Saturday, February 22, 2014

Ode to the Gastrolith

I'm falling behind on my novel writing goals, so instead of a Weekly Science Roundup, you get this!

"Ode to the Gastrolith" is a piece I did back in college for the one and only creative writing class I ever took. My instructor was an...interesting fellow. To put it nicely, he had a lot of quirks and weird rules for writing that I didn't entirely agree with. So by the end of the semester, I just submitted things that I knew would mess with him.

I wrote this based on the biggest gastrolith I'd ever found.
The prompt was to write a short poetic reflection on an object that most people would overlook. As the class's only science nerd, I decided to write about something appropriately nerdy...something my instructor wouldn't know what to do with...GASTROLITHS.

Gastroliths are rocks that dinos swallowed, likely to help mush and digest their food since they didn't really do a lot of chewing. Modern day dinosaurs do this, too. Gastroliths fit my instructor's prompt perfectly. They're often overlooked, since they really do just look like rocks (because they are).

Anyway, I got a lot of question marks on this from my instructor, so mission accomplished. Up until a couple of days ago, I had forgotten all about this, until I stumbled upon it when I was looking for a different file from my college years. When I reread it, I knew I had to put it on my blog.

This is from college and was written to taunt my instructor, so it's obviously pretty terrible. But I have no shame and I'm posting it anyway.

Ode to the Gastrolith 

Like a lumpy chicken egg, you sit in the dirt.
You are no egg, though. Inorganic and inedible, you’ve seen more than any hatchling could ever dream of seeing.

Forced underground by the planet’s sinking crust, incinerating heat and pressure from the world on top of you strained your minerals to a swirl. You only resurfaced after getting scraped upwards for millions of years, when you then broke off from your formation and were carried long distances by rushing water, freezing glaciers, and the ever present force of gravity.

And then a pause.

But not forever.

Your rest, interrupted. A Sauropod swallowed you. Down the long neck, the long gullet, smashed alongside others from across the world, shredding soggy dead plants, attacked by bile all before being shoved through the winding pathways of the intestines; it could have been years before you were ejected from this massive body.

Post defecation, polished smooth, you waited by yourself, as contrasting jagged rocks broke apart into shattered piles around your resting place. Alone and different, you waited until now, unaffected and patient.

This is your story of survival. Survival on your own.
colored green and purple by metamorphosis, rounded and beautified by dark biotic chambers and churning acid, you were sentenced to weather the past 80 million years at the mercy of a drying environment.

Find solace in your lifelessness, Gastrolith,
and in the aged wisdom
of your dense ignorance.

Thursday, February 20, 2014

Science of the Olympics: The Gear

Let's face it: the Winter Olympics require a lot more specialized gear than the Summer Olympics. The athletes in the Winter Olympics are doing what they do on top of ice and snow, sometimes with the help of skates or skis, and other times with the help of man-powered vehicles.

Before we take a look at how some of this gear actually works, I'm going to introduce the topic of Work to help make all this make way more sense for everyone.

Work, in science, is applying a force over a distance. The more force used, the more work gets done. The more distance the force is applied over, the more work gets done. It's a straightforward concept and will help to explain a lot of what Olympians use to accomplish their sports.

Now, onwards! To the gear!

The Science of Ice Skates

Ice skates allow for controlled movements over slick least, as long as the wearer knows how to balance properly.

But as far as balancing goes, skaters don't actually move around on the edge of a true knife-like blade. Ice skates have two parallel edges to their blade, rather than one central sharp edge. This distributes weight over a slightly wider surface area under the blade, which helps to stop the ice from melting too quickly under a skater's weight. (The force a skater exerts on the ice through their blade forces ice to melt from compression, which allows them to glide.)

In the Olympics, several sporting events rely on ice skates, such as hockey, figure skating, and speed skating. Let's focus in on the difference of the blades that you would see between each of these types of skates.

In hockey, the blade is simple and short, to allow for fast turns and ease of braking (and, I'd like to think, to avoid violence-prone hockey players from having daggers sticking out of the fronts of their boots). The blade typically runs only the length of the boot itself. Any longer, and it would require more force to change direction when skating. The longer the blade, the more friction it has when moved sideways, so turning quickly on a long blade takes a lot more effort than turning on a short one.

Because of this, hockey players do give up a certain amount of speed they could gain from having longer blades. Figure skaters actually have a bit longer of blades than hockey players, which they need to help accelerate them into jumps. The longer blade allows for the skater to use their force over a bigger distance. Remember Work? Great. More distance means more work! A longer skate allows for greater amounts of work to be done, without having to apply greater amounts of force. In the case of skating, this work is often related to speed and acceleration.

In speed skating, this concept is taken to an extreme. A speed skate's blade is typically 50% longer than a figure skate's. Some even detach at the back to lengthen the stride of the skater by giving them a long lever arm to continue to apply force over after their foot has already moved on to the next step. This is used in long track speed skating. 

A detachable style speed skate.
In speed skating, the blade is also thinner, since the wearer is traveling much faster and has little need to stop or twirl about. This compresses ice in a thinner band, with a higher concentration of force, thereby melting ice even more and making gliding even faster. Of course, all this compromises the ability to maneuver, so short track speed skaters make up for this by having their blades slightly bent to help them round corners.

It's all a tradeoff between speed and maneuverability. Figure skaters attempt to find the sweet spot between the two, while hockey players favor quick turns and speed skaters favor straight-on speed.

The Science of Skis and Snowboards

The idea of Work and using force over long distances also applies to skiing and snowboarding, as you might have already deduced. However, the way in which is applies might be more surprising.

Skis and snowboards are designed to "float" a person on top of snow. Just like being in a boat, a person needs a certain amount of surface area on their floating device so that they don't sink. Skis and snowboards have enough surface area to keep their riders upright, but not much more than that, so as to reduce excess weight or bulkiness in the equipment.

Cross country skis divide up this surface area differently than downhill (or "alpine") skis. Cross country skis are much more narrow throughout their length, to reduce drag as the skier moves through the snow. This require them to have a longer length than alpine skis, just by the nature of needing to keep up the right amount of surface area.

Alpine skis, in contrast, tend to be shorter and to have a waisted shape (where they narrow only towards the middle section). Much like with skates, the shorter length of an alpine ski allows skiers to turn more quickly. Additionally, the specialized shape creates differences in weight along the length of the ski--which allows for the ski to bend and be more flexible during a turn.

To increase the Work in skiing, the extra distance is achieved not by the length of the ski alone, but also by the pole. The pole acts as a lever to extend the arm, and give an extra set of limbs to push a skier along the ground.

But in snowboarding, there is no pole. As far as getting help from gear goes, snowboarders must solely rely on the length and shape of their board to change their speeds.

Image Credit: Alain Carpentier
Lengthier boards are favored for events that need intense speed, such as races. A longer snowboard will be more stable at higher speeds, and snowboarders can increase that speed by shifting their body weight, as discussed in the last Science of the Olympics post. But, as seems to be the theme today, longer boards mean less maneuverability, so for events that need more tricks and jumps, different boards are needed. For these types of events, shorter snowboards that are waisted towards the middle (like alphine skis) are used instead.

Now that we've covered all the things athletes stand on, let's take a look the things they don't stand on. Let's look at the sleds!

The Science of Bobsled, Luge, and Skeleton

When athletes go hurdling down ice slides at over eighty miles per hour, they need something to help them out. That something might take the form of a bobsled (the biggest of the sled-types, and the one that offers the most protection) or the luge or skeleton style sled (both essentially a smaller bobsled stripped of its protective siding).

Luge-style sled.
All three types are derived from toboggans, which rely on runners under the sled to guide the vehicle, much like a bigger version of an ice skate. The intense speeds reached by these sleds is a result of the icy trackway and the narrow runners, which combined create an incredibly low amount of friction. In addition, the sloping angle of the course helps build acceleration.

All three sled types are designed to be as aerodynamic and lightweight as possible. Extra weight actually helps speed things along when a sled is hurdling down a slide, but it's important to be able to control where that weight is. Having that weight with the athletes is better than having it with the sled, since the athletes can shift themselves accordingly to center their masses, and thereby steer.

Old-style bobsled, complete with steering rings!
However, unlike in skeleton and luge, in bobsled it isn't just shifting an athlete's mass around that allows for steering control. In bobsled, the "pilot" (front seat) can actually move the front runners by tugging on metal rings attached to pulleys at the head of the sled. The pulleys inside of bobsleds once again demonstrate our favorite topic today: Work.

Rather than tugging on strings just directly attached to the front runners, athletes double their work by doubling their distance--using strings that are looped around a pulley system. Using a pulley takes less muscle force by the athlete, so they can be more precise and less strained during steering. Which, when you're going close to 90 mph, can only be a good thing!


Alas, with the Olympics coming to a close in a few short days, this post concludes my 2014 Science of the Olympics blog series. Perhaps we shall meet again in 2016, when we're back to the Summer Games! Until then...!

Saturday, February 15, 2014

Weekly Science Roundup #26

Some big stories this week, and all are human-related. Let's work our way backwards through time to see how they all connect.

1. International Pledge to Make Poaching a Serious Crime

White Rhino. Photo Credit: Rob Hooft

With poaching of endangered species on a terrifying rise, nations met in London this past week to discuss what they could do to combat what's happening. In the past year, over 1,000 rhinos were killed in Africa. That's out of approximately 25,000 total. 20,000 African elephants were killed last year, out of around 450,000

To put this in perspective, this means that 1 out of 25 rhinos and elephants in Africa were poached in 2013. Just let that horrifying fact sink in.

But in some cautiously good news, this meeting resulted in international agreement to change poaching to be categorized as a "serious crime", which is apparently a big deal. As a serious crime, nations can enact much tougher penalties for anyone convicted of poaching, dealing, or trading in endangered animals.

They're calling this the "London Declaration", and it's a step in the right direction at the very least. Fingers crossed this really does make a difference. But for now, let's leave the present behind and go back a few thousand years...

2. Ancient Baby Provides Clue to Native American Ancestry

Clovis point tool technology.
The Clovis culture is the first well-documented North American culture. It dates back to around 13,000 years ago, and has often been argued to be the stem population from which all Native American populations arose from. The Clovis people have in turn been argued to have come from Asia/Siberia, though a few holdouts say they may have come from Europe around the Atlantic.

Now, thanks to the genetic sequencing of a 12,000 year-old baby boy (found in Montana), another piece of evidence lines up to support the idea that Native Americans came from a population that migrated into North America from Asia at least 13,000 years ago. This strengthens the idea that Native Americans truly are the descendents of the first people to ever come to the Americas.

The baby boy himself was found buried with over a hundred artifacts, placed with great care. With the almost surprising level of extreme genetic similarity to modern Native American peoples, scientists who worked on the project are planning on reburying the boy in an undisclosed location near the original site, out of respect. A memorial at the site is also planned.

Going back even further now...

3. Really, Really Old Footprints in Great Britain

Source: Hominin Footprints from Early Pleistocene Deposits at Happisburgh, UK

From the shores of Great Britain, something really cool was finally announced last week. Out of the water, the tides revealed fossilized footprints of up at as many as five individual hominins in May, 2013. Those footprints date back to somewhere between 780,000 years to 1,000,000 years of age, making them the third oldest human ancestor trackways in the world, and the oldest outside of Africa.

By measuring the footprints, it looks like the people walking were between 3 feet and 5 and a half feet tall, which likely means a mix of adults and children. They'd been walking along mudflats at the time, possibly near an estuary.

It's thought that these prints belong to Homo antecessor, which predated Homo heidelbergensis as a European hominin possibly on the line to Neanderthals. Of course, linking a species to fossil footprints is never 100% accurate, but at the moment this is the leading hypothesis.

The footprints themselves are gone already now, washed away by the same tides that originally exposed them. We were lucky to ever get to see them at all, and unfortunately were unable to save them.

Which, in a sad poetic sense, brings up full circle back to the first story of this blog post.

Monday, February 10, 2014

Science of the Olympics: Jumps, Spins, and Other Awesomeness

Continuing the fun of my Science of the Olympics blog series, it's time to take a look at how skiers, snowboarders, and figure skaters do all those totally awesome tricks they do.

To understand these moves, we're going to dive into a bit of a physics lesson. Let's address the most basic idea in physics first: forces.

The way I explain forces to elementary school kids is that forces are pushes and pulls. Forces themselves are invisible, so you can't actually see a force, but you can see the effect it causes. Gravity is an easy example of a force, and especially great for thinking about the invisibility factor.

Other examples include the force of friction, the electrical force, and forces generated by your own muscles.
The force of friction is less on ice, so
skaters can "stay in motion" longer.

Do you remember Newton's laws?

An overview:

1. Objects in motion stay in motion (and objects at rest stay at rest), unless a force acts upon them.

2. Force is equal to mass x acceleration.

3. Forces come in pairs. For every force observed, there is an opposite and equal force.

Now that we've gotten that out of the way, on to the flips and jumps and stuff!

The Science of Jumps

Let's go basic first. Jumping is at the core of not just figure skating, but many other winter sports, such as snowboarding and skiing.

By pushing off the ground, an athlete creates a vertical velocity--that is, an upward motion at a particular speed. The bigger the push, the higher they go. But what the push is actually doing is showing off Newton's Third Law (see above). The athlete pushes into the snow and/or ice, and then the snow and/or ice pushes back. That's what allows for lift to occur.

There is another way athletes get into the air in the Olympic Games, and that is to fling themselves off an edge. Eep. Think ski jumpers, or snowboarders on the halfpipe. In these cases, what propels the athlete upwards isn't just their legs pushing down, but rather the momentum of the athlete prior to reaching that edge they're going to fly off of.

Momentum is mass x velocity. A bigger mass will create more momentum, as would a larger velocity (which, by the way, is speed with an assigned direction). Skiers, for example, gain velocity by traveling downhill rapidly before doing the flinging-themselves-off-an-edge thing.

But what about once an athlete's airborn? At that point, they can go onto do loads of other awesome stuff.

The Science of Flips and Twists
So once an athlete has gotten into the air, sometimes they do amazing things like flip themselves around. They'll accomplish this by shifting their mass and letting gravity assist. Gravity is a pulling force that conveniently always pulls in the same direction here on Earth: down.

With the help of gravity, athletes can tap into a rotational energy and start utilizing angular momentum. What that means, is that they use gravity to tip them and start a spin, and then pull their body inwards to keep that spin going. This causes them to flip around in the air, in whichever direction they shifted their mass towards. And the more angular momentum the get, the faster they will twirl through their flip or twist.

Now, to make this possible, they'll need a pivot point--a place in space to rotate around. And this leads us nicely into my final section for this post...

The Science of Spin

In this diagram, I've made two different arrows to help make sense of angular momentum.

Imagine going around this green pivot point on the black oval I've drawn. The trajectory out by the blue arrow is farther from the pivot point, and the trajectory near the red is closer. Both have the same momentum, but since the red arrow section is closer, it moves past the pivot point much faster than the blue arrow's section does.

Moral: Closer in = faster spin. This is the Law of Conservation of Angular Momentum. Angular momentum stays the same at every point of orbit, and is calculated by multiplying a few elements, such as velocity and radius. To make sure this law is heeded, velocity (speed in a certain direction) increases when the radius (distance out from the center) decreases. Simple as that!

A smaller radius for a bigger velocity. It's a trade-off that all these Olympic trick-doers rely on, but perhaps none so beautifully and dramatically as the figure skaters.

Figure skaters use the law of conservation of angular momentum to increase the speed of their spin as they go. They start spread out (big radius), and pull in their body to a tight form (small radius) as the spin goes on. This results in a spin that appears to magically speed up as it goes.

So as much as scientists and athletes stereotypically don't have much to do with one another, the pinnacle of athletes people--aka Olympians--actually rely on science a great deal to make them look as awesome as physically possible. Heck yeah! Gold medal for Physics!

Saturday, February 8, 2014

Weekly Science Roundup #25

Weekly Science Roundups are back! I've decided I miss too much awesome science news when I fiddle around and wait for the end of the month. Such as...

1. First Fish to Move off of Endangered List!

In some happy conservation news for a change, the Oregon Chub has become the first fish to escape the Endangered Species list! Congratulations, Oregonichthys crameri!

This minnow was put on the list back in 1993, with an estimate of only 1000 left in the wild. But through habitat protection programs and careful reintroductions, that number has climbed over the past two decades. There may be as many as 150,000 in the wild now!

This fish is considered an indicator species for how watershed species in general are doing in Oregon, so to see it make a comeback gives hope for many other plants and animals.

Hooray for quantifiable conservation success!

2. Prosthetic Hand Provides Sense of Touch

Okay, so we're not quite this advanced yet.

Every day, science gets closer to making a Luke Skywalker hand an actual possibility. This time, the breakthrough comes in giving a sense of stiffness and shape of objects to the wearer of a particular prosthetic.

By inserting electrodes into the nerves of what was left of the patient's arm, doctors were able to connect actual nerves to sensors in the fingertips of the prosthetic. The patient could tell the difference, while blindfolded, between holding a bottle, a mandarin orange, and a baseball.

Control over motion of prosthetic limbs has advanced leaps and bounds over the past few years, but sensory feeling from these limbs has been a difficult hurdle to clear. With this news, science has made a decided step in the right direction.

...That was a lot of lower limb metaphors for an upper limb story. Whoops. Anyway, moving on...

3. Real Reason Mammoths Went Extinct?

Why did mammoths--along with all the other Ice Age megafauna--go extinct? It's been debated for decades. The leading theories always have to do with climate changing (end of the Ice Age) and human hunting. More and more often, these ideas get combined into a double smackdown for these ancient animals.

Now, there's evidence of a different sort. A new study suggests that the decline of forbs (wildflowers) may be the real culprit. Stomach contents of frozen woolly mammoth show that these flowering herbs were a big part of their diet. 12,000 years ago, though, grasses and shrubs took over and the herbaceous wildflowers went into severe decline.

This would actually explain the survival of reindeer while every other big herbivorous animal kicked the bucket. Reindeer don't eat a lot of forbs, concentrating rather on sedges, grasses, and lichen.

I'm not sure I'm convinced that this really is "the" culprit yet, but it's at least another piece of the puzzle. I'll be curious to see where this study takes the Ice Age extinction debate next!

Wednesday, February 5, 2014

Science of the Olympics: Snow and Ice

In 2012, I did a special series of blogs focusing on the science behind the Olympics. I covered a lot of biology in that series, as I discussed the science behind the human shoulder joint, the science of legs and running, and the science behind how muscles work in general. This time around, our focus will be on physics instead of bio.

Before we get started, though, I should say that 2012 wasn't all biology. It started with a physical chemistry lesson--namely, the science of the Olympic Flame. But in the spirit of the Winter Olympics, I thought I'd kickstart my 2014 Science of the Olympics series with a post not about fire...but about ice.

Sorry, Elsa. I love you dearly, but this is the science--not the magic--of snow and ice. I'll save you for a different blog series.


Image credit: Michael.
Technically, snow is ice. It's water in its solid state. However, meteorologically speaking, snow is a very special type of ice: a crystalline version of ice that falls from the sky in little chunks, remaining solid through its descent.

When water crystallizes in the atmosphere--freezing from tiny suspended liquid droplets into eensy flakes (or frozen fractals, as Elsa would say)--eventually, those flakes fall due to the effects of gravity. And as they fall, any number of things could happen. Below, I've run through the five most common options:

1. The flake could stay cold (below freezing) all the way down. This would create a snowfall.

2. It could warm up on the way down. This could make the crystal flake melt and result in rain.

3. It could warm up on the way down and then get cold again. If it warms to above freezing and cools back to below freezing, this could melt the flake, then refreeze it, creating a new, more ball-like pellet of sleet.

4. It could warm up on the way down, and only get cold again upon reaching the surface of Earth. This would result in freezing rain.

5. It could warm up on the way down, but only a little, and with some added winds this could simply result in snowflakes clumping together to make bigger snowflakes.

Image Credit: Emmanuel Boutet
Eventually, you might get snow accumulation on the ground. And there, the snow will go through continued changes, depending on temperature variation. But let's instead focus on the appearance of the accumulation itself.

Once snow piles up, its crystal structure reflects light so amazingly well that it will appear white to our eyes. Since the snow doesn't typically break light apart, the white is simply the color of all the wavelengths of the light combined, coming back at us. Occasionally, though, snow looks more blue.

Blue snow can occur when there's a lot of snow around, and light gets scattered bunches and bunches. When this happens, some light absorption does occur, but it's mostly red light that gets absorbed. Therefore, blue is still reflected!

Now, the reason we love snow and ice so much in the Olympics is because they allow for activities that would normally be impossible for humans to achieve.

The molecular structure of ice.
The crystalline, hexagon structure of typical ice results in amazingly smooth, flat surfaces. Therefore...low friction! WHOOSH! ZOOM! SWISH!

In fact, low friction is pretty much the point of nearly all winter sports. You can't glide over the ground on skis, sleds, or skates without snow and ice! For the time being, though, I'm not going to go into the physics details of all this just yet, because the following blog posts will take a closer look at how exactly these sports work. So stay tuned for that!

In the meantime, I'll leave everyone contemplating this: what if we did the Winter Olympics with one of the other forms of ice? There are 15 known forms, after all, including an amorphous form that has no crystal structure, a highly dense form that would actually sink in liquid water, and a form that can change polarity when exposed to an electric field.


But here on Earth, we typically deal with what is known as ice Ih.That's what allows for ice rinks, ski hills, frost on your glass, and blizzards outside. And that's what will allow for the sheer awesome display of skills over the next few weeks.

So, without further ado... let the Snow and Ice Games begin!