill), which means that animals have to deal with it in some fashion. And by “deal with” I mean “get rid of”.

Generally speaking, mammals will mix it with some of the waste carbon dioxide (CO2) they produce through breathing and convert it into urea (CO(NH3)2) – a far less toxic chemical (the lethal dose is 8,471 mg/kg) that also happens to be water soluble. Mammals then, generally speaking, expel it (along with other waste chemicals) in the form of urine.

Birds don’t do this. Birds, it seems, don’t even have bladders.

Sigh. Tell me more.

To start with, most birds convert ammonia into uric acid (C5H4N3O3, lethal dose around 5040 mg/kg) instead of urea. The other thing they do, which is the reason why they simultaneously poop and pee, has to do with anatomy. See, bird excretory systems work a lot like lizards. They have kidneys, of course, and ureters (the ducts that allow urine to leave the kidney). However, they lack bladders. Instead, they have something called a cloaca – a multipurpose organ that serves as both the reproductive and excretory organ.

The urine enters the cloaca through the ureters, where it is pushed up into the large intestine. The large intestine re-absorbs much of the water content, allowing the urine to be concentrated into a thick paste before it is passed by the bird. since uric acid dries white, this lends bird droppings their distinctive appearances.

So, in short, birds poop and pee at the same time because of evolution.  And because they aren’t equipped to poop and pee separately.

Why Do Sharks Eat So Many People?

“Dad?” my son asked as we got out of the car. “Why do sharks eat so many people?”

I assume he’d seen something about sharks at school, but the question still came out of nowhere. Thirty seconds before, he’d been telling me about his school’s Mardi Gras party and asking me if I felt better (because I’ve been sick, which is why this article still isn’t looking at the fossils he found). So, I put my mind to it. “I don’t think they do,” I answer.

“They don’t eat people?” he responds, sounding skeptical.

“Well, they can,” I concede. “But they don’t eat people all that often.”

“Why not?” he asks, and I swear he sounds disappointed.

“Well, a lot of them are kind of small. And we aren’t the kind of things they normally hunt.” I’m trying to remember shark facts, now. “Most of them are probably just wondering what we are, and people get scared of them and think they’re attacking.”

“Why do people get scared?” he asks.

I shrug. “Why did you get scared of them, when we went to the aquariam?”

“Because they look mean!” Then he grabs my hand. “Since you’re not feeling good, can we take a break and play Star Wars?”

Do sharks eat a lot of people?

This is one of those questions where I really hope I told my son the right thing, because I was working from half-remembered articles I’d read years ago, and memory is a fickle, tricky thing. Fortunately, it turns out that the University of Florida maintains the International Shark Attack File (ISAF), which they describe as “the longest running database on shark attacks, has a long-term scientifically documented database containing information on all known shark attacks, and is the only globally-comprehensive, scientific shark attack database in the world”.

Before we dive into the numbers, though, it’ll be important to define two terms the ISAF uses: provoked attacks and unprovoked attacks.

  • An unprovoked attack is edfined as “incidents where an attack on a live human occurs in the shark’s natural habitat with no human provocation of the shark.”
  • A provoked attack, on the other hand, usually occurs “when a human initiates physical contact with a shark, e.g. a diver bitten after grabbing a shark, attacks on spearfishers and those feeding sharks, bites occurring while unhooking or removing a shark from a fishing net, etc.”

The ISAF reports that 2016 was a pretty typical year, with a total of 150 alleged shark attacks. Out of those 150 attacks, here’s how the results broke out:

  • 81 were classified as unprovoked attacks (53 total in the United States, 43 of which were in Hawaii).
  • 37 were classified as provoked attacks.
  • 12 were sharks biting boats (aka “boat attacks”).
  • 1 was a shark eating part of an already dead human cadaver.
  • 12 had insufficient evidence to prove a shark attack.
  • 7 were determined to be attacks by other marine animals (including a barracuda and an eel).
  • 5 were determined to be abiotic injuries (that is, an environmental injury – scraping coral or rock, for instance).

So, in the fairly typical year of 2016, there were 118 total shark attacks on humans (131 if you count the boat attacks and the scavenging). 2015, by contract, hit 98 unprovoked shark attacks- the highest yearly total on record. On average, shark attacks result in 6 to 8 fatalities per year (depending on what period of time you average out), but 2016 only had 4 shark attack fatalities. Statistically, surfers are most likely to be attacked 958% of the total), followed by recreational swimmers and waders (32.1% of the attacks).

That’s not a lot of attacks, is it?

No, not really. In fact, there’s a whole lot of animals that are much more likely to kill you. According to the BBC, venomous snakes kill an estimated 50,000 people each year, rabid dogs kill an average 25,000 people each year, crocodiles kill an estimated 1,000 humans per year, and hippos kills an estimated 500 people per year. All of which makes the paltry 6-8 shark kills each year pretty tame.

friendly-shark

Still, it’s probably best not to do this unless you know what you’re doing.

The ISAF provides some other interesting comparisons. The odds of dying from a shark attack are 1 in 3,748,067. Fireworks are about 11 times more lethal (odds of death: 1 in 340,733), sun and heat exposure are 273 times more lethal (odds of death: 1 in 13,729), and the flu is 59,664 times more likely to kill you (odds of death: 1 in 63).

Why do shark attacks get so much attention, then?

Rarity, in my opinion. Rarity and shock/

See, we notice things that appear out of the ordinary. According to the CDC, heart disease is the leading cause of death in the United States (614,348 deaths in 2014), followed by chronic lower respiratory diseases (147,101 deaths), accidents (136,053 deaths), stroke (133,103 deaths), Alzheimer’s disease (93,541 deaths), diabetes (76,488 deaths), and influenza and pneumonia (55,227 deaths). Most of those get no attention at all, unless they’re really spectacular or they happen to someone famous. But death by animal attack? That’s unusual, particularly in the United States. And particularly because we like to think we’re outside the food chain. Homo sapiens sapiens is, realistically, the ultimate alpha predator and one of the dominant environmental forces on the planet. It’s unsettling to be reminded that we’re still animals, and that we can still become prey.

Also, sharks inhabit an alien environment that we can only meaningfully visit with the benefit of technology. A wolf or bear attack happens on dry land, so the surroundings aren’t inherently hostile to us. But sharks? A shark could kill us with their own environment, even if the bite isn’t fatal. So, they seem frightening.

Just in case I am one of the unlucky ones, any tips?

Actually, yes. Here’s what the ISAF says: “If one is attacked by a shark, we advise a proactive response. Hitting a shark on the nose, ideally with an inanimate object, usually results in the shark temporarily curtailing its attack. One should try to get out of the water at this time. If this is not possible, repeated blows to the snout may offer a temporary reprieve, but the result is likely to become increasingly less effective. If a shark actually bites, we suggest clawing at its eyes and gill openings, two sensitive areas. One should not act passively if under attack as sharks respect size and power. “