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Posts Tagged ‘Physics

“If you think this Universe is bad, you should see some of the others”*…

 

copernicus

FIRST OF FOUR?: The first Copernican revolution moved the Earth out of the center of the solar system. The second recognized that there are many planets in our galaxy, and the third that there are many galaxies in the observable universe. Proving that our universe is one among many would represent a fourth Copernican revolution.

 

A challenge for 21st-century physics is to answer two questions. First, are there many “big bangs” rather than just one? Second—and this is even more interesting—if there are many, are they all governed by the same physics?

If we’re in a multiverse, it would imply a fourth and grandest Copernican revolution; we’ve had the Copernican revolution itself, then the realization that there are billions of planetary systems in our galaxy; then that there are billions of galaxies in our observable universe. But now that’s not all. The entire panorama that astronomers can observe could be a tiny part of the aftermath of “our” big bang, which is itself just one bang among a perhaps infinite ensemble.

At first sight, the concept of parallel universes might seem too arcane to have any practical impact. But it may (in one of its variants) actually offer the prospect of an entirely new kind of computer: the quantum computer, which can transcend the limits of even the fastest digital processor by, in effect, sharing the computational burden among a near infinity of parallel universes…

Cambridge physicist and Astronomer Royal Martin Rees suspects that our universe is one island in an archipelago: “The Fourth Copernican Revolution.”

* Philip K. Dick

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As we find our place, we might recall that it was on this date in 1884 that 41 delegates from 25 nations, meeting in Washington, DC for the International Meridian Conference, adopted Greenwich as the universal meridian.  They also established that all longitude would be calculated both east and west from this meridian up to 180°.

PrimeMeridianThm source

 

Written by LW

October 13, 2018 at 1:01 am

“I’ve never seen contraptions with so many dials and knobs before”*…

 

control panels

Control room, Klingenberg Power Station, Berlin, 1928. Photos by E.O. Hoppé.

 

Just one selection from the plethora of “dials, toggles, buttons, and bulbs” at “Control Panel.”

* “Lampy,” in The Brave Little Toaster

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As we twist and turn, we might spare a thought for Guillaume Amontons; he died on this date in 1705.  A physicist who made formative contributions to the understanding of friction, he was also an accomplished designer of scientific instruments– perhaps most notably, the air thermometer, which relies on increase in volume of a gas (rather than a liquid) with temperature.  His approach led to the emergence of the concept of “absolute zero.”

amonton thermometer source

Amontons source

 

Written by LW

October 10, 2018 at 10:01 pm

“There will be time, there will be time”*…

 

Infinity-Time1

Poets often think of time as a river, a free-flowing stream that carries us from the radiant morning of birth to the golden twilight of old age. It is the span that separates the delicate bud of spring from the lush flower of summer.

Physicists think of time in somewhat more practical terms. For them, time is a means of measuring change—an endless series of instants that, strung together like beads, turn an uncertain future into the present and the present into a definite past. The very concept of time allows researchers to calculate when a comet will round the sun or how a signal traverses a silicon chip. Each step in time provides a peek at the evolution of nature’s myriad phenomena.

In other words, time is a tool. In fact, it was the first scientific tool. Time can now be sliced into slivers as thin as one ten-trillionth of a second. But what is being sliced? Unlike mass and distance, time cannot be perceived by our physical senses. We don’t see, hear, smell, touch, or taste time. And yet we somehow measure it. As a cadre of theorists attempt to extend and refine the general theory of relativity, Einstein’s momentous law of gravitation, they have a problem with time. A big problem…

The crisis inside the physics of time: “Is It Time to Get Rid of Time?

See also: “Forget everything you know about time.”

[image above: source]

* T. S. Eliot

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As we check our watches, we might say a grateful Happy Birthday to Winsor McCay, the cartoonist and animator, who was born on this date in 1867.  His two best-known creations are the pioneering comic strip Little Nemo in Slumberland, which ran from 1905 to 1914, and the animated cartoon Gertie the Dinosaur (1914),which set the standard for animators for decades to come.

Little Nemo… for a more legible image, click here

 

Written by LW

September 26, 2018 at 1:01 am

“All you can do is hope for a pattern to emerge”*…

 

smiling_baby_10-1024x576

If you construct a Lego model of the University of London’s Senate House – the building that inspired the Ministry of Truth in George Orwell’s novel Nineteen Eighty-Four – the Lego blocks themselves remain unchanged. Take apart the structure, reassemble the blocks in the shape of the Great Pyramid of Giza or the Eiffel Tower, and the shape, weight and colour of the blocks stay the same.

This approach, applied to the world at large, is known as atomism. It holds that everything in nature is made up of tiny, immutable parts. What we perceive as change and flux are just cogs turning in the machine of the Universe – a huge but ultimately comprehensible mechanism that is governed by universal laws and composed of smaller units. Trying to identify these units has been the focus of science and technology for centuries. Lab experiments pick out the constituents of systems and processes; factories assemble goods from parts composed of even smaller parts; and the Standard Model tells us about the fundamental entities of modern physics.

But when phenomena don’t conform to this compositional model, we find them hard to understand. Take something as simple as a smiling baby: it is difficult, perhaps impossible, to explain a baby’s beaming smile by looking at the behaviour of the constituent atoms of the child in question, let alone in terms of its subatomic particles such as gluons, neutrinos and electrons. It would be better to resort to developmental psychology, or even a narrative account (‘The father smiled at the baby, and the baby smiled back’). Perhaps a kind of fundamental transformation has occurred, producing some new feature or object that can’t be reduced to its parts.

The notion of emergence can help us to see what’s going on here. While atomism is all about burrowing down to basic building blocks, emergence looks upward and outward, to ask whether strange new phenomena might pop out when things get sufficiently large or complex…

Does everything in the world boil down to basic units – or can emergence explain how distinctive new things arise?  Paul Humphreys helps us understand at “Out of nowhere.”

[Image above: source]

* Chuck Palahniuk, Lullaby

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As we forage for the fundamental, we might send insightful birthday greetings to Ernest Everett Just; he was born on this date in 1883.  A pioneering biologist, academic, and science writer, he contributed mightily to the understanding of cell division, the fertilization of egg cells, experimental parthenogenesis, hydration, cell division, dehydration in living cells, and the effect of ultra violet rays on egg cells.

An African-American, he had limited academic prospects on his graduation from Dartmouth, but was able to land a teaching spot at Howard University.  Just met  Frank R. Lillie, the head of the Department of Zoology at the University of Chicago and director of the Marine Biological Laboratory (MBL) at Woods Hole, Mass.  In 1909 Lillie invited Just to spend first one, then several summers at Woods Hole, where Just pioneered the study of whole cells under normal conditions (rather than simply breaking them apart in a laboratory setting).  In 1915, Just was awarded the first Spingarn Medal, the highest honor given by the NAACP.

But outside MBL, Just experienced discrimination.  Seeking more opportunity, he spent most of the 1930s in various European universities– until the outbreak of WW II hostilities caused him to return to the U.S. in late 1940.  He died of pancreatic cancer the next year.

Ernest_Everett_Just source

 

Written by LW

August 14, 2018 at 1:01 am

“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

source

 

 

Written by LW

July 9, 2018 at 1:01 am

“Doubtless we cannot see that other higher Spaceland now, because we have no eye in our stomachs”*…

 

An ” Amplituhedron“, an illustration of multi-dimensional spacetime

Our architecture, our education and our dictionaries tell us that space is three-dimensional. The OED defines it as ‘a continuous area or expanse which is free, available or unoccupied … The dimensions of height, depth and width, within which all things exist and move.’ In the 18th century, Immanuel Kant argued that three-dimensional Euclidean space is an a priori necessity and, saturated as we are now in computer-generated imagery and video games, we are constantly subjected to representations of a seemingly axiomatic Cartesian grid. From the perspective of the 21st century, this seems almost self-evident.

Yet the notion that we inhabit a space with any mathematical structure is a radical innovation of Western culture, necessitating an overthrow of long-held beliefs about the nature of reality. Although the birth of modern science is often discussed as a transition to a mechanistic account of nature, arguably more important – and certainly more enduring – is the transformation it entrained in our conception of space as a geometrical construct.

Over the past century, the quest to describe the geometry of space has become a major project in theoretical physics, with experts from Albert Einstein onwards attempting to explain all the fundamental forces of nature as byproducts of the shape of space itself. While on the local level we are trained to think of space as having three dimensions, general relativity paints a picture of a four-dimensional universe, and string theory says it has 10 dimensions – or 11 if you take an extended version known as M-Theory. There are variations of the theory in 26 dimensions, and recently pure mathematicians have been electrified by a version describing spaces of 24 dimensions. But what are these ‘dimensions’? And what does it mean to talk about a 10-dimensional space of being?…

Experience says we live in three dimensions; relativity says four; string theory says it’s 10– or more… What are “dimensions” and how do they affect reality? Margaret Wertheim offers a guide: “Radical dimensions.”

* Edwin A. Abbott, Flatland: A Romance of Many Dimensions

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As we tax our senses, we might spare a thought for Robert Jemison Van de Graaff; he died on this date in 1967.  A physicist and engineer, he is best remembered for his creation of the Van de Graaff Generator, an electrostatic generator that creates very high electric potentials– very high voltage direct current (DC) electricity (up to 5 megavolts) at low current levels.  A tabletop version can produce on the order of 100,000 volts and can store enough energy to produce a visible spark. Such small Van de Graaff machines are used in physics education to teach electrostatics; larger ones are displayed in some science museums.

Boy touching Van de Graaff generator at The Magic House, St. Louis Children’s Museum. Charged with electricity, his hair strands repel each other and stand out from his head.

source

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Written by LW

January 16, 2018 at 1:01 am

“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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