Signal And The Noise Quotes

I sat in the dark and thought: There’s no big apocalypse. Just an endless procession of little ones.

If people were silent, they could hear the noise of their own lives better. If people were silent, it would make what they did say, whenever they chose to say it, more important. If people were silent, they could read one another's signals, the way underwater creatures flash lights at one another, or turn their skin different colors.

Distinguishing the signal from the noise requires both scientific knowledge and self-knowledge: the serenity to accept the things we cannot predict, the courage to predict the things we can, and the wisdom to know the difference.

The signal is the truth. The noise is what distracts us from the truth.

The world is always ending for someone. It’s a good line. I give it to the father of the child. He says it to his wife. ‘The world is always ending for someone,’ he says. She is trying to quieten the baby, and does not hear him. I doubt that it would matter if she did.

The world is always ending for someone.

And that was that. You don't get to rewind your life like a tape and splice it back together, pretending it never knotted and tore, when it did and you know it did.

Kya remembered, those many years ago, Ma warning her older sisters about young men who overrevved their rusted-out pickups or drove jalopies around with radios blaring. “Unworthy boys make a lot of noise,” Ma had said. She read a consolation for females. Nature is audacious enough to ensure that the males who send out dishonest signals or go from one female to the next almost always end up alone.

The irony is that by being less focused on your results, you may achieve better ones.

We need to stop, and admit it: we have a prediction problem. We love to predict things—and we aren’t very good at it.

We are always living in the final days. What have you got? A hundred years or much, much less until the end of your world.

It is not depression or anxiety that truly hurts us. It is our active resistance against these states of mind and body. If you wake up with low energy, hopeless thoughts, and a lack of motivation - that is a signal from you to you. That is a sure sign that something in your mind or in your life is making you sick, and you must attend to that signal. But what do most people do? They hate their depressed feelings. They think "Why me?" They push them down. They take a pill. And so, the feelings return again and again, knocking at your door with a message while you turn up all the noise in your cave, refusing to hear the knocks. Madness. Open the door. Invite in depression. Invite anxiety. Invite self-hatred. Invite shame. Hear their message. Give them a hug. Accept their tirades as exaggerated mistruths typical of any upset person. Love your darkness and you shall know your light.

One of the pervasive risks that we face in the information age, as I wrote in the introduction, is that even if the amount of knowledge in the world is increasing, the gap between what we know and what we think we know may be widening.

Most of you will have heard the maxim "correlation does not imply causation." Just because two variables have a statistical relationship with each other does not mean that one is responsible for the other. For instance, ice cream sales and forest fires are correlated because both occur more often in the summer heat. But there is no causation; you don't light a patch of the Montana brush on fire when you buy a pint of Haagan-Dazs.

You know you can set fire to the capacity to say.

To find signals in data, we must learn to reduce the noise - not just the noise that resides in the data, but also the noise that resides in us. It is nearly impossible for noisy minds to perceive anything but noise in data.

Nora:"We could have a secret signal to fund each other in the forest! Ren, can you imatate a sloth?" Ren:"Nora?" Nora:"Yeah?" "I don't think sloths make a lot of noise.

In ten years time I’ll be… (dead) sixty.

If political scientists couldn’t predict the downfall of the Soviet Union—perhaps the most important event in the latter half of the twentieth century—then what exactly were they good for?

Shakespeare's plays often turn on the idea of fate, as much drama does. What makes them so tragic is the gap between what his characters might like to accomplish and what fate provides them.

The forest is only waiting for their signal to start trembling, hissing, and roaring from its depths. An enormous, love-maddened, unlighted railway station, full to bursting. Whole trees bristling with living noise makers, mutilated erections, horror.

Wherever there is human judgment there is the potential for bias.

Data Is Useless Without Context

That which doesn't kill us makes us stronger." That's as maybe. But that which does kill us, kills us, and ain't that a bitch...

I hurt people, once.' 'Did they deserve to be hurt?' Grandma touched Meche's chin. 'Don't they always, when you're a girl?

Who knows what I want to do? Who knows what anyone wants to do? How can you be sure about something like that? Isn't it all a question of brain chemistry, signals going back and forth, electrical energy in the cortex? How do you know whether something is really what you want to do or just some kind of nerve impulse in the brain? Some minor little activity takes place somewhere in this unimportant place in one of the brain hemispheres and suddenly I want to go to Montana or I don't want to go to Montana. How do I know I really want to go and it isn't just some neurons firing or something? Maybe it's just an accidental flash in the medulla and suddenly there I am in Montana and I find out I really didn't want to go there in the first place. I can't control what happens in my brain, so how can I be sure what I want to do ten seconds from now, much less Montana next summer? It's all this activity in the brain and you don't know what's you as a person and what's some neuron that just happens to fire or just happens to misfire.

When catastrophe strikes, we look for a signal in the noise - anything that might explain the chaos that we see all around us and bring order to the world again.

The more interviews that an expert had done with the press, Tetlock found, the worse his predictions tended to be.

The story the data tells us is often the one we’d like to hear, and we usually make sure that it has a happy ending.

I toyed briefly with an image someone once mentioned to me, of a village in the shadow of a twin-peaked mountain. In the morning the sun rises. At lunch it sets behind the mountain. In the early afternoon it rises once more. The cocks crow for the second time, and later the sun sets again. No. One peak. Metaphors should not be belaboured.

Economy is not baseball, where the game is always played by the same rules.

Love dies in different ways. For most, it is a slow, agonizing death. Meche, however, cut her love the same way the executioner might chop a head: with a single, accurate swing.

As the statistician George E. P. Box wrote, "All models are wrong, but some models are useful." What he meant by that is that all models are simplifications of the universe, as they must necessarily be. As another mathematician said, "The best model of a cat is a cat." ... The key is in remembering that a model is a tool to help us understand the complexities of the universe, and never a substitute for the universe itself.

The latest technologies are often sexy, but beware of solutions that vendors dress up like trollops, unless you're looking for a one-night stand.

Finding patterns is easy in any kind of data-rich environment; that’s what mediocre gamblers do. The key is in determining whether the patterns represent noise or signal.

You are not dead, until every person who knew you is dead as well." Where did I hear that? It doesn't matter. There is a village in my head.

Why can’t music be magic? Aren’t spells just words you repeat? And what are songs? Lyrics that play over and over again. The words are like a formula.” All

Guys, I just want to remind you I have to be home by seven,” Daniela said. “I’m also not allowed to do any Satanic stuff.” Sebastian

Good innovators typically think very big and they think very small. New ideas are sometimes found in the most granular details of a problem where few others bother to look. And they are sometimes found when you are doing your most abstract and philosophical thinking, considering why the world is the way that it is and whether there might be an alternative to the dominant paradigm. Rarely can they be found in the temperate latitudes between they two spaces, where we spend 99 percent of our lives.

Who needs theory when you have so much information? But this is categorically the wrong attitude to take toward forecasting, especially in a field like economics where the data is so noisy.

Mortality is a hard thing to face. 'That which doesn't kill us makes us stronger.' That's as maybe. But that which does kill us, kills us, and ain't that a bitch...How do you make sense of your life? Signal to noise: what's signal? What's noise?

If there is a mutual distrust between the weather forecaster and the public, the public may not listen when they need to most.

For Popper, a hypothesis was not scientific unless it was falsifiable—meaning that it could be tested in the real world by means of a prediction.

In the distance an elk bull bellowed, the strange screaming noise a signal to a cow as strong as the urine that covered its belly.

You don’t get to rewind your life like a tape and splice it back together, pretending it never knotted and tore, when it did and you know it did.

As John Maynard Keynes said, “The market can stay irrational longer than you can stay solvent.

When they play against each other, the game usually comes down to who can find his opponent’s blind spots first.

We stumble, but we don't fall, and we pick ourselves up and we keep walking -- walking on a road that is built from the bodies and the dreams of those who have gone before us.

Absolutely nothing useful is realized when one person who holds that there is a 0 percent probability of something argues against another person who holds that the probability is 100 percent.

Ever been in love?' The question was direct, matter-of-fact. 'Halfway, half a dozen times. But'—she glanced at the nearest telescope—"there was always so much noise, the signal was hard to find.

When we advance more confident claims and they fail to come to fruition, this constitutes much more powerful evidence against our hypothesis. We can't really blame anyone for losing faith when this occurs

We face danger whenever information growth outpaces our understanding of how to process it. The last forty years of human history imply that it can still take a long time to translate information into useful knowledge, and that if we are not careful, we may take a step back in the meantime.

What makes him successful is the way that he analyzes information. He is not just hunting for patterns. Instead, Bob combines his knowledge of statistics with his knowledge of basketball in order to identify meaningful relationships in the data.

But forecasters often resist considering these out-of-sample problems. When we expand our sample to include events further apart from us in time and space, it often means that we will encounter cases in which the relationships we are studying did not hold up as well as we are accustomed to. The model will seem to be less powerful. It will look less impressive in a PowerPoint presentation (or a journal article or a blog post). We will be forced to acknowledge that we know less about the world than we thought we did. Our personal and professional incentives almost always discourage us from doing this.

The leap is into the Bayesian way of thinking about prediction and probability.

All models are wrong, but some models are useful.”90 What he meant by that is that all models are simplifications of the universe, as they must necessarily be.

We are undoubtedly living with many delusions that we do not even realize.

Signals always come with noise: It is trying to separate out the two that makes the subject interesting.

How can we apply our judgment to the data—without succumbing to our biases?

The litmus test for whether you are a competent forecaster is if more information makes your predictions better.

A forecaster who says he doesn’t care about the science is like the cook who says he doesn’t care about food.

Human beings have an extraordinary capacity to ignore risks that threaten their livelihood, as though this will make them go away.

After adjusting for inflation, a $10,000 investment made in a home in 1896 would be worth just $10,600 in 1996.

What a well-designed forecasting system can do is sort out which statistics are relatively more susceptible to luck; batting average, for instance, is more erratic than home runs.

If my brain can ttell the difference between noise and signal, my heart cannot.

In Mexico City everything returns. The rains and the past and everything in between.

We live in a world in which the only utopian visions arrive in commercial breaks: magical visions of an impossibly hospitable world, peopled by bright-eyed attractive men, women, children...Where nobody dies...Where all it takes is cheap, easily available product -- a packet of salted peanuts or a new type of carpet cleaner -- to bring immediate, undiluted joy.

We may, without even realizing it, work backward to generate persuasive-sounding theories that rationalize them, and these will often fool our friends and colleagues as well as ourselves.

If you compare the number of children who are diagnosed as autistic64 to the frequency with which the term autism has been used in American newspapers,65 you’ll find that there is an almost perfect one-to-one correspondence (figure 7-4), with both having increased markedly in recent years.

The key to making a good forecast, as we observed in chapter 2, is not in limiting yourself to quantitative information. Rather, it’s having a good process for weighing the information appropriately.

In mathematical modeling, as in all of science, we always have to make choices about what to stress and what to ignore. The art of abstraction lies in knowing what is essential and what is minutia, what is signal and what is noise, what is trend and what is wiggle. It's an art because such choices always involve an element of danger; they come close to wishful thinking and intellectual dishonesty.

We are all antennae for creative thought. Some transmissions come on strong, others are more faint. If your antenna isn’t sensitively tuned, you’re likely to lose the data in the noise. Particularly since the signals coming through are often more subtle than the content we collect through sensory awareness. They are energetic more than tactile, intuitively perceived more than consciously recorded.

They're on a cusp; a highly heterogeneous but highly connected--and stressedly connected--civilization. I'm not sure that one approach could encompass the needs of their different systems. The particular stage of communication they're at, combining rapidity and selectivity, usually with something added to the signal and almost always with something missed out, means that what passes for truth often has to travel at the speed of failing memories, changing attitudes, and new generations. Even when this form of handicap is recognized all they ever try to do, as a rule, is codify it, tidy it up. Their attempts of filter become part of the noise, and they seem unable to bring any more thought to bear on the matter than that which leads them to try and simplify what can only be understood by coming to terms with its complexity.

He leaned down and whispered. “I don’t have a puppy-cannon.” “No puppy-cannon?” she echoed. “No. The physics of cannons are actually really unkind for dogs. I can’t endorse the idea, however cuddly it sounds in principle. Although I have to admit that it would make an excellent parliamentary tactic. You could sit in the Ladies’ Gallery. On my signal, when someone said something ridiculous…” He made a noise that sounded something like a rocket.

Signals always point to something. In this sense, a signal is not a thing but a relationship. Data becomes useful knowledge of something that matters when it builds a bridge between a question and an answer. This connection is the signal.

A forecaster should almost never ignore data, especially when she is studying rare events like recessions or presidential elections, about which there isn’t very much data to begin with. Ignoring data is often a tip-off that the forecaster is overconfident, or is overfitting her model—that she is interested in showing off rather than trying to be accurate.

Making predictions based on our beliefs is the best (and perhaps even the only) way to test ourselves. If objectivity is the concern for a greater truth beyond our personal circumstances, and prediction is the best way to examine how closely aligned our personal perceptions are with that greater truth, the most objective among us are those who make the most accurate predictions.

The alchemy that the ratings agencies performed was to spin uncertainty into what looked and felt like risk. They took highly novel securities, subject to an enormous amount of systemic uncertainty, and claimed the ability to quantify just how risky they were. Not only that, but of all possible conclusions, they came to the astounding one that these investments were almost risk-free.

Quite a lot of evidence suggests that aggregate or group forecasts are more accurate than individual ones, often somewhere between 15 and 20 percent more accurate depending on the discipline. That doesn’t necessarily mean the group forecasts are good. (We’ll

This is what comes from the wrong kind of attentiveness. People get brain fade. This is because they've forgotten how to listen and look as children. They've forgotten how to collect data. In the psychic sense a forest fire on TV is on a lower plane than a ten-second spot for Automatic Dishwasher All. The commercial has deeper waves, deeper emanations. But we have reversed the relative significance of these things. This is why people's eyes, ears, brains and nervous systems have grown weary. It's a simple case of misuse.

It’s like we've been flung back in time," he said. "Here we are in the Stone Age, knowing all these great things after centuries of progress but what can we do to make life easier for the Stone Agers? Can we make a refrigerator? Can we even explain how it works? What is electricity? What is light? We experience these things every day of our lives but what good does it do if we find ourselves hurled back in time and we can’t even tell people the basic principles much less actually make something that would improve conditions. Name one thing you could make. Could you make a simple wooden match that you could strike on a rock to make a flame? We think we’re so great and modern. Moon landings, artificial hearts. But what if you were hurled into a time warp and came face to face with the ancient Greeks. The Greeks invented trigonometry. They did autopsies and dissections. What could you tell an ancient Greek that he couldn’t say, ‘Big Deal.’ Could you tell him about the atom? Atom is a Greek word. The Greeks knew that the major events in the universe can’t be seen by the eye of man. It’s waves, it’s rays, it’s particles." “We’re doing all right.” “We’re sitting in this huge moldy room. It’s like we’re flung back.” “We have heat, we have light.” “These are Stone Age things. They had heat and light. They had fire. They rubbed flints together and made sparks. Could you rub flints together? Would you know a flint if you saw one? If a Stone Ager asked you what a nucleotide is, could you tell him? How do we make carbon paper? What is glass? If you came awake tomorrow in the Middle Ages and there was an epidemic raging, what could you do to stop it, knowing what you know about the progress of medicines and diseases? Here it is practically the twenty-first century and you’ve read hundreds of books and magazines and seen a hundred TV shows about science and medicine. Could you tell those people one little crucial thing that might save a million and a half lives?” “‘Boil your water,’ I’d tell them.” “Sure. What about ‘Wash behind your ears.’ That’s about as good.” “I still think we’re doing fairly well. There was no warning. We have food, we have radios.” “What is a radio? What is the principle of a radio? Go ahead, explain. You’re sitting in the middle of this circle of people. They use pebble tools. They eat grubs. Explain a radio.” “There’s no mystery. Powerful transmitters send signals. They travel through the air, to be picked up by receivers.” “They travel through the air. What, like birds? Why not tell them magic? They travel through the air in magic waves. What is a nucleotide? You don’t know, do you? Yet these are the building blocks of life. What good is knowledge if it just floats in the air? It goes from computer to computer. It changes and grows every second of every day. But nobody actually knows anything.

Authors are curators of experience. They filter the world's noise, and out of that noise they make the purest signal they can-out of disorder they create narrative. They administer this narrative in the form of a book, and preside, in some ineffable way, over the reading experience. Yet no matter how pure the data set that authors provide to readers-no matter how diligently prefiltered and tightly reconstructed-readers' brains will continue in their prescribed assignment: to analyze, screen, and sort. Our brains will treat a book as if it were any other of the world's many unfiltered, encrypted signals. That is, the author's book, for readers, reverts to a species of noise. We take in as much of the author's world as we can, and mix this material with our own in the alembic of our reading minds, combining them to alchemize something unique. I would propose that this is why reading "works": reading mirrors the procedure by which we acquaint ourselves with the world. It is not that our narratives necessarily tell us something true about the world (though they might), but rather that the practice of reading feels like, and is like, consciousness itself: imperfect; partial; hazy; co-creative.

The most calamitous failures of prediction usually have a lot in common. We focus on those signals that tell a story about the world as we would like it to be, not how it really is. We ignore the risks that are hardest to measure, even when they pose the greatest threats to our well-being. We make approximations and assumptions about the world that are much cruder than we realize. We abhor uncertainty, even when it is an irreducible part of the problem we are trying to solve.

Introduction to bits. Things are going up on the curb, every few months. Maybe. Bottle of the inside of the lines of the landing, not as we can set of brightness. But the houses get repayed, man. Anywhere. There’s nowhere else to be late at a number of me? But it’s visible from the house. It’s early evening, but it crackles and perhaps they own. It means that perhaps the result of bubbly waiting for a few moments. I have to flinch at the forthcoming disaster strikes. Nathan: He travels. While most of the hoarded seconds of the moon given flesh. Inanna is that they own. That which does the theme afterwards. They become bitter. Not a level on a few moments I see. Thank you. Yeah. Arty stuff.

John P. Ioannidis published a controversial paper titled “Why Most Published Research Findings Are False.”39 The paper studied positive findings documented in peer-reviewed journals: descriptions of successful predictions of medical hypotheses carried out in laboratory experiments. It concluded that most of these findings were likely to fail when applied in the real world. Bayer Laboratories recently confirmed Ioannidis’s hypothesis. They could not replicate about two-thirds of the positive findings claimed in medical journals when they attempted the experiments themselves.40

Chaos is not noise, it’s signal; disorder is not a mistake, it’s a design element. If we view these periods as aberrations, we risk their becoming missed opportunities. If we view them as openings, we just might open up to them. Transitions are not going away; the key to benefiting from them is to not turn away. Don’t shield your eyes when the scary parts start; that’s when the heroes are made.

The “losers” in memory competitions, this research suggests, stumble not because they remember too little. They have studied tens, perhaps hundreds of thousands of words, and often they are familiar with the word they ultimately misspell. In many cases, they stumble because they remember too much. If recollecting is just that—a re-collection of perceptions, facts, and ideas scattered in intertwining neural networks in the dark storm of the brain—then forgetting acts to block the background noise, the static, so that the right signals stand out. The sharpness of the one depends on the strength of the other.

Meanwhile, exposure to so many new ideas was producing mass confusion. The amount of information was increasing much more rapidly than our understanding of what to do with it, or our ability to differentiate the useful information from the mistruths. Paradoxically, the result of having so much more shared knowledge was increasing isolation along national and religious lines. The instinctual shortcut that we take when we have “too much information” is to engage with it selectively, picking out the parts we like and ignoring the remainder, making allies with those who have made the same choices and enemies of the rest.

He sat back, his head against the door of the building. Meche, in turn, rested her head against his shoulder. For others, it might have been an intimate gesture. Maybe it was, but not in the way most people might think. Meche and Sebastian were used to each other, comfortable in their proximity. They folded and kept their dreams in the same drawer, spun fantasies side by side, lived in the easy harmony of youth which did not know the need for tall walls and sturdy defenses.

It is much easier after the event to sort the relevant from the irrelevant signals. After the event, of course, a signal is always crystal clear; we can now see what disaster it was signaling, since the disaster has occurred. But before the event it is obscure and pregnant with conflicting meanings. It comes to the observer embedded in an atmosphere of “noise,” i.e., in the company of all sorts of information that is useless and irrelevant for predicting the particular disaster.

Political experts had difficulty anticipating the USSR’s collapse, Tetlock found, because a prediction that not only forecast the regime’s demise but also understood the reasons for it required different strands of argument to be woven together. There was nothing inherently contradictory about these ideas, but they tended to emanate from people on different sides of the political spectrum,11 and scholars firmly entrenched in one ideological camp were unlikely to have embraced them both.

Risk, as first articulated by the economist Frank H. Knight in 1921,45 is something that you can put a price on. Say that you’ll win a poker hand unless your opponent draws to an inside straight: the chances of that happening are exactly 1 chance in 11.46 This is risk. It is not pleasant when you take a “bad beat” in poker, but at least you know the odds of it and can account for it ahead of time. In the long run, you’ll make a profit from your opponents making desperate draws with insufficient odds. Uncertainty, on the other hand, is risk that is hard to measure. You might have some vague awareness of the demons lurking out there. You might even be acutely concerned about them. But you have no real idea how many of them there are or when they might strike. Your back-of-the-envelope estimate might be off by a factor of 100 or by a factor of 1,000; there is no good way to know. This is uncertainty. Risk greases the wheels of a free-market economy; uncertainty grinds them to a halt.

Johannes Gutenberg’s invention in 1440 made information available to the masses, and the explosion of ideas it produced had unintended consequences and unpredictable effects. It was a spark for the Industrial Revolution in 1775,1 a tipping point in which civilization suddenly went from having made almost no scientific or economic progress for most of its existence to the exponential rates of growth and change that are familiar to us today. It set in motion the events that would produce the European Enlightenment and the founding of the American Republic. But the printing press would first produce something else: hundreds of years of holy war. As mankind came to believe it could predict its fate and choose its destiny, the bloodiest epoch in human history followed.2

She understood that pain was necessary in the world, a sense as critical as sight or hearing. It functioned to keep people safe, a very persuasive stop sign. In a way it was the mother to us all, slapping us back from the hot stove, forcing us to put down the sharp knife, teaching us self-preservation, training care into our bones. Pain was the reason we were alive. It was why as children we didn't toss ourselves down the staircase for the thrill of the ride, didn't stop eating just to bother our parents, didn't nibble off our fingertips to examine our insides. Pain made our existence in this world possible, opened life up to us... Unstoppable pain was different. The sensation in this case was not a mother. It was an abuser. It taught nothing. Instead it wrapped itself around the ribs, settled on the shoulders, a weight to be borne, making it hard to breathe or talk.

I AM NOT SO INTELLIGENT The epiphany I had in my career in randomness came when I understood that I was not intelligent enough, nor strong enough, to even try to fight my emotions. Besides, I believe that I need my emotions to formulate my ideas and get the energy to execute them. I am just intelligent enough to understand that I have a predisposition to be fooled by randomness—and to accept the fact that I am rather emotional. I am dominated by my emotions—but as an aesthete, I am happy about that fact. I am just like every single character whom I ridiculed in this book. Not only that, but I may be even worse than them because there may be a negative correlation between beliefs and behavior (recall Popper the man). The difference between me and those I ridicule is that I try to be aware of it. No matter how long I study and try to understand probability, my emotions will respond to a different set of calculations, those that my unintelligent genes want me to handle. If my brain can tell the difference between noise and signal, my heart cannot. Such unintelligent behavior does not just cover probability and randomness. I do not think I am reasonable enough to avoid getting angry when a discourteous driver blows his horn at me for being one nanosecond late after a traffic light turns green. I am fully aware that such anger is self-destructive and offers no benefit, and that if I were to develop anger for every idiot around me doing something of the sort, I would be long dead. These small daily emotions are not rational. But we need them to function properly. We are designed to respond to hostility with hostility. I have enough enemies to add some spice to my life, but I sometimes wish I had a few more (I rarely go to the movies and need the entertainment). Life would be unbearably bland if we had no enemies on whom to waste efforts and energy.

For several months they'd been drifting toward political involvement, but the picture was hazy and one of the most confusing elements was their geographical proximity to Berkeley, the citadel of West Coast radicalism. Berkeley is right next door to Oakland, with nothing between them but a line on the map and a few street signs, but in many ways they are as different as Manhattan and the Bronx. Berkeley is a college town and, like Manhattan, a magnet for intellectual transients. Oakland is a magnet for people who want hour-wage jobs and cheap housing, who can't afford to live in Berkeley, San Francisco or any of the middle-class Bay Area suburbs. [10] It is a noisy, ugly, mean-spirited place, with the sort of charm that Chicago had for Sandburg. It is also a natural environment for hoodlums, brawlers, teenage gangs and racial tensions. The Hell's Angels' massive publicity -- coming hard on the heels of the widely publicized student rebellion in Berkeley -- was interpreted in liberal-radical-intellectual circles as the signal for a natural alliance. Beyond that, the Angels' aggressive, antisocial stance -- their alienation, as it were -- had a tremendous appeal for the more aesthetic Berkeley temperament. Students who could barely get up the nerve to sign a petition or to shoplift a candy bar were fascinated by tales of the Hell's Angels ripping up towns and taking whatever they wanted. Most important, the Angels had a reputation for defying police, for successfully bucking authority, and to the frustrated student radical this was a powerful image indeed. The Angels didn't masturbate, they raped. They didn't come on with theories and songs and quotations, but with noise and muscle and sheer balls.

One article on reproductive strategies was titled "Sneaky Fuckers." Kya laughed. As is well known, the article began, in nature, usually the males with the most prominent secondary sexual characteristics, such as the biggest antlers, deepest voices, broadest chests, and superior knowledge secure the best territories because they have fended off weaker males. The females choose to mate with these imposing alphas and are thereby inseminated with the best DNA around, which is passed on to the female's offspring- one of the most powerful phenomena in the adaptation and continuance of life. Plus, the females get the best territory for their young. However, some stunted males, not strong, adorned, or smart enough to hold good territories, possess bags of tricks to fool the females. They parade their smaller forms around in pumped-up postures or shout frequently- even if in shrill voices. By relying on pretense and false signals, they manage to grab a copulation here or there. Pint-sized male bullfrogs, the author wrote, hunker down in the grass and hide near an alpha male who is croaking with great gusto to call in mates. When several females are attracted to his strong vocals at the same time, and the alpha is busy copulating with one, the weaker male leaps in and mates one of the others. The imposter males were referred to as "sneaky fuckers." Kya remembered, those many years ago, Ma warning her older sisters about young men who overrevved their rusted-out pickups or drove jalopies around with radios blaring. "Unworthy boys make a lot of noise," Ma had said. She read a consolation for females. Nature is audacious enough to ensure that the males who send out dishonest signals or go from one female to the next almost always end up alone. Another article delved into the wild rivalries between sperm. Across most life-forms, males compete to inseminate females. Male lions occasionally fight to the death; rival bull elephants lock tusks and demolish the ground beneath their feet as they tear at each other's flesh. Though very ritualized, the conflicts can still end in mutilations. To avoid such injuries, inseminators of some species compete in less violent, more creative methods. Insects, the most imaginative. The penis of the male damselfly is equipped with a small scoop, which removes sperm ejected by a previous opponent before he supplies his own. Kya dropped the journal on her lap, her mind drifting with the clouds. Some female insects eat their mates, overstressed mammal mothers abandon their young, many males design risky or shifty ways to outsperm their competitors. Nothing seemed too indecorous as long as the tick and the tock of life carried on. She knew this was not a dark side to Nature, just inventive ways to endure against all odds. Surely for humans there was more.

Metalearning: First Draw a Map. Start by learning how to learn the subject or skill you want to tackle. Discover how to do good research and how to draw on your past competencies to learn new skills more easily. Focus: Sharpen Your Knife. Cultivate the ability to concentrate. Carve out chunks of time when you can focus on learning, and make it easy to just do it. Directness: Go Straight Ahead. Learn by doing the thing you want to become good at. Don’t trade it off for other tasks, just because those are more convenient or comfortable. Drill: Attack Your Weakest Point. Be ruthless in improving your weakest points. Break down complex skills into small parts; then master those parts and build them back together again. Retrieval: Test to Learn. Testing isn’t simply a way of assessing knowledge but a way of creating it. Test yourself before you feel confident, and push yourself to actively recall information rather than passively review it. Feedback: Don’t Dodge the Punches. Feedback is harsh and uncomfortable. Know how to use it without letting your ego get in the way. Extract the signal from the noise, so you know what to pay attention to and what to ignore. Retention: Don’t Fill a Leaky Bucket. Understand what you forget and why. Learn to remember things not just for now but forever. Intuition: Dig Deep Before Building Up. Develop your intuition through play and exploration of concepts and skills. Understand how understanding works, and don’t recourse to cheap tricks of memorization to avoid deeply knowing things. Experimentation: Explore Outside Your Comfort Zone. All of these principles are only starting points. True mastery comes not just from following the path trodden by others but from exploring possibilities they haven’t yet imagined.

Flow is an extremely potent response to external events and requires an extraordinary set of signals. The process includes dopamine, which does more than tune signal-to-noise ratios. Emotionally, we feel dopamine as engagement, excitement, creativity, and a desire to investigate and make meaning out of the world. Evolutionarily, it serves a similar function. Human beings are hardwired for exploration, hardwired to push the envelope: dopamine is largely responsible for that wiring. This neurochemical is released whenever we take a risk or encounter something novel. It rewards exploratory behavior. It also helps us survive that behavior. By increasing attention, information flow, and pattern recognition in the brain, and heart rate, blood pressure, and muscle firing timing in the body, dopamine serves as a formidable skill-booster as well. Norepinephrine provides another boost. In the body, it speeds up heart rate, muscle tension, and respiration, and triggers glucose release so we have more energy. In the brain, norepinephrine increases arousal, attention, neural efficiency, and emotional control. In flow, it keeps us locked on target, holding distractions at bay. And as a pleasure-inducer, if dopamine’s drug analog is cocaine, norepinephrine’s is speed, which means this enhancement comes with a hell of a high. Endorphins, our third flow conspirator, also come with a hell of a high. These natural “endogenous” (meaning naturally internal to the body) opiates relieve pain and produce pleasure much like “exogenous” (externally added to the body) opiates like heroin. Potent too. The most commonly produced endorphin is 100 times more powerful than medical morphine. The next neurotransmitter is anandamide, which takes its name from the Sanskrit word for “bliss”—and for good reason. Anandamide is an endogenous cannabinoid, and similarly feels like the psychoactive effect found in marijuana. Known to show up in exercise-induced flow states (and suspected in other kinds), this chemical elevates mood, relieves pain, dilates blood vessels and bronchial tubes (aiding respiration), and amplifies lateral thinking (our ability to link disparate ideas together). More critically, anandamide also inhibits our ability to feel fear, even, possibly, according to research done at Duke, facilitates the extinction of long-term fear memories. Lastly, at the tail end of a flow state, it also appears (more research needs to be done) that the brain releases serotonin, the neurochemical now associated with SSRIs like Prozac. “It’s a molecule involved in helping people cope with adversity,” Oxford University’s Philip Cowen told the New York Times, “to not lose it, to keep going and try to sort everything out.” In flow, serotonin is partly responsible for the afterglow effect, and thus the cause of some confusion. “A lot of people associate serotonin directly with flow,” says high performance psychologist Michael Gervais, “but that’s backward. By the time the serotonin has arrived the state has already happened. It’s a signal things are coming to an end, not just beginning.” These five chemicals are flow’s mighty cocktail. Alone, each packs a punch, together a wallop.

And if you wish to receive of the ancient city an impression with which the modern one can no longer furnish you, climb—on the morning of some grand festival, beneath the rising sun of Easter or of Pentecost—climb upon some elevated point, whence you command the entire capital; and be present at the wakening of the chimes. Behold, at a signal given from heaven, for it is the sun which gives it, all those churches quiver simultaneously. First come scattered strokes, running from one church to another, as when musicians give warning that they are about to begin. Then, all at once, behold!—for it seems at times, as though the ear also possessed a sight of its own,—behold, rising from each bell tower, something like a column of sound, a cloud of harmony. First, the vibration of each bell mounts straight upwards, pure and, so to speak, isolated from the others, into the splendid morning sky; then, little by little, as they swell they melt together, mingle, are lost in each other, and amalgamate in a magnificent concert. It is no longer anything but a mass of sonorous vibrations incessantly sent forth from the numerous belfries; floats, undulates, bounds, whirls over the city, and prolongs far beyond the horizon the deafening circle of its oscillations. Nevertheless, this sea of harmony is not a chaos; great and profound as it is, it has not lost its transparency; you behold the windings of each group of notes which escapes from the belfries. You can follow the dialogue, by turns grave and shrill, of the treble and the bass; you can see the octaves leap from one tower to another; you watch them spring forth, winged, light, and whistling, from the silver bell, to fall, broken and limping from the bell of wood; you admire in their midst the rich gamut which incessantly ascends and re-ascends the seven bells of Saint-Eustache; you see light and rapid notes running across it, executing three or four luminous zigzags, and vanishing like flashes of lightning. Yonder is the Abbey of Saint-Martin, a shrill, cracked singer; here the gruff and gloomy voice of the Bastille; at the other end, the great tower of the Louvre, with its bass. The royal chime of the palace scatters on all sides, and without relaxation, resplendent trills, upon which fall, at regular intervals, the heavy strokes from the belfry of Notre-Dame, which makes them sparkle like the anvil under the hammer. At intervals you behold the passage of sounds of all forms which come from the triple peal of Saint-Germain-des-Prés. Then, again, from time to time, this mass of sublime noises opens and gives passage to the beats of the Ave Maria, which bursts forth and sparkles like an aigrette of stars. Below, in the very depths of the concert, you confusedly distinguish the interior chanting of the churches, which exhales through the vibrating pores of their vaulted roofs. Assuredly, this is an opera which it is worth the trouble of listening to. Ordinarily, the noise which escapes from Paris by day is the city speaking; by night, it is the city breathing; in this case, it is the city singing. Lend an ear, then, to this concert of bell towers; spread over all the murmur of half a million men, the eternal plaint of the river, the infinite breathings of the wind, the grave and distant quartette of the four forests arranged upon the hills, on the horizon, like immense stacks of organ pipes; extinguish, as in a half shade, all that is too hoarse and too shrill about the central chime, and say whether you know anything in the world more rich and joyful, more golden, more dazzling, than this tumult of bells and chimes;—than this furnace of music,—than these ten thousand brazen voices chanting simultaneously in the flutes of stone, three hundred feet high,—than this city which is no longer anything but an orchestra,—than this symphony which produces the noise of a tempest.