WRAY4PAY

She got the idea for the study while walking with her advisor at Stanford to discuss her thesis topic, and the paper she eventually published in the Journal of Experimental Psychology in 2014 is sharp enough that it should have ended the seated meeting on the day it came out.

She ran 4 experiments on 176 people. Same person tested twice. Once sitting, once walking. The creativity tasks were the standard ones psychologists have used for decades to measure how good a brain is at generating novel useful ideas.

81% of participants in the first experiment produced more creative ideas while walking than while sitting. In the second experiment, 88%. In the third, 100%. Every single person walked into a more creative version of themselves. On average, people generated 60% more novel useful ideas the moment their legs started moving.

The skeptical question is the obvious one. Maybe it was the fresh air. Maybe it was the scenery passing by. Maybe it was the change of environment doing the work, not the walking itself.

Oppezzo killed every one of those explanations with one experimental decision. She put people on a treadmill facing a blank wall. No scenery. No fresh air. No environmental change. Just legs moving in place while staring at white drywall. The 60% boost held.

Then she ran the experiment that closed the case completely. She took participants outside in two conditions. Half of them walked through a Stanford courtyard. The other half were pushed through the exact same courtyard in a wheelchair. Same outdoor stimulation. Same scenery passing at the same speed. The only difference was whether the legs were moving.

The walkers produced dramatically more novel high-quality ideas than the wheelchair group. The outdoors did almost nothing on its own. The walking did everything.

She also tested the opposite kind of thinking. Convergent thinking. The kind where there is one right answer and you have to narrow down to it. Word puzzles where 3 words share a hidden fourth word that connects them. The seated participants did slightly better on these. Walkers got slightly worse.

Walking is not a general intelligence enhancer. It does one specific thing. It opens up the divergent search inside your brain. The part that generates options. The part that produces unexpected connections. The part that takes a problem and finds five ways into it instead of one.

When you need to converge on the single right answer, sit down. When you need to find the answer in the first place, get up.

The mechanism is now well understood. Walking selectively activates what neuroscientists call the default mode network, the system inside your brain that runs when you are not consciously focused on anything. The DMN is where mind-wandering happens. Where memories cross-reference each other. Where ideas that have been sitting in separate folders inside your head finally bump into each other.

When you sit at a desk and force yourself to concentrate, you suppress the DMN. When you walk at a natural pace, the executive part of your brain gets just busy enough handling the walking that the DMN comes online and starts doing the work that focus was blocking.

The most useful finding in the entire paper is the one almost nobody quotes. The boost did not turn off the moment people stopped walking. Participants who walked first and then sat back down stayed elevated. Their next round of seated creativity work was still significantly better than people who had been sitting the whole time. The rest lingered for at least several minutes after the legs stopped moving.

You do not need to do creative work while walking. You need to walk before the creative work. The brain holds the state.

I’ve posted this before but I’m doing it again and I just like how Jean de Joinville’s Memoirs of his time in the 7th Crusade are so tsundere towards his understanding of Shia Islam

Like he was a crusading knight and was not there to do ethnography or to understand the beliefs of Muslims but rather to kill them though he still does come off as a naturally curious man with how he gives very detailed and objective-in-intent analysis of the enemy from a military perspective. That said it’s really interesting how his description the Shia attitude towards death as a reflection of Shia views on predestination where ‘God determines when you die but your actions determine how’ is shockingly not that off the mark considering the circumstances and that this is someone who thinks Ali was the uncle of Muhammad (and thus obv was not getting his info from actual Muslim or even native Christians). It’s fairly strongly implied imo that he was awed by Bedouins wearing no armor charging into battle with courage and bravery equaling or many times exceeding that of Eliezer Frankish knights covered in plate armor. The fact that he even goes out of his way to mention this twice and also makes it clear he doesn’t agree with the underlying theology (since this would’ve been dictated to Church clerical scribes as his memoirs were commissioned to serve as part of of Louis IX’s biographical hagiography) when he never does that elsewhere makes it clear this left him a bit shook.

Not to mention the idea that the Bedouins supposedly used Crusader knights in heavy armor to scold their children, not to frighten them but to scold them to not become frightened like them who clad themselves in heavy metal armor because their faithlessness shows how little they trust God. Like imagine being a holy warrior that is us used to seeing the will of the enemy crumble as they panic and scatter beneath your charge l; but suddenly in the heat of battle you see enemy soldiers wearing no armor charging towards you and you can sense in it not blind recklessness but determination and shedding of fear. realize that these enemies are trusting in God not to protect their lives but that if this is their chosen hour to die then they wish to show that they accept it by fighting for God. You the knight covered in plate armor take a step backwards from the man covered in rags and get the sudden realization, he may have the wrong faith but nonetheless, he has more faith in his false God than you do in the true God. I think that’d leave a mark inside

Found another very interesting paper, on the physics of life. (Branscomb, E., Biancalani, T., Goldenfeld, N., & Russell, M. 2017, Escapement mechanisms and the conversion of disequilibria; the engines of creation)

Living organisms have to maintain a highly complex internal environment that, left to itself, would degrade over time. Common wisdom is that organisms do so by consuming energy (in sunlight, food, etc.) The paper makes the point that this is not true -- after all, energy is conserved and cannot be consumed or destroyed, only transferred around. What organisms require is "negative entropy", as Schrodinger put it in 1944, or destroying disequilibria, in the wording of Branscomb et al. Now, I'll admit most of the actual explanation goes way above my head. Thankfully, the paper has pictures.

In the universe, there are many gradients or disequilibria, in which a system contains a great unbalance of some quantity: temperature, pressure, salinity, voltage, etc. These gradients always tend to dissipate spontaneously, until the quantity has spread out evenly. If you put hot and cold objects in a box, heat will flow from hot to cold until all is at the same temperature; salt dissolved in a glass of water will spread evenly through its volume; the sun will send out radiation until the pressure at its core is no higher than the surrounding space; and so on. This is the increase of entropy prescribed by thermodynamics (which is often popularized as "increase in disorder", although it includes e.g. crystal growth).

Here's such a gradient. The little balls may represent gas pressure, or salts in a solution, or anything else. Pressure is high on one side of the membrane, and low on the other. If the membrane allows passage, then even completely random motion will produce a net flow of particles from high to low pressure until the gradient is gone and pressure is equalized.

Now here are little gates that flip between states (closed on left vs. closed on right). They do not produce the flow of particles: it proceeds in the same direction as before. In fact, it's the particles that have some control on the gates: they open on the high-pressure side when empty, and open on the low-pressure side when full. That said, the gates can control the flow's rate, by dividing it into discrete little movements.

An organism also has to keep a very steep gradient between itself and its environment. Now, creation of gradients does not occur spontaneously; air in a room isn't going to concentrate into a high-pressure corner all by itself. However, it's possible to build a new gradient if the reaction is coupled with the destruction of another. For example, unbound water flows downhill until it is all at sea level. But sunlight can cause it to evaporate and precipitate back at higher altitude. This is the creation of a new gradient (water at different levels) coupled with the destruction of a greater one (pressure in the Sun's core). Then we can destroy that gradient (let water flow down through a turbine) to create yet another (charged batteries).

There's two conditions to that: 1) the net overall effect must be destruction of gradients over creation: at the end, the universe must contain a little less gradient than before in total (= entropy always increases in isolated systems). And 2) the reactions must be coupled so that the spontaneous gradient destruction can only occur if it helps the non-spontaneous gradient creation (e.g. water is only allowed through the turbine if it makes its rotor spin).

So here's the interesting stuff. In the blue room above, there is a gradient of pressure that can be destroyed. In the red room below, there is none: particle flow in either direction would create a gradient. This would not occur on its own. But now let's couple the barrier gates: the one on bottom opens on the left or right exactly when the one on top does so. Pressure in the blue room only gets an outlet if it creates pressure in the red room; though note that the created gradient must be smaller than the destroyed one.

Enzymes in living cells act like the little gates. They allow spontaneous gradient dissipation, through a series of discrete state changes, in exchange for creating new ones. Like a ratchet, they stop backflow that would dissipate the new forming gradient. Hower, they don't make non-spontaneous reactions occur: enzymes are catalysts, they can widen or lubricate the gate to ease a flow that was already going to occur.

We can then refine the process, by building up the new gradient in multiple steps.

And if the outlet for gradient dissipation is a machine (represented here by the gear), we can use the increase of entropy to do actual mechanical work.

For a practical example, here's how a mitochondrion "makes energy". Dismantling of glucose into carbon dioxide in the citric acid cycle (A) has left around some high-energy electrons, which are carried by a molecule called NADH (B). This molecule gives up its electrons to a series of enzymes inserted in the membrane (C), so that the electrons may ultimately flow into the warm embrace of oxygen, which is reduced to water (D). (The electron-affinity of oxygen drives the flow: this is why we need oxygen to live.) This too is the dissipation of a gradient: the electron bond energy in carbon dioxide and water are much more level than those of glucose and oxygen. Changes in conformation of the enzymes (labelled I, III, and IV), much like the flipping of the gate in the red room, pumps protons (indicated as H+) into the space outside (E). This creates a gradient in proton concentration across the membrane. Protons are given only one outlet to dissipate this gradient: flowing back through the ATP synthase (F). Exactly like water flowing downhill through a turbin, the flow of protons is exploited to build one final gradient, by synthesizing ATP, the universal "energy currency" (actually the "gradient building currency") of the cell.

(Examples of gradients and the entropy-increasing processes that dissipate them. I'd never thought of friction or erosion for gradient-dissipating mechanism -- equalizing momentum and gravitational potential, respectively -- but it makes sense.)

There are two fundamental thermal super-gradients that power every interesting process on Earth: one between our fusion-powered Sun and the cold emptiness of space, the other between the radiogenic heat in Earth's core and, again, space. Both of them ultimately come from gravitational collapse. (The papers mentions two other sources of free energy, cosmic radiation and the gravitational exchange of angular momentum between Earth, Moon, and Sun, but they are negligible in comparison to the first two.)

Differential heating from the Sun causes masses of air to have different buoyancy, creating convective motion (e.g. wind). This creates a disequilibrium in water saturation of air: warm, moist air finds itself rising, cooling, and losing the ability to store so much vapor, while the sea is now in contact with fallen cold, dry air. This new disequilibrium dissipates itself through evaporation and rain, but this creates another disequilibrium by transporting water against gravity, onto continents. Water returns to gravitational equilibrium by flowing back toward the sea, which transports minerals and creates another chemical disequilibrium...

Similarly, nuclear fission in the core causes convective currents in the mantle, which drive plate tectonics, which produces chemical and gravitational disequilibria in the crust (different types of rocks, at different heights), which is rebalanced by erosion thanks to the water cycle, and so on.

Until life shows up, and finds a way to exploit the chemical gradients produced by these two processes, or directly the potential of sunlight.

Life, as mentioned, does not consume energy from the Sun or the core. Every joule of energy that Earth's surface receives, is then radiated away into space as infrared light. If it were not so, the Earth would increase in temperature, glowing hotter and hotter, until its emission of light balanced exactly that received from the Sun. However, while the amount of energy received and leaked is the same, its form is not. The energy that comes to Earth as a single high-frequency photon of visible light leaves in about 20 low-frequency photons of infrared light. (Why 20? Because the Sun's surface is about 20 times hotter than Earth's.)

The 20 outgoing photons have higher entropy than the single incoming photon. This 20-fold increase of entropy -- the dissipation of the thermal gradient between Sun and deep space -- pays for the smaller decrease of entropy on Earth's surface, and thus the formation of complex dissipative structures: plate tectonics, weather, and life.