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Physicist Derives Laws of Thermodynamics For Life Itself

Physicist Derives Laws of Thermodynamics For Life Itself | Reality | Scoop.it
The laws of thermodynamics must apply to self-replicating systems.

 

In the past, biologists have studied the catalytic properties of RNA that are crucial for living cells and noted that DNA does not share these properties. So the thinking is that RNA must have come first in the replicating timeline, with DNA evolving later as life became more complex .  

 

England's work backs up this idea but for completely different reasons--RNA is thermodynamically better at self replication. A fascinating result.

 

The work has an important limitation, however. It fails to tackle the definition of nature of life and instead defers the problem to an omniscient microbiologist who, it is assumed, can always provide an answer. 

 

There is a tantalising hint that England's approach could one day solve this problem. By exploring the role of statistical physics in more detail, it maybe possible to define life in terms of precise thermodynamic limits.

 

Which is why it'll be worth watching where England takes his idea next.

 

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AristotlesPoeticsRhetoric.pdf the formation of taste--the physical reaction to objects--is the key to character formation.

Aristotle's Poetics and Rhetoric

 

 

 

1. Productive vs Practical science

2. The relevant definition of humans: the embodied imitative political animal with logos

3. Tragedy as cathartic

4. Logos, ethos, pathos

 

1. Productive vs Practical science

 

The Poetics and the Rhetoric are productive sciences: they look at processes w/ external products. If the Ethics and the Politics are practical sciences, concerned w/ self-directed action, then the Poetics and the Rhetoric are productive not just in the sense that a poem or a speech is the product of a labor that aimed at it, but also because they both discuss ways in which action is produced from outside a person: ways in which people are manipulated, are "moved," as we say.

 

2. The relevant definition of humans: the embodied imitative political animal with logos To understand how people can be moved, let us first recall the definition of the human as the political animal with logos. Humans live in groups, with speech as the medium.

 

Next, we have to remember that humans are embodied. Not only is this the reason we are pulled down out of activity, but it is also the positive source of training of character excellences: Aristotle is clear  as was Plato, that pleasure and pain is the key to upbringing, as an appropriate regime of rewards and punishments will instill disgust at the ugly and disgraceful and pleasure at the beautiful and noble before logos can take root.

 

In other words, the formation of taste--the physical reaction to objects--is the key to character formation.

 

And, let's remember that taste is the key to desire: we want things that make us feel good, so that character formation is the channeling of desire, the rendering of desire and action predictable. Moreover, the body is important for intellectual activity as well as practical: recall that an appropriately ordered body is necessary for the withdrawal of the body from consciousness to allow the transcendent vision of the intellect. We have dealt extensively with the questions of social position and leisure in producing such bodies trained for thinking and correct character. Let's recall that the ideal male body, after all, is capable of becoming either a killing or a thinking machine, with trained, predictable, and transparent flows, even if its everyday political existence retains only the power to assume such machinic qualities……..

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CERN closes in on primeval plasma at birth of cosmos

CERN closes in on primeval plasma at birth of cosmos | Reality | Scoop.it
Scientists at CERN have smashed together various particles for the first time, moving closer to learning what was in the super-hot plasma wonderland that formed right after the primeval Big Bang, the European physics research center said on Thursday.
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David Lynch: Consciousness, Creativity and the Brain

The inside story on transcending the brain, with David Lynch, Award-winning film director of Blue Velvet, Twin Peaks, Mullholland Drive, Inland Empire (filmi...
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QuantumLevitation

Suspending a superconducting disc above or below a set of permanent magnets. The magnetic field is locked inside the superconductor ; a phenomenon called 'Qu...
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Hinduism: The Universe is an Illusion (Maya) but Consciousness isn't

Hinduism: The Universe is an Illusion (Maya) but Consciousness isn't | Reality | Scoop.it

Reality: A 'new age' interpretation

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We believe experts who confirm our beliefs

(PhysOrg.com) -- Turns out that Average Joe doesn't rate the credibility of an expert based on rigor, clarity, prestige, reputation or the diplomas he or she holds, but rather on whether or not the expert says what we want to hear!

 

It's our values that determine the credibility that we give to experts,”

 

“We judge based on our political predispositions. This highlights the limit of rationality when shaping an opinion.”

 

“It's important to be conscious of the importance of bias,” says Montpetit. “It is often implied that people face issues with a virgin mind and that they will decide based on the opinions of experts. But that is clearly false!”

 

Read more at: http://phys.org/news/2010-12-experts-beliefs.html#jCp

 

Read more at: http://phys.org/news/2010-12-experts-beliefs.html#jCp

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David Hilbert - Wikipedia

David Hilbert - Wikipedia | Reality | Scoop.it

Hilbert asks:

 

"When we are engaged in investigating the foundations of a science, we must set up a system of axioms which contains an exact and complete description of the relations subsisting between the elementary ideas of that science. ... But above all I wish to designate the following as the most important among the numerous questions which can be asked with regard to the axioms: To prove that they are not contradictory, that is, that a definite number of logical steps based upon them can never lead to contradictory results. In geometry, the proof of the compatibility of the axioms can be effected by constructing a suitable field of numbers, such that analogous relations between the numbers of this field correspond to the geometrical axioms. ... On the other hand a direct method is needed for the proof of the compatibility of the arithmetical axioms."

 

In mathematics, Hilbert's second problem was posed by David Hilbert in 1900 as one of his 23 problems. It asks for a proof that arithmetic is consistent – free of any internal contradictions.

 

In the 1930s, Kurt Gödel and Gerhard Gentzen proved results that cast new light on the problem. Some feel that these results resolved the problem, while others feel that the problem is still open.

 

 

 

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First images of chemical bond differences captured - physics-math - 13 September 2012 - New Scientist

First images of chemical bond differences captured - physics-math - 13 September 2012 - New Scientist | Reality | Scoop.it
Highly detailed images of molecular bonds shed new light on the physical differences between bond types – and could have applications in molecular...

 

The new pictures, taken with a modified atomic force microscope, marks the first time that scientists have been able to observe the true physical differences between these bond types, which could give a deeper understanding of chemical reactions. It may also help researchers size up molecules for use as electrical components in tiny circuits.

 

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Before The Big Bang: Where did the Beginning Begin? And Where does Superstring theory Fit In?

 

   It seems fairly likely that there was a Big Bang. The obvious question that could be asked to challenge or define the boundaries between physics and metaphysics is: what came before the Big Bang?

   Physicists define the boundaries of physics by trying to describe them theoretically and then testing that description against observation. Our observed expanding Universe is very well described by flat space, with critical density supplied mainly by dark matter and a cosmological constant, that should expand forever.

   If we follow this model backwards in time to when the Universe was very hot and dense, and dominated by radiation, then we have to understand the particle physics that happens at such high densities of energy. The experimental understanding of particle physics starts to poop out after the energy scale of electroweak unification, and theoretical physicists have to reach for models of particle physics beyond the Standard Model, to Grand Unified Theories, supersymmetry, string theory and quantum cosmology.

   This exploration is guided by three outstanding problems with the Big Bang cosmological model:

1. The flatness problem

2. The horizon problem

3. The magnetic monopole problem

Flatness problem

 

    The Universe as observed today seems to enough energy density in the form of matter and cosmological constant to provide critical density and hence zero spatial curvature. The Einstein equation predicts that any deviation from flatness in an expanding Universe filled with matter or radiation only gets bigger as the Universe expands. So any tiny deviation from flatness at a much earlier time would have grown very large by now. If the deviation from flatness is very small now, it must have been immeasurably small at the start of the part of Big Bang we understand.

    So why did the Big Bang start off with the deviations from flat spatial geometry being immeasurably small? This is called the flatness problem of Big Bang cosmology.

    Whatever physics preceded the Big Bang left the Universe in this state. So the physics description of whatever happened before the Big Bang has to address the flatness problem.

 

Horizon problem

 

    The cosmic microwave background is the cooled remains of the radiation density from the radiation-dominated phase of the Big Bang. Observations of the cosmic microwave background show that it is amazingly smooth in all directions, in other words, it is highly isotropic thermal radiation. The temperature of this thermal radiation is 2.73° Kelvin. The variations observed in this temperature across the night sky are very tiny.

    Radiation can only be so uniform if the photons have been mixed around a lot, or thermalized, through particle collisions. However, this presents a problem for the Big Bang model. Particle collisions cannot move information faster than the speed of light. But in the expanding Universe that we appear to live in, photons moving at the speed of light cannot get from one side of the Universe to the other in time to account for this observed isotropy in the thermal radiation. The horizon size represents the distance a photon can travel as the Universe expands. 

   The horizon size of our Universe today is too small for the isotropy in the cosmic microwave background to have evolved naturally by thermalization. So that's the horizon problem.

 

Magnetic monopole problem

 

   Normally, as we observe on Earth, magnets only come with two poles, North and South. If one cuts a magnet in half, the result will not be one magnet with only a North pole and one magnet with only a South pole. The result will be two magnets, each of which has its own North and South poles. 

   A magnetic monopole would be a magnet with only one pole. But magnetic monopoles have never been seen? Why not? 

This is different from electric charge, where we can separate an arrangement of positive and negative electric charges so that only positive charge is in one collection and only negative charge is in another.

    Particle theories like Grand Unified Theories and superstring theory predict magnetic monopoles should exist, and relativity tells us that the Big Bang should have produced a lot of them, enough to make one hundred billion times the observed energy density of our Universe. 

   But so far, physicists have been unable to find even one.

   So that's a third motivation to go beyond the Big Bang model to look for an explanation of what could have happened when the Universe was very hot and very small.

 

 

Inflationary universe?

 

   Matter and radiation are gravitationally attractive, so in a maximally symmetric spacetime filled with matter, the gravitational force will inevitably cause any lumpiness in the matter to grow and condense. That's how hydrogen gas turned into galaxies and stars. But vacuum energy comes with a high vacuum pressure, and that high vacuum pressure resists gravitational collapse as a kind of repulsive gravitational force. The pressure of the vacuum energy flattens out the lumpiness, and makes space get flatter, not lumpier, as it expands.

   So one possible solution to the flatness problem would be if our Universe went through a phase where the only energy density present was a uniform vacuum energy. If this phase occurred before the radiation-dominated era, then the Universe could evolve to be extraordinarily flat when the radiation-dominated era began, so extraordinarily flat that the lumpy evolution of the radiation- and matter-dominated periods would be consistent with the high degree of remaining flatness that is observed today.

   This type of solution to the flatness problem was proposed in the 1980s by cosmologist Alan Guth. The model is called the Inflationary Universe. In the Inflation model, our Universe starts out as a rapidly expanding bubble of pure vacuum energy, with no matter or radiation. After a period of rapid expansion, or inflation, and rapid cooling, the potential energy in the vacuum is converted through particle physics processes into the kinetic energy of matter and radiation. The Universe heats up again and we get the standard Big Bang.

   So an inflationary phase before the Big Bang could explain how the Big Bang started with such extraordinary spatial flatness that it is still so close to being flat today.

   Inflationary models also solve the horizon problem. The vacuum pressure accelerates the expansion of space in time so that a photon can traverse much more of space than it could in a spacetime filled with matter. To put it another way, the attractive force of matter on light in some sense slows the light down by slowing down the expansion of space itself. In an inflationary phase, the expansion of space is accelerated by vacuum pressure from the cosmological constant, and light gets farther faster because space is expanding faster.

   If there were an inflationary phase of our Universe before the radiation-dominated era of the Big Bang, then by the end of the inflationary period, light could have crossed the whole Universe. And so the isotropy of the radiation from the Big Bang would no longer be inconsistent with the finiteness of the speed of light.

   The inflationary model also solves the magnetic monopole problem, because in the particle physics that underlies the inflationary idea, there would only be one magnetic monopole per vacuum energy bubble. That means only one magnetic monopole per Universe.

   That's why the inflationary universe theory is still the favored pre-Big Bang cosmology among cosmologists. 

 

But how does Inflation work?

 

   The vacuum energy that drives the rapid expansion in an inflationary cosmology comes from a scalar field that is part of the spontaneous symmetry breaking dynamics of some unified theory particle theory, say, a Grand Unified Theory or string theory. 

   This field is sometimes called the inflaton. The average value of the inflaton at temperature T is the value at the minimum of its potential energy at that temperature. The location of this minimum changes with temperature, as is shown in the animation to the right.

   For temperatures T above some critical temperature Tcrit, the minimum of the potential is at zero. But as the temperature cools, the potential changes and a second minimum develops in the potential at a nonzero value. This signals something called a phase transition, like when steam cools and condenses into water. For water the critical temperature Tcrit where this phase transition happens is 100°C, or 373°K.

   The two minima in the potential represent the two possible phases of the inflaton field, and of the Universe, at the critical temperature. One phase has the minimum of the field f=0, and the other phase represents the vacuum energy if the ground state has f=f0.

   According to the inflationary model, at the critical temperature, spacetime starts to under go this phase transition from one minimum to the other. But it doesn't do it smoothly, it stays in the old "false" vacuum too long. This is called supercooling. This region of false vacuum expands exponentially fast, and the vacuum energy of this false vacuum is the cosmological constant for the expansion. It is this process that is called Inflation and solves the flatness, horizon and monopole problems.

   This region of false vacuum expands until bubbles of the new broken symmetry phase with f=f0 form and collide, and eventually end the inflationary phase. The potential energy of the vacuum is converted through to kinetic energy of matter and radiation, and the Universe expands according to the Big Bang model already outlined.

 

A testable prediction?

 

   It's always good to have testable predictions from a theory of physics, and the inflation theory has a distinct prediction about the density variations in the cosmic microwave background. A bubble of inflation consists of accelerating vacuum. In this accelerating vacuum, a scalar field will have very small thermal fluctuations that are nearly the same at every scale, and the fluctuations will be have a Gaussian distribution. This prediction fits current observations and will be tested with greater precision by future measurements of the cosmic microwave background.

 

So are all the problems solved?

 

   Despite the prediction above, inflation as described above is far from an ideal theory. It's too hard to stop the inflationary phase, and the monopole problem has other ways of resurfacing in the physics. Many of the assumptions that go into the model, such as an initial high temperature phase and a single inflating bubble have been questioned and alternative models have been developed. 

   Today's inflation models have evolved beyond the original assumption of a single inflation event giving birth to a single Universe, and feature scenarios where universes nucleate and inflate out of other universes in the process called eternal inflation.

   There is also another attempt to solve the problems of Big Bang cosmology using a scalar field that never goes through an inflationary period at all, but evolves so slowly so that we observe it as being constant during our own era. This model is called quintessence, after the ancient spiritual belief in the Quinta Essentia, the spiritual matter from which the four forms of physical matter are made.

   So where does string theory fit in all of this? That's the next topic.

 

 

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String Theory: a multihistory: a Movie

String Theory: a multihistory: a Movie | Reality | Scoop.it

This SMIL movie uses animation, video and music to tell the story of string theory from the points of view of four string theorists: John Schwarz of Caltech, Michael Green of Cambridge, Lars Brink of Göteborg University and Pierre Ramond of the University of Florida. 

 Technical requirements: this movie requires a Real Player, version G2 or later. The video and animation will perform best on a computer with processor speed of P266 or better, through an Internet connection with 80k or better.

 

The Early Days 

 

 Particle physicists in the sixties were trying to find some sense and order in the results of their particle scattering experiments. Dual resonance models took on a life of their own, however, when they were explained in terms of the modes of vibrating relativistic strings, in the work of Nambu, Veneziano, Susskind and others. This new string theory had a fascinating mathematical structure that it captivated the young physicists who worked to develop the subject. 

 

The Decline of Dual Models 

 

 In the late sixties, Steven Weinberg and others developed relativistic quantum gauge field theory as a way of unifying the electromagnetic and weak interactions. Until 1971 this was not taken seriously by the mainstream in physics. But when Gerard 't Hooft showed that these theories made good mathematical sense, the community switched focus very rapidly and soon almost all of particle physics could be explained using the new relativistic quantum field theory. 

 Which left string theories, and the people who worked on them, out in the cold. 

 

A Theory of Gravity? 

 

 One big problem with string theories as theories of hadronic scattering is that every string theory constructed had a particle in its spectrum with zero mass and two units of particle spin. There is no such particle in the hadronic spectrum, of course, and for years this appeared to be a serious weakness in string theory that John Schwarz and Joel Scherk tried very hard, without success, to eliminate. 

 But the graviton, the fundamental quantum that carries the gravitational force, is supposed to have zero mass and two units of particle spin. 

 Like Madonna, string theory reinvented itself. But would anybody listen? 

 

The Superstring Revolution 

 

 John Schwarz and Michael Green began working together in 1980 to develop supersymmetric string theories. They were delighted to learn that superstring theories were viable candidates for a quantum theory of gravity, unlike quantum gauge field theory. In parallel with string theorists, the quantum field theory community was exploring supersymmetric theories of gravity, called supergravity, in higher dimensions, typically eleven. But work on such theories was called into doubt by a paper in 1983 by Ed Witten and Luis Alvarez-Gaumé which showed that higher dimensional supersymmetric theories suffered from mathematical disasters called anomalies. 

 In the summer of 1984, Green and Schwarz discovered that in superstring theory, there was a way to avoid the deadly anomaly problem and still have a theory with sensible and realistic quantum gravity and particle interactions. 

 

 The course of theoretical physics was changed forever on that day. 

 

Credits

 

 This movie was made in its entirety, including video, animation, writing and coding, by Patricia Schwarz. The soundtrack was composed using ACID Pro with loops from the loops for ACID collection Whiskey, Cigarettes and Gumbo. The animations were done using Flash 4 by Macromedia, and the video editing was done with Adobe Premiere. 

 

 

 

 

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One NASA Scientist's Quest To Prove We're All Trapped Inside A Video Game

One NASA Scientist's Quest To Prove We're All Trapped Inside A Video Game | Reality | Scoop.it
I've seen The Matrix. You've seen The Matrix. And so we've both had the same thought: "Woah. Maybe we really are living inside a computer!

 

(Since The Matrix is copyrighted and everything, this is more commonly referred to as "The Simulation Argument," as put forth by Oxford professor Nick Bostrom. (Thanks, Seth))

 

At least one scientist is actually trying to prove this to be true. In a new interview at Vice, NASA's Rich Terrile talks about his quest to prove that we are living inside of a computer simulation created by a programmer from the future.

 

By Terrile's reckoning, Moore's Law supports the idea that computers will grow advanced enough that this kind of thing will be possible. Among other things, Terrile supports his theory by pointing out "the observable pixelation of the tiniest matter and the eerie similarities between quantum mechanics, the mathematical rules that govern our universe, and the creation of video game environments."

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Nick Bostrom's Home Page

Nick Bostrom's Home Page | Reality | Scoop.it
Oxford philosopher (videos, papers, interviews, bio, etc.)...

 

SEPTEMBER 2012

Talks in Alpbach (Technology Forum), Rome (U.S. State Department), Moscow (Open Innovations), Oxford (St Cross College), and London (The Economist), but mostly focusing on book project (on superintelligence).  Also working on a couple of collaborative papers, one in applied ethics ('The Unilateralist's Curse'), the other describing a possible empirical test of the simulation hypothesis.

SOME RECENT ADDITIONS

The Superintelligent Will: Motivation and Instrumental Rationality in Advanced Artificial Agents, forthcoming in Minds and Machines

How Hard is Artificial Intelligence? Evolutionary Arguments and Selection Effects, w/ Carl Shulman, revised version, forthcoming in J. of Consciousness Studies

Existential Risk Reduction as the Most Important Task for Humanity, working paper, forthcoming in Global Policy

A Patch for the Simulation Argument. w/ Marcin Kulczycki, in Analysis

Anthropic Shadow: Observation Selection Effects and Existential Risks. w/ Milan Cirkovic & Anders Sandberg, in Risk Analysis

Thinking Inside the Box: Controlling and Using and Oracle AI. w/ Stuart Armstrong & Anders Sandberg, forthcoming in Minds and Machines

Bio, CV, media appearances

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Zeno’s Paradoxes 

n the fifth century B.C.E., Zeno of Elea offered arguments that led to conclusions contradicting what we all know from our physical experience–that runners run, that arrows fly, and that there are many different things in the world. The arguments were paradoxes for the ancient Greek philosophers. Because most of the arguments turn crucially on the notion that space and time are infinitely divisible—for example, that for any distance there is such a thing as half that distance, and so on—Zeno was the first person in history to show that the concept of infinity is problematical.

 

In his Achilles Paradox, Achilles races to catch a slower runner–for example, a tortoise that is crawling away from him. The tortoise has a head start, so if Achilles hopes to overtake it, he must run at least to the place where the tortoise presently is, but by the time he arrives there, it will have crawled to a new place, so then Achilles must run to this new place, but the tortoise meanwhile will have crawled on, and so forth. Achilles will never catch the tortoise, says Zeno. Therefore, good reasoning shows that fast runners never can catch slow ones. So much the worse for the claim that motion really occurs, Zeno says in defense of his mentor Parmenides who had argued that motion is an illusion.

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The Nature of Consciousness: How the Internet Could Learn to Feel

The Nature of Consciousness: How the Internet Could Learn to Feel | Reality | Scoop.it
"Romantic reductionist" neuroscientist Christof Koch discusses the scientific side of consciousness, including the notion that all matter is, to varying degrees, sentient.

 

If you had to list the hardest problems in science -- the questions even some scientists say are insoluble -- you would probably end up with two: 

 

Where do the laws of physics come from?  

How does the physical stuff in our brains produce conscious experience? 

Even though philosophers have obsessed over the "mind-body problem" for centuries, the mystery of consciousness wasn't considered a proper scientific question until two or three decades ago. Then, a couple of things happened. Brain-imaging technologies finally gave neuroscience some high-powered tools to peer inside our brains while we think. And a few renowned scientists -- most famously, Francis Crick -- claimed that neuroscientists had to tackle consciousness if they were ever going to understand the brain.

 

By the 1980s, Crick had jumped from molecular biology to neuroscience and moved from England to California. There he found a brilliant young collaborator, Christof Koch, the son of German diplomats who'd recently landed a job as an assistant professor of biology and engineering at the California Institute of Technology. For the next 16 years -- until Crick's death in 1994 -- they worked together, searching for the neural correlates of consciousness.

 

Koch remains on the front lines of neurobiology. In fact, he will soon leave Caltech to work full-time as Chief Scientific Officer of the Allen Institute for Brain Science in Seattle. After years of publishing scientific papers, he has now written a trade book, Consciousness: Confessions of a Romantic Reductionist. Somewhere between memoir and popular science, the book offers a highly personal glimpse into the mind of an unconventional scientist: a lapsed Catholic who teamed up with the staunch atheist Crick, and the eminent neuroscientist who speculates about the consciousness of bees and squid and even bacteria. In the first of a two-part interview, we talked about the wiring of our brains and the possibility that the Internet itself may become conscious.

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Treatment of chronic low back pain can reverse abnormal brain activity and function

If you can alleviate chronic low back pain, can you reverse these changes in the brain?

 

The answer is, Yes.

 

Read more at: http://medicalxpress.com/news/2011-05-treatment-chronic-pain-reverse-abnormal.html#jCp

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Chronic Pain Harms the Brain

Chronic Pain Harms the Brain | Reality | Scoop.it
People with unrelenting pain don't only suffer from the non-stop sensation of throbbing pain. They also have trouble sleeping, are often depressed, anxious and even have difficulty making simple decisions.
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World's shortest laser pulse to shed new light on quantum mechanics

World's shortest laser pulse to shed new light on quantum mechanics | Reality | Scoop.it
The world's shortest laser pulse, measuring only 67 attoseconds in duration, has been generated at the University of Central Florida.
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Mississippi River flows backwards for 24 hours

Mississippi River flows backwards for 24 hours | Reality | Scoop.it
Hurricane Isaac was able to make the Mississippi River run backwards for 24 hours after hitting the Gulf Coast this week.

 

The U.S. Geological Survey (USGS) instruments recorded the flow of the river, and found that it was running in reverse on Tuesday.

 

The flow reached nearly 182,000 cubic feet per second upriver, and gathered up a height of about 10 feet above average. The agency said that the average flow of the river is about 125,000 cubic feet per second towards the Gulf of Mexico.

 

The agency said that as Hurricane Isaac pushes inland, it is causing . . .

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Being ignored hurts, even by a stranger

(Medical Xpress) -- Feeling like you’re part of the gang is crucial to the human experience. All people get stressed out when we’re left out.

 

A research assistant walked along a well-populated path, picked a subject, and either met that person’s eyes, met their eyes and smiled, or looked in the direction of the person’s eyes, but past them—past an ear, for example, “looking at them as if they were air,” Wesselmann says. When the assistant had passed the person, he or she gave a thumbs-up behind the back to indicate that another experimenter should stop that person. The second experimenter asked, “Within the last minute, how disconnected do you feel from others?” People who had gotten eye contact from the research assistant, with or without a smile, felt less disconnected than people who had been looked at as if they weren’t there. “These are people that you don’t know, just walking by you, but them looking at you or giving you the air gaze—looking through you—seemed to have at least momentary effect,” Wesselmann says. Other research has found that even being ostracized by a group you want nothing to do with, like the Ku Klux Klan, can make people feel left out, so it’s not surprising that being pointedly ignored can have the same effect. “What we find so interesting about this is that now we can further speak to the power of human social connection,” Wesselmann says. “It seems to be a very strong phenomenon.”

 

Read more at: http://medicalxpress.com/news/2012-01-stranger.html#jCp

 

 

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Kurt Gödel : the Incompleteness Theorem

Kurt Gödel : the Incompleteness Theorem | Reality | Scoop.it

…. THERE ARE TRUE STATEMENTS [expressible in its language] THAT ARE UNPROVABLE. 

 

Thus no formal system (satisfying the hypotheses of the theorem) that aims to characterize the natural numbers can actually do so, as there will be true number-theoretical statements which that system cannot prove. ….

 

The existence of an incomplete formal system is, in itself, not particularly surprising. A system may be incomplete simply because not all the necessary axioms have been discovered. For example, Euclidean geometry without the parallel postulate is incomplete; it is not possible to prove or disprove the parallel postulate from the remaining axioms.

 

Gödel's theorem shows that, in theories that include a small portion of number theory, a complete and consistent finite list of axioms can never be created, nor even an infinite list that can be enumerated by a computer program. Each time a new statement is added as an axiom, there are other true statements that still cannot be proved, even with the new axiom. If an axiom is ever added that makes the system complete, it does so at the cost of making the system inconsistent…..

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Heavy photons are too light to be behind dark matter - physics-math - 15 September 2012 - New Scientist

Heavy photons are too light to be behind dark matter - physics-math - 15 September 2012 - New Scientist | Reality | Scoop.it
Although some theorists were holding out hope, spinning black holes show that the elusive substance is almost certainly not made of heavy photons...

 

SADLY, dark matter is not made of light. That may sound obvious, but many physicists were hoping that photons - particles of light - could help us to piece together the nature of the mysterious stuff thought to make up 85 per cent of the universe's matter.

 

Instead, readings from Vitor Cardoso of the Technical University of Lisbon in Portugal and colleagues seem to have quashed this idea.

 

Some theories had hinted that "heavy photons", hypothetical versions of the more familiar massless particles, might be dark matter. According to that idea, the heavy photon would have a small amount of mass and might carry an unknown fundamental force that allows it to interact only with ordinary photons - effectively hiding it from the visible world.

 

In that case, heavy photons passing close to black holes would have noticeable effects, says Cardoso.

 

When most particles with mass get too near to a black hole, they fall in, never to be seen again. Photons with no mass can skirt past danger if they are on the right trajectory. But a photon with a very tiny "in between" mass can enter into an orbit of the spinning black hole and steal some of its angular momentum. If conditions are right, this process can continue until orbiting particles slow the hole down so much that it stops spinning.

 

Cardoso and colleagues calculated how long photons of given masses would take to sap a black hole's spin. Then they examined data on the ages and rotation speeds of eight supermassive black holes. The age of the oldest spinning black holes effectively puts an upper limit on the photon's mass. If it does exist, the heavy photon must be lighter than 10-20 electronvolts - an extreme improbability - the team concluded (arxiv.org/abs/1209.0465).

 

"We are constraining and putting aside what is not dark matter," Cardoso says.

 

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A Super-string Theory Website

Isaac Newton made a Bible-based estimate of a few thousand years. Einstein believed in a steady state, ageless Universe. Since then, data collected from the Universe puts the probable answer somewhere in the middle.

basic / advanced

 

The Einstein equation predicts several possible ways for the Universe to evolve in time and space. What are these models and how do they compare with observation? basic / advanced

 

 

Take a tour through the chain of physical events that cosmologists believe occurred while the expanding Universe we observe today was very small and very young. 

Take the trip

 

 

There's a lot of compelling evidence for the Big Bang, but what preceded it? The most accepted model is called Inflation, but it's not the kind of inflation that Alan Greenspan need fear.

basic / advanced 

 

 

What happens when the early universe is gummed up with string? And are any of these scenarios testable in the near future? 

 

basic / advanced 

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Darwin Lecture Series 2011: Professor Frank Wilczek

James Cox interviews Nobel Prize winning Physicist Frank Wilczek about the elegance of nature and his life in Theoretical Physics. Professor Wilczek was at t...
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Are You Living in a Simulation? Nick Bostrom:Faculty of Philosophy, Oxford University Published in Philosophical Quarterly (2003)

The original paper that introduced the simulation argument...

 

Many works of science fiction as well as some forecasts by serious technologists and futurologists predict that enormous amounts of computing power will be available in the future.

 

Let us suppose for a moment that these predictions are correct. One thing that later generations might do with their super-powerful computers is run detailed simulations of their forebears or of people like their forebears. Because their computers would be so powerful, they could run a great many such simulations. Suppose that these simulated people are conscious (as they would be if the simulations were sufficiently fine-grained and if a certain quite widely accepted position in the philosophy of mind is correct). Then it could be the case that the vast majority of minds like ours do not belong to the original race but rather to people simulated by the advanced descendants of an original race. It is then possible to argue that, if this were the case, we would be rational to think that we are likely among the simulated minds rather than among the original biological ones.

 

Therefore, if we don’t think that we are currently living in a computer simulation, we are not entitled to believe that we will have descendants who will run lots of such simulations of their forebears. That is the basic idea. The rest of this paper will spell it out more carefully.

 

            Apart form the interest this thesis may hold for those who are engaged in futuristic speculation, there are also more purely theoretical rewards. The argument provides a stimulus for formulating some methodological and metaphysical questions, and it suggests naturalistic analogies to certain traditional religious conceptions, which some may find amusing or thought-provoking.

 

            The structure of the paper is as follows. First, we formulate an assumption that we need to import from the philosophy of mind in order to get the argument started. Second, we consider some empirical reasons for thinking that running vastly many simulations of human minds would be within the capability of a future civilization that has developed many of those technologies that can already be shown to be compatible with known physical laws and engineering constraints.

 

This part is not philosophically necessary but it provides an incentive for paying attention to the rest. Then follows the core of the argument, which makes use of some simple probability theory, and a section providing support for a weak indifference principle that the argument employs. Lastly, we discuss some interpretations of the disjunction, mentioned in the abstract, that forms the conclusion of the simulation argument.....

 

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