UNIVERSE

Quantum Hanky-Panky

[8.22.16]

Thinking about the future of quantum computing, I have no idea if we're going to have a quantum computer in every smart phone, or if we're going to have quantum apps or quapps, that would allow us to communicate securely and find funky stuff using our quantum computers; that's a tall order. It's very likely that we're going to have quantum microprocessors in our computers and smart phones that are performing specific tasks.

This is simply for the reason that this is where the actual technology inside our devices is heading anyway. If there are advantages to be had from quantum mechanics, then we'll take advantage of them, just in the same way that energy is moving around in a quantum mechanical kind of way in photosynthesis. If there are advantages to be had from some quantum hanky-panky, then quantum hanky‑panky it is. 

SETH LLOYD, Professor, Quantum Mechanical Engineering, MIT; Principal Investigator, Research Laboratory of Electronics; Author, Programming the UniverseSeth Lloyd's Edge Bio Page

The Exquisite Role of Dark Matter

[6.10.15]

It is definitely the golden age in cosmology because of this unique confluence of ideas and instruments. We live in a very peculiar universe—one that is dominated by dark matter and dark energy—the true nature of both of these remains elusive. Dark matter does not emit radiation in any wavelength and its presence is inferred by its gravitational influence on the motions of stars and gas in its vicinity. Dark Energy, discovered in 1998, meanwhile is believed to be powering the accelerated expansion of the universe. Despite not knowing what the dark matter particle is or what dark energy really is, we still have a very successful theory of how galaxies form and evolve in a universe with these mysterious and invisible dominant components. Technology has made possible the testing of our cosmological theories at a level that was unprecedented before. All of these experiments have delivered very exciting results, even if they're null results. For example, the LHC, with the discovery of the Higgs, has given us a lot more comfort in the standard model. The Planck and WMAP satellites probing the leftover hiss from the Big Bang—the cosmic microwave background radiation—have shown us that our theoretical understanding of how the early fluctuations in the universe grew and formed the late universe that we see is pretty secure. Our current theory, despite the embarrassing gap of not knowing the true nature of dark matter or dark energy, has been tested to a pretty high degree of precision.                      

It's also consequential that the dark matter direct detection experiments have not found anything. That's interesting too, because that's telling us that all these experiments are reaching the limits of their sensitivity, what they were planned for, and they're still not finding anything. This suggests paradoxically that while the overall theory might be consistent with observational data, something is still fundamentally off and possibly awry in our understanding. The challenge in the next decade is to figure out which old pieces don't fit. Is there a pattern that emerges that would tell us, is it a fundamentally new theory of gravity that's needed, or is it a complete rethink of some aspects of particle physics that are needed? Those are the big open questions.

PRIYAMVADA NATARAJAN is a professor in the Departments of Astronomy and Physics at Yale University, whose research is focused on exotica in the universe—dark matter, dark energy, and black holes. Priyamvada Natarajan's Edge Bio Page 


THE EXQUISITE ROLE OF DARK MATTER

I'm a theoretical astrophysicist, working on what I think are some of the most exciting, open and challenging questions. The first is trying to understand the nature of dark matter, and the second question pertains to the physics of black holes. Part of my interest in these two questions, aside from the fact that we now have an enormous amount of data that can help us understand these very enigmatic objects in the universe, is that we have a standard theory—a theoretical model—that works extremely well.

This is a model of structure formation in which dark matter, which is the dominant matter component in the universe, is in the driving seat. It's the scaffolding in which all the first galaxies form, the first stars form, and so on. While we have this exquisite inventory and role for dark matter, we do not know what it is, what it's composed of, what kind of particle it is, when it was created in the universe, and so on and so forth. Similarly, with black holes; we know that they exist. They are real. There is one in the center of our galaxy, which is a few million times the mass of the sun. The one in the center of our galaxy is a dormant black hole. It's not doing very much at present, it was likely active in the past. We see in the early universe that there are massive black holes that are 1000 times, 10,000 times more massive than the one in the center of the galaxy that play a very important role in shaping the properties of the galaxy which hosts them.

What is the life-story of a black hole? How do they grow? How do they form, evolve, and then end up as dead black holes? This is an open question because we know that black holes feed on gas, but what we don't understand is precisely how the gas makes it onto this peculiar surface that all black holes have called the "event horizon." The physics, the astrophysics, if you will, or the details of the flow, are very poorly understood. Once again, these are both problems where we have a good, in fact, a rather specialized, detailed broad-brush understanding; however, the very nature of these objects remains unknown. The situation is very similar to that of dark matter that appears to be ubiquitous.

The Exquisite Role of Dark Matter

Topic: 

  • UNIVERSE
https://vimeo.com/129461640

It is definitely the golden age in cosmology because of this unique confluence of ideas and instruments. We live in a very peculiar universe—one that is dominated by dark matter and dark energy—the true nature of both of these remains elusive. Dark matter does not emit radiation in any wavelength and its presence is inferred by its gravitational influence on the motions of stars and gas in its vicinity. Dark Energy, discovered in 1998, meanwhile is believed to be powering the accelerated expansion of the universe.

Layers Of Reality

Topic: 

  • UNIVERSE
https://vimeo.com/126636819

We know there's a law of nature, the second law of thermodynamics, that says that disorderliness grows with time. Is there another law of nature that governs the complexity of what happens? That talks about multiple layers of the structures and how they interact with each other? Embarrassingly enough, we don't even know how to define this problem yet. We don't know the right quantitative description for complexity. This is very early days. This is Copernicus, not even Kepler, much less Galileo or Newton. This is guessing at the ways to think about these problems.

Layers Of Reality

[5.28.15]

We know there's a law of nature—the second law of thermodynamics—that says that disorderliness grows with time. Is there another law of nature that governs the complexity of what happens? That talks about multiple layers of the structures and how they interact with each other? Embarrassingly enough, we don't even know how to define this problem yet. We don't know the right quantitative description for complexity. This is very early days. This is Copernicus, not even Kepler, much less Galileo or Newton. This is guessing at the ways to think about these problems.

SEAN CARROLL is a research professor at Caltech and the author of The Particle at the End of the Universe, which won the 2013 Royal Society Winton Prize, and From Eternity to Here: The Quest for the Ultimate Theory of Time. He has recently been awarded a Guggenheim Fellowship, the Gemant Award from the American Institute of Physics, and the Emperor Has No Clothes Award from the Freedom From Religion Foundation. Sean Carroll's Edge Bio Page

Formulating Science in Terms of Possible and Impossible Tasks

[12.6.14]

It turns out that in the constructor theoretic view, humans, as knowledge creating systems, are quite central to fundamental physics in an objective, non-anthropocentric, way. This is a very deep change in perspective. One of the ideas that will be dropped if constructor theory turns out to be effective is that the only fundamental entities in physics are laws of motion and initial conditions. In order for physics to accommodate more of physical reality, there needs to be a switch to this new mode of explanation, which accepts that scientific explanation is more than just predictions. Predictions will be supplemented with statements about what tasks are possible, what are impossible and why.

CHIARA MARLETTO is a Junior Research Fellow at Wolfson College and Postdoctoral Research Assistant at the Materials Department, University of Oxford; Currently working with David Deutsch. Chiara Marletto's Edge Bio Page

THE REALITY CLUB: NEW Arnold Trehub


FORMULATING SCIENCE IN TERMS OF POSSIBLE AND IMPOSSIBLE TASKS 

I’ve been thinking about constructor theory a lot in the past few years. Constructor theory is this theory that David Deutsch proposed—a proposal for a new fundamental theory to formulate science in a completely different way from the prevailing conception of fundamental physics. It has the potential to change the way we formulate science because it’s a new mode of explanation.

When you think about physics, you usually describe things in terms of initial conditions and laws of motion; so what you say is, for example, where a comet goes given that it started in a certain place and time. In constructor theory, what you say is what transformations are possible, what are impossible, and why. The idea is that you can formulate the whole of fundamental physics this way; so, not only do you say where the comet goes, you say where it can go. This incorporates a lot more than what it is possible to incorporate now in fundamental physics.

Formulating Science in Terms of Possible and Impossible Tasks

Topic: 

  • UNIVERSE
http://vimeo.com/111429354

It turns out that in the constructor theoretic view, humans, or knowledge creating systems, are quite central to fundamental physics in an objective way and not an anthropocentric way. This is a very deep change in perspective. One of the ideas that will be dropped if constructor theory turns out to be effective is that the only fundamental entities in physics are laws of motion and initial conditions.

Chiara Marletto on Extinction

[11.6.14]

 

There is a new fundamental theory of physics that’s called constructor theory, and was proposed by David Deutsch who pioneered the theory of the universe of quantum computer. David and I are working this theory together. The fundamental idea in this theory is that we formulate all laws of physics in terms of what tasks are possible, what are impossible, and why. In this theory we have an exact physical characterization of an object that has those properties, and we call that knowledge. Note that knowledge here means knowledge without knowing the subject, as in the theory of knowledge of the philosopher, Karl Popper.

 

We’ve just come to the conclusion that the fact that extinction is possible means that knowledge can be instantiated in our physical world. In fact, extinction is the very process by which that knowledge is disabled in its ability to remain instantiated in physical systems because there are problems that it cannot solve. With any luck that bit of knowledge can be replaced with a better one. 

 
[8:57]

CHIARA MARLETTO is a Junior Research Fellow at Wolfson College and Postdoctoral Research Assistant at the Materials Department, University of Oxford.  Chiara Marletto's Edge Bio Page


MOLLY CROCKETT: I’m pleased to welcome our second speaker, Chiara Marletto. She’s a quantum physicist working at the University of Oxford. She’s a bit of a polymath. She’s dabbled in Italian literature, engineering science, and quantum computation. Currently, she’s working with David Deutsch on constructor theory, which is a new fundamental theory of physics, and this touches on ideas that have been traditionally regarded as highly emergent and derivative, so for example, information, human knowledge, and the nature of life. Let’s welcome Chiara to the stage.

What's New In The Universe

Direct Evidence Of Cosmic Inflation
[3.17.14]

 

Alan Guth, a charter member of the Reality Club, came to New York in 1980, to give one of the first Reality Club talks. He presented his new theory on the early universe, which he had been working on for the past couple of years and had described earlier that year in a paper titled "The Inflationary Universe: A Possible Solution to the Horizon and Flatness Problems." It was a revolution in our understanding of the universe—a new theory that filled in the blanks left by earlier versions of the Big Bang theory. A few years later, Andrei Linde developed a version of Guth’s theory he refers to as Eternal Chaotic Inflation, which is now the most popular version of inflation.

Some thirty years later, I'm sitting in a hotel in Vancouver reading the news about what might turn out to be the most important scientific discovery of my lifetime: a possible direct confirmation of Guth's ideas. Using a radio telescope at the South Pole, John M. Kovac and his team of astronomers were able to glimpse the very early universe—capturing traces of light from 13.8 billion years ago. If their data are accurate, Guth was right.

Edge contributor and New York Times deputy science editor Dennis Overbye wrote about the developments in a story on the front page of Tuesday's New York Times: "...Inflation has been the workhorse of cosmology for 35 years, though many, including Dr. Guth, wondered whether it could ever be proved. ... If corroborated, Dr. Kovac’s work will stand as a landmark in science comparable to the recent discovery of dark energy pushing the universe apart, or of the Big Bang itself. It would open vast realms of time and space and energy to science and speculation."

How important is this development? MIT cosmologist Max Tegmark is quoted by Overbye as saying, "I think that if this stays true, it will go down as one of the greatest discoveries in the history of science." According to mathematical physicist Brian Greene, "If the results stand, they are a landmark discovery." Physicist Lawrence Krauss of Arizona State University, in a post on newyorker.com, wrote, "At rare moments in scientific history, a new window on the universe opens up that changes everything. Today was quite possibly such a day."

But nothing is more prescient than Guth's own talks from two Edge Eastover Farm events, in 2001 ("A Golden Age of Cosmology") and 2002 ("The Inflationary Universe"), and Linde's Edge interview in 2012 ("A Balloon Producing Balloons, Producing Balloons: a Big Fractal"). Continue below for EdgeVideo and texts.

John Brockman

FREE WILL, DETERMINISM, QUANTUM THEORY AND STATISTICAL FLUCTUATIONS: A PHYSICIST'S TAKE

[7.8.13]

Any attempt to link this discussion to moral, ethical or legal issues, as is often been done, is pure nonsense. The fact that it is possible to say that a criminal has been driven to kill because of the ways in which Newton's laws have acted on the molecules of his body has nothing to do either with the opportunity of punishment, nor with the moral condemnation. It is respecting those same laws by Newton that putting criminals in jail reduces the murders, and it is respecting those same laws by Newton that society as a whole functions, including its moral structure, which in turn determines behavior.  There is no contradiction between saying that a stone flew into the sky because a force pushed it, or because a volcano exploded.  In the same manner, there is no contradiction in saying we do not commit murder because something is encoded in the decision-making structure of our brain or because we are bound by a moral belief.

Free will has nothing to do with quantum mechanics. We are deeply unpredictable beings, like most macroscopic systems. There is no incompatibility between free will and microscopic determinism.  The significance of free will is that behavior is not determined by external constraints, not by the psychological description of our neural states to which we access. The idea that free will may have to do with the ability to make different choices on equal internal states is an absurdity, as the ideal experiment I have described above shows. The issue has no bearing on questions of a moral or legal nature. Our idea of being free is correct, but it is just a way to say that we are ignorant on why we make choices.

CARLO ROVELLI is a theoretical physicist, working on quantum gravity and on foundations of spacetime physics. He is Professor of Physics at Centre De Physique Théorique De Luminy at Aix-Marseille University, France and member of the Intitut Universitaire de France. He is the author of The First Scientist: Anaximander and His Legacy; and Quantum Gravity. 

Carlo Rovelli's Edge Bio Page

THE REALITY CLUB: Lee Smolin

A PHYSICIST LOOKS AT FREE WILL, DETERMINISM, QUANTUM THEORY AND STATISTICAL FLUCTUATIONS

Since Democritus suggested that the world can be seen as the result of accidental clashing of atoms, the question of free will has disturbed the sleeps of the naturalist: how to reconcile the deterministic dynamics of the atoms with man's freedom to choose? Modern physics has altered the data a bit, and the ensuing confusion requires clarification. 

Democritus assumed the movement of atoms to be deterministic: a different future does not happen without a different present. But Epicurus, who in physical matters was a close follower of Democritus, had already perceived a difficulty between this tight determinism and human freedom, and modified the physics of Democritus, introducing an element of indeterminism at the atomic level.

The new element was called "clinamen." The "clinamen" is a minimum deviation of an atom from its natural rectilinear path, which takes place in a completely random fashion. Lucretius, who presents the Democritean-Epicurean theory in his poem, "De Rerum Natura", "On Things Of Nature," notes in poetic words: the deviation from straight motion happens "uncertain tempore ... incertisque loci ", in an uncertain time and an uncertain place [Liber II, 218].

A very similar oscillation between determinism and indeterminism has happened again in modern physics. Newton's atomism is deterministic in a similar manner as Democritus's.  But at the beginning of the twentieth century, Newton's equations have been replaced by those of quantum theory, which bring back an element of indeterminism, quite similar, in fact, to Epicurus's correction of Democritus's determinism. At the atomic scale, the motion of the elementary particles is not strictly deterministic.

Can there be a relationship between this atomic-scale quantum indeterminism and human freedom to choose?

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