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runlai_jiang

8 Infinity Facts That Will Blow Your Mind - 0 views

  • Infinity has its own special symbol: ∞. The symbol, sometimes called the lemniscate, was introduced by clergyman and mathematician John Wallis in 1655. The word "lemniscate" comes from the Latin word lemniscus, which means "ribbon," while the word "infinity" comes from the Latin word infinitas, which means "boundless."
  • Of all Zeno's paradoxes, the most famous is his paradox of the Tortoise and Achilles. In the paradox, a tortoise challenges the Greek hero Achilles to a race, providing the tortoise is given a small head start. The tortoise argues he will win the race because as Achilles catches up to him, the tortoise will have gone a bit further, adding to the distance.
  • Pi as an Example of Infinity Pi is a number consisting of an infinite number of digits. Jeffrey Coolidge / Getty Images Another good example of infinity is the number π or pi. Mathematicians use a symbol for pi because it's impossible to write the number down. Pi consists of an infinite number of digits. It's often rounded to 3.14 or even 3.14159, yet no matter how many digits you write, it's impossible to get to the end.
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  • Fractals and Infinity A fractal may be magnified over and over, to infinity, always revealing more detail. PhotoviewPlus / Getty Images A fractal is an abstract mathematical object, used in art and to simulate natural phenomena. Written as a mathematical equation, most fractals are nowhere differentiable. When viewing an image of a fractal, this means you could zoom in and see new detail. In other words, a fractal is infinitely magnifiable.The Koch snowflake is an interesting example of a fractal. The snowflake starts as an equilateral triangle. For each iteration of the fractal:Each line segment is divided into three equal segments.
  • Cosmology and Infinity Even if the universe is finite, it might be one of an infinite number of "bubbles.". Detlev van Ravenswaay / Getty Images Cosmologists study the universe and ponder infinity. Does space go on and on without end? This remains an open question. Even if the physical universe as we know it has a boundary, there is still the multiverse theory to consider. Our universe may be but one in an infinite number of them.
grayton downing

BBC News - New galaxy 'most distant' yet discovered - 0 views

  • The galaxy is about 30 billion light-years away and is helping scientists shed light on the period that immediately followed the Big Bang.
  • "This is the most distant galaxy we've confirmed. We are seeing this galaxy as it was 700 million years after the Big Bang."
  • Astronomers were able to measure how far it was from Earth by analysing its colour.
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  • The system is small: about 1-2% the mass of the Milky Way and is rich in heavier elements.
  • astronomers are likely to discover even more distant galaxies when Nasa's James Webb Space Telescope (JWST) is launched and other ground-based telescopes come online.
  • One very interesting way to learn about the Universe is to study these outliers and that tells us something about what sort of physical processes are dominating galaxy formation and galaxy evolution. "What was great about this galaxy is not only is it so distant, it is also pretty exceptional."
  • But it has a surprising feature: it is turning gas and dust into new stars at a remarkable rate, churning them out hundreds of times faster than our own galaxy can.
  • This is an important step forward, but we need to continue looking for more.
johnsonle1

Milky Way being pushed through space by cosmic dead zone, say scientists | Science | Th... - 0 views

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    The movement of the Milky Way is dominated by the gravitational attraction of the galaxies around it. If galaxies were scattered randomly through space, the pull would be the same in every direction. But galaxies are not evenly spread out in the universe. As a result, patches of space that are dense in galaxies draw others towards them, while regions that are emptier than normal literally fail to pull their weight: they effectively push objects away from them.
Javier E

A New Alternative to Dark Matter - The Atlantic - 0 views

  • The challenges for alternative gravity theories—collectively known as modified Newtonian dynamics, or MOND—were spelled out in a separate preprint coincidentally published the day after the new model appeared. Chief among them is recasting the leading role dark matter plays in drawing the universe together, as described by a well-established cosmological model known as LCDM, or Lambda cold dark matter.
  • Simply put, LCDM says that we wouldn’t be here without dark matter. The infant universe was so smooth that the gravitational attraction of ordinary matter alone wouldn’t have been enough to gather particles into galaxies, stars, and planets. Enter dark-matter particles. Under the LCDM model, their collective bulk sculpts normal matter into the modern cosmic structures studied by astronomers.
  • LCDM became the standard model of cosmology in part because it so precisely agrees with the CMB. This map of the early universe shows almost imperceptibly thick and thin spots rippling through the cosmos. More recently, researchers have been able to measure the orientation or polarization of the CMB’s light more precisely. Any successful cosmology will need to establish a comprehensive history of the cosmos by reproducing these three observations: the CMB’s temperature, the CMB’s polarization, and the current distribution of galaxies and galaxy clusters.
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  • Recreating these and other features without LCDM’s titular ingredient, Spergel showed, requires the finest of theoretical needle threading. “We haven’t disproven the existence of all these [modified-gravity theories],” he says. “But any alternative theory has to jump through these hoops.”
  • Złosnik and Skordis believe they’ve done just that—although in a way that might surprise MOND skeptics and fans alike. They managed to construct a theory of gravity that contains an ingredient that acts exactly like an invisible form of matter on cosmic scales, blurring the line between the dark matter and MOND paradigms.
  • Their theory, dubbed RelMOND, adds to the equations of general relativity an omnipresent field that behaves differently in different arenas. On the grandest scales, where the universe noticeably stretches as it expands, the field acts like invisible matter. In this mode, which Złosnik calls “dark dust,” the field could have shaped the visible universe just as dark matter would
  • RelMOND “cannot do worse than LCDM,” says Złosnik, who notes that it very closely mimics that theory for the universe as a whole.
  • But if we zoom in on a galaxy, where the fabric of space holds rather still, the field acts in a way that’s true to its MOND roots: It entwines itself with the standard gravitational field, beefing it up just enough to hold a galaxy together without extra matter
  • (The researchers aren’t yet sure how the field acts for larger clusters of galaxies, a perennial MOND sore spot. They suggest that this intermediate scale might be a good place to look for observational clues that could set the theory apart.)
  • Despite this mathematical achievement by Złosnik and Skordis, dark matter remains the simpler theory. Constructing the new field takes four new moving mathematical parts, while LCDM handles dark matter with just one. Hooper likens the situation to a detective debating whether a person at a murder scene is the murderer or has been framed by the CIA. Even if the available evidence matches both theories, one requires less of a leap.
johnsonel7

A new map reveals radio waves from tens of thousands of galaxies | Science News - 0 views

  • Radio telescopes are good probes of star formation. But until now, they haven’t been sensitive enough to see radio waves coming from the vast majority of galaxies that produced stars during the peak of star production, an epoch roughly 10 billion years ago known as cosmic noon (SN: 6/20/14).
  • In that image, more than 17,000 pinpoints of radio energy — nearly every one a star-forming galaxy — fill a patch of sky that, as seen from Earth, could be covered by about five full moons.
  • What’s more, he says, there are a little less than twice as many of these sources as expected, suggesting that star formation was much higher around cosmic noon than predicted by calculations based on infrared, optical and ultraviolet data
katherineharron

Mysterious repeating fast radio burst traced to nearby galaxy - CNN - 0 views

  • Astronomers have traced the signal of an enigmatic repeating fast radio burst for only the second time -- and it's in a spiral galaxy similar to our own, not so far away.
  • Multiple individual fast radio bursts in past years have been traced back to their sources in other galaxies, although those have yet to shed light on what created them.But this newly discovered repeating FRB has a different source from the first one that was found in 2019, deepening the mystery of how these radio waves are created.
  • "The FRB is among the closest yet seen, and we even speculated that it could be a more conventional object in the outskirts of our own galaxy," said Mohit Bhardwaj, study co-author and McGill University doctoral student. "However, the observation proved that it's in a relatively nearby galaxy, making it still a puzzling FRB but close enough to now study using many other telescopes."
maxwellokolo

Ultra-rare galaxy could be 'one of a kind' - 0 views

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    A few years ago, it caught the attention of researcher Patrick Treuthardt as he analyzed a span of galaxies. At first, he thought it was a small, fairly common elliptical galaxy that happened to be more circular than usual. But a closer look revealed that he had stumbled across something incredibly rare.
katherineharron

Mysterious fast radio bursts helped detect missing matter in the universe, study says -... - 0 views

  • Mysterious fast radio bursts have been used to unlock another strange aspect of the universe: the case of the "missing matter."
  • Astronomers have yet to determine what causes these fast radio bursts, which are unpredictable but can be spotted and traced back to their origin using sensitive telescopes.
  • Normal matter, called baryonic matter in this study, is made of the protons and neutrons that comprise both humans and star stuff. But astronomers could only account for about half of it that should exist in the universe.
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  • Unaccounted for, this missing matter was predicted to exist, but hard to find. In fact, astronomers have been searching for it over the last 30 years, the researchers said. Measurements of the Big Bang show how much matter was present in the early days of the universe, suggesting its existence.
  • "It turned out that it was hiding in a density so low that it does not emit light, it doesn't absorb it, and it doesn't reflect it," he said.
  • "The radiation from fast radio bursts gets spread out by the missing matter in the same way that you see the colors of sunlight being separated in a prism," Macquart said.
  • "Their millisecond durations made it very easy to measure the effect of dispersion — the process by which their longer wavelength emission is delayed with respect to their shorter wavelength emission is delayed — and hence to measure exactly how much matter they have encountered on their multi-billion year intergalactic journeys to Earth," Macquart said.
  • Astronomers were able to pin down the source of a repeating fast radio burst in 2017. But single radio bursts are harder to pinpoint because they don't reoccur.
  • "ASKAP both has a wide field of view, about 60 times the size of the full Moon, and can image in high resolution," said Ryan Shannon, study coauthor and associate professor at Swinburne University of Technology, in a statement. "This means that we can catch the bursts with relative ease and then pinpoint locations to their host galaxies with incredible precision.
  • "We've discovered the equivalent of the Hubble-Lemaître Law for galaxies, only for fast radio bursts," Macquart said. "The Hubble-Lemaître Law, which says the more distant a galaxy from us, the faster it is moving away from us, underpins all measurements of galaxies at cosmological distances."
Javier E

Ta-Nehisi Coates's 'Letter to My Son' - The Atlantic - 0 views

  • The question is not whether Lincoln truly meant “government of the people” but what our country has, throughout its history, taken the political term “people” to actually mean. In 1863 it did not mean your mother or your grandmother, and it did not mean you and me.
  • When the journalist asked me about my body, it was like she was asking me to awaken her from the most gorgeous dream. I have seen that dream all my life. It is perfect houses with nice lawns. It is Memorial Day cookouts, block associations, and driveways. The Dream is tree houses and the Cub Scouts. And for so long I have wanted to escape into the Dream, to fold my country over my head like a blanket. But this has never been an option, because the Dream rests on our backs, the bedding made from our bodies.
  • The destroyers will rarely be held accountable. Mostly they will receive pensions.
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  • you know now, if you did not before, that the police departments of your country have been endowed with the authority to destroy your body. It does not matter if the destruction is the result of an unfortunate overreaction. It does not matter if it originates in a misunderstanding. It does not matter if the destruction springs from a foolish policy
  • But a society that protects some people through a safety net of schools, government-backed home loans, and ancestral wealth but can only protect you with the club of criminal justice has either failed at enforcing its good intentions or has succeeded at something much darker.
  • It is hard to face this. But all our phrasing—race relations, racial chasm, racial justice, racial profiling, white privilege, even white supremacy—serves to obscure that racism is a visceral experience, that it dislodges brains, blocks airways, rips muscle, extracts organs, cracks bones, breaks teeth
  • ou must never look away from this. You must always remember that the sociology, the history, the economics, the graphs, the charts, the regressions all land, with great violence, upon the body.
  • And should one live in such a body? What should be our aim beyond meager survival of constant, generational, ongoing battery and assault? I have asked this question all my life.
  • The question is unanswerable, which is not to say futile. The greatest reward of this constant interrogation, of confrontation with the brutality of my country, is that it has freed me from ghosts and myths.
  • I was afraid long before you, and in this I was unoriginal. When I was your age the only people I knew were black, and all of them were powerfully, adamantly, dangerously afraid. It was always right in front of me. The fear was there in the extravagant boys of my West Baltimore neighborhood
  • The fear lived on in their practiced bop, their slouching denim, their big T- shirts, the calculated angle of their baseball caps, a catalog of behaviors and garments enlisted to inspire the belief that these boys were in firm possession of everything they desired.
  • To be black in the Baltimore of my youth was to be naked before the elements of the world, before all the guns, fists, knives, crack, rape, and disease. The law did not protect us. And now, in your time, the law has become an excuse for stopping and frisking you, which is to say, for furthering the assault on your body
  • I remember being amazed that death could so easily rise up from the nothing of a boyish afternoon, billow up like fog. I knew that West Baltimore, where I lived; that the north side of Philadelphia, where my cousins lived; that the South Side of Chicago, where friends of my father lived, comprised a world apart. Somewhere out there beyond the firmament, past the asteroid belt, there were other worlds where children did not regularly fear for their bodies
  • here will surely always be people with straight hair and blue eyes, as there have been for all history. But some of these straight-haired people with blue eyes have been “black,” and this points to the great difference between their world and ours. We did not choose our fences. They were imposed on us by Virginia planters obsessed with enslaving as many Americans as possible. Now I saw that we had made something down here, in slavery, in Jim Crow, in ghettoes. At The Mecca I saw how we had taken their one-drop rule and flipped it. They made us into a race. We made ourselves into a people.
  • I came to understand that my country was a galaxy, and this galaxy stretched from the pandemonium of West Baltimore to the happy hunting grounds of Mr. Belvedere. I obsessed over the distance between that other sector of space and my own. I knew that my portion of the American galaxy, where bodies were enslaved by a tenacious gravity, was black and that the other, liberated portion was not. I knew that some inscrutable energy preserved the breach. I felt, but did not yet understand, the relation between that other world and me. And I felt in this a cosmic injustice, a profound cruelty, which infused an abiding, irrepressible desire to unshackle my body and achieve the velocity of escape.
  • Before I could escape, I had to survive, and this could only mean a clash with the streets, by which I mean not just physical blocks, nor simply the people packed into them, but the array of lethal puzzles and strange perils which seem to rise up from the asphalt itself. The streets transform every ordinary day into a series of trick questions, and every incorrect answer risks a beat-down, a shooting, or a pregnancy. No one survives unscathed
  • When I was your age, fully one-third of my brain was concerned with who I was walking to school with, our precise number, the manner of our walk, the number of times I smiled, who or what I smiled at, who offered a pound and who did not—all of which is to say that I practiced the culture of the streets, a culture concerned chiefly with securing the body.
  • Why were only our heroes nonviolent? Back then all I could do was measure these freedom-lovers by what I knew. Which is to say, I measured them against children pulling out in the 7-Eleven parking lot, against parents wielding extension cords, and the threatening intonations of armed black gangs saying, “Yeah, nigger, what’s up now?” I judged them against the country I knew, which had acquired the land through murder and tamed it under slavery, against the country whose armies fanned out across the world to extend their dominion. The world, the real one, was civilization secured and ruled by savage means. How could the schools valorize men and women whose values society actively scorned? How could they send us out into the streets of Baltimore, knowing all that they were, and then speak of nonviolence?
  • the beauty of the black body was never celebrated in movies, in television, or in the textbooks I’d seen as a child. Everyone of any import, from Jesus to George Washington, was white. This was why your grandparents banned Tarzan and the Lone Ranger and toys with white faces from the house. They were rebelling against the history books that spoke of black people only as sentimental “firsts”—first black four-star general, first black congressman, first black mayor—always presented in the bemused manner of a category of Trivial Pursuit.
  • erious history was the West, and the West was white. This was all distilled for me in a quote I once read, from the novelist Saul Bellow. I can’t remember where I read it, or when—only that I was already at Howard. “Who is the Tolstoy of the Zulus?,” Bellow quipped
  • this view of things was connected to the fear that passed through the generations, to the sense of dispossession. We were black, beyond the visible spectrum, beyond civilization. Our history was inferior because we were inferior, which is to say our bodies were inferior. And our inferior bodies could not possibly be accorded the same respect as those that built the West. Would it not be better, then, if our bodies were civilized, improved, and put to some legitimate Christian use?
  • now I looked back on my need for a trophy case, on the desire to live by the standards of Saul Bellow, and I felt that this need was not an escape but fear again—fear that “they,” the alleged authors and heirs of the universe, were right. And this fear ran so deep that we accepted their standards of civilization and humanity.
  • “Tolstoy is the Tolstoy of the Zulus,” wrote Wiley. “Unless you find a profit in fencing off universal properties of mankind into exclusive tribal ownership.” And there it was. I had accepted Bellow’s premise. In fact, Bellow was no closer to Tolstoy than I was to Nzinga. And if I were closer it would be because I chose to be, not because of destiny written in DNA. My great error was not that I had accepted someone else’s dream but that I had accepted the fact of dreams, the need for escape, and the invention of racecraft.
  • still and all I knew that we were something, that we were a tribe—on one hand, invented, and on the other, no less real. The reality was out there on the Yard, on the first warm day of spring when it seemed that every sector, borough, affiliation, county, and corner of the broad diaspora had sent a delegate to the great world party
  • I could see now that that world was more than a photonegative of that of the people who believe they are white. “White America” is a syndicate arrayed to protect its exclusive power to dominate and control our bodies. Sometimes this power is direct (lynching), and sometimes it is insidious (redlining). But however it appears, the power of domination and exclusion is central to the belief in being white, and without it, “white people” would cease to exist for want of reasons
  • There is nothing uniquely evil in these destroyers or even in this moment. The destroyers are merely men enforcing the whims of our country, correctly interpreting its heritage and legacy. This legacy aspires to the shackling of black bodies
  • Think of all the embraces, all the private jokes, customs, greetings, names, dreams, all the shared knowledge and capacity of a black family injected into that vessel of flesh and bone. And think of how that vessel was taken, shattered on the concrete, and all its holy contents, all that had gone into each of them, was sent flowing back to the earth. It is terrible to truly see our particular beauty, Samori, because then you see the scope of the loss. But you must push even further. You must see that this loss is mandated by the history of your country, by the Dream of living white.
  • I don’t know if you remember how the film we saw at the Petersburg Battlefield ended as though the fall of the Confederacy were the onset of a tragedy, not jubilee. I doubt you remember the man on our tour dressed in the gray wool of the Confederacy, or how every visitor seemed most interested in flanking maneuvers, hardtack, smoothbore rifles, grapeshot, and ironclads, but virtually no one was interested in what all of this engineering, invention, and design had been marshaled to achieve. You were only 10 years old. But even then I knew that I must trouble you, and this meant taking you into rooms where people would insult your intelligence, where thieves would try to enlist you in your own robbery and disguise their burning and looting as Christian charity. But robbery is what this is, what it always was.
  • American reunion was built on a comfortable narrative that made enslavement into benevolence, white knights of body snatchers, and the mass slaughter of the war into a kind of sport in which one could conclude that both sides conducted their affairs with courage, honor, and élan. This lie of the Civil War is the lie of innocence, is the Dream.
  • I, like every kid I knew, loved The Dukes of Hazzard. But I would have done well to think more about why two outlaws, driving a car named the General Lee, must necessarily be portrayed as “just some good ole boys, never meanin’ no harm”—a mantra for the Dreamers if there ever was one. But what one “means” is neither important nor relevant. It is not necessary that you believe that the officer who choked Eric Garner set out that day to destroy a body. All you need to understand is that the officer carries with him the power of the American state and the weight of an American legacy, and they necessitate that of the bodies destroyed every year, some wild and disproportionate number of them will be black.
  • Here is what I would like for you to know: In America, it is traditional to destroy the black body—it is heritage. Enslavement was not merely the antiseptic borrowing of labor—it is not so easy to get a human being to commit their body against its own elemental interest. And so enslavement must be casual wrath and random manglings, the gashing of heads and brains blown out over the river as the body seeks to escape. It must be rape so regular as to be industrial. There is no uplifting way to say this.
  • It had to be blood. It had to be the thrashing of kitchen hands for the crime of churning butter at a leisurely clip. It had to be some woman “chear’d ... with thirty lashes a Saturday last and as many more a Tuesday again.” It could only be the employment of carriage whips, tongs, iron pokers, handsaws, stones, paperweights, or whatever might be handy to break the black body, the black family, the black community, the black nation. The bodies were pulverized into stock and marked with insurance. And the bodies were an aspiration, lucrative as Indian land, a veranda, a beautiful wife, or a summer home in the mountains. For the men who needed to believe themselves white, the bodies were the key to a social club, and the right to break the bodies was the mark of civilization.
  • “The two great divisions of society are not the rich and poor, but white and black,” said the great South Carolina senator John C. Calhoun. “And all the former, the poor as well as the rich, belong to the upper class, and are respected and treated as equals.” And there it is—the right to break the black body as the meaning of their sacred equality. And that right has always given them meaning, has always meant that there was someone down in the valley because a mountain is not a mountain if there is nothing below.
  • There is no them without you, and without the right to break you they must necessarily fall from the mountain, lose their divinity, and tumble out of the Dream. And then they would have to determine how to build their suburbs on something other than human bones, how to angle their jails toward something other than a human stockyard, how to erect a democracy independent of cannibalism. I would like to tell you that such a day approaches when the people who believe themselves to be white renounce this demon religion and begin to think of themselves as human. But I can see no real promise of such a day. We are captured, brother, surrounded by the majoritarian bandits of America. And this has happened here, in our only home, and the terrible truth is that we cannot will ourselves to an escape on our own.
  • I think now of the old rule that held that should a boy be set upon in someone else’s chancy hood, his friends must stand with him, and they must all take their beating together. I now know that within this edict lay the key to all living. None of us were promised to end the fight on our feet, fists raised to the sky. We could not control our enemies’ number, strength, or weaponry. Sometimes you just caught a bad one. But whether you fought or ran, you did it together, because that is the part that was in our control. What we must never do is willingly hand over our own bodies or the bodies of our friends. That was the wisdom: We knew we did not lay down the direction of the street, but despite that, we could—and must—fashion the way of our walk. And that is the deeper meaning of your name—that the struggle, in and of itself, has meaning.
  • I have raised you to respect every human being as singular, and you must extend that same respect into the past. Slavery is not an indefinable mass of flesh. It is a particular, specific enslaved woman, whose mind is as active as your own, whose range of feeling is as vast as your own; who prefers the way the light falls in one particular spot in the woods, who enjoys fishing where the water eddies in a nearby stream, who loves her mother in her own complicated way, thinks her sister talks too loud, has a favorite cousin, a favorite season, who excels at dressmaking and knows, inside herself, that she is as intelligent and capable as anyone. “Slavery” is this same woman born in a world that loudly proclaims its love of freedom and inscribes this love in its essential texts, a world in which these same professors hold this woman a slave, hold her mother a slave, her father a slave, her daughter a slave, and when this woman peers back into the generations all she sees is the enslaved. She can hope for more. She can imagine some future for her grandchildren. But when she dies, the world—which is really the only world she can ever know—ends. For this woman, enslavement is not a parable. It is damnation. It is the never-ending night. And the length of that night is most of our history. Never forget that we were enslaved in this country longer than we have been free. Never forget that for 250 years black people were born into chains—whole generations followed by more generations who knew nothing but chains.
  • You must resist the common urge toward the comforting narrative of divine law, toward fairy tales that imply some irrepressible justice. The enslaved were not bricks in your road, and their lives were not chapters in your redemptive history. They were people turned to fuel for the American machine. Enslavement was not destined to end, and it is wrong to claim our present circumstance—no matter how improved—as the redemption for the lives of people who never asked for the posthumous, untouchable glory of dying for their children. Our triumphs can never redeem this. Perhaps our triumphs are not even the point. Perhaps struggle is all we have
  • I am not a cynic. I love you, and I love the world, and I love it more with every new inch I discover. But you are a black boy, and you must be responsible for your body in a way that other boys cannot know. Indeed, you must be responsible for the worst actions of other black bodies, which, somehow, will always be assigned to you. And you must be responsible for the bodies of the powerful—the policeman who cracks you with a nightstick will quickly find his excuse in your furtive movements. You have to make your peace with the chaos, but you cannot lie.
  • “I could have you arrested,” he said. Which is to say: “One of your son’s earliest memories will be watching the men who sodomized Abner Louima and choked Anthony Baez cuff, club, tase, and break you.” I had forgotten the rules, an error as dangerous on the Upper West Side of Manhattan as on the West Side of Baltimore. One must be without error out here. Walk in single file. Work quietly. Pack an extra No. 2 pencil. Make no mistakes.
  • the price of error is higher for you than it is for your countrymen, and so that America might justify itself, the story of a black body’s destruction must always begin with his or her error, real or imagined—with Eric Garner’s anger, with Trayvon Martin’s mythical words (“You are gonna die tonight”), with Sean Bell’s mistake of running with the wrong crowd, with me standing too close to the small-eyed boy pulling out.
  • You are called to struggle, not because it assures you victory but because it assures you an honorable and sane life
  • I am sorry that I cannot save you—but not that sorry. Part of me thinks that your very vulnerability brings you closer to the meaning of life, just as for others, the quest to believe oneself white divides them from it. The fact is that despite their dreams, their lives are also not inviolable. When their own vulnerability becomes real—when the police decide that tactics intended for the ghetto should enjoy wider usage, when their armed society shoots down their children, when nature sends hurricanes against their cities—they are shocked by the rages of logic and the natural world in a way that those of us who were born and bred to understand cause and effect can never be.
  • I would not have you live like them. You have been cast into a race in which the wind is always at your face and the hounds are always at your heels. And to varying degrees this is true of all life. The difference is that you do not have the privilege of living in ignorance of this essential fact.
  • I never wanted you to be twice as good as them, so much as I have always wanted you to attack every day of your brief bright life determined to struggle. The people who must believe they are white can never be your measuring stick. I would not have you descend into your own dream. I would have you be a conscious citizen of this terrible and beautiful world.
haubertbr

Milky Way galaxy is being pushed across the universe - 0 views

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    Researchers have known that the galaxy was moving at a relative speed for the past 30 years, but they didn't know why. "Now we find an emptiness in exactly the opposite direction, which provides a 'push' in the sense of a lack of pull," said Brent Tully, one of the study authors and an astronomer at the Institute for Astronomy in Honolulu.
grayton downing

BBC News - Exoplanet tally soars above 1,000 - 0 views

  • The number of observed exoplanets - worlds circling distant stars - has passed 1,000.
  • These new worlds are listed in the Extrasolar Planets Encyclopaedia.
  • The Kepler space telescope, which spotted many of these worlds in recent years, broke down earlier this year. Scientists still have to trawl through more than 3,500 other candidates from this mission so the number could rapidly increase.
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  • In January 2013, astronomers used Kepler's data to estimate that there could be at least 17 billion Earth-sized exoplanets in the Milky Way galaxy.
  • The number of confirmed planets frequently increases because as scientists analyse the data they are able publish their results online immediately. But as the finds are not yet peer reviewed, the total figure remains subject to change.
  • "That's why the other catalogues just lag behind. The review is reliable as it's exactly the same as what the journals do."
  • "no consensus for the definition of a planet" a
  • "Some objects, like some Kepler planets, are declared 'confirmed planets' but have not been published in [referenced] articles. It does not mean that they will not be published later on, but it introduces another fuzziness in the tally," he added.
  • "I don't just want to know where the exoplanets are, I want to understand the stars, because they are the hosts for the planets. I want to understand the whole galaxy and the distribution of the stars because everything is connected," he explained.
  • For him, the most exciting discoveries are Earth-like planets which could be habitable.
  • This planet likely has the same mass as Earth but is outside the "habitable zone" as it circles its star far closer than Mercury orbits our Sun.
qkirkpatrick

Pluto's moons tumble in orbit, Hubble measurements reveal | Science | The Guardian - 0 views

  • Pluto’s moons have been tracked closely for the first time, showing that they tumble unpredictably rather than keeping one face fixed on their host planet.
  • Astronomers also observed that Pluto, whose status was downgraded to a dwarf planet in 2006, might be better regarded as a binary dwarf as it is locked in orbit with its largest moon, called Charon.
  • “Like good children, our moon and most others keep one face focused attentively on their parent planet,’ said Douglas Hamilton, professor of astronomy at the University of Maryland and a co-author of the study. “What we’ve learned is that Pluto’s moons are more like ornery teenagers who refuse to follow the rules.”
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  • “They speed up and slow down, rock their north pole towards the planet and back again and maybe even reverse direction,” said Hamilton. “It would be a pretty confusing system to be in.”
  • The findings, published in the journal Nature, were based on ten years of observations of Pluto from the Hubble space telescope, which the researchers re-analysed after the relatively recent discovery of the four small moons
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    How does technology help toward finding truth? Is the physics we see on earth different from the phsics on other stars and in other galaxies?
anniina03

It's Cold Outside, but Earth Is at Its Closest Approach to the Sun - The New York Times - 0 views

  • This story was updated to reflect 2020’s perihelion.In the wee hours of Sunday (2:47 a.m. Eastern time, to be exact), Earth will make its closest approach to the sun and reach a point in its orbit known as perihelion.
  • Chilly as winter may feel in the Northern Hemisphere, we’re more than three million miles closer to our fiery star than we were in the dead of summer.
  • The change in distance occurs because our planet’s orbit is stretched into an ellipse
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  • Although three million miles sounds vast, it’s not much on the scale of our solar system. In fact, despite the planet’s elliptical path through the heavens, most astronomers say that Earth’s orbit is basically circular. On a scale of 0 to 100 percent, where 0 is a perfect circle and nearly 100 is a very thin oval, Earth only scores a 1.7.
  • It’s a defining trait that keeps our planet at roughly the same distance from our sun, and keeps the climate relatively stable. This has led many astronomers to wonder whether a circular orbit just might be a crucial ingredient in the cocktail of life — and a key factor to consider as they search for signs of alien life around the thousands of exoplanets known to be circling other stars within the galaxy.
  • Consider the exoplanet known as HD 20782 b, which boasts the highest eccentricity yet discovered — a whopping 97 percent. Although the alien world is likely more akin to Jupiter than Earth in mass, it’s easy to imagine what might happen to a wildly eccentric Earthlike planet.At its closest approach to the star, the planet would face an explosion of heat that would evaporate the planet’s oceans and strip the planet’s atmosphere, sending crucial molecules such as oxygen streaming into space.
  • Such a dire portrait could suggest that life prefers a circle. But do most exoplanets orbit their host stars in bands similar to the Earth, or are their orbits more like that of HD 20782 b?
  • This suggests that most of these rocky worlds might be able to host a stable climate and, therefore, life.But Dr. Kane and other researchers warned against dismissing the possibility of life forming on worlds with highly-eccentric orbits.
  • Last year, Dr. Kane and his colleagues estimated that a planet with an eccentricity as high as 30 or even 40 percent could remain habitable
  • the galaxy and its many orbiting planets could surprise us. “I think it’s often assumed that life is wimpy and needs ‘just so’ conditions to exist,” Dr. Raymond said. “But life on Earth did indeed survive some tough times.”
Javier E

Elon Musk Is Not Playing Four-Dimensional Chess - 0 views

  • Musk is not wrong that Twitter is chock-full of noise and garbage, but the most pernicious stuff comes from real people and a media ecosystem that amplifies and rewards incendiary bullshit
  • This dynamic is far more of a problem for Twitter (but also the news media and the internet in general) than shadowy bot farms are. But it’s also a dilemma without much of a concrete solution
  • Were Musk actually curious or concerned with the health of the online public discourse, he might care about the ways that social media platforms like Twitter incentivize this behavior and create an information economy where our sense of proportion on a topic can be so easily warped. But Musk isn’t interested in this stuff, in part because he is a huge beneficiary of our broken information environment and can use it to his advantage to remain constantly in the spotlight.
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  • Musk’s concern with bots isn’t only a bullshit tactic he’s using to snake out of a bad business deal and/or get a better price for Twitter; it’s also a great example of his shallow thinking. The man has at least some ability to oversee complex engineering systems that land rockets, but his narcissism affords him a two-dimensional understanding of the way information travels across social media.
  • He is drawn to the conspiratorial nature of bots and information manipulation, because it is a more exciting and easier-to-understand solution to more complex or uncomfortable problems. Instead of facing the reality that many people dislike him as a result of his personality, behavior, politics, or shitty management style, he blames bots. Rather than try to understand the gnarly mechanics and hard-to-solve problems of democratized speech, he sorts them into overly simplified boxes like censorship and spam and then casts himself as the crusading hero who can fix it all. But he can’t and won’t, because he doesn’t care enough to find the answers.
  • Musk isn’t playing chess or even checkers. He’s just the richest man in the world, bored, mad, and posting like your great-uncle.
Javier E

Holly the Cat's Incredible Journey - NYTimes.com - 0 views

  • “I really believe these stories, but they’re just hard to explain,” said Marc Bekoff, a behavioral ecologist at the University of Colorado. “Maybe being street-smart, maybe reading animal cues, maybe being able to read cars, maybe being a good hunter. I have no data for this.”There is, in fact, little scientific dogma on cat navigation. Migratory animals like birds, turtles and insects have been studied more closely, and use magnetic fields, olfactory cues, or orientation by the sun.
  • Strange, faraway locations would seem problematic, although he and Patrick Bateson, a behavioral biologist at Cambridge University, say that cats can sense smells across long distances. “Let’s say they associate the smell of pine with wind coming from the north, so they move in a southerly direction,”
  • Professor Tabor cited longer-distance reports he considered credible: Murka, a tortoiseshell in Russia, traveling about 325 miles home to Moscow from her owner’s mother’s house in Voronezh in 1989; Ninja, who returned to Farmington, Utah, in 1997, a year after her family moved from there to Mill Creek, Wash.; and Howie, an indoor Persian cat in Australia who in 1978 ran away from relatives his vacationing family left him with and eventually traveled 1,000 miles to his family’s home.
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  • The closest, said Roger Tabor, a British cat biologist, may have been a 1954 study in Germany which cats placed in a covered circular maze with exits every 15 degrees most often exited in the direction of their homes, but more reliably if their homes were less than five kilometers away.
  • “We haven’t the slightest idea how they do this,” Mr. Galaxy said. “Anybody who says they do is lying, and, if you find it, please God, tell me what it is.”
  • Nobody knows how it happened: an indoor housecat who got lost on a family excursion managing, after two months and about 200 miles, to return to her hometown.
kortanekev

Beyond Drake's Equation --"Life on Other Planets is More Optimism Than Science" (Monday... - 0 views

  • the Princeton University researchers have found that the expectation that life — from bacteria to sentient beings — has or will develop on other planets as on Earth might be based more on optimism than scientific evidence.
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    The optimism fallacy -- being biased based on what one hopes to find -- is impeding the accuracy of our research into life beyond earth. This fallacy causes one to form false assumptions from data we have already collected and jump to conclusions that are most probably, fallacious. 
Javier E

Which Is Bigger: A Human Brain Or The Universe? : Krulwich Wonders... : NPR - 0 views

  • If a brain can make crazy leaps across the cosmos and bring extra passengers along (like you when you listen to me), then in a metaphorical way, the brain is bigger than what's around it, wrote 19th century poet Emily Dickinson. The brain is wider than the sky,For, put them side by side,The one the other will includeWith ease, and you beside.
  • If a brain can make crazy leaps across the cosmos and bring extra passengers along (like you when you listen to me), then in a metaphorical way, the brain is bigger than what's around it, wrote 19th century poet Emily Dickinson. The brain is wider than the sky,For, put them side by side,The one the other will includeWith ease, and you beside.
  • "The universe is not only queerer than we suppose," said the biologist J.B.S. Haldane, "but queerer than we can suppose." In Haldane's view, the universe is bigger than the brain. There are things we just can't know, or even conjure with the brains we've got.
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  • If a brain can make crazy leaps across the cosmos and bring extra passengers along (like you when you listen to me), then in a metaphorical way, the brain is bigger than what's around it, wrote 19th century poet Emily Dickinson. The brain is wider than the sky,For, put them side by side,The one the other will includeWith ease, and you beside.
  • "The universe is not only queerer than we suppose," said the biologist J.B.S. Haldane, "but queerer than we can suppose." In Haldane's view, the universe is bigger than the brain. There are things we just can't know, or even conjure with the brains we've got.
  • If a brain can make crazy leaps across the cosmos and bring extra passengers along (like you when you listen to me), then in a metaphorical way, the brain is bigger than what's around it, wrote 19th century poet Emily Dickinson. The brain is wider than the sky,For, put them side by side,The one the other will includeWith ease, and you beside.
  • "The universe is not only queerer than we suppose," said the biologist J.B.S. Haldane, "but queerer than we can suppose." In Haldane's view, the universe is bigger than the brain. There are things we just can't know, or even conjure with the brains we've got.
  • "It's beyond our intellectual limits as a species. Put yourself into the position
  • "The universe is not only queerer than we suppose," said the biologist J.B.S. Haldane, "but queerer than we can suppose." In Haldane's view, the universe is bigger than the brain. There are things we just can't know, or even conjure with the brains we've got.
  • "The universe is not only queerer than we suppose," said the biologist J.B.S. Haldane, "but queerer than we can suppose." In Haldane's view, the universe is bigger than the brain. There are things we just can't know, or even conjure with the brains we've got.
  • "The universe is not only queerer than we suppose," said the biologist J.B.S. Haldane, "but queerer than we can suppose." In Haldane's view, the universe is bigger than the brain. There are things we just can't know, or even conjure with the brains we've got.
  • If a brain can make crazy leaps across the cosmos and bring extra passengers along (like you when you listen to me), then in a metaphorical way, the brain is bigger than what's around it, wrote 19th century poet Emily Dickinson. The brain is wider than the sky,For, put them side by side,The one the other will includeWith ease, and you beside.
  • "The universe is not only queerer than we suppose," said the biologist J.B.S. Haldane, "but queerer than we can suppose." In Haldane's view, the universe is bigger than the brain. There are things we just can't know, or even conjure with the brains we've got.
  • There are philosophers and scientists who say we will never understand the universe, we can't fathom the endless details or make good sense of the whole. We can try, but the universe is too big. The writer John Updike once explained the argument this way to reporter Jim Holt: "It's beyond our intellectual limits as a species. Put yourself into the position of a dog. A dog is responsive, shows intuition, looks at us with eyes behind which there is intelligence of a sort, and yet a dog must not understand most of the things it sees people doing. It must have no idea how they invented, say, the internal combustion engine. So maybe what we need to do is imagine that we're dogs and that there are realms that go beyond our understanding."
  • So does the universe get the crown?
  • Carl Sagan thought that we humans are good at finding patterns in nature, and if we know the rules, we can skip the details and understand the outline, the essence. It's not necessary for us to know everything. The problem is we don't know how many rules the cosmos has.
  • et the brain has its champions. "Consider the human brain," says physicist Sir Roger Penrose. "If you look at the entire physical cosmos, our brains are a tiny, tiny part of it. But they're the most perfectly organized part. Compared to the complexity of a brain, a galaxy is just an inert lump
  • my hunch is the universe will still outwit us, will still be "too wonderful" to be decoded, because we are, in the end, so much smaller than it is. And that's not a bad thing. To my mind, it's the search that matters, that sharpens us, gives us something noble to do.
  • Steven Weinberg famously said, "The effort to understand the universe is one of the very few things that lifts human life a little above the level of farce, and gives it some of the grace of tragedy."
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