Welcome back to A Little Wiser! We hope you’re having a lovely week. As always, please feel free to reply with any feedback. We love hearing your ideas, questions, and, of course, any features you’d love to see us bring to the Athenaeum!

Today’s wisdom explores:

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Moore's Law and the Prophecy That Built the Modern World
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The Council That Defined Christianity
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The Science of the Runner's High
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Grab your coffee and let’s dive in.

In 1965, an engineer named Gordon Moore was asked by a trade magazine to predict how computing might develop over the coming decade. Looking at just five data points, he noticed something fascinating. The number of tiny electronic switches, called transistors, that engineers could pack onto a single chip had been roughly doubling every year. He boldly extrapolated that trend into the future. A decade later, by then a co-founder of Intel, he revised the pace to a doubling roughly every two years. This simple observation became known as Moore's Law and the steady doubling is what produced the exponential explosion of computing power behind almost everything in modern life, from the smartphone in your pocket to the servers running the internet.

Doubling something over and over produces increases that quickly become almost incomprehensible, which is why a computer chip today is millions of times more powerful than one from the 1970s. Transistors have shrunk from being measured in millimeters in the 1940s to just a handful of nanometers now, a reduction of over a hundred thousand times. A modern chip crams a mind-bending number of switches into a space smaller than a fingernail. To grasp the scale, one of the most transistor-dense processors available in 2025, a graphics chip built for artificial intelligence, holds more than 92 billion transistors on a single piece of silicon. Perhaps the most remarkable part is that this doubling came with falling costs. Computing became dramatically cheaper at the same time, which is what put a supercomputer in the hands of ordinary people.

The great question now is whether the prophecy is finally running out of road. Moore himself always knew it could not last forever, because transistors cannot shrink indefinitely. Engineers are now building features so small they are approaching the size of individual atoms, where the strange rules of quantum physics begin to interfere with how the switches work. The familiar cadence of doubling has visibly slowed, and each new step forward is now brutally expensive and difficult, with a single cutting-edge chip factory costing tens of billions of dollars to build. Many have declared Moore's Law dead, yet the reality is subtler as the industry has kept finding clever ways around the wall. Rather than simply cramming transistors closer together, engineers now stack chips vertically, break processors into smaller specialized pieces called chiplets, and design custom silicon tailored to specific jobs like running AI. The relentless pace of raw miniaturization may be fading, but the deeper spirit of Moore's Law, the expectation of steady exponential progress, has proven remarkably stubborn.

In the year 325, the Roman Emperor Constantine summoned around 300 Christian bishops from across his sprawling empire to the city of Nicaea, in what is now Turkey. The gathering would shape the beliefs of billions of people for the next seventeen centuries. Constantine had recently legalized Christianity after centuries of persecution and now saw the faith as a potential glue to bind his fractious empire together. The emperor, who was not even baptized himself and understood little of the finer points of doctrine, cared less about who was right than about restoring unity and peace. He paid for the bishops to travel, hosted them, and personally opened the proceedings. This made it the first "ecumenical" council, the first attempt to gather representatives of the whole Christian world to agree on what Christians actually believed.

The dispute at the heart of it all was deceptively simple to state and explosive in its implications. A priest from Alexandria named Arius had been teaching that Jesus, the Son, was created by God the Father, and was therefore not eternal and not fully equal to God, but rather a lesser, subordinate being. This view, known as Arianism, had spread widely and won many followers. Opposing him fiercely was a faction championing the view that the Son was co-eternal and of the very same divine substance as the Father, uncreated and fully God, a cause the young deacon Athanasius would come to embody. The debate grew so heated that Arius was reportedly struck in the face during the arguments.

The council came down decisively against Arius. After weeks of debate, the bishops rejected Arianism as heresy and produced a formal statement of belief, the famous Nicene Creed, still recited in churches around the world today. Its crucial move was to describe the Son as homoousios, a Greek word meaning "of the same substance" as the Father, a single term deliberately chosen to slam the door on any idea that Jesus was created or inferior. Arius was banished and his writings ordered burned. The council also settled a long-running practical dispute by fixing the date of Easter, decreeing it should fall on the first Sunday after the first full moon following the spring equinox, which is why the holiday still moves around the calendar each year. Yet the neat story of a matter settled forever is a myth, because the fight was far from over. Constantine himself later softened toward the Arians and was, in a final irony, baptized on his deathbed by an Arian bishop. Arianism remained a powerful force for decades, even becoming the official orthodoxy of the Eastern empire for a time, until another council reaffirmed Nicaea's verdict in 381.

For anyone who has pushed through a long run and felt a sudden, unexpected wave of euphoria wash over them, the sensation is unforgettable. The runner's high is real, and it describes a cluster of feelings that arrive during sustained endurance exercise: a rush of well-being, a melting away of anxiety, a strange dulling of pain, and a deep sense of calm. Some runners feel bright, effortless bliss, others simply notice their worries quieten, and many finish a hard run with nothing they would call a high at all. For those who do experience it, the effect can be profound enough to explain why some people become genuinely hooked on running, chasing a feeling their body seems to hand out as a reward for endurance.

For nearly fifty years, the explanation seemed settled, and you have almost certainly heard it. The high was credited to endorphins, the body's natural opioid painkillers, whose name is a blend of "endogenous" and "morphine." Exercise does raise the level of these endorphins in the bloodstream, and since opioids are linked to pleasure and pain relief, the story felt intuitive and was repeated everywhere. There was, however, a glaring problem hiding in plain sight. Endorphins are large, water-soluble molecules, and they cannot easily cross the blood-brain barrier, the highly selective filter that guards the brain from the bloodstream. A rise of endorphins in the blood cannot, by itself, produce a feeling generated inside the brain, which meant the classic explanation was built on a shaky foundation from the start.

The decisive evidence came from a clever experiment. Researchers gave runners a drug called naltrexone, which blocks the body's opioid receptors, reasoning that if endorphins truly caused the high, blocking them should erase the euphoria. It did not. The runners still felt the familiar rush and calm, proving the endorphin pathway was not required. Attention has now turned to a different set of chemicals, the endocannabinoids, the body's own cannabis-like signaling molecules, which act on the very same receptors that marijuana's THC targets. The leading candidate is one called anandamide, aptly named after the Sanskrit word for "bliss." Unlike endorphins, anandamide is fat-soluble, so it slips across the blood-brain barrier with ease, and it rises sharply during sustained aerobic exercise. Studies in mice bred to lack cannabinoid receptors show they do not gain the calming, pain-dulling benefits of running, which points to these molecules as the real drivers. Endorphins were not a myth so much as a misattribution, and the full experience likely involves several brain systems working in concert, with dopamine and other chemicals joining the party.

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The A Little Wiser Team