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  • feedwordpress 08:01:49 on 2018/10/16 Permalink
    Tags: Andreas Cellarius, astronomy, , Harmonia Macrocosmica, , , , , Sir William Rowan Hamilton,   

    “The Bible shows the way to go to heaven, not the way the heavens go”*… 

     

    cellarius-seasons-banner-1024x689

     

    Harmonia Macrocosmica (1660), an atlas of the stars from the Dutch Golden Age of cartography, maps the structure of the heavens in twenty-nine extraordinary double-folio spreads. We are presented with the motions of the celestial bodies, the stellar constellations of the northern hemisphere, the old geocentric universe of Ptolemy, the newish heliocentric one of Copernicus [as above], and Tycho Brahe’s eccentric combination of the two — in which the Moon orbits the Earth, and the planets orbit the Sun, but the Sun still orbits the Earth. The marginal area of each brightly coloured map is a hive of activity: astronomers bent over charts debate their findings, eager youngsters direct their quadrants skywards, and cherubs fly about with pet birds in tow…

    northern stars

    The Northern Stellar Hemisphere of Antiquity

    More marvelous maps of the heavens at “The Celestial Atlas of Andreas Cellarius (1660)

    * Galileo (quoting a librarian at the Vatican)

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    As we look to the stars, we might recall that it was on this date in 1843 that Sir William Rowan Hamilton conceived the theory of quaternions.  A physicist, astronomer, and mathematician who made important contributions to classical mechanics, optics, and algebra, he had been working since the late 1830s on the basic principles of algebra, resulting in a theory of conjugate functions, or algebraic couples, in which complex numbers are expressed as ordered pairs of real numbers.  But he hadn’t succeeded in developing a theory of triplets that could be applied to three-dimensional geometric problems.  Walking with his wife along the Royal Canal in Dublin, Hamilton realized that the theory should involve quadruplets, not triplets– at which point he stopped to carve carve the underlying equations in a nearby bridge lest he forget them.

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  • feedwordpress 08:01:42 on 2018/10/15 Permalink
    Tags: astronomy, death of the universe, , Jesse L. Greenstein, quasar, , , , university, vacuum, vacuum decay   

    “And so the Universe ended”*… 

     

    implosion

    Conceptual illustration of the Higgs Field that physicists believe permeates the Universe, and that could theoretically bring about its end.

     

    Every once in a while, physicists come up with a new way to destroy the Universe. There’s the Big Rip (a rending of spacetime), the Heat Death (expansion to a cold and empty Universe), and the Big Crunch (the reversal of cosmic expansion). My favourite, though, has always been vacuum decay. It’s a quick, clean and efficient way of wiping out the Universe…

    Learn more about a possibility that really sucks: “Vacuum decay: the ultimate catastrophe.”

    * Douglas Adams, The Restaurant at the End of the Universe

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    As we we abhor a vacuum even more than nature does, we might send closely-observed birthday greetings to Jesse Leonard Greenstein; he was born on this date in 1909.  An astronomer who ran Cal Tech’s storied program for decades, he co-discovered (with Maarten Schmidt) the quasar.  While other astronomers had previously observed the bright bodies, Greenstein and Schmidt were the first to to interpret the red shift of quasars and correctly identify them as compact, very distant– and thus very old– objects.  Later, working with Louis Henyey, Greenstein designed and built a new spectrograph and wide-view camera to improve astronomical observations,

    greenstein source

     

     
  • feedwordpress 08:01:51 on 2018/09/28 Permalink
    Tags: astrobiology, astronomy, , , meteor, meteorite, Murchison, risk, ,   

    “The blazing meteor, when it descends to earth, is only a stone”*… 

     

    Meteors

     

    The odds of being hit by a meteorite are extremely low. You’re far more likely to die in a car crash or a fire than you are to die from a meteorite strike. It’s also more likely that you’ll be killed by lightning or a tornado – both of which are extremely rare. However, there’s bad news too – you have a higher chance of being hit by a meteorite than you do of winning the lottery…

    Oh, and avoid the United States (and India)!  See why at: “What Are Your Chances of Being Hit by a Meteorite?

    * Henry Wadsworth Longfellow

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    As we duck and cover, we might recall that it was on this date in 1969 that a large meteorite fell near Murchison in Victoria, Australia.  Both because it was an observed fall (its bright fireball was seen by many) and because it proved to be rich in organic compounds (an abundance of amino acids), it has been one of the most-studied meteorites.

    220px-Murchison_crop source

     

     
  • feedwordpress 08:01:14 on 2018/07/09 Permalink
    Tags: astronomy, , , , Mysterium cosmographicum, , , ,   

    “The truth is not always beautiful, nor beautiful words the truth.”*… 

     

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    Does anyone who follows physics doubt it is in trouble? When I say physics, I don’t mean applied physics, material science or what Murray-Gell-Mann called “squalid-state physics.” I mean physics at its grandest, the effort to figure out reality. Where did the universe come from? What is it made of? What laws govern its behavior? And how probable is the universe? Are we here through sheer luck, or was our existence somehow inevitable?

    In the 1980s Stephen Hawking and other big shots claimed that physics was on the verge of a “final theory,” or “theory of everything,” that could answer these big questions and solve the riddle of reality. I became a science writer in part because I believed their claims, but by the early 1990s I had become a skeptic. The leading contender for a theory of everything held that all of nature’s particles and forces, including gravity, stem from infinitesimal, stringy particles wriggling in nine or more dimensions.

    The problem is that no conceivable experiment can detect the strings or extra dimensions…

    John Horgan examines physicist Sabine Hossenfelder‘s claim that desire for beauty and other subjective biases have led physicists astray: “How Physics Lost Its Way.”

    * Lao Tzu, Tao Te Ching

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    As we contemplate certainty, we might recall that it was on this date in 1595 that Johann Kepler (and here) published Mysterium cosmographicum (Mystery of the Cosmos), in which he described an invisible underlying structure determining the six known planets in their orbits.  Kepler thought as a mathematician, devising a structure based on only five convex regular solids; the path of each planet lay on a sphere separated from its neighbors by touching an inscribed polyhedron.

    It was a beautiful, an elegant model– and one that fit the orbital data available at the time.  It was, nonetheless, wrong.

    Detailed view of Kepler’s inner sphere

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  • feedwordpress 09:01:58 on 2018/01/10 Permalink
    Tags: Arno Penzias, astronomy, , Foreign Policy Association, , , , , Robert Woodrow Wilson, Toward the Year 2018,   

    “Life can only be understood backwards; but it must be lived forwards”*… 

     

    If you wanted to hear the future in late May, 1968, you might have gone to Abbey Road to hear the Beatles record a new song of John Lennon’s—something called “Revolution.” Or you could have gone to the decidedly less fab midtown Hilton in Manhattan, where a thousand “leaders and future leaders,” ranging from the economist John Kenneth Galbraith to the peace activist Arthur Waskow, were invited to a conference by the Foreign Policy Association. For its fiftieth anniversary, the F.P.A. scheduled a three-day gathering of experts, asking them to gaze fifty years ahead. An accompanying book shared the conference’s far-off title: “Toward the Year 2018”…

    More amazing than science fiction,” proclaims the cover, with jacket copy envisioning how “on a summer day in the year 2018, the three-dimensional television screen in your living room” flashes news of “anti-gravity belts,” “a man-made hurricane, launched at an enemy fleet, [that] devastates a neutral country,” and a “citizen’s pocket computer” that averts an air crash. “Will our children in 2018 still be wrestling,” it asks, “with racial problems, economic depressions, other Vietnams?”

    Much of “Toward the Year 2018” might as well be science fiction today. With fourteen contributors, ranging from the weapons theorist Herman Kahn to the I.B.M. automation director Charles DeCarlo, penning essays on everything from “Space” to “Behavioral Technologies,” it’s not hard to find wild misses. The Stanford wonk Charles Scarlott predicts, exactly incorrectly, that nuclear breeder reactors will move to the fore of U.S. energy production while natural gas fades. (He concedes that natural gas might make a comeback—through atom-bomb-powered fracking.) The M.I.T. professor Ithiel de Sola Pool foresees an era of outright control of economies by nations—“They will select their levels of employment, of industrialization, of increase in GNP”—and then, for good measure, predicts “a massive loosening of inhibitions on all human impulses save that toward violence.” From the influential meteorologist Thomas F. Malone, we get the intriguing forecast of “the suppression of lightning”—most likely, he figures, “by the late 1980s.”

    But for every amusingly wrong prediction, there’s one unnervingly close to the mark…

    Those uncannily-accurate predictions, and their backstories, at “The 1968 book that tried to predict the world of 2018.”

    * Søren Kierkegaard

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    As we ponder posterity, we might send static-y birthday greetings to Robert Woodrow Wilson; he was born on this date in 1936.  An astronomer, he detected– with Bell Labs colleague Arno Penzias– cosmic microwave background radiation: “relic radiation”– that’s to say. the “sound “– of the Big Bang.  Their 1964 discovery earned them the 1978 Nobel Prize in Physics.

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  • feedwordpress 09:01:23 on 2017/11/22 Permalink
    Tags: astronomy, Caleb Scharf, , , , Paolo Frisi, , , ,   

    “Equipped with his five senses, man explores the universe around him and calls the adventure Science”*… 

     

    Caleb Scharf wants to take you on an epic tour. His latest book, The Zoomable Universe, starts from the ends of the observable universe, exploring its biggest structures, like groups of galaxies, and goes all the way down to the Planck length—less than a billionth of a billionth of a billionth of a meter. It is a breathtaking synthesis of the large and small. Readers journeying through the book are treated to pictures, diagrams, and illustrations all accompanied by Scharf’s lucid, conversational prose. These visual aids give vital depth and perspective to the phenomena that he points out like a cosmic safari guide. Did you know, he offers, that all the Milky Way’s stars can fit inside the volume of our solar system?

    Scharf, the director of Columbia University’s Astrobiology Center, is a suitably engaging guide. He’s the author of the 2012 book Gravity’s Engines: How Bubble-Blowing Black Holes Rule Galaxies, Stars, and Life in the Universe, and last year he speculated in Nautilus about whether alien life could be so advanced as to be indistinguishable from physics.

    In The Zoomable Universe, Scharf puts the notion of scale—in biology and physics—center-stage. “The start of your journey through this book and through all known scales of reality is at that edge between known and unknown,” he writes…

    Another entry in a collection that long-time readers know your correspondent cultivates, visualizations of relative scale (inspired by Charles and Ray Eames’ Powers of Ten—see, e.g., here, here, here, and here): “This Will Help You Grasp the Sizes of Things in the Universe.”

    * Edwin Powell Hubble

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    As we keep things in perspective, we might spare a thought for Paolo Frisi; he died on this date in 1784.  A mathematician, astronomer, and physicist who worked in hydraulics (he designed a canal between Milan and Pavia) and introduced the lightning conductor into Italy, he is probably best remembered for his compilation, interpretation, and dissemination of the work of other scientists, especially Galileo Galilei and Sir Isaac Newton.

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    Your correspondent is headed into the Thanksgiving Holiday– and so into a brief hiatus in posting.  Regular service will resume on Sunday the 26th… or when the tryptophan haze clears, whichever comes first.

     
  • feedwordpress 08:01:46 on 2017/07/11 Permalink
    Tags: astronomy, , , laser, Maiman, , , speed of light,   

    “No matter how fast light travels, it finds the darkness has always got there first”*… 

     

    In our terrestrial view of things, the speed of light seems incredibly fast. But as soon as you view it against the vast distances of the universe, it’s unfortunately very slow…

    An illustration of what one would see, traveling at the speed of light from the sun toward the edge of our solar system.  The filmmaker decided to end the video after Jupiter (at 45 minutes) to keep it “short,” since it could have gone on another half hour just to get to Saturn, let alone Uranus, Neptune, the former-planet Pluto (#neverforget), or the Kuiper Belt.

    Take the tour at: “Ever wonder what it ‘looks’ like to travel at the speed of light? Here you go.

    * Terry Pratchett, Reaper Man

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    As we examine enormity, we might send sharply-focused birthday greetings to Theodore Harold “Ted” Maiman; he was born on this date in 1927.  A physicist and inventor, Maiman is credited with the invention of the first working laser, a synthetic ruby crystal laser, which was announced to the world in a July 7 press conference hosted by his employer, Hughes Aircraft.  Maiman’s work, for which he was granted a patent, led to the development of a variety of other types of lasers, and laid the foundation for the myriad uses in storage, scanning, communications, and other applications that have emerged since.

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  • feedwordpress 08:01:26 on 2017/07/09 Permalink
    Tags: astronomy, , history of maps, , , , planets, ,   

    “The map is not the territory”*… 

     

    With the advent of GPS systems and cell-phone-based mapping guidance…

    …many of us have stopped paying attention to the world around us because we are too intent on following directions. Some observers worry that this represents a new and dangerous shift in our style of navigation. Scientists since the 1940s have argued we normally possess an internal compass, “a map-like representation within the ‘black box’ of the nervous system,” as geographer Rob Kitchin puts it. It’s how we know where we are in our neighborhoods, our cities, the world.

    Is it possible that today’s global positioning systems and smartphones are affecting our basic ability to navigate? Will technology alter forever how we get around?

    Most certainly—because it already has. Three thousand years ago, our ancestors began a long experiment in figuring out how they fit into the world, by inventing a bold new tool: the map…

    Get your bearings at: “From Ptolemy to GPS, the Brief History of Maps

    * Alfred Korzybski

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    As we follow the directions, we might recall that it was on this date in 1595 that Johann Kepler (and here) published Mysterium cosmographicum (Mystery of the Cosmos), in which he described an invisible underlying structure determining the six known planets in their orbits.  Kepler thought as a mathematician, devising a structure based on only five convex regular solids; the path of each planet lay on a sphere separated from its neighbors by touching an inscribed polyhedron.

    It was an elegant model– and one that fit the orbital data available at the time.  It was, nonetheless, wrong.

    Detailed view of Kepler’s inner sphere

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  • feedwordpress 08:01:48 on 2017/04/30 Permalink
    Tags: 1006, astronomy, , event horizon, Event Horizon Telescope, , , supernova, ,   

    “The history of astronomy is a history of receding horizons”*… 

     

    The closest astronomers have come to directly “seeing” a black hole happened last year, when the LIGO observatory detected the spacetime-warping gravitational waves radiating from a pair of black holes that collided some 1.3 billion years ago.

    That’s cool. But for astronomers, it’s not enough. What’s eluded them is a view of the event horizon, the boundary of the black hole from which, when crossed, there is no return. After the event horizon, gravity is so intense that not even light can escape.

    We’ve never seen a direct image of a black hole. But if an audacious experiment called the Event Horizon Telescope is successful, we’ll see one for the first time…

    Find out how at “Astronomers just turned on a planet-size telescope to take a picture of a black hole.”

    * Edwin Hubble

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    As we look into it, we might recall that it was on this date in 1006 CE that observers across China, Japan, Iraq, Egypt, and Europe recorded their observation of a supernova (now known as SN 1006).  Likely the brightest observed stellar event in recorded history, it reached an estimated −7.5 visual magnitude (more than sixteen times the brightness of Venus).  Many experts believe that it was also recorded in the Native American petroglyphs in White Tank Mountain Regional Park, Arizona, making them the first North American record of a supernova sighting.

    SN 1006 supernova remnant

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  • feedwordpress 09:01:57 on 2017/02/14 Permalink
    Tags: astronomy, , , Fritz Zwicky, , , holographic universe, , ,   

    “When the going gets weird, the weird turn pro”*… 

     

    An international study claims to have found first observed evidence that our universe is a hologram.

    What is the holographic universe idea? It’s not exactly that we are living in some kind of Star Trekky computer simulation. Rather the idea, first proposed in the 1990s by Leonard Susskind and Gerard ‘t Hooft, says that all the information in our 3-dimensional reality may actually be included in the 2-dimensional surface of its boundaries. It’s like watching a 3D show on a 2D television…

    Just when one thought that things couldn’t get any stranger: “Scientists Find First Observed Evidence That Our Universe May Be a Hologram.”

    Pair with this piece on recent experimental confirmation of what Albert Einstein called “spooky action at a distance.”

    * Hunter S. Thompson

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    As we batten down the hatches, we might send shady birthday greetings to Fritz Zwicky; he was born on this date in 1898.  A distinguished astronomer who worked at Cal Tech most of his life, Zwicky is best remembered for being the first to infer the existence of “dark matter“: while examining the Coma galaxy cluster in 1933, he used the virial theorem to deduce the existence of what he then called dunkle Materie. Colleagues knew him as both both a genius and a curmudgeon. One of his favorite insults was to refer to people of whom he didn’t approve as “spherical bastards”– because, he explained, they were bastards no matter which way you looked at them.

    [For more on dunkle Materie:Will We Ever Know What Dark Matter Is?“]

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