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How Fighter Jets Lock On (and How the Targets Know)
The primary technology that a military aircraft uses to lock and track an enemy aircraft is its onboard radar. Aircraft radars typically have two modes: search and track. In search mode, the radar sweeps a radio beam across the sky in a zig-zag pattern. When the radio beam is reﬂected by a target aircraft, an indication is shown on the radar display. In search mode, no single aircraft is being tracked, but the pilot can usually tell generally what a particular radar return is doing because with each successive sweep, the radar return moves slightly. This is an example of the ﬁre control radar display for an F-16 Fighting Falcon when the radar is in a search mode:Each white brick is a radar return. Because the radar is only scanning, not tracking, no other information is available about the radar targets. (There is one exception: The Doppler shift of the radar return can be measured, to estimate how fast the aircraft traveling towards or away from you, much like the pitch of an oncoming train’s whistle can tell you how fast it’s coming at you. This is displayed as the small white trend line originating from each brick.)Note that the cursors are over the bottom-most brick (closest to our aircraft). The pilot is ready to lock up this target. This will put the radar into a track mode. In track mode, the radar focuses its energy on a particular target. Because the radar is actually tracking a target, and not just displaying bricks when it gets a reﬂection back, it can tell the pilot a lot more about the target. This is what the F-16′s ﬁre control radar display looks like when a target is locked:G/O Media may get a commission15% off Your First OrderGet it for $11 at Hum Nutrition Along the top we have a lot of information about what our radar target is doing:Its aspect angle (angle between its nose position and our nose position) is 160° to the left,and our closure rate is 828 knots. With this information, the pilot gets a much better idea of what the aircraft is doing, but at the expense of information about other aircraft in the area.Note that in the above picture, the bottom-most (closest) target is locked (circle around it), the two targets further away are tracked (yellow squares), and there are two radar returns even further away (white bricks). This is demonstrating an advanced feature of modern radars, situational awareness modes. A radar in SAM combines both tracking and scanning to allow a pilot to track one or a small number of “interesting” targets while not losing the big picture of what other targets are doing. In this mode, the radar beam sweeps the sky, while brieﬂy and regularly pausing its scan to check up on a locked target.Note that all of this comes with tradeoffs. In the end, a radar is only as powerful as it is, and you can put a lot of radar energy on one target, or spread it out weakly throughout the sky, or some compromise in between. In the above photo you can see two vertical bars spanning the height of the display — these are the azimuth scan limits. It’s the aircraft’s way of telling you, “OK, I can both track this target, and scan for other targets, but in return, I’m only going to scan a 40° wide cone in front of the aircraft, instead of the usual 60°. Radar, like life, is full of tradeoffs.An important thing to note is that a radar lock is not always required to launch weapons at a target. For guns kills, if the aircraft has a radar lock on a target, it can accurately gauge range to the target, and provide the pilot with the appropriate corrections for lead and gravity drop, to get an accurate guns kill. Without the radar, the pilot simply has to rely on his or her own judgement.As an example of that, let’s take a look at the F-16′s HUD (heads-up display) when in the process of employing guns at a radar-locked target:It becomes incredibly simple; that small circle labeled “bullets at target range” is called the “death dot” by F-16 pilots. Basically, it represents where the cannon rounds would land if you ﬁred right now, and the rounds traveled the distance between you and the locked target. In other words, if you want a solid guns kill, simply ﬂy the death dot onto the airplane. Super simple.But what if there’s no radar lock? Well now the HUD looks like this:No death dot — but you still have the funnel. The funnel represents the path the cannon rounds would travel out in front of you if you ﬁred right now. The width of the funnel is equal to the apparent width of a predetermined wingspan at that particular range. So, if you didn’t have a lock on your target, but you knew it had a wingspan of 35 feet, you could dial in 35 feet, then ﬂy the funnel until the width exactly lined up with the width of the enemy aircraft’s wings, then squeeze the trigger.And what about missiles? Again, a radar lock is not required. For heat-seeking missiles, a radar lock is only used to train the seeker head onto the target. Without a radar lock, the seeker head scans the sky looking for “bright” (hot) objects, and when it ﬁnds one, it plays a distinctive whining tone to the pilot. The pilot does not need radar in this case, he just needs to maneuver his aircraft until he has “good tone,” and then ﬁre the missile. The radar only makes this process faster.Now, radar-guided missiles come in two varieties: passive and active. Passive radar missiles do require a radar lock, because these missiles use the aircraft’s reﬂected radar energy to track the target.Active radar missiles however have their own onboard radar, which locks and tracks a target. But this radar is on a one-way trip, so it’s considerably less expensive (and less powerful) than the aircraft’s radar. So, these missiles normally get some guidance help from the launching aircraft until they ﬂy close enough to the target where they can turn on their own radar and “go active.” (This allows the launching aircraft to turn away and defend itself.) It is possible to ﬁre an active radar missile with no radar lock (so-called “maddog”); in this case, the missile will ﬂy until it’s nearly out of fuel, and then it will turn on its radar and pursue the ﬁrst target it sees. This is not a recommended strategy if there are friendly aircraft in close proximity to the enemy.As to the last part of your question — yes, an aircraft can tell if a radar is painting it or locked onto it. Radar is just radio waves, and just as your FM radio converts radio waves into sound, so can an aircraft analyze incoming radio signals to ﬁgure out who’s doing what. This is called an RWR, or radar warning receiver, and has both a video and audio component. This is a typical RWR display:Although an aircraft’s radar can only scan out in front of the aircraft, an aircraftcan listen for incoming radar signals in any direction, so the scope is 360°. A digital signal processor looks for recognizable radio “chirps” that correspond to known radars, and displays their azimuth on the scope. A chirp is a distinctive waveform that a radio uses. See, if two radios use the same waveform simultaneously, they’ll confuse each other, because each radio won’t know which radar returns are from its own transmitter. To prevent this, different radios tend to use distinct waveforms. This can also be used by the target aircraft to identify the type of radar being used, and therefore possibly, the type of aircraft.In this display, the RWR has detected an F-15 (15 with a hat on it indicating aircraft) at the 7-o’clock position. The strength of the radar is plotted as distance from the center — the closer to the center, the stronger the detected radar signal, and therefore possibly the closer the transmitting aircraft.Detected at the 12- to 1-o’clock position are two surface-to-air missile (SAM) sites, an SA-5 “Gammon” and an SA-6 “Gainful”. These are Russian SAM launching radars and represent a serious threat. The RWR computer has determined the SA-6 to be the highest priority threat in the area, and thus has enclosed it with a diamond.RWR also has an audio component. Each time a new radar signal is detected, it is converted into an audio wave and played for the pilot. Because different radars “sound” different, pilots learn to recognize different airborne or surface threats by their distinctive tones. The sound is also an important cue to tell the pilot what the radar is doing: If the sound plays once, or intermittently, it means the radar is only painting our aircraft (in search mode). If a sound plays continuously, the radar has locked onto our aircraft and is in track mode, and thus the pilot’s immediate attention is demanded. In some cases, the RWR can tell if the radar is in launch mode (sending radar data to a passive radar-guided missile), or if the radar is that of an active radar-guided missile. In either of these cases, a distinctive missile launch tone is played and the pilot is advised to immediately act to counter the threat. Note that the RWR has no way of knowing if a heat-seeking missile is on its way to our aircraft.Aside from radar, there are other technologies that are used to lock on to enemy aircraft and ground targets. A targeting pod is a very powerful camera mounted on an articulating swivel that allows it to look in nearly every direction. This camera is connected to image processor that is able to tell apart vehicles and buildings from surrounding terrain, and track moving targets. This is the SNIPER XR targeting pod:And this is what the pilot sees when he operates it:The pod is able to track vehicles day and night, using visual or infra-red cameras. Heat-seeking missiles obviously use this same technology to home in on aircraft, and electro-optical missiles use this technology to track ground targets.Lastly, there are laser-guided missiles as well. These “beam riders” follow a laser beam emanating from the aircraft to the target. Many ground vehicles use laser rangeﬁnders as well, and some aircraft include a laser warning system (LWS) that works similarly to an RWR, but displays incoming laser signals instead.How does a ﬁghter jet lock onto and keep track of an enemy aircraft?originally appeared on Quora. You can follow Quora on Twitter, Facebook, and Google+.This answer has been lightly edited for grammar and clarity.
This article was published online on March 10, 2021.
The United States had long been a holdout among Western democracies, uniquely and perhaps even suspiciously devout. From 1937 to 1998, church membership remained relatively constant, hovering at about 70 percent. Then something happened. Over the past two decades, that number has dropped to less than 50 percent, the sharpest recorded decline in American history. Meanwhile, the “nones”—atheists, agnostics, and those claiming no religion—have grown rapidly and today represent a quarter of the population.
But if secularists hoped that declining religiosity would make for more rational politics, drained of faith’s inﬂaming passions, they are likely disappointed. As Christianity’s hold, in particular, has weakened, ideological intensity and fragmentation have risen. American faith, it turns out, is as fervent as ever; it’s just that what was once religious belief has now been channeled into political belief. Political debates over what America is supposed to mean have taken on the character of theological disputations. This is what religion without religion looks like.
Not so long ago, I could comfort American audiences with a contrast: Whereas in the Middle East, politics is war by other means—and sometimes is literal war—politics in America was less existentially fraught. During the Arab Spring, in countries like Egypt and Tunisia, debates weren’t about health care or taxes—they were, with sometimes frightening intensity, about foundational questions: What does it mean to be a nation? What is the purpose of the state? What is the role of religion in public life? American politics in the Obama years had its moments of ferment—the Tea Party and tan suits—but was still relatively boring.
We didn’t realize how lucky we were. Since the end of the Obama era, debates over what it means to be American have become suffused with a fervor that would be unimaginable in debates over, say, Belgian-ness or the “meaning” of Sweden. It’s rare to hear someone accused of being un-Swedish or un-British—but un-American is a common slur, slung by both left and right against the other. Being called un-American is like being called “un-Christian” or “un-Islamic,” a charge akin to heresy.
From the October 2018 issue: The Constitution is threatened by tribalism
This is because America itself is “almost a religion,” as the Catholic philosopher Michael Novak once put it, particularly for immigrants who come to their new identity with the zeal of the converted. The American civic religion has its own founding myth, its prophets and processions, as well as its scripture—the Declaration of Independence, the Constitution, and The Federalist Papers. In his famous “I Have a Dream” speech, Martin Luther King Jr. wished that “one day this nation will rise up and live out the true meaning of its creed.” The very idea that a nation might have a creed—a word associated primarily with religion—illustrates the uniqueness of American identity as well as its predicament.
The notion that all deeply felt conviction is sublimated religion is not new. Abraham Kuyper, a theologian who served as the prime minister of the Netherlands at the dawn of the 20th century, when the nation was in the early throes of secularization, argued that all strongly held ideologies were effectively faith-based, and that no human being could survive long without some ultimate loyalty. If that loyalty didn’t derive from traditional religion, it would ﬁnd expression through secular commitments, such as nationalism, socialism, or liberalism. The political theorist Samuel Goldman calls this “the law of the conservation of religion”: In any given society, there is a relatively constant and ﬁnite supply of religious conviction. What varies is how and where it is expressed.
No longer explicitly rooted in white, Protestant dominance, understandings of the American creed have become richer and more diverse—but also more fractious. As the creed fragments, each side seeks to exert exclusivist claims over the other. Conservatives believe that they are faithful to the American idea and that liberals are betraying it—but liberals believe, with equal certitude, that they are faithful to the American idea and that conservatives are betraying it. Without the common ground produced by a shared external enemy, as America had during the Cold War and brieﬂy after the September 11 attacks, mutual antipathy grows, and each side becomes less intelligible to the other. Too often, the most bitter divides are those within families.
No wonder the newly ascendant American ideologies, having to ﬁll the vacuum where religion once was, are so divisive. They are meant to be divisive. On the left, the “woke” take religious notions such as original sin, atonement, ritual, and excommunication and repurpose them for secular ends. Adherents of wokeism see themselves as challenging the long-dominant narrative that emphasized the exceptionalism of the nation’s founding. Whereas religion sees the promised land as being above, in God’s kingdom, the utopian left sees it as being ahead, in the realization of a just society here on Earth. After Supreme Court Justice Ruth Bader Ginsburg died in September, droves of mourners gathered outside the Supreme Court—some kneeling, some holding candles—as though they were at the Western Wall.
On the right, adherents of a Trump-centric ethno-nationalism still drape themselves in some of the trappings of organized religion, but the result is a movement that often looks like a tent revival stripped of Christian witness. Donald Trump’s boisterous rallies were more focused on blood and soil than on the son of God. Trump himself played both savior and martyr, and it is easy to marvel at the hold that a man so imperfect can have on his soldiers. Many on the right ﬁnd solace in conspiracy cults, such as QAnon, that tell a religious story of earthly corruption redeemed by a godlike force.
From the June 2020 issue: Adrienne LaFrance on the prophecies of Q
Though the United States wasn’t founded as a Christian nation, Christianity was always intertwined with America’s self-definition. Without it, Americans—conservatives and liberals alike—no longer have a common culture upon which to fall back.
Unfortunately, the various strains of wokeism on the left and Trumpism on the right cannot truly ﬁll the spiritual void—what the journalist Murtaza Hussain calls America’s “God-shaped hole.” Religion, in part, is about distancing yourself from the temporal world, with all its imperfection. At its best, religion confers relief by withholding ﬁnal judgments until another time—perhaps until eternity. The new secular religions unleash dissatisfaction not toward the possibilities of divine grace or justice but toward one’s fellow citizens, who become embodiments of sin—“deplorables” or “enemies of the state.”
This is the danger in transforming mundane political debates into metaphysical questions. Political questions are not metaphysical; they are of this world and this world alone. “Some days are for dealing with your insurance documents or ﬁghting in the mud with your political opponents,” the political philosopher Samuel Kimbriel recently told me, “but there are also days for solemnity, or fasting, or worship, or feasting—things that remind us that the world is bigger than itself.”
Absent some new religious awakening, what are we left with? One alternative to American intensity would be a world-weary European resignation. Violence has a way of taming passions, at least as long as it remains in active memory. In Europe, the terrors of the Second World War are not far away. But Americans must go back to the Civil War for violence of comparable scale—and for most Americans, the violence of the Civil War bolsters, rather than undermines, the national myth of perpetual progress. The war was redemptive—it led to a place of promise, a place where slavery could be abolished and the nation made whole again. This, at least, is the narrative that makes the myth possible to sustain.
For better and worse, the United States really is nearly one of a kind. France may be the only country other than the United States that believes itself to be based on a unifying ideology that is both unique and universal—and avowedly secular. The French concept of laïcité requires religious conservatives to privilege being French over their religious commitments when the two are at odds. With the rise of the far right and persistent tensions regarding Islam’s presence in public life, the meaning of laïcité has become more controversial. But most French people still hold ﬁrm to their country’s founding ideology: More than 80 percent favor banning religious displays in public, according to one recent poll.
In democracies without a pronounced ideological bent, which is most of them, nationhood must instead rely on a shared sense of being a distinct people, forged over centuries. It can be hard for outsiders and immigrants to embrace a national identity steeped in ethnicity and history when it was never theirs.
Take postwar Germany. Germanness is considered a mere fact—an accident of birth rather than an aspiration. And because shame over the Holocaust is considered a national virtue, the country has at once a strong national identity and a weak one. There is pride in not being proud. So what would it mean for, say, Muslim immigrants to love a German language and culture tied to a history that is not theirs—and indeed a history that many Germans themselves hope to leave behind?
An American who moves to Germany, lives there for years, and learns the language remains an American—an “expat.” If America is a civil religion, it would make sense that it stays with you, unless you renounce it. As Jeff Gedmin, the former head of the Aspen Institute in Berlin, described it to me: “You can eat strudel, speak ﬂuent German, adapt to local culture, but many will still say of you Er hat einen deutschen Pass—‘He has a German passport.’ No one starts calling you German.” Many native-born Americans may live abroad for stretches, but few emigrate permanently. Immigrants to America tend to become American; emigrants to other countries from America tend to stay American.
The last time I came back to the United States after being abroad, the customs ofﬁcer at Dulles airport, in Virginia, glanced at my passport, looked at me, and said, “Welcome home.” For my customs ofﬁcer, it went without saying that the United States was my home.
In In the Light of What We Know, a novel by the British Bangladeshi author Zia Haider Rahman, the protagonist, an enigmatic and troubled British citizen named Zafar, is envious of the narrator, who is American. “If an immigration ofﬁcer at Heathrow had ever said ‘Welcome home’ to me,” Zafar says, “I would have given my life for England, for my country, there and then. I could kill for an England like that.” The narrator reﬂects later that this was “a bitter plea”:
When Americans have expressed disgust with their country, they have tended to frame it as fulﬁllment of a patriotic duty rather than its negation. As James Baldwin, the rare American who did leave for good, put it: “I love America more than any other country in the world, and, exactly for this reason, I insist on the right to criticize her perpetually.” Americans who dislike America seem to dislike leaving it even more (witness all those liberals not leaving the country every time a Republican wins the presidency, despite their promises to do so). And Americans who do leave still ﬁnd a way, like Baldwin, to love it. This is the good news of America’s creedal nature, and may provide at least some hope for the future. But is love enough?
Conﬂicting narratives are more likely to coexist uneasily than to resolve themselves; the threat of disintegration will always lurk nearby.
On January 6, the threat became all too real when insurrectionary violence came to the Capitol. What was once in the realm of “dreampolitik” now had physical force. What can “unity” possibly mean after that?
Can religiosity be effectively channeled into political belief without the structures of actual religion to temper and postpone judgment? There is little sign, so far, that it can. If matters of good and evil are not to be resolved by an omniscient God in the future, then Americans will judge and render punishment now. We are a nation of believers. If only Americans could begin believing in politics less fervently, realizing instead that life is elsewhere. But this would come at a cost—because to believe in politics also means believing we can, and probably should, be better.
In History Has Begun, the author, Bruno Maçães—Portugal’s former Europe minister—marvels that “perhaps alone among all contemporary civilizations, America regards reality as an enemy to be defeated.” This can obviously be a bad thing (consider our ineffectual ﬁght against the coronavirus), but it can also be an engine of rejuvenation and creativity; it may not always be a good idea to accept the world as it is. Fantasy, like belief, is something that humans desire and need. A distinctive American innovation is to insist on believing even as our fantasies and dreams drift further out of reach.
This may mean that the United States will remain unique, torn between this world and the alternative worlds that secular and religious Americans alike seem to long for. If America is a creed, then as long as enough citizens say they believe, the civic faith can survive. Like all other faiths, America’s will continue to fragment and divide. Still, the American creed remains worth believing in, and that may be enough. If it isn’t, then the only hope might be to get down on our knees and pray.
In 2019, facing down extensive investigations by The Wall Street Journal and The New York Times that showed Apple’s App Store clearly and consistently ranking its own apps ahead of competitors, Apple claimed it had done nothing wrong — a secret algorithm containing 42 different variables was working as intended, top executives told the Times, insisting that Apple doesn’t manually alter search results.
Why do I bring this up? An intriguing email chain has surfaced during the Epic v. Apple trial where it sure looks like Apple did the exact opposite — seemingly admitting it manually boosted the ranking of its own Files app ahead of the competition for 11 entire months.
“We are removing the manual boost and the search results should be more relevant now,” wrote Apple app search lead Debankur Naskar, after the company was confronted by Epic Games CEO Tim Sweeney over Apple’s Files app showing up ﬁrst when searching for Dropbox. “Dropbox wasn’t even visible on the ﬁrst page [of search results],” Sweeney wrote. You can read the whole email chain embedded a little ways below.
As you’ll see, Naskar suggested that Files had been intentionally boosted for that exact search result during the “last WWDC.” That would have been WWDC 2017, nearly a year earlier, when the Files apps ﬁrst debuted.
The email chain actually reﬂects fairly well on Apple overall. Apple’s Matt Fischer (VP of the App Store) clearly objects to the idea at ﬁrst. “[W]ho green lit putting the Files app above Dropbox in organic search results? I didn’t know we did that, and I don’t think we should,” he says. But he does end the conversation with “In the future, I want any similar requests to come to me for review/approval,” suggesting that he’s not entirely ruling out manual overrides.
But Apple tells The Verge that what we think we’re seeing in these emails isn’t quite accurate. While Apple didn’t challenge the idea that Files was unfairly ranked over Dropbox, the company says the reality was a simple mistake: the Files app had a Dropbox integration, so Apple put “Dropbox” into the app’s metadata, and it was automatically ranked higher for “Dropbox” searches as a result.
I’m slightly skeptical of that explanation — partially because it doesn’t line up with what Naskar suggests in the email, partially because Apple also told me it immediately ﬁxed the error (despite it apparently continuing to exist for 11 months, hardly immediate), and partially because the company repeatedly ignored my questions about whether this has ever happened with other apps before.
The most Apple would tell me is that it didn’t manually boost Files over competitors, and that “we do not advantage our apps over those of any developer or competitor” as a general rule.
But honestly, it may not matter whether Apple manually boosted its own apps or not. What matters is the result: for 11 months, Apple’s new Files app owned exact searches for its competitor Dropbox, a company Steve Jobs reportedly swore he would kill off, and it took the CEO of a prominent Apple partner emailing the company before Apple did something about it. And based on The Wall Street Journal’s investigation, Apple may not have done much: the Files app still ranked #1 in the App Store for cloud storage in June 2018, a month after this email chain was resolved, according to an infographic that accompanied the WSJ story.
Besides, the distinction between a “manual” boost and any other kind of boost may be purely academic. Algorithms are written by people, after all. If Apple can build a 42-factor algorithm that gives its own apps favorable results, why would it need to override that algorithm and risk its emails getting caught up in a lawsuit years from now?
It could just tweak that algorithm at will — which is exactly what it did to resolve the WSJ and NYT’s scrutiny two years ago. It only took a single engineer to change the algorithm in July 2019, according to the Times, and Apple’s own apps immediately fell in App Store rankings. But that time, executives said the previous formula wasn’t a mistake. Apple simply wanted to make it look less like its own apps were getting special treatment. So it “improved” the algorithm to achieve the new result it wanted.
We created the App Store to be a safe and trusted place for customers to discover and download apps, and a great business opportunity for all developers. App Store Search has only one goal — to get customers what they are looking for. We do that in a way that is fair to all developers and we do not advantage our apps over those of any developer or competitor. Today, developers have many options for distributing their apps and that’s why we work hard to make it easy, fair and a great opportunity for them to develop apps for our customers around the world.
The System Is DownHow To Win At Risk By Using Systems ThinkingSystems Thinking gives you an advantage in almost every area of life - even the game of Risk. Systems thinking is a way of viewing complicated networks in reality in terms of the relationships between the parts and the whole. It is about thinking holistically about such relationships so as to (1) truly understand how they work and (2) change them for the better. The best strategies in life (and in games) come from systems thinking. This is the case because things are far more complicated than they seem at ﬁrst glance and it takes careful attention to come to know them. Systems thinking offers names and categories for understanding the complexity of reality—and you can’t really know anything without ﬁrst giving it a name. Before we apply the power of systems thinking to the game of Risk, let’s take a crash course in systems thinking ﬁrst. Note: I’m assuming you know the rules of the game of Risk, but if not, read the rules of Risk here.The Simplest Example of a System: A BathtubYou might not think of a bathtub as a system, but it is. You ﬁll the tub to the desired level and temperature, constantly adjusting the faucet in response to the feedback you are getting from the temperature of the water and the current amount of water in the tub. Then, when your goal is met, you take your bath and then let the water out—a complete system. Granted, a bathtub is a very simple system, but it serves as an introduction to the discipline of systems thinking. If you want to go deeper, read Donella Meadow’s Thinking in Systems. It is brilliant. Let’s dig into the bathtub example a bit more and use it to examine the discrete parts of a system.Every System Is Made of These PartsStocks: Stocks are the collection of resources or inputs into a system. In a bathtub, the stock is the amount of water in the tub.Flows: Flows are movements between stocks. A bathtub has two ﬂows, the faucet letting water into the drain letting water out of the tub. The amount of water in the stock of the tub is the result of the interaction between the in-ﬂow (the faucet) and the out-ﬂow (the drain).Reinforcing Feedback: Change in systems happen in loops, not lines. These loops take the form of feedback forces that interact with the stocks and ﬂows. Reinforcing feedback, also known as “growth force,” happens when the stocks in a system are increasing. In the bathtub example, the growth force is the water coming out of the faucet, increasing the stock of water in the tub. Limiting Factor: Systems collapse if the growth force is allowed to run unchecked. At a certain point, the system hits a limiting factor. In the bathtub example, the limiting factor is the desired level of water in the tub. You can always spot the limiting factors in a system by looking at the (1) carrying capacities of the stocks or (2) the goals of the players in the system. Balancing Feedback: Balancing feedback, or “balance force,” kicks as the system approaches one of its limiting factors. In a bathtub, as the amount of water in the tub approaches the desired water level, the person ﬁlling the tub reaches out and turns the faucet off. Suddenly, the system is balanced. Anywhere there is a goal, for example, the desired water level in a bath, you’ll ﬁnd forces at work that are trying to achieve that goal by balancing the system.Equilibrium: When a system is balanced, it reaches equilibrium. There are two types of equilibrium: static and dynamic. In the tub example, if the faucet is off and the drain is plugged, static equilibrium has been reached since no ﬂows (in-ﬂow or out-ﬂow) is coming off the stock. Dynamic equilibrium is reached when the total ﬂows into and out of a stock continue, but are equal, as would be the case if the water in a tub was ﬁlling at the same rate it was draining. Leverage: Systems are hard to change because balancing feedback does such a good job of returning the system to equilibrium. Leverage refers to the forces that are applied to a system in an attempt to change it, but, as you will see below, not all levers are created equal, nor equally effective. In fact, pulling on some levers only makes the sleeping dragons of balancing feedback wake up and lock down the system. However, savvy systems thinkers are able to ﬁnd the leverage points in a system that can change it so dramatically that a new balance is reached—perhaps tipped in your favor.But what does all this have to do with Winning At Risk?A lot, as it turns out. The magic starts to happen when you do two things:Map the parts of Risk onto the parts of a system.Analyze the system of Risk to ﬁnd the best strategy according to the rules of systems thinking. Here we go.Step One: Map the Parts of Risk onto the Parts of a SystemStocks: In the game of Risk, your stocks are the number of armies in your countries, the number of countries under your command, and the number of continents you control.Flows: The in-ﬂow in the game of Risk are the number of new armies you get each turn. The out-ﬂow is the number of armies you lose in battle each round.Reinforcing Feedback: There is a strong growth force at play in the game of Risk since the number of extra armies you get is tied to the number of countries and continents you control. So the stronger your armies become, the faster they become stronger. If left unchecked, this would quickly become an exponentially reinforcing loop that would result in the strongest player quickly taking over the game. Balancing Feedback: But, unlike reality, a good game would never let that happen. If you push the system in the wrong way, the system always pushes back. In Risk, the wrong way to push the system is to try to ride the reinforcing feedback all the way to victory, getting more and more continents until you win. However, reinforcing feedback always triggers balancing feedback to kick in and keep the strong player in check. In fact, the stronger any single player gets, the stronger the balancing feedback arrayed against them becomes. In Risk, the main balancing feedback is the opposition the strongest player encounters from all the other players. That is why it is such a terrible idea to grab a continent too early; it awakens the balancing feedback before you are too strong to repel it. (Taking Australia is an exception to this. For some reason, everyone expects Australia to get taken in the ﬁrst two turns and thus the balancing feedback of the other player’s fear isn’t awakened. This exception is probably explained by the fact that you only get two bonus armies from keeping Australia. The small number lulls players into feeling that it is safe to allow the player who controls Australia to keep control of it.)Limiting Factor: Because the balancing feedback is awakened by the perceived advantage any one player has (or is about to have) over the other players, the clearest limiting factor is almost always taking a continent. Remember, the limiting factors are triggers that the system deems dangerous enough to deploy balancing forces against. Because of this, taking a continent can be a bad strategy even though it promises to increase the ﬂow of armies into your stocks. If the other players unite to oppose you, the result will be a diminishment of your stock of armies.Equilibrium: In Risk, equilibrium sets a cap on how strong any one player is allowed to become. If you want to win, you have to wait until the equilibrium has risen high enough to allow you to have large enough armies for quick, devastating strikes. The more unexpected those strikes are, the more successful they will be. People only tend to defend against their immediate neighbors, so they will not be worrying about your country with 30 armies because it is all the way across the board, when the reality is that (depending on what stage the game is in) a country with 30 armies can usually ﬁnd a path to go wherever it wants, leaving a trail of death in its wake. Now that we have mapped the parts, lets try to ﬁgure out what to do with them.In Risk, “the game of global domination,” the goal is pretty clear: take over the world. Determining the goal of a system won’t always be this easy, but this time it’s a gimme. Let’s press on.Step Three: Start with the Goal and Strategize Backward.Starting with the goal of global domination, let’s walk backward and see if we can ﬁnd our way into a viable strategy that will let us reach the goal. I’ll write it as a logical chain of If/then statements.If the goal is global domination, then you need to make sure you have greater strength in armies than any other player.If you need to have more armies than any other player, then you should do everything you can to (1) increase the rate at which you gain armies and (2) avoid losing the armies you receive.[We’ll cover the best way to increase the rate at which you gain armies below, so let’s focus on the second one here.] If you need to avoid losing the armies you receive, then you need to avoid battles, specifically, you need to reduce the number of times you roll the dice as much as possible. And there it is, one half of the winning strategy: Roll the dice as little as possible. You can’t lose armies that never ﬁght.But how do you accomplish this? Just do these things:Consolidate most of your armies on a handful of adjacent countries that are strong enough that no one wants to attack them. Keep the number of armies in the rest of your countries low. This makes you continue to look weak, reduces the number of armies you might lose if another player takes that country from you, and makes your opponents divide their forces if they want to move into one of your weak countries. Initiate as few attacks as possible. When you do initiate an attack, make sure you have an overwhelming advantage. Better yet, don’t attack at all. Remember, you are trying to avoid having to roll the diceIf you have to attack, do so only from a place of great advantage. Nothing wastes more armies than long, drawn-out battles between countries with many armies on them. If you only engage in short battles whenever possible, you will roll the dice fewer times.Let your enemies break up each other’s continents, not you. If you can get people to ﬁght among themselves by not being the one to enforce the balancing feedback (i.e. attack someone to break up their control of a continent), someone else will have to do it. Just wait. Don’t be the global police, let your opponents do the dirty work. Take only one country per turn. Again, let your enemies kill one another’s armies as they squabble for territory. They are doing your work for you. Your job is to grow stronger, not to win battles. Growing stronger slowly lets you keep a strong core of armies in a cluster of key countries without arousing the other player’s worry. “But,” you might be asking, “If I only take one country per turn, how will I ever win the game?” Keep reading.Step Four: Find Leverage that will Avoid Awakening Balancing FeedbackThere are three ways to get more armies in the game of Risk:Of these three, controlling continents is the surest way to awaken balancing forces in the game that will oppose you on your path to global domination. That means if you can grow the size of your armies without taking a continent, you gain leverage that can change the whole game. The ﬁrst two are “safe.” Most of the time, only taking continents way awakens the dragons of balancing feedback.To get this leverage, you have to do two things:Find a way to grow in strength by taking lots of countries (but not taking a whole continent). There is only one area of the board that will let you do this, luckily, it is also the part of the board that no one wants: Asia. Even though you get seven bonus armies for controlling Asia, most players don’t pursue it because it is so hard to hold. That means that it can only be successfully controlled in the ﬁnal stages of the game. Thus, in the early stages, it can be your playground. There are enough countries in Asia to allow your in-ﬂow of armies to continue to rise as the game progresses without triggering balancing feedback.Make sure you get lots of cards for bonus armies. The best way to do this is just to take one country every turn. This will allow you to keep getting cards without spreading your forces too thin. When you get enough cards to get bonus armies, you can (if the timing is right), move on to Step Five.Step Five: Increase Your Stock of Armies Until You Can Make a Fast, Devastating AttackTo review, the strategy up to this point consists of (1) waiting, (2) not spreading yourself too thin, (3) taking one country per turn (4) consolidating your armies on a few, very strong countries, and (5) enabling your opponents to target one another. This strategy is a slow burn in the early parts of the game, but there comes a time when you need to go on the warpath. If you succeed in laying low and not getting in too many battles, you should be able to build up a good number of armies in at least one country (especially with card bonuses). If you play this strategy well, you might end up with even three or four times the number of armies in the average country on the board (in fact, this should be a goal). When you reach that level, you have some decisions to make. Should you go on the offensive. Is it time to take over an entire continent in one fell swoop? Maybe. Is it time to completely annihilate one of your opponents from the board, taking their unspent cards in the process? Perhaps. Is it time to split your force in half, using one half as a beachhead to hold territory in another part of the board? Possibly. It is up to you and will depend on the current situation on the game board.The important thing is to make a choice that will set you up well in the future, but not too well. Even after you make this big move, you are going to want to continue to avoid becoming the object of balancing feedback, which means the mission is still to strengthen your own position without being perceived as the top player. Sometimes this will mean not taking a whole continent. In this case, using your big offensive push to just weaken key opponents can be a good strategy. You’re going to have to use your judgment.The key thing to remember here is that when you reach this stage in the strategy, the strategy isn’t over. Just go back to step one and keep it going. Rinse, conquer, repeat.Step Six: Don’t Forget All This Other StuffPlay the Players Too: The other players are part of the system of the game too. If you are going to have a hope of winning, you have to beat the others at playing the “player-level” of the game. The strategy of avoiding taking continents will serve you well in the player-level of the game because it sets you on a course of waiting at the back of the pack and drafting off of your opponent’s poor choices. The players at the bottom are always on the same team, or, at least, that is the mentality you should encourage every chance you get.Lose Fewer Armies Than Your Opponents: This may sound self-explanatory, but there are two ways to have more armies than your opponents: to gain them faster (in-ﬂow) or to lose them more slowly (out-ﬂow). Most people pour all their attention into getting more in-ﬂow than everyone else (more reinforcements per turn), but there is a competitive advantage to be found if you dedicate yourself instead to getting more armies than your opponents by not losing the ones you get. If you follow the rest of this strategy, the effects of your conservative play should be compounded as you allow and encourage your opponents to hack away at each other and leave you alone. Find the limiting factors. Limiting factors will show themselves as the system begins to try to maintain equilibrium, but you have to learn how to recognize them when they do. Some of those limiting factors will originate on the player-level of the game. When you hear people say things like, “If someone doesn’t take that country away from Sam, he is going to run away with this game” it means Sam has hit a limiting factor on the social level of the game. Fan those sparks into ﬂames. This is balancing feedback waiting to be triggered. Helping other players become the object of balancing feedback is a big part of this strategy.Use the Threat of Your Strength to Control the Game. As you get stronger, specifically, as you have one country with a large number of armies on it, you can begin to exert an inﬂuence on the social level of the game. The other players will begin to wonder what you are going to do with all that strength once you go on the warpath. Use that question in their minds to bend events in your favor. Make an alliance. Leak your plans to key allies. Work together with them to be a part of the balancing feedback directed against the top player(s).Know What Stage You’re In. Risk has stages. Things that are possible in the early stages are not possible in later ones, and vice versa. To succeed, you have to read the stage of the system and make your moves accordingly. Early stages will largely be about jockeying for position on the map, staking out territory, claiming a continent, and encountering light resistance from the other players. The middle stage will be about consolidating your ﬁrst continent (unless you are using this brilliant strategy) and fending off the harrying attacks by people who don’t want you to control that continent. By the late stage of the game, a few players may have been eliminated, each player is entrenched in a corner of the board, and they are trying to build enough strength to take out their fellow players one by one. Watch Out For The Death Spiral: The Death Spiral is another kind of reinforcing feedback at play in the middle and late stages of the game. This happens when one player becomes too weak to fend off the other players and the stronger players try to completely eliminate them from the game, thus taking their unused cards and getting a huge bonus for themselves. Don’t let this happen to you! If it does, revert to the player-level of the game and try to awaken the balancing feedback inherent in the pity of your fellow players. Also, if you are in danger of becoming the victim of the Death Spiral, don’t hoard cards—use them as soon as you can so you don’t tempt your opponents to come and take them. Lastly, if you are one of the strong players, you can use the Death Spiral to your advantage by keeping weak enemy-controlled countries near your strong countries. If one of your fellow players is about to be knocked out of the game, just make sure their last country is within your range of attack, then grab it and the bonus cards that come with it. TopNewCommunityWhat is The System Is Down?About
A boatman waits for the fog to lift on the Thames, London. November 1931. Photo by Topical Press/GettyHow to think clearlyBy learning to question and clarify your thoughts, you’ll improve your self-knowledge and become a better communicatorA boatman waits for the fog to lift on the Thames, London. November 1931. Photo by Topical Press/Gettyis an author and tech philosopher, with a special interest in critical thinking. His most recent book is How to Think (2021). He lives in Kent, UK. Need to knowThink it throughNeed to knowSometimes, when I’m grappling with a tricky topic, I pretend that I need to explain it to a child. For example, here is my attempt at explaining the purpose of this Guide to a notional nine-year-old:
I want to help people work out what they really think and mean, and then to share the results with other people. This is surprisingly hard. It’s easy to talk about what you want and like. But it can be really difﬁcult to work out why you want or like particular things — and why other people should pay attention. I’m going to set out a three-part process that can help with this.
As the parent of two young children, I often get to skip the pretending part of this exercise. But I’d recommend giving it a try, no matter what your domestic situation. It can be both challenging and powerful to talk someone else through an idea, step by step, in terms that take as little as possible for granted. Often, it’s only when I try to explain something in this way that I discover that I don’t fully understand it myself.
As it happens, there’s a subreddit devoted to precisely this principle. It’s called ‘Explain Like I’m Five’, and features tens of thousands of attempts at explaining complex ideas as simply as possible. Question: how can archaeologists translate ancient scriptures or languages? Answer: ‘It’s basically a giant jigsaw puzzle.’ Q: how do conferencing programmes such as Zoom handle so many different screens? A: ‘Everyone has one connection to Zoom’s central servers.’ Q: if carbs are sugar, why can’t we just eat sugar? A: ‘It would be a bit like replacing the ﬁrewood in your ﬁre pit with a tub of gasoline …’ And so on.
I enjoy browsing ‘Explain Like I’m Five’ partly because it isn’t interested in perfection. Instead, it’s packed with comments, debates and works-in-progress; with points and counterpoints, gags and squibs. Much like the business of explaining something to an actual ﬁve-year-old, it’s full of distractions and dead ends. But it’s also relentlessly committed to dispelling errors and unexamined assumptions; and in privileging honest questions and confessions of uncertainty over any performance of expertise.
All of this emphasises a fundamental point about clarifying your thinking. It asks you to admit your thoughts are unclear to begin with — and thus, that certain elements within them need to be rethought, or placed upon more secure foundations. It’s as if you’re shedding layers of preconception, misconception and false consciousness. And the ultimate prize isn’t being right, gratifying though this might be. It’s being understood.
Why should anyone care about any of this? Without wishing to be grandiose, I’d argue that seeking clarity is both humane and life-enhancing. To idealise, it entails the mutual and respectful pursuit of knowledge. To be more pragmatic, it can help us know ourselves a little better, dispel prejudices and misapprehensions — and communicate more richly and persuasively amid the 21st century’s tumult.
Aspiring towards clarity is also inexorably iterative. Whenever you set out to clarify your thinking, you’re not aiming to articulate an ultimate truth. Rather, you’re aiming at a process, the result of which will always be an act of communication, complete with all the imperfections and contingencies this implies.
In this Guide, I want to help you think about what this process looks like for you. As promised, I’ll do this in three stages (preceded by a pause). The ﬁrst stage entails reﬂecting on why you believe something to be true or important. The second entails teasing out the assumptions this reasoning relies upon. The third entails acknowledging what you do and don’t know, where you’re uncertain — and what it might mean to redress these things.Need to knowThink it throughThink it through
To start with, let’s take a moment. Draw a breath. Slow yourself down. What’s going on? What are you thinking and feeling? What most deserves your attention? There’s a great line in Robert Poynton’s book Do Pause (2019) that speaks to the significance of taking stock in this way:
In a pause you can question existing ways of acting, have new ideas or simply appreciate the life you are living. Without ever stopping to observe yourself, how can you explore what else you might do or who you might become?
Inviting people to pause is among the easiest advice in the world to give, and the hardest to take. Yet it’s foundational to clarifying your thinking, because this is where it all begins: with a moment of self-reﬂection. Without pauses, there can be no second thoughts and no self-interrogations. There is no process until you take the time to embark upon it.
You might think that this point is too obvious to be worth making. Yet, in my experience, it’s where most of us fall down. We all carry around countless unclear, confused, contradictory thoughts and feelings. And precisely because we have neither the time nor the tools to sort them out, they mostly stay this way.
Once you’ve paused, a common psychotherapeutic exercise can help you take a ﬁrst step towards clearer thinking. It’s about observing yourself as neutrally as possible. You make yourself comfortable, relax, then try to notice the ﬂow of your thoughts and feelings in a nonjudgmental way: the ﬂickers of anxiety, anticipation, regret; the memories and ideas bubbling into consciousness.
These are the raw materials that any process of clariﬁcation must work with. The more carefully you’re able to attend to them, the more likely you are to tease out their complexities and contradictions. And the less likely you are to mistakenly assume that whatever seems obvious to you will necessarily seem obvious, or compelling, to someone else.
What are you claiming, and why?
When I perform the above exercise, I notice one thing that’s on my mind is a nagging question around what I eat. Should I become a vegetarian, or a vegan, for ethical and environmental reasons? And if not, why not?
In philosophy, what’s known as standard form is often used to set out the essentials of a line of thought as clearly as possible. Expressing your thinking in standard form means writing out a numbered list of statements followed by a conclusion. If you’ve done it properly, the numbered statements should present a line of reasoning that justiﬁes your ﬁnal conclusion. For example, here’s a ﬁrst attempt at organising my thoughts around diet: Both eating meat and using animal products are associated with vast amounts of unnecessary animal suffering. They also use more energy and resources than most plant-based alternatives. It’s perfectly possible to have a healthy diet and live a full life without eating meat or using most animal products. So far as possible, I should try to prevent unnecessary animal suffering, excessive energy usage and the overconsumption of resources.If I believe all of the above to be true, I should thus adopt a vegetarian or a vegan diet.
You might have seen examples of this approach before, or used it in your own work. You might also have encountered a great deal of discussion around logical forms, reasonable and unreasonable justiﬁcations, and so on. What I ﬁnd most useful about standard form, however, is not so much its promise of logical rigour as its insistence that I break down my thinking into individual steps, and then ask two questions of each one:
Why should a reasonable person accept this particular claim? What follows from this claim, once it’s been accepted?
When it comes to clarifying my thoughts and feelings, the power of such an approach is that anything relevant can potentially be integrated into its accounting — but only if I’m able to make this relevance explicit. Here’s how a few further thoughts might ﬁt into my example: Both eating meat and using animal products are associated with vast amounts of unnecessary animal suffering. They also use more energy and resources than most plant-based alternatives. It’s perfectly possible to have a healthy diet and live a full life without eating meat or using most animal products. So far as possible, I should try to prevent unnecessary animal suffering, excessive energy usage and the overconsumption of resources. If I believe all of the above to be true, I should thus adopt a vegetarian or a vegan diet. However, I’m not currently a vegetarian or a vegan. This suggests that either: I don’t believe the above reasons to be true, or to be the whole story; or that I do, yet somehow still don’t ﬁnd them compelling.If I want to clarify my thinking around this issue, I need to investigate the divide between my apparent beliefs and my actions.
How might you apply such an approach yourself? As you’ll have noticed, the thoughts I’ve just added bring further complexities and qualiﬁcations into focus. They take what was once a relatively straightforward conclusion and turn it into something more complex — and revealing.
Paradoxically enough, this is a vital component of clarifying your thinking: stripping away oversimpliﬁcations, no matter how compelling or appealing, and replacing them with an honest acknowledgment of circumstances. The logic of my initial argument might have seemed admirably clear; but this clarity doesn’t correspond as closely as I might wish to reality.
Honest self-examination and iteration are vital, here. Even now, reading back my own words, I’m not sure I’ve managed to describe my state of mind accurately — or the issues at stake. Is it really true that there’s no ethical way of eating meat or of using animal products? Are there shades of meaning I’ve neglected in an effort to establish clear categories of right and wrong? Or am I simply failing to act on my beliefs because of a combination of inertia and self-indulgence?
These are just a few of the questions my scenario begs. And behind them is a fundamental point: that it’s only by repeatedly questioning both the why and the what of our claims, and the claims they in turn rely on, that we can hope to strip away the layers of habit, confusion and self-justiﬁcation that all too often typify everyday thoughts.
What have you taken for granted?
Upon what basis can I justify any claims? Some will rely on external evidence; some on personal preferences and experiences; some on a combination of these factors. But all of them will at some point invoke certain assumptions that I’m prepared to accept as fundamental. And it’s in unearthing and analysing these assumptions that the most important clariﬁcations await.
Assumptions are those things we take for granted: whatever we don’t explicitly spell out, but that our thinking relies upon. Assumptions are also extremely important. Indeed, it’s the existence of shared assumptions that makes communication (and much else) possible. As I write these words, I’m assuming they mean approximately the same thing to you as they do to me. It would be incredibly tiresome if I tried to explain every word in a sentence. It would also, in the end, be futile. I’d still have to explain my words via other words, my ideas via other ideas, and so on. Without some shared assumptions, there would be no way of building either common understandings or meaningful disagreements.
While common understanding and meaningful disagreement might sound like opposites, they’re actually two sides of the same coin. No matter how self-evident they might seem to us, the assumptions that our ideas rest upon might need spelling out to others. Some people could, for example, view animal suffering as a non-issue, on the grounds that human experience is all that counts when it comes to ethics. Some could believe that no further justiﬁcation of veganism is required beyond the self-evident evil of inﬂicting unnecessary suffering on our fellow creatures. And some (among whom I tentatively count myself) might believe that most forms of industrial farming and ﬁshing are abhorrent, but that there are some circumstances under which animal products can be ethically and sustainably sourced.
Our assumptions, in other words, aren’t just unexamined ideas. They’re also the roots of identity and allegiance; the stuff of our personal and shared histories; of our communities and our morality. They are the sources of much of the greatest good and deepest harm we do to one another. That which we take as ‘given’ is nothing less than the bedrock of what we believe the world to be.
What follow from this? When it comes to clarifying your thinking, it means that you need to be very clear about the difference between what follows from your assumptions and the status of those assumptions. To take things step by step:
Any line of thought must begin with certain assumptions: those things that you both explicitly and implicitly accept as given. No matter how deep you dig, you’ll never be able to ﬁnd a wholly clear, self-evident and uncontroversial claim. A careful process of analysis can show where your assumptions lead: what reasonably follows from them, if you assume that they’re true or accurate. But different lines of reasoning based on different sets of assumptions are likely to take you in very different directions. One of the most useful things you can thus do is to spell out both your own and other people’s key assumptions, then to compare what follows from each. If you’re sufﬁciently open-minded, this can help you identify assumptions you hold in common with others, challenge faulty ones on both sides, and respectfully engage with alternative perspectives from your own.
Working out the implications of your assumptions is, in other words, far from the same thing as being deﬁnitively correct; and grasping the difference between these lies at the heart of honestly and persuasively articulating your views.
Embrace dialogue — and know your limits
What do you make of my attempts to clarify my thinking about meat-eating, thus far? Hopefully, even if you disagree with every single word I’ve written, you’re more likely to understand where I’m coming from than if I just blurted out: ‘I think that maybe I ought to stop eating meat.’ I certainly feel more conﬁdent about what’s going on in my head. And this suggests that, if we ever end up discussing these things in person, we’re more likely to be able to debate our differences constructively. We’ll perhaps be able to work out where we do and don’t disagree — and why — rather than falling back upon blanket assertions or aspersions. In the end, we might even arrive at a new, clearer understanding together.
This, I’d suggest, is the most precious thing about clearly presenting the thinking behind any point of view: not that it proves your rightness or righteousness, but that it volunteers your willingness to participate in a reasoned exchange of ideas. At least in principle, it suggests that you’re prepared to:
Justify your position via evidence and reasoned analysis. Listen to, and learn from, perspectives other than your own. Accept that, in the face of sufﬁciently compelling arguments or evidence, it might be reasonable to change your mind.
This approach is underpinned by what’s known as the principle of charity: a phrase that can sound strange in the context of disagreements, but that embodies one of our oldest and most practical guides to constructive debate. It exists in various formulations, all rooted in the same idea:
So far as possible, you should try to extract the maximum truthful and reasonable content from what others say, especially if they disagree with you.
Importantly, the principle of charity extends not only to what someone is saying, but also to your assumptions around why they are saying it:
Unless you have decisive evidence to the contrary, you should start off by assuming that someone else’s position is reasonable and sincerely held, rather than that they’re malicious, ignorant or mistaken.
Why? In both cases, the answer isn’t because this is a nice thing to do, but because it’s only by beginning with charitable assumptions that you can get to grips with the underpinnings of someone else’s perspective — and ensure that any judgment you eventually pass is based on a careful, fair-minded assessment.
All of which brings us back to the most important point of all: that clarifying your thinking means being as honest as possible about what you don’t know, and then putting a frank engagement with these limitations at the heart of your account.
Indeed, perhaps the most important tool in any attempt at clear thinking is the capacity to test (and to keep on testing and reﬁning) your ideas as if they belonged to someone else: as acts of reasoned persuasion that must stand, or fall, on their own terms.Need to knowThink it through Clarifying your thinking is a process: one that’s necessarily incremental, iterative and imperfect. There’s no such thing as a perfectly clear statement. Clariﬁcation comes from setting out your thinking, step by step, in as straightforward and explicit a manner as possible — and then stepping back, revisiting the result, and seeking to redress its limitations. First of all: pause. It’s only by slowing down and attending carefully to your own thoughts that you can hope to embark upon a process of clariﬁcation. What’s on your mind? Once you’ve worked out what deserves your attention, try to spell out why you believe it to be true or important. This entails reconstructing your reasoning systematically. Set it out in numbered sequence, being sure to ask of each claim: why should a reasonable person accept this; and what does (and doesn’t) follow once it’s been accepted. Don’t be seduced by oversimpliﬁcations or too tidy a formulation of complex issues. It’s important to be as clear as possible about the tensions, ambivalences and ambiguities you’re grappling with. Addressing complex ideas lucidly isn’t the same as pretending they’re simple. Be explicit about the relevant assumptions your reasoning relies on. These will invariably include some claims you believe to be fundamental. Be aware that two perfectly reasonable lines of argument based upon different fundamental assumptions could lead to very different conclusions. Engage charitably and rigorously with perspectives other than your own, and don’t assume dishonesty or bad faith in others without good reason. To idealise, a constructive exchange of views is one in which you ﬁrst ensure you’ve stated someone else’s position in a manner they agree is fair — and only set about addressing your differences once you’ve done this.Need to knowThink it throughWhat does it mean to make the kind of process I’ve outlined above habitual — and what might it mean, for you, to apply it effectively in different areas of your life?
This is the point at which your personal preferences come into play. For me, the props and routines of clear thinking include (in no particular order) strong cups of coffee, directionless neighbourhood strolls, a desk surrounded by heaped books and scrap paper, and as much serendipitous reading as I can squeeze in between school runs.
For you, the twin realms of the possible and the desirable might look very different. But the same principle applies. We both need to take a close interest in the times, places, habits and contexts that bring out the best in us — and that give us permission to contemplate, then try to explain, what’s really going on when it comes to the questions that matter most.
Another way of putting this is that willpower is overrated. Among all the potted insights I’ve drawn from social science, this is perhaps the handiest and most humbling. Unless you seek out contexts, routines and environments that support your best self, you’ll struggle to be that self at any but the very best of times.
Aim to interrogate and audit your habits in the light of this insight. Find ways of thinking and working that work for you. Be as ruthless as possible about identifying the ones that don’t work, and why; and how far you can minimise the toll they take. Try to take a lively and systematic interest in your own blind spots and limitations. Be honest about what you do and don’t know, where you’re uncertain; and what kind of conversations, investigations, predictions and discoveries might reduce this uncertainty.
Above all, don’t forget to ask for help when you need it — and to offer it whenever you can. When it comes to clarity and communication alike, this is perhaps the simplest and most important thing any of us can do: keep talking to one another, and try to truly listen to what’s being said in response.Need to knowThink it throughThe Critical Thinking course from the University of Auckland is available, for free, online, and covers everything from evidence and reasoning to law and morality.
The Philosophy Bites podcast offers an extensive archive of bite-sized interviews with world-leading thinkers, and is hard to beat for insights into big ideas.
Mary Midgley’s book What Is Philosophy For? (2018) accessibly explores what it means to think clearly about the questions that matter most.
Oliver Burkeman’s weekly column ‘This Column Will Change Your Life’ ran in The Guardian from 2006 until 2020, and is a wise, witty treasure trove full of practical, humane advice about thinking and working well — and cutting yourself some slack along the way.
My own book How to Think (July 2021) addresses clear thinking in the context of everyday experience, with an emphasis on habits and practical skills.Don’t believe everything you hear, read and watch. To puncture received ideas about culture, start thinking like Jacques DerridaWonder and the sublimeAwe might seem an unobtainable luxury to many but, with the right approach, you can enjoy it daily — no mountain requiredPlato and Aristotle can help you resist conventional worldly success, direct your energy and ﬁnd your own highest callingIntriguing articles, practical know-how and immersive ﬁlms, straight to your inbox.
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A while back there was a thread on one of our company mailing lists about
SSH quoting, and I posted a long answer to it. Since then a few people have asked me questions that caused me to reach for it, so I thought it might be helpful if I were to anonymize the original question and post my answer here.
The question was why a sequence of commands involving ssh and ﬁddly quoting produced the output they did. The ﬁrst example was this:
Oh hi, my dubious life choices have been such that this is my specialist subject!
This is because SSH command-line parsing is not quite what you expect.
First, recall that your local shell will apply its usual parsing, and the actual OS-level execution of ssh will be like this:
Now, the SSH wire protocol only takes a single string as the command, with the expectation that it should be passed to a shell by the remote end. The OpenSSH client deals with this by taking all its arguments after things like options and the target, which in this case are:
It then joins them with a single space:
This is passed as a string to the server, which then passes that entire string to a shell for evaluation, so as if you’d typed this directly on the server:
The shell then parses this as two commands:
The directory change thus happens in a subshell (actually it doesn’t quite even do that, because bash -lc cd /tmp in fact ends up just calling cd
because of the way bash -c parses multiple arguments), and then that subshell exits, then pwd is called in the outer shell which still has the original working directory.
The second example was this:
Following the logic above, this ends up as if you’d run this on the server:
The third example was this:
And this is as if you’d run:
Now, I wouldn’t have implemented the SSH client this way, because I agree that it’s confusing. But /usr/bin/ssh is used as a transport for other things so much that changing its behaviour now would be enormously disruptive, so it’s probably impossible to ﬁx. (I have occasionally agitated on openssh-unix-dev@ for at least documenting this better, but haven’t made much headway yet; I need to get round to preparing a documentation patch.) Once you know about it you can use the proper quoting, though. In this case that would simply be:
Or if you do need to specifically invoke bash -l there for some reason (I’m assuming that the original example was reduced from something more complicated), then you can minimise your confusion by passing the whole thing as a single string in the form you want the remote sh -c to see, in a way that ensures that the quotes are preserved and sent to the server rather than being removed by your local shell:
Taildrop was the main new feature we launched in Tailscale v1.8. People seem to like it.
This is so cool. Point to point drag & drop ﬁles (phone to desktop, iPhone to Android, Windows to Linux…) with Wireguard security. Reason # 376 why you should be tracking @Tailscale. https://t.co/Tu0TxtdlTF
— Kenn White (@kennwhite) May 28, 2021
Taildrop works for large ﬁles, it goes point to point rather than through the cloud, it’s secured using your existing identity provider, and best of all, it doesn’t need any bluetooth.
I just shared a 3GB ﬁle from a Macbook to an iPhone using @Tailscale to test if it was able to handle big ﬁles well and it is!
No more trying to discover Airdrop devices or dealing with broken Bluetooth to send media around!
— Felipe O. Carvalho (@_Felipe) May 30, 2021
ohhhhh!!! Being able to easily share ﬁles between devices over an encrypted socket is amazing to have! https://t.co/piBDpmk6w5
— yosh (@yoshuawuyts) May 25, 2021
And it leads some users to infer world domination plans even though we are, in actuality, just very nice people, anybody would say so:
You guys are gonna take over the world. Seriously. This is so cool.
— Tyler Stillwater (@TylerStillwater) May 19, 2021
Seriously though, Taildrop is a thing that lets you transfer ﬁles between your own devices, over your point-to-point Tailscale+WireGuard mesh network, across various different OS platforms. It never stores your ﬁles in the cloud or sends them to us. They’re end-to-end encrypted with keys that we never see. And it costs us, effectively, nothing to run, because it’s your bandwidth (mostly LAN bandwidth), not ours. We just bust some NATs and negotiate the session. Which is why we can give Taildrop away to everybody, for unlimited use, with no ﬁle size limits, as part of the Tailscale free plan. It’s also open source…
…although there’s so little code that it’s hard to spot. That’s the topic of this post.
When we wrote How Tailscale Works and How NAT Traversal Works, we had a not-so-subtle goal of explaining that, in fact, making those things work is pretty hard. We’ve spent thousands of person-hours on it, and maybe you should just use Tailscale instead. You know how this story goes.
But Taildrop is different. It’s just an unauthenticated ﬁle transfer layer on top of Tailscale. It can be unauthenticated because Tailscale is already authenticated, and controls who can access each port, and for those who are allowed, it securely tells you who’s connecting right now. Taildrop can itself be unencrypted because Tailscale is already end-to-end encrypted (an architecture called Zero Trust Networking).
I tried to write an article called How Taildrop Works but it was just the following diagram, and they wouldn’t let me publish it. I had to put a fancy font in the title to distract you from how boring the rest of the diagram is.
Can you implement an iOS or Windows sharing pane? Can you deliver an HTTP PUT request? Then great, you’ve built Taildrop.
As an “Internet insider” joke, we wanted to release Taildrop on the 50th anniversary of FTP (April 16, 2021), but sadly, our release date slipped just a bit too far. Still, FTP is a big inspiration for us:
Along with telnet (the precursor to ssh), FTP was one of the ﬁrst two application protocols used on the Internet.
Transferring big ﬁles from one computer to another is one of the fundamental things we all want to do, and which, perversely, somehow is nowadays harder to do than it was with FTP decades ago.
Taildrop is fewer lines of code than the ftp command, more secure than FTP, and easier to use than FTP, even though it was easier to invent than FTP.
In short, to me, Taildrop is a sign that maybe, just maybe, the Internet is ﬁnally once again evolving in the right direction. For the ﬁrst time in longer than I can remember, we can write an app that just transfers some data, and not worry about hosting costs, or privacy issues, or logins or passwords or account recovery or DNS or open ports or ﬁrewalls or expired TLS certiﬁcates. We made a server that accepts PUT requests, and a GUI that generates PUT requests, and we shipped it.
But Avery, you may be asking yourself, if it was so easy, why did it take 7 weeks to develop and launch? I’m sure, you say to yourself, I’m sure I can make a one-page HTTP server in less than 7 weeks. And, you continue, I’m guessing you didn’t spend the whole 7 weeks working on this beautiful Windows GUI:
I wrote our Windows Taildrop GUI. I reserve the right to make fun of it.
Indeed, you are correct. The Windows GUI took maybe a couple of days (and deserves more than a couple of days). The HTTP PUT responder took a few hours at most. So where did the time go?
In truth, we didn’t set out just to build another FTP. We wanted to demonstrate, to ourselves, how to build another FTP. And we wanted to make it easy for the next people, who won’t be us, to build the next app the easy way.
Behind the scenes of that HTTP PUT request, there’s some machinery we needed to add:
The new Tailscale “localapi” lets local apps query the local tailscale instance over HTTP. For example, it can get a list of peer devices that might be Taildrop targets, or which services are running on those peers.
The new “whois” service lets you ﬁnd out the user identity of a secure TCP or UDP session established over the Tailscale network. (Taildrop currently restricts ﬁle transfers to only be allowed from devices that you yourself own, even on a multi-user network. That lets us safely delay a bunch of privacy and security questions for now, such as what to do when someone sends you an, er, unwanted photo. We’ll have to do more work when we allow inter-user transfers later.)
The new “peerapi” lets Tailscale nodes send messages to each other, over the encrypted Tailscale link. The ﬁrst useful peerapi endpoint is Taildrop, and there’s a thingy for inspecting goroutine status. It’ll soon be expanded to include at least a few extra diagnostic features.
Some aggravation also arose around what to do with the ﬁles once we got them to their destination, especially on mobile platforms. (As of this writing, the Android client for Taildrop isn’t done yet, but it’s coming soon.) iOS gave us some pain, since the Tailscale backend isn’t allowed to write to user-visible ﬁle storage such as the Files app. Instead, we have to deliver a notiﬁcation, which when clicked, can open the frontend GUI, which can move the ﬁles into their ﬁnal location.
We’re not sure yet exactly where we’ll take the peerapi; maybe it’ll be useful mainly for features provided directly inside Tailscale, like Taildrop. After all, every other port you listen on is also reachable over the p2p network once established, so if you’re writing your own app, you can just use another port, like a retro 1990s Unix programmer inventing rlogin. We’ll see.
What we didn’t do: cloud edition
It’s instructive to think about what you might have had to do if you were instead trying to transfer ﬁles between your devices without all that nice infrastructure.
First of all, you’d have to decide whether to (a) beam everything to the cloud and back, or (b) establish a p2p link between two devices and send the ﬁles directly.
Okay, that’s a trick question; almost nobody ever chooses option (b) anymore. It’s just too hard. If you could establish a secure direct link between devices, you could just use FTP, and we already know those days are gone.
So ﬁne, let’s use the cloud. How will our protocol work?
The service will store in-transit ﬁle contents in, say, S3.
Ah, but which S3 region? Better do a whole bunch of regions to be safe. Don’t want to be transferring ﬁles halfway around the world for no reason. That means we need a load balancer. Don’t worry, AWS can sell us one for a mostly reasonable price.
Our server is going to need a DNS name and an HTTPS cert. Let’s use LetsEncrypt, I guess. Which LetsEncrypt client to use? Meh, any of them will do. This is easy, any Senior SWE with a few years of experience can do LetsEncrypt in their sleep.
Great! Now we can go build a client that uploads ﬁles to the cloud.
But wait, who is allowed to upload ﬁles? Time to add an identity system. Maybe Sign-in with Google? Well, not everyone uses Google. Perhaps pull in an existing user account management library. 2FA? Account recovery emails? I’m sure there’s an npm for this. Done.
To which region do we upload the ﬁles? Well, the closest one, of course! We’ll set up our load balancer to connect users to the closest instance. Do we need edge computing for this? I don’t know, but edge computing sounds amazing, let’s add some. I heard ﬂy.io is good.
How long do we keep the ﬁles after uploading, if the recipient doesn’t retrieve them? I don’t know. Pick something. A week. Too long and we waste money on storage costs; too short and we get weird errors when people download too slowly. Don’t worry, they can retry.
How do we notify the recipient that there is a ﬁle waiting for them to download? Oh, I know this one! Push notiﬁcations! Well, on mobile we can use push notiﬁcations. On desktop, we’ll need to use HTTP long polls. Honestly I don’t know how to do HTTP long polls, it seems like a good way to pull out all my hair. How about we just poll periodically instead. Say, every 5 seconds.
Okay, uploading works, polling is implemented, and… wait, how do we connect the upload stream with the right download poller? I guess we need a database to keep track of uploaded ﬁles. And something to clear stuff out of the database and delete the S3 ﬁle after a successful download. Is that a message queue? Yes, yes, I think it is. No problem, AWS will sell me a message queue and it’s going to be awesome, with literally dozens of transactions per second per thread, like a 1960s IBM mainframe. Wait, no, 1960s mainframes could do way more transactions than that. Where was I? Anyway, dozens of transactions per second is plenty.
After all that, downloading is pretty easy. It authenticates through the same identity system, polls periodically, and when a ﬁle is ready to download, generates an authenticated S3 redirect so that it can securely…
…um, let me lock down those S3 bucket permissions real quick…
…AHEM so it can securely retrieve the ﬁle and nobody else can.
Oh. Wait. I forgot about encryption! We can’t just store people’s ﬁles, unencrypted, in S3, can we? A security breach would be a disaster, it would give the attacker access to all the in-ﬂight ﬁles in the world. Let’s read about S3 encryption-at-rest features. Sweet, it has those! Let’s turn them on. But come to think of it, why is encryption-at-rest just a ﬂag? Doesn’t that mean I could still easily send the ﬁles to the wrong person?
…Yes. If I want end-to-end encryption, I have to roll my own. So the uploader needs to encrypt the ﬁle with, uh, the downloader’s public key, and…
…oh no. Where can I get the downloader’s public key? Let’s go back. Okay, the downloader uploads their public key to the server in advance, before we transfer anything. Now the upload client, when it wants to upload a ﬁle, ﬁrst asks for a list of public keys of the available downloaders. Then the user picks one, it encrypts the ﬁle and uploads it, and the downloader we chose will have the right key to decrypt.
Look. Do not even talk to me about key rotation. I am not in the mood.
Success! And with that simple effort, and maybe some terraform or something, and some continuous integration, you have built yourself an approximate clone of Firefox Send, the now-cancelled project that, in addition to being expensive to run, turns out to have been a magnet for botnets and abuse because of some further design problems not explored above.
If this is what it takes to transfer a ﬁle nowadays, no wonder every service that does it needs to charge money, or put arbitrary limits on ﬁle sizes, or show you ads, or worse.
You know what, on second thought, all this was a terrible idea, maybe we should have tried the p2p method after all. How NAT Traversal Works> Okay, no, not that.
And this is why Tailscale is different.
 Security side note: it turns out HTTP PUT requests cannot be initiated by a web browser without using CORS. This prevents XSRF attacks on Taildrop. Otherwise we would have needed to add a session cookie or something.
 To pay proper homage to the Old Ones, this perhaps should have been called identd instead. The Internet’s whois service is a different (kind of misnamed) thing entirely. And nobody knows what identd is anymore. Oh well.