Sunday SciKu | A Cloudy Forecast

Photo by Ales Krivec


We tend to think of our senses as the gathering of data, as if we’re video cameras that are always running, because that’s how it feels to perceive. But that’s not how perception works. That’s fine for electronics, but too inefficient for biology.

What’s really always running while we’re conscious is a model that we project onto the world—a hypothesis about the way things are. We only use our senses to test and adjust that model as necessary. Emphasis on necessary, because the model is actually a map of the tools and obstacles the world has lain before us. A cup isn’t a cup; it’s a handled drinking thing. A low branch is something to duck.

And we’re fortune it evolved this way, because this process is how consciousness was able bootstrap itself into existence, creating an evolutionary pressure for increasing brain power, allowing for more accurate and elaborate models, which we were eventually able to push into the future, imagining external realities that don’t yet exist and perspectives we can’t access. Without sensory perception being this kind of interactive process, we’d have remained as self-aware as a smartphone, programmatically reacting to stimuli.

There are serious downsides, though, in the modern world. Because so much of our experience is based on our expectations, we’re loaded with an array of cognitive biases that bury the truth about everything, and which are often exploited to our detriment. It’s almost impossible to overestimate our own disconnection from reality.

But many researchers have shown it in the lab, and that’s what was done at Dresden Technical University, inspiring this week’s sciku. Researchers hooked people up to MRI machines and watched their subcortical auditory pathways as patterns of sounds were repeated and broken. What they demonstrated, basically, is that once a sound pattern is established, it isn’t even processed by the ears until it changes. We hear the expectation and not the sound itself.

This theory of sense cognition explains a lot of things—why it’s so difficult to proofread our own work, for example. We see what we expect to see, not what’s there. It’s also likely what explains neurological disorders like dyslexia, which has been correlated with audio pathway disruption—it manifests so strangely, with words seeming to crawl around the page, because of a mismatch between audio and visual expectation. The experience of dyslexia is how difficult reading would be if our predictive text module in the sound-sensing area of the brain were turned off, and we couldn’t anticipate the next word as well as we usually do. No matter what we think we’re doing, most of perception is expectation.

Anyway, interesting stuff.

 

waiting on
the local weather report
clouds tomorrow

 

Sunday SciKu | Quantum Clocks

Image from the researchers at MIT

This week’s #SciKu was inspired by the development of a new type of atomic clock at MIT. Optical atomic clocks work using lasers to measure the vibration rates of atoms, usually cesium. But because of the Heisenberg Uncertainty Principle, it’s impossible to measure the vibration of a single atom—they have to be grouped together and measured probabilistically, which adds a (very) small amount of imprecision. So small that if an atomic clock were running over the entire age of the universe, it would be less than 100 milliseconds off. But still! With this new technique, scientists quantum entangle the vibrating atoms first to get even closer to perfection, which will help in the effort to detect gravity waves and other exotic physics phenomena.

 

Just Married
they find that time’s best kept
entangled

 

Sunday SciKu | The Geminids

Photo by ESA


This Sunday’s SciKu doesn’t need much explaining but serves as a reminder that tonight is the peak of probably the best annual meteor shower of the year: the Geminids. Unlike most meteor showers, the Geminids are created by the debris field of an asteroid rather than a comet.

Orbiting the sun once every 1.4 years, the 3.6-mile-wide 3200 Phaethan asteroid dips halfway between the Sun and Mercury before it’s flung back out toward Mars, heating the surface to 1,500° F and gradually breaking it apart via thermal expansion. The trail of dust, which the Earth is flying through tonight, is full of all sorts of rocky elements as a result, creating over 100 shooting stars per hour in a range of colors. Last night I saw 9 or 10 on my midnight walk with the dog, but that was just a preview.

The moon is almost completely dark tonight, so go out and take a look toward Gemini (just behind Orion’s back shoulder in the sky). But be sure to bundle up if it’s as cold as it is here!

 

the stars fall
through my winter
breath

 

Sunday SciKu | Polarity All the Way Down

Photo by Jong Marshes via Unsplash

Life as we know it couldn’t exist without the strange properties of water, which are due to its exceptional polarity. A water molecule is a big negative oxygen atom on one end with two positive hydrogen atoms on the other, making it an extreme dipole. It’s not the most extreme (that would be all-cis hexafluorocyclohexane), but nothing comes close in abundance. That arrow-like shape allows it to cut like a knife through anything else that’s even slightly polarized, making it the universal solvent of biochemistry. Water isn’t just that life happened to emerge from the sea—it couldn’t have appeared in anything but a sea of water forcing all of the necessary chemicals together. It’s not just the universal solvent, but also the universal catalyst. As life on land, we’re really just bags of water that brought the sea with us.

The polarity of water also provides its bizarre physical properties—the melting and boiling points of water are abnormally high, allowing it to be liquid on Earth. Solids are less dense than liquids, so ice floats. It’s surface tension is much higher than other liquids. There are around 70 physical properties like this that make water a physical anomaly. Even more interestingly, the molecular polarity alone isn’t enough to explain it all.

That’s where this week’s sciku story comes in. One of the hypotheses has been that water actually has two liquid states—a traditional one, and another that’s more like a liquid crystal. Even though the traditional liquid state dominates at room temperature, there’s always a slight amount of flux between the two states, giving water’s bizarre behavior an extra boost.

If that’s hard to imagine, think about the surface of a lake, where a few molecules are always evaporating into gas as others are condensing back into liquid, creating an equilibrium that’s constant while always changing. That’s happening inside every glass of water, according to this hypothesis, only the flux is between liquid and liquid rather than liquid and gas.

The problem is that it could only be modeled by computer and had never been proven in the real world. The process is too rare and rapid to observe at room temperature, and ice forms too quickly at cold temperatures. Until this week, when a team at Stockholm University managed to use X-ray lasers to examine supercooled water at high pressure to prove this to be true. Every glass of water and droplet in your body is in constant flux between these liquid and liquid crystal states.

Thinking about this as I dozed off to sleep last night, it occurred to me that the necessity of polarity isn’t just a metaphor for our broader society, it’s metonymous, and on every level. Human cognition isn’t functional without something akin to a dipole moment—we need the competing approach and avoidance circuits; it’s why we have two brain hemispheres. We carve up the world into patterns and name them—that’s what an idea is, from the Greek, a pattern. And to see a pattern, idein, is literally to see. We pull those ideas apart and put them back together, and that process is the scaffolding of everything we’ve ever done as a technological species.

In the same way, without a constant frothy sea of division, societies wouldn’t be able to spark or sustain themselves. Polarity is the knife blade that allows us to cleave and recombine into something better, swimming forward against the current of entropy, embodied now in two political halves always at war with each other. It’s not just turtles all the way down, it’s polarity all the way down. This is another example of the fractal substrate of the universe (which is what my old book American Fractal was actually about). We’re all bags of polarity moving through that fractal fabric, blinking into and out of existence, nodes of flux in our own states of flux, catalyzing a larger chemistry, never realizing, as Vonnegut put it, that we were making champagne.

 

election year—
the extreme polarity
of water

 

Sunday SciKu | Test Tube Randomness

In this paper from Nature, researchers at ETH Zurich used DNA synthesis to create test tubes full of randomness—7 million GB of random data per run, to be exact—which could turn out to be very useful for encryption. Synthesizers basically drip the four nucleotides one at a time to make whatever chain you want. This team turned on all four droppers at once and let the chips fall where they may. It’s funny that it’s 2020 and no one had thought of that before.

 

canned chaos—
as if there weren’t
enough