Posts Tagged ‘Universe’
“All you really need to know for the moment is that the universe is a lot more complicated than you might think, even if you start from a position of thinking it’s pretty damn complicated in the first place”*…
When you gaze out at the night sky, space seems to extend forever in all directions. That’s our mental model for the universe, but it’s not necessarily correct. There was a time, after all, when everyone thought the Earth was flat, because our planet’s curvature was too subtle to detect and a spherical Earth was unfathomable.
Today, we know the Earth is shaped like a sphere. But most of us give little thought to the shape of the universe. Just as the sphere offered an alternative to a flat Earth, other three-dimensional shapes offer alternatives to “ordinary” infinite space.
We can ask two separate but interrelated questions about the shape of the universe. One is about its geometry: the fine-grained local measurements of things like angles and areas. The other is about its topology: how these local pieces are stitched together into an overarching shape.
Cosmological evidence suggests that the part of the universe we can see is smooth and homogeneous, at least approximately. The local fabric of space looks much the same at every point and in every direction. Only three geometries fit this description: flat, spherical and hyperbolic…
Alternatives to “ordinary” infinite space: “What Is the Geometry of the Universe?”
* Douglas Adams, The Hitchhiker’s Guide to the Galaxy
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As we tinker with topology, we might recall that it was on this date in 1811 that Percy Bysshe Shelley was expelled from the University of Oxford for publishing the pamphlet The Necessity of Atheism. Shelley, of course, went on to become a celebrated lyric poet and one of the leaders of the English Romantic movement… one who had a confident (if not to say exalted) sense of his role in society:
Poets are the hierophants of an unapprehended inspiration; the mirrors of the gigantic shadows which futurity casts upon the present; the words which express what they understand not; the trumpets which sing to battle, and feel not what they inspire; the influence which is moved not, but moves. Poets are the unacknowledged legislators of the world.
“Nothing happens until something moves”*…
What determines our fate? To the Stoic Greek philosophers, fate is the external product of divine will, ‘the thread of your destiny’. To transcendentalists such as Henry David Thoreau, it is an inward matter of self-determination, of ‘what a man thinks of himself’. To modern cosmologists, fate is something else entirely: a sweeping, impersonal physical process that can be boiled down into a single, momentous number known as the Hubble Constant.
The Hubble Constant can be defined simply as the rate at which the Universe is expanding, a measure of how quickly the space between galaxies is stretching apart. The slightest interpretation exposes a web of complexity encased within that seeming simplicity, however. Extrapolating the expansion process backward implies that all the galaxies we can observe originated together at some point in the past – emerging from a Big Bang – and that the Universe has a finite age. Extrapolating forward presents two starkly opposed futures, either an endless era of expansion and dissipation or an eventual turnabout that will wipe out the current order and begin the process anew.
That’s a lot of emotional and intellectual weight resting on one small number…
How scientists pinned a single number on all of existence: “Fate of the Universe.”
[Readers might remember that the Big Bang wasn’t always an accepted paradigm— and that on-going research continues to surface challenges.]
* Albert Einstein
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As we center ourselves, we might spare a thought for Kurt Friedrich Gödel; he died on this date in 1978. A logician, mathematician, and philosopher, he is considered (along with Aristotle, Alfred Tarski— whose birthday this also is– and Gottlob Frege) to be one of the most important logicians in history. Gödel had an immense impact upon scientific and philosophical thinking in the 20th century. He is, perhaps, best remembered for his Incompleteness Theorems, which led to (among other important results) Alan Turing’s insights into computational theory.
Kurt Gödel’s achievement in modern logic is singular and monumental – indeed it is more than a monument, it is a landmark which will remain visible far in space and time. … The subject of logic has certainly completely changed its nature and possibilities with Gödel’s achievement. — John von Neumann
“Why should things be easy to understand?”*…
The universe is kind of an impossible object. It has an inside but no outside; it’s a one-sided coin. This Möbius architecture presents a unique challenge for cosmologists, who find themselves in the awkward position of being stuck inside the very system they’re trying to comprehend.
It’s a situation that Lee Smolin has been thinking about for most of his career. A physicist at the Perimeter Institute for Theoretical Physics in Waterloo, Canada, Smolin works at the knotty intersection of quantum mechanics, relativity and cosmology. Don’t let his soft voice and quiet demeanor fool you — he’s known as a rebellious thinker and has always followed his own path. In the 1960s Smolin dropped out of high school, played in a rock band called Ideoplastos, and published an underground newspaper. Wanting to build geodesic domes like R. Buckminster Fuller, Smolin taught himself advanced mathematics — the same kind of math, it turned out, that you need to play with Einstein’s equations of general relativity. The moment he realized this was the moment he became a physicist. He studied at Harvard University and took a position at the Institute for Advanced Study in Princeton, New Jersey, eventually becoming a founding faculty member at the Perimeter Institute.
“Perimeter,” in fact, is the perfect word to describe Smolin’s place near the boundary of mainstream physics. When most physicists dived headfirst into string theory, Smolin played a key role in working out the competing theory of loop quantum gravity. When most physicists said that the laws of physics are immutable, he said they evolve according to a kind of cosmic Darwinism. When most physicists said that time is an illusion, Smolin insisted that it’s real.
Smolin often finds himself inspired by conversations with biologists, economists, sculptors, playwrights, musicians and political theorists. But he finds his biggest inspiration, perhaps, in philosophy — particularly in the work of the German philosopher Gottfried Leibniz, active in the 17th and 18th centuries, who along with Isaac Newton invented calculus. Leibniz argued (against Newton) that there’s no fixed backdrop to the universe, no “stuff” of space; space is just a handy way of describing relationships. This relational framework captured Smolin’s imagination, as did Leibniz’s enigmatic text The Monadology, in which Leibniz suggests that the world’s fundamental ingredient is the “monad,” a kind of atom of reality, with each monad representing a unique view of the whole universe. It’s a concept that informs Smolin’s latest work as he attempts to build reality out of viewpoints, each one a partial perspective on a dynamically evolving universe. A universe as seen from the inside…
Lee Smolin explains his radical idea for how to understand an object with no exterior–imagine it built bit-by-bit from relationships between events: “How to Understand the Universe When You’re Stuck Inside of It.”
* Thomas Pynchon
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As we muse on monads, we might send delightful birthday greetings to Fernando Arrabal Terán; he was born on this date in 1932. A playwright, screenwriter, film director, novelist, and poet, Arrabal co-founded the Panic Movement with Alejandro Jodorowsky and Roland Topor (inspired by the god Pan).
Early in his career, he spent three years as a member of André Breton’s surrealist group and was a friend of Andy Warhol and Tristan Tzara. Later (in 1990), he was elected Transcendent Satrap of the Collège de ‘pataphysique (following such predecessors as Marcel Duchamp, Eugène Ionesco, Man Ray, Boris Vian, Dario Fo, Umberto Eco, and Jean Baudrillard).
And throughout, he was very productive: Arrabal has directed seven full-length feature films and has published over 100 plays; 14 novels; 800 poetry collections, chapbooks, and artists’ books; several essays; and his notorious “Letter to General Franco” during the dictator’s lifetime. His complete plays have been published, in multiple languages, in a two-volume edition totaling over two thousand pages. The New York Times‘ theater critic Mel Gussow has called Arrabal the last survivor among the “three avatars of modernism.”
“The Universe is under no obligation to make sense to you”*…
Uppsala University researchers have devised a new model for the Universe – one that may solve the enigma of dark energy. Their new article, published in Physical Review Letters, proposes a new structural concept, including dark energy, for a universe that rides on an expanding bubble in an additional dimension.
We have known for the past 20 years that the Universe is expanding at an ever accelerating rate. The explanation is the “dark energy” that permeates it throughout, pushing it to expand. Understanding the nature of this dark energy is one of the paramount enigmas of fundamental physics.
It has long been hoped that string theory will provide the answer. According to string theory, all matter consists of tiny, vibrating “stringlike” entities. The theory also requires there to be more spatial dimensions than the three that are already part of everyday knowledge. For 15 years, there have been models in string theory that have been thought to give rise to dark energy. However, these have come in for increasingly harsh criticism, and several researchers are now asserting that none of the models proposed to date are workable.
In their article, the scientists propose a new model with dark energy and our Universe riding on an expanding bubble in an extra dimension. The whole Universe is accommodated on the edge of this expanding bubble. All existing matter in the Universe corresponds to the ends of strings that extend out into the extra dimension. The researchers also show that expanding bubbles of this kind can come into existence within the framework of string theory. It is conceivable that there are more bubbles than ours, corresponding to other universes.
The Uppsala scientists’ model provides a new, different picture of the creation and future fate of the Universe, while it may also pave the way for methods of testing string theory…
(For a different emerging new theory– that may or may not be contradictory– see “Our universe has antimatter partner on the other side of the Big Bang.”)
* Neil deGrasse Tyson
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As we fumble with the fundamentals, we might send carefully-deduced birthday greetings to Richard Bevan Braithwaite; he was born on this date in 1900. A Cambridge philosopher who specialized in the philosophy of science, he focused on the logical features common to all sciences. Braithwaite was concerned with the impact of science on our beliefs about the world and the appropriate responses to that impact. He was especially interested in probability (and its applications in decision theory and games theory) and in the statistical sciences. He was president of the Aristotelian Society from 1946 to 1947, and was a Fellow of the British Academy.
It was Braithwaite’s poker that Ludwig Wittgenstein reportedly brandished at Karl Popper during their confrontation at a Moral Sciences Club meeting in Braithwaite’s rooms in King’s. The implement subsequently disappeared. (See here.)
“And so the Universe ended”*…
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.”
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,
“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.
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.
“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
