UNIVERSE

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?

THINK ABOUT NATURE

A Conversation with
[5.14.13]

Feynman once told me, "Whatever you do—you're going to have to do crazy things to think about quantum gravity—but whatever you do, think about nature. If you think about the properties of a mathematical equation, you're doing mathematics and you're not going to get back to nature. Whatever you do, have a question that an experiment could resolve at the front of your thinking." So I always try to do that.

 


TIME REBORN:
From the Crisis in Physics
to the Future of the Universe

 

LEE SMOLIN is a founding and senior faculty member at Perimeter Institute for Theoretical Physics in Waterloo, Canada. He is also Adjunct Professor of Physics at the University of Waterloo and is a member of the graduate faculty of the Department of Philosophy of the University of Toronto. His is the author od Time Reborn: From the Crisis in Physics to the Future of the Universe. Lee Smolin's Edge Bio Page

 


[58:16 minutes]

THE REALITY CLUB: Arnold Trehub, Sean Carroll, Lee Smolin, Bruce SterlingArnold Trehub, Amanda Gefter

 


THINK ABOUT NATURE

The main question I'm asking myself, the question that puts everything together, is how to do cosmology; how to make a theory of the universe as a whole system. This is said to be the golden age of cosmology and it is from an observational point of view, but from a theoretical point of view it's almost a disaster. It's crazy the kind of ideas that we find ourselves thinking about. And I find myself wanting to go back to basics—to basic ideas and basic principles—and understand how we describe the world in a physical theory.

What's the role of mathematics? Why does mathematics come into physics? What's the nature of time? These two things are very related since mathematical description is supposed to be outside of time. And I've come to a long evolution since the late 80's to a position, which is quite different from the ones that I had originally, and quite surprising even to me. But let me get to it bit by bit. Let me build up the questions and the problems that arise.

One way to start is what I call "physics in a box" or, theories of small isolated systems. The way we've learned to do this is to make an accounting or an itinerary—a listing of the possible states of a system. How can a possible system be? What are the possible configurations? What were the possible states? If it's a glass of Coca Cola, what are the possible positions and states of all the atoms in the glass? Once we know that, we ask, how do the states change? And the metaphor here—which comes from atomism that comes from Democritus and Lucretius—is that physics is nothing but atoms moving in a void and the atoms never change. The atoms have properties like mass and charge that never change in time. The void—which is space in the old days never changed in time—was fixed and they moved according to laws, which were originally given by or tried to be given by Descartes and Galileo, given by Newton much more successfully.

THINK ABOUT NATURE

Topic: 

  • UNIVERSE
https://vimeo.com/82413843

Feynman once told me, "Whatever you do—you're going to have to do crazy things to think about quantum gravity—but whatever you do, think about nature. If you think about the properties of a mathematical equation, you're doing mathematics and you're not going to get back to nature. Whatever you do, have a question that an experiment could resolve at the front of your thinking." So I always try to do that.

CONSTRUCTOR THEORY

A Conversation with
[10.22.12]

There's a notorious problem with defining information within physics, namely that on the one hand information is purely abstract, and the original theory of computation as developed by Alan Turing and others regarded computers and the information they manipulate purely abstractly as mathematical objects. Many mathematicians to this day don't realize that information is physical and that there is no such thing as an abstract computer. Only a physical object can compute things.

~ ~ ~ ~

I think it's important to regard science not as an enterprise for the purpose of making predictions, but as an enterprise for the purpose of discovering what the world is really like, what is really there, how it behaves and why.
 

DAVID DEUTSCH is a Physicist at the University of Oxford. His research in quantum physics has been influential and highly acclaimed. He is the author of The Beginning of Infinity and The Fabric of Reality. David Deutsch's Edge Bio Page

REALITY CLUB: Arnold Trehub, Harold Levey

CONSTRUCTOR THEORY

Topic: 

  • UNIVERSE
http://vimeo.com/83527852

There's a notorious problem with defining information within physics, namely that on the one hand information is purely abstract, and the original theory of computation as developed by Alan Turing and others regarded computers and the information they manipulate purely abstractly as mathematical objects. Many mathematicians to this day don't realize that information is physical and that there is no such thing as an abstract computer. Only a physical object can compute things.

~~

A BALLOON PRODUCING BALLOONS, PRODUCING BALLOONS:A BIG FRACTAL

[8.24.12]

Think about it this way: Previously, we thought that our universe was like a spherical balloon. In the new picture, it's like a balloon producing balloons, producing balloons. This is a big fractal. The Greeks were thinking about our universe as an ideal sphere, because this was the best image they had at their disposal. The 20th-century idea is a fractal, the beauty of a fractal. How many different types of these elements of fractals are there, which are irreducible to each other? The number will be exponentially large; in the simplest models, it is about 10 to the degree 10, to the degree 10, to the degree 7. It actually may be much more than that, even though nobody can see all of these universes at once.

ANDREI LINDE, a Russian-American theoretical physicist and professor of physics at Stanford University, is the father of "eternal chaotic inflation," one of the varieties of the inflationary multiverse theory, which proposes that the universe may consist of many universes with different properties. He is an inaugural winner of the $3 million Fundamental Physics Prize, awarded by the Milner Foundation. In 2002, he was awarded the Dirac Medal, along with Alan Guth of MIT and Paul Steinhardt of Princeton University. Andrei Linde's Edge Bio Page

A BALLOON PRODUCING BALLOONS, PRODUCING BALLOONS:A BIG FRACTAL

Topic: 

  • UNIVERSE
http://vimeo.com/80814823

Think about it this way: previously we thought that our universe was like a spherical balloon. In the new picture, it's like a balloon producing balloons, producing balloons. This is a big fractal. The Greeks were thinking about our universe as an ideal sphere, because this was the best image they had at their disposal. The 20th century idea is a fractal, the beauty of a fractal. Now, you have these fractals. We ask, how many different types of these elements of fractals are there, which are irreducible to each other?

Carlo Rovelli - Science Is Not About Certainty: A Philosophy Of Physics

Topic: 

  • UNIVERSE
https://vimeo.com/66561242

"I seem to be saying two things that contradict each other. On the one hand, we trust scientific knowledge, on the other hand, we are always ready to modify in-depth part of our conceptual structure about the world. But there is no contradiction, because the idea of a contradiction comes from what I see as the deepest misunderstanding about science: the idea that science is about certainty."

SCIENCE IS NOT ABOUT CERTAINTY: A PHILOSOPHY OF PHYSICS

[5.30.12]

I seem to be saying two things that contradict each other. On the one hand, we trust scientific knowledge, on the other hand, we are always ready to modify in-depth part of our conceptual structure about the world. But there is no contradiction, because the idea of a contradiction comes from what I see as the deepest misunderstanding about science: the idea that science is about certainty.                    

Introduction
by Lee Smolin 

Carlo Rovelli is a leading contributor to quantum gravity, who is also made influential proposals regarding the foundation of quantum mechanics and the nature of time. Shortly after receiving his Ph.D he did work which made him regarded as one of the three founders of the approach to quantum gravity called loop quantum gravity-the other two being Abhay Ashtekar and Lee Smolin. Over the last 25 years he has made numerous contributions to the field, the most important of which developed the spacetime approach to quantum gravity called spin foam models.These have culminated over the last five years in a series of discoveries which give strong evidence that loop quantum gravity provides a consistent and and plausible quantum theory of gravity.  

Rovelli's textbook, Quantum Gravity has been the main introduction to the field since its publication in 2004, and his research group in Marseille has been a major center for incubating and developing new talent in the field in Europe.Carlo Rovelli's approach to the foundations of quantum mechanics is called relational quantum theory, he also, with the mathematician Alain Connes, proposed a mechanism by which time could emerge from a timeless world called the thermal time hypothesis.

– Lee Smolin

CARLO ROVELLI is a theoretical physicist, working on quantum gravity and on foundations of spacetime physics. He is professor of physics at the University of the Mediterranean in Marseille, 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
Lee Smolin's Edge Bio Page

 

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