Leonardo da Vinci's life and legacy, in a vintage illustrated pop-up book adapted in animated GIFs
Behold, the GIFtruvian Man!
This post is an explainer to go along with this week’s It’s Okay To Be Smart video, an animated ode to the cycles that oxygen and carbon take through the biosphere. Click here to watch it.
I’ve always been fascinated with the elegant cycle that oxygen takes through our bodies and through the biosphere. While equally elegant, the biological cycle of carbon is a lot more straightforward, so I’m not going to talk about it today. My apologies to Team Carbon :)
If you ask me, more than any other, your life depends on the following two chemical equations:
What isn’t immediately obvious when you look just at the equations is why these connections exist. Where exactly do the oxygen atoms that a plant exhales come from? Out of CO2, or water? And does the oxygen we breathe end up in CO2, or H2O? There is little elegance in an equation, only simplicity.
A beautiful recycled chain of oxygen chemistry supports a vast majority of Earth’s living universe upon its back. While it is certainly poetic in its recursive harmony, we’re not here to view it only as art. It is because of decades of scientific research that we have unlocked the beautiful secrets of the living oxygen cycle.
Take a deep breath, and join me…
When we inhale oxygen gas, it diffuses into our blood via the alveoli of our lungs. Inside our red blood cells, that dissolved gas is caged by iron-containing hemoglobin proteins that shuttle it to hungry cells throughout your body. As oxygen-rich capillaries pass near oxygen-starved cells, the double-O’s diffuse across the cell membrane.
Inside your cells, that oxygen makes its way to the mitochondria. In the early 1960’s, it was discovered that those cellular powerhouses use diatomic oxygen, the stuff you breathe, as an “electron acceptor" during the electron transport chain, the reactions that drive ATP production in our cells. Thanks to biochemistry, we know without a doubt that the oxygen you breathe ends up as water, and not CO2. You’d never learn that from the equation.
What happens to that water? You’ll be reminded next time you go to the bathroom.
Eventually, the H2O you “release” joins with rivers and rainclouds, which deliver it back to thirsty plants. Within their veins, water molecules (some containing oxygen atoms that were once breathed in by a living creature) are delivered to chloroplasts, where they begin the next phase of their cyclical journey.
We know that photosynthesis eats up light, water, and carbon dioxide in order to produce oxygen gas and sugars. But what are the fates of those atoms? Biologists had figured out the basics of photosynthesis by the early 1800’s, but argued for decades about the detailed atomic journeys within a leaf.
In 1941, at the age of just 27, a biologist named Sam Ruben wanted to find out once and for all if the oxygen that plants exhaled came from CO2, or from H2O. Again, the equation fails to tell the story. Ruben fed plants both water and carbon dioxide that contained a heavy isotope of oxygen. Only when the heavy oxygen began as water did he find it in oxygen gas, meaning the O you breathe comes from entirely from water!
That oxygen eventually makes its way back to us, along a long and frantic journey through the atmosphere, where some of it is now entering your lungs, ready to fuel the same curious brain that now understands the cycle of the breath that feeds it. Seems like we’re finding cycles within cycles now, eh?
The living world, at least according to the oxygen cycle, seems to be a very elaborate means to trade electrons between photosynthetic and respiratory branches of the Tree of Life. Richard Feynman once said that “all life is fermentation” … perhaps he should have said all life is electricity.
Breathe that in, and stay curious :)
This week’s It’s Okay To Be Smart video is about cycles.
This is a special one, and although you don’t get to hear my voice this week, you’ll find out about the connections between C, O, and you.
After you watch it, keep your eye out for a longer post coming up later today, explaining the beautifully simple cycles that these two atoms take through the biosphere. Watch here:
Why Does Time Exist?
We know that yesterday is different from today, and that the future is different from the past. But why is that?
Mathematically speaking, the equations that govern how atoms move, how heat is transferred, or how chemical bonds are made and broken can run in reverse with no problem. But they don’t. The arrow of time points forward.
Are You Alone?
Well, that kind of depends on how you define “you”.
First, let’s distill our living bodies down to their most basic elements, the cells that you’re built of and that build you. Within those cells are countless chemical machines (embodied adorably in the above GIF), doing the work of converting certain arrangements of atoms into other, more useful arrangements of atoms.
And when we tally up just what those atoms are, and where they come from, we begin to realize that we are fundamentally connected to the universe itself, and although we may sometimes find our bodies and minds alone in the conscious sense, our atoms are with the always and forever, always and forever.
With that in mind, enjoy this wonderful video from Kurzgesagt:
So now that you’ve had time to think about it, are you alone?
My (vintage GIF) heart goes out to all of you. Have a wonderful weekend, and stay curious.
EXCERPTS >|< Mechanism Of Normal Heart (1930)
A series of Animated GIFs excerpted from Mechanism Of Normal Heart. Shows diagrams of heart and sinus-node mechanism, excitation-wave pathway, interpretation of electrocardiagraph.
We invite you to watch the full video HERE.
The intriguing science behind Bruce Lee’s one-inch punch
It’s a punch that has captivated our imagination for decades. From the distance of one-inch, Bruce Lee could break boards, knock opponents off their feet and look totally badass doing it. It’s one of the most famous — and fabled — blows in the world.
Drawing upon both physical and neuro power, Lee’s devastating one-inch punch involved substantially more than arm strength. It was achieved through the fluid teamwork of every body part. It was his feet. It was hips and arms. It was even his brain. In several milliseconds, a spark of kinetic energy ignited in Lee’s feet and surged through his core to his limbs before its eventual release.
Now THAT’s what I call a useful application of science. The answer (at the link above) is a lot like how slender athletes can still whack the hell out of a golf ball or baseball. A fascinating blend of physics and neuroscience.
Next we’ll have to tackle the fluid dynamics of Bruce Lee:
“Empty your mind, be formless, shapeless — like water. Now you put water in a cup, it becomes the cup; You put water into a bottle it becomes the bottle; You put it in a teapot it becomes the teapot. Now water can flow or it can crash. Be water, my friend.”
It’s been said that we know less about our own oceans than we do some other planets. So perhaps it’s not surprising that we only need to go for a dive to come face to face with “alien” biology.
Of course, no terrestrial life form, no matter how frightful or exotic it may be, is truly “alien”. But evolution, in its many trials and transformations, has molded some very strange forms from the clay of Earth’s long history. Many of these creature features, via their novelty, spark feelings of shock and discomfort in our terrestrial brains.
Moray eels are one of those forms. Morays are a group of more than 200 species of bony fishes that inhabit all of the world’s oceans. Along their evolutionary journey, the many families of eels (of which morays are but one) have gradually slendered and lost their fins, some to a degree that they look more like snakes than fish. It’s a wonderful example of convergent evolution, two only distantly-related organisms meeting the same end result (long and slithery body shapes) independently.
It’s natural to feel a bit unsettled when you first lay eyes upon such pelagic poltergeists and benthic beasts, whether it’s the relatively familiar eel or the spiral of dental terror that is a lamprey’s mouth:
Can I just say NOPE?
Our disquiet makes biological sense. Human neural circuitry evolved in the presence of (and has adapted to recognize) the body forms of terrestrial fauna, so when faced with the incomprehensible biological distortions resulting from eons spent evolving in a wet, dark world quite unlike our own, a little unease is to be expected. We recognize that these aquatic animals are alive, that their bodies have directions we can understand and parts that we can name, but there’s something that’s just… off about ‘em. I came across a Latin term that fits these oddities quite well: ”xenomorph” meaning ”strange shape.”
Xenomorph is also the name given to the deadly parasitoid extraterrestrials from the Alien movies. They, too, reside in that uncanny valley between familiar forms (head/mouth/arms/hands/legs) and extraordinary strangeness, creepy chimeras with skulls but no eyes, familiar bipedal anatomy sheathed in insect-like armor stretched over quasi-mechanic skeletons oozing with acidic blood. Oh, and we can’t forget their second set of jaws, ready to snap through your skull like a toothy bolt pistol.
Yet that second set of jaws is not alien at all. We find it in our friends the moray eels.
Morays possess a second set of retractable chompers called pharyngeal jaws (seen in the GIF up top), which are crucial to how they feed. Many fish have realted crushing structures in their throats, but none are able to extend them to grab prey like the moray. So why do eels have them? We think it’s because they had to make an evolutionary tradeoff.
Most fish gulp down their prey using suction. By very quickly extending their jaws open wide, they create a flow of negative water pressure that they use to slurp prey down their throat:
But to do that, gulping fish need wide, flexible jaws that they can expand blazingly fast. The moray eel family has adapted such a narrow head and body shape that they lost the ability to create that suction motion. So instead, it grew a second mouth!
In 2007, scientists from UC Davis used high-speed cameras to capture moray eels using their second jaws to snag prey. To hunt, the eel waits in its dark coral crevice or murky hollow, eyes unblinking and mouth agape, doing its best impression of scenery while it waits for something edible to float near its mouth. Then, in the blink of an eye, it snaps its forward jaws shut around the prey, extending its second pharyngeal set to pull the food down the throat. What a way to go.
Alien monster designer H.R. Giger, who passed away May 12, maintained his movie monster wasn’t inspired by the moray eel, or any other animal. He said his only goal with the Alien xenomorph was to make something “frightening and horrible.”
He certainly succeeded, and in doing so accomplished some convergent evolution of his own. Two sets of pharyngeal jaws, each unsettling in their own way, blending the familiar with the unfamiliar, keeping one terrifying foot rooted in reality and by resting the other just outside the bounds of what we know. Whether a creature is from outer space or just the shadowy parts of the sea, sometimes they’re just too close for comfort.
"Spin Spot… now stay. Hey! I said stay!"
Jupiter’s Great Red Spot is shrinking, and scientists aren’t sure exactly why. The massive, rust-red storm resides in Jupiter’s southern hemisphere, a cyclone of unknown crimson gases swirling around at hundreds of kilometers per hour.
At its largest, the Great Red Spot was wide enough to hold three Earths within its boundaries, but according to the latest observations it would (only!) barely hold more than one Earth. It’s unknown if the spot is set to disappear completely, but scientists are watching its evolution closely.
As familiar as it is to us, there’s no reason to think the spot has always been there, or that it always will be. Its first confirmed observation comes from Giovanni Cassini in 1665, seen in his sketches below (the spot is flipped vertically because that’s what telescope lenses do!):
German astronomer Samuel Heinrich Schwabe saw it again as early as 1831, and it was certainly prominent in the 1880’s when Étienne Trouvelot was drawing his gorgeous planetary pastels:
This persistence has led us to believe that it is a long-lasting feature that was there long before we ever saw it, and would therefore continue to ≥ BE there, you know? I mean, what is Jupiter without its spot?
Of course, we know better. Just because it has always been there doesn’t mean that it always will be. Indeed, there are reports that suggest that the Red Spot has fluctuated greatly in size before, perhaps even disappearing altogether for decades at a time.
In fact, a new spot in the region, nicknamed “Red Spot Jr.” (technically named Oval BA), has popped up in the past decade or so, and may one day overtake its older sibling in size and intensity:
If you’d like to learn more about the science behind the shrinking spot, check out this article at Bad Astronomy. Also be sure to catch this Google Hangout discussion on the fate of the featuring some Jovian astronomers and brought to you by the folks at HubbleSite (embedded below):
What will be the ultimate fate of the Great Red Spot? We don’t know… yet. In the meantime, we are wise to remember that nothing in this universe lasts forever, so we should savor its beauty while we can: