UNIVERSE

NASA GOES DEEP

[2.26.07]

...instead of having a ubiquitous presence throughout the solar system, humans haven’t set foot on the Moon in 35 years, and even our robotic explorations in that time have been throttled because we deliberately reduced our access to deep space.

 

CAROLYN PORCO is a planetary scientist, the leader of the Imaging Science Team on the Cassini mission and director of the Cassini Imaging Central Laboratory for Operations.

 

Carolyn Porco's Edge Bio Page

MY EINSTEIN'S SUSPENDERS

The 2006 Nobel Prize for Physics
[11.9.06]

Last month, Edge contributor Berkeley astrophysicist George Smoot was awarded the Nobel prize in Physics (along with Nasa's John Mather). In 1992, Smoot made headlines around the world with his images of the birth of the universe, the beginning of time itself, taken with the Cosmic Background Explorer (COBE) space probe. Backed by a large team, Smoot used COBE to pick up the faint whispers left by the cosmic explosion of creation almost 14 billion years ago, revealing embryonic structures in the baby universe. When he announced their astonishing find, Stephen Hawking said it was "the discovery of the century, if not all time."

Ever since, there has been increasing recognition of the importance of his work. Cobe was followed by WMap, and "Plank" will launch in 200x. Also, next year the Large hadron Collider (LHC) launches at Cern. Smoot's  Nobel prize is the confirmation of the importance of his work that has led to the elevation of cosmology to a precision science. Smoot's research stands at a momentous intersection of the empirical and the epistemological: by confirming the reality of the Big Bang with precise calculations, we have entered a new age, the golden age of cosmology.Last year Smoot was honored as the Albert Einstein scientist. he also wrote the following essay, "My Einstein's Suspenders" which was recently published in My Einstein.

GEORGE F. SMOOT is the leader of a group at Lawrence Berkeley National Laboratory that conducts experiments observing our galaxy and the cosmic background radiation. The best known of these is COBE (the Cosmic Background Explorer satellite), which has shown that the cosmic background radiation intensity has a wavelength dependence precisely that of a perfectly absorbing body, indicating that it is the relic radiation from the Big Bang. For this work, has been awarded the 2006 Nobel Prize for physics. He shares the award with John C. Mather of NASA Goddard Space Flight Center. The citation reads "for their discovery of the blackbody form and anisotropy of the cosmic microwave background radiation."

He is the author (with Keay Davidson) of Wrinkles in Time.

George F. Smoot's Edge Bio Page

THE PRINCIPLE OF MEDIOCRITY

[9.14.06]

A striking consequence of the new picture of the world is that there should be an infinity of regions with histories absolutely identical to ours. That's right, scores of your duplicates are now reading copies of this article. They live on planets exactly like Earth, with all its mountains, cities, trees, and butterflies. There should also be regions where histories are somewhat different from ours, with all possible variations. For example, some readers will be pleased to know that there are infinitely many O-regions where Al Gore is the President of the United States.

In this astonishing world view, our Earth and our civilization are anything but unique. Instead, countless identical civilizations are scattered across the infinite expanse of the cosmos. With humankind reduced to absolute cosmic insignificance, our descent from the center of the world, a process begun by Copernicus, is now complete.

Introduction

In 1981, Alan Guth made what some considered at the time to be the most important contribution to cosmology in a generation: the theory of inflation. In Guth's model, the very early universe underwent a period of rapid expansion; this accounts for, among other puzzles in big-bang theory, the present-day universe's puzzling homogeneity.

Today, more than 25 years later, Guth's inflationary model still holds sway, as other cosmologists have moved the theory in new directions, i.e. chaotic inflation, eternal inflation, brane inflation, among others.

The implications of inflation are particularly important in the context of the landscape of string theory. One of the leading researchers studying how inflationary cosmology evolves through the landscape is Alex Vilenkin, a theoretical physicist at Tufts who has been working in the field of cosmology for 25 years and is a pioneer in introducing the ideas of eternal inflation and quantum creation of the universe from nothing. Here he sets forth his ideas of how the set of theories which began with Guth's inflationary scenario are playing out.

—JB

 

ALEXANDER VILENKIN is Professor of Physics and Director of the Institute of Cosmology at Tufts University. A theoretical physicist who has been working in the field of cosmology for 25 years, Vilenkin has written over 150 papers and is responsible for introducing the ideas of eternal inflation and quantum creation of the universe from nothing.

Alexander Vilenkin's Edge Bio Page

BRAIDS

[8.11.06]

Theoretical physicists working in the rarefied field of loop quantum gravity have developed a way to describe elementary particles as merely tangles in space. If they are right, it could be the most profound scientific generalisation of all time, in which everything in the universe emerges from a simple network of relationships, with no fundamental building blocks at all. — New Scientist, Editorial [12 August 06]

About a decade ago, in my book The Third Culture (1995), Lee Smolin's chapter ("A Theory of the Whole Universe") began with the following comments:

"What is space and what is time? This is what the problem of quantum gravity is about. In general relativity, Einstein gave us not only a theory of gravity but a theory of what space and time are — a theory that overthrew the previous Newtonian conception of space and time. The problem of quantum gravity is how to combine the understanding of space and time we have from relativity theory with the quantum theory, which also tells us something essential and deep about nature. If we can do this, we'll discover a single unified theory of physics that will apply to all phenomena, from the very smallest scales to the universe itself. This theory will, we're quite sure, require us to conceive of space and time in new ways that take us beyond even what relativity theory has taught us.

"But, beyond even this, a quantum theory of gravity must be a theory of cosmology. As such, it must also tell us how to describe the whole universe from the point of view of observers who live in it — for by definition there are no observers outside the universe. This leads directly to the main issues we're now struggling with, because it seems very difficult to understand how quantum theory could be extended from a description of atoms and molecules to a theory of the whole universe. As Bohr and Heisenberg taught us, quantum theory seems to make sense only when it's understood to be the description of something small and isolated from its observer — the observer is outside of it. For this reason, the merging of quantum theory and relativity into a single theory must also affect our understanding of the quantum theory. More generally, to solve the problem of quantum gravity we'll have to invent a good answer to the question: How can we, as observers who live inside the universe, construct a complete and objective description of it?"

Discover Magazine had run a cover story proclaiming Smolin "The New Einstein". It may have impressed the general reader, but not mainstream physicists. As cosmologist Alan Guth, father of the inflationary theory of the Universe, noted in The Third Culture:

"The relativity physicists belong to a small club. It's a club that has yet to convince the majority of the community that the approach they're pursuing is the right one. Certainly Smolin is welcome to come and give seminars, and at major conferences he and his colleagues are invited to speak. The physics community is interested in hearing what they have to say. But the majority looks to the superstring approach to answer essentially the same questions."

Also weighing in was particle physicist and Nobel Laureate Murray Gell-Mann:

"Smolin? Oh, is he that young guy with those crazy ideas? He may not be wrong!"

 

A decade later, Smolin's ideas are beginning to get traction.New Scientist has published a cover story [12 August 06] reporting on the work on "Braids" and Loop Quantum Gravity by Smolin, Carlo Rovelli, Sundance Bilson-Thompson, and Fotini Markopoulou. An accompanying editorial proclaims that "it could be the most profound scientific generalisation of all time."

Is it time to overthrow decades of work on string theory? The jury is out on the ideas generated by Smolin and his colleagues, but the question is now being asked by more than a few physicists.

—JB

THE ENERGY OF EMPTY SPACE THAT ISN'T ZERO

[7.5.06]

I invited a group of cosmologists, experimentalists, theorists, and particle physicists. Stephen Hawking came. We had three Nobel laureates: Gerard 't Hooft, David Gross, Frank Wilczek; well-known cosmologists and physicists such as Jim Peebles at Princeton, Alan Guth at MIT, Kip Thorne at Caltech, Lisa Randall at Harvard; experimentalists, such as Barry Barish of LIGO, the gravitational wave observatory; we had observational cosmologists, people looking at the cosmic microwave background; we had Maria Spiropulu from CERN, who's working on the Large Hadron Collider—which, a decade ago, people wouldn't have thought it was a probe of gravity, but now due to recent work in the possibility of extra dimensions it might be.


THE ENERGY OF EMPTY SPACE THAT ISN'T ZERO
 

Introduction

Physicist/cosmologist Lawrence Krauss, who recently was featured on Edge("How Do You Fed-ex the Pope?"), recently convened a physics conference on St. Thomas, which included an all-star cast of cutting-edge theorists and physicists.

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Stephen Hawking, David Gross, Kip Thorne, Lisa Randall

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Lawrence Krauss and Stephen Hawking on the way to Atlantis Submarine

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Frank Wilczek, Betsy Devine, and Alan Guth

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Krauss scuba diving to meet Atlantis Submarine

The topic of the meeting was "Confronting Gravity." Krauss intended to have "a meeting where people would look forward to the key issues facing fundamental physics and cosmology". They could meet, discuss, relax on the beach, and take a trip to the nearby private island retreat of the science philanthropist Jeffrey Epstein, who funded the event.

For Krauss, what came out of the conference was the over-riding issue that "there appears to be energy of empty space that isn't zero! This flies in the face of all conventional wisdom in theoretical particle physics. It is the most profound shift in thinking, perhaps the most profound puzzle, in the latter half of the 20th century. And it may be the first half of the 21st century, or maybe go all the way to the 22nd century. Because, unfortunately, I happen to think we won't be able to rely on experiment to resolve this problem."

"It's not clear to me", he says, "that the landscape idea will be anything but impotent. Ultimately it might lead to interesting suggestions about things, but real progress will occur when we actually have new ideas. If string theory is the right direction, and I'm willing to argue that it might be, even if there's just no evidence that it is right now, then a new idea that tells us a fundamental principle for how to turn that formalism to a theory will give us a direction that will turn into something fruitful. Right now we're floundering. We're floundering, in a lot of different areas."

Other physicists, whether present at the conference or not, will no doubt feel diiferently. Edge looks forward to their comments.

JB

LAWRENCE M. KRAUSS, a physicist/cosmologist, is the Ambrose Swasey Professor of Physics and chairman of the Physics Department of Case Western Reserve University. He is the author of The Fifth Essence, Quintessence, Fear of Physics, The Physics of Star Trek, Beyond Star Trek, Atom, and Hiding in the Mirror.


COSMOLOGICAL EVOLUTION

[5.30.06]

 

...there is a deep relation between Einstein's notion that everything is just a network of relations and Darwin's notion because what is an ecological community but a network of individuals and species in relationship which evolve?  There's no need in the modern way of talking about biology for any absolute concepts for any things that were always true and will always be true.


TRIVERS, SMOLIN, HAUSER"DARWIN Y LA TERCERA CULTURA" IN BARCELONA

Last year Edge received an invitation from Juan Insua, Director of Kosmopolis, a traditional literary festival in Barcelona, to stage an event at Kosmopolis 05 as part of an overall program "that ranges from the lasting light of Cervantes to the (ambiguous) crisis of the book format, from a literary mapping of Barcelona's Raval district to the dilemma raised by the influence of the Internet in the kitchen of writing, from the emergence of a new third culture humanism to the diverse practices that position literature at the core of urban creativity."

Something radically new is in the air: new ways of understanding physical systems, new focuses that lead to our questioning of many of our foundations. A realistic biology of the mind, advances in physics, information technology, genetics, neurobiology, engineering, the chemistry of materials: all are questions of capital importance with respect to what it means to be human.

Charles Darwin's ideas on evolution through natural selection are central to many of these scientific advances. Lee Smolin, a theoretical physicist, Marc D. Hauser, a cognitive neuroscientist, and Robert Trivers, an evolutionary biologist, travelled to Barcelona last October to explain how the common thread of Darwinian evolution has led them to new advances in their respective fields.

The evening was presented by Eduard Punset, host of the internationally-viewed Spanish-language science television program Redes, and a best-selling author in Spain. A Redes television program based on the event was broadcast throughout Spain and Latin America.

The house was packed. The Barcelona press was present (see El PaisLa VanguardiaEl PaisEl Mundo, and a cover story in "Culturas", the magazine fo La Vanguardia).

Back to Event page

TRIVERS, SMOLIN, HAUSER: "DARWIN Y LA TERCERA CULTURA" IN BARCELONA

THAT FAMOUS EQUATION AND YOU

[10.5.05]

Einstein's derivation of E = mc² was wholly mathematical. I know his derivation, as does just about anyone who has taken a course in modern physics. Nevertheless, I consider my understanding of a result incomplete if I rely solely on the math. Instead, I've found that thorough understanding requires a mental image - an analogy or a story - that may sacrifice some precision but captures the essence of the result.

Here's a story for E = mc². Two equally strong and skilled jousters, riding identical horses and gripping identical (blunt) lances, head toward each other at an identical speed. As they pass, each thrusts his lance across his breastplate toward his opponent, slamming blunt end into blunt end. Because they're equally matched, neither lance pushes farther than the other, and so the referee calls it a draw.

This story contains the essence of Einstein's discovery. Let me explain.

BRIAN GREENE, a professor of physics and mathematics at Columbia, is the author of The Elegant Universe and The Fabric of the Cosmos.

Brian Greene's Edge Bio page 

WHO DESIGNED THE DESIGNER?

[9.2.05]

If I had the opportunity to meet the assumed designer, I'd ask what, to me, is the most important question of them all: ''Mr. Designer, who designed you?"

If the designer answers that it doesn't know, that perhaps it was also designed, we fall into an endless regression, straight back to the problem of the first cause, the one that needs no cause. At this point the mask tumbles and we finally discover the true identity of the IDists' Designer. We should capitalize the word, as this is how we are taught to refer to God.

MARCELO GLEISER, a professor of physics and astronomy at Dartmouth College, is the author of The Prophet and the Astronomer: A Scientific Journey to the End of Time.

Marcelo Gleiser's Edge Bio Page

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