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1. Recommended Reading in Physics and Computer Science.
My recommendations for further study of quantum mechanics, information theory, and computer science. No hard scientific texts -- these are mostly written for liberal arts majors.


2. Links to Web Resources relating to the Fredkin Hypothesis (the universe is a cellular automata computer simulation), theology and science. My collection of bookmarks and favorites, visited over the years. These links were last tested in the beginning of June, 2000.

3. Recent Technical Papers of Interest 
Only if you're interested in the harder science.  If you have the gist of the BottomLayer, you should be able to get something out of these papers.  Even skimming through the math to get to the conclusions is often stimulating.

2. Links to Web Resources
Ancient Antecedents
Alternative Physics, New Age & Eastern
Beer [sic]
Collections of Quotations
Digital Physics, Fredkin, Cellular Automata, Computer Simulations
Lists of Links and Resources

Mainstream Science Magazines

Physics with a Religious Bent (Mostly Christian)

    Evangelical Resources Focused on Science
    Journals and Societies About Science and Religion
Science & Mathematics


Digital Physics, Fredkin, Cellular Automata, Computer Simulations

Digital Philosophy

Edward Fredkin
Edward Fredkin finally took the step of posting his writings in December 2001.  This is FABULOUS NEWS.  Browse here for his seminal papers on the nature of the universe, the human soul,  conservative logic, and etc.  Also, join discussion groups on topics of digital philosophy and digital metaphysics.  Put in your two cents.

Click here for:
Introduction to Digital Philosophy
On the Soul
Finite Nature
A New Cosmogony
A Physicist's Model
Digital Mechanics (1990)
Digital Mechanics (2000 book)
Conservative Logic

Robert Wright, "Did the Universe Just Happen?"

This article in the April 1988 issue of The Atlantic is what started the public discussion of Fredkin's work and the whole subject of computer universes.  Finally posted by The Atlantic (thank you!).

Wright reworked this material as a chapter in his 1989 book, "Three Scientists and their Gods."

New and highly recommended

Wired magazine: December 2002 issue on theme of Science and Religion [Issue 10.12]

God is the Machine (Kevin Kelly) excellent survey of Fredkin/Wolfram/Zuse thinking.
The New Convergence (Gregg Easterbrook)  excellent survey of intrusion of metaphysics into science, refusal of religion to fade. 

Karl Svozil, "Computational Universes." (13-May-2003).

Karl Svozil, "Science at the crossroad between randomness and determinism." (2002).

Karl Svozil's Home Page.

Svozil has been studying the universe-as-computer concept for many years.  This is a philosophical survey, not very technical.  Excellent analysis of viewpoints available to the Western believer, including strict determinism a la Fredkin and interactive gaming a la Rhodes.

Digital Physics
A group devoted to exploring Fredkin's hypothesis that the universe is a cellular automata computer program. Several CA simulations are posted, and discussion about the CA qualities necessary to design a universe. Run by knowledgeable computer programmers.
Digital Physics Mailing List
Discussions range from the technical to the philosophical. Given a basic familiarity with the CA concept, lay persons can benefit.
Digital Physics Links
Resources in the basics of cellular automata programming, Fredkin's papers, and further research in CA as an alternative explanation of phenomena.

Tim Tyler's page and postings, borrowing the title from Fredkin.  Essays and implementations on cellular automata as universe.

"An Information Systems model of the universe is a radically different paradigm. There are no fundamental fields or forces or space and time, there is only information about events and the logical relationships they exhibit." - Jim Whitescarver

Tommaso Toffoli's Home Page
Toffoli has been associated with Fredkin, but speaks with his own authority. He gets more respect as a scientist.
Anton Zeilinger, "A Foundational Principle for Quantum Mechanics"
Anton Zeilinger, "On the Interpretation and Philosophical Foundation of Quantum Mechanics"
These are terrific papers on QM from an information theory point of view by one of the foremost experimental physicists of our day. "A Foundational Principle ..." is courtship in the eventual marriage of physics and computer science. For a thumbnail sketch of Zeilinger's concepts, see "In the Beginning was the Bit" from The New Scientist, 17 February 2001.
Marvin Minsky Home Page
A mover and shaker in the MIT Artificial Intelligence community. Minsky has worked with Fredkin and appears to have been influenced.
David Deutsch, The Fabric of Reality (Penguin 1997).
This is Chapter 14, posted by Frank Tipler of Tulane University (and author of The Physics of Immortality). An exposition of the logic of computation as the basis of physics. Lousy formatting, but it's a free sample.  Buy the book at Amazon.com.
Billiard Ball Machines: Reversible Cellular Automata
Page devoted to reversible cellular automata concepts, focusing on the "billiard ball machine" model of computing developed by Norman Margolus and Edward Fredkin. From Lotus Artificial Life.
Quantum Theory Paradoxes Resolved
Joseph Spigelman ("Quantum Joe") presents a model of computer simulation which would replicate the quantum paradoxes without being so overbroad as to replicate anything at all. An alternative to cellular automata for the universe-as-computer-simulation hypothesis.

"P.W. Adkins, P. [sic] Fredkin, and others argue that the universe is, in essence, a computer. The idea is compelling because everything in the universe can be represented in the computers binary code. That, however, is the problem, because the binary code can represent anything at all, however absurd or impossible. Need, therefore, an exclusion principle.

"I [Spigelman] propose such a principle, from which can be generated an object language that can be used to model, and thus explicate, actual physical phenomena."

Access to Spigelman's website has been sporadic of late.  Spigelman's 1987 book, Toward a New Foundation for Physics, is listed by Amazon.com.  If you order it, let me know.

Stephen Wolfram: Official Web Site
Most interesting for its blurbs about Wolfram's upcoming book (projected for September, 2000 some time in 2001 2002) called A New Kind of Science. ANKOS is published, May 2002.  Go to Recommended Reading for more details.
Also many excellent articles on the subject.  For instance, S. Wolfram, "Computer Software in Science and Mathematics", Scientific American, 251 (September 1984) 188-203, posted at the site.
Mysteries of Science
Jonathan J. Dickau's thoughts on science's new frontiers. Includes some beautiful fractal images.

Mainstream Science Magazines

Scientific American
Discover Magazine - Editors' Web Tour
SKY Online - Sky Publishing Corporation
Science News Online - The Weekly Newsmagazine of Science

Science & Mathematics

Image Calculation Techniques
The next time somebody tells you that we can now take pictures of individual atoms and that they are real objects -- refer them to this interesting treatise. It is not quite so simple. P. Stadelmann, CIME-EPFL, CH-1015 Lausanne, Switzerland explains the process.
Computer generated holography
Stephen Cason's senior thesis at the Univ. of Calif. at Santa Barbara. A good demonstration of the concept of computer generated functions without the use of any live models.
Fundamental Physical Constants from the NIST (1998 CODATA Values)
"Throughout all of the formulations of the basic theories of physics and their application to the real world, there appear again and again certain fundamental invariant quantities." The National Institute of Standards and Technology (NIST) publishes the latest experimentally determined values of a vast number of these physical constants. It's as good as a textbook. You could look it up.
Fundamental Theory Notes
A posting of the CCQC, with many good synopses of physics theories. Just what is a Hamiltonian, you might ask? Is it not a horse race? This probably tells you more than you were interested in.
Heisenberg Uncertainty Principle
A concise discussion of what Heisenberg was talking about. Determinacy and indeterminacy.
John Baez's Home Page
Baez is a mathematical physicist at the Unversity of California at Riverside, and a moderator of and prolific contributor to sci.physics research (also sci.physics). A widely quoted expert-on-everything. His material ranges from the highly technical to the relatively accessible.  Because of his work in quantum gravity, he is being drawn to the hypothesis that space and time are discrete.  He is a smart cookie, and I expect he is pondering the significance of this insight, along the lines of Finite Nature.
Introduction to the Physics FAQ
The FAQ for sci.physics and sci.physics.research. Thumbnail descriptions of many basic findings and open questions in physics.
Measurement in quantum mechanics FAQ
An offshoot of the Physics FAQ. It's all about measurement (sic).
Institute for Theoretical Atomic and Molecular Physics Home Page at Harvard
Particle Displacement and Wave Motion
Quantum Cosmology
Standard Model
A posting by FermiLab with a concise description of the Standard Model of quantum particles and forces (except gravity). The Standard Model has the odd distinction of being almost perfect and almost universally disliked. Like the intricate model of the cosmos before the Copernican revolution, the Standard Model achieves its accuracy at the expense of elegance. Almost everybody feels that the Standard Model is missing some very basic explanatory principle (probably related to its failure to explain gravity), and that when such a principle emerges the superseding model will look nothing like the Standard Model.
SLAC Virtual Visitor Center
The Stanford Linear Accellerator's visitor center is both entertaining and full of useful information. The problem, of course, is that by constantly analyzing "particles" as if they were objects, one begins to think that they really are objects.
The Particle Adventure
An educational site devoted to the zoo of particles predicted and explained by the Standard Model. "The Particle Adventure is an award-winning site that introduces the theory of fundamental particles and forces, called the Standard Model. It also explores the experimental evidence and the reasons physicists want to go beyond this theory."
MathPages: History of Mathematics
A good collection of math references, leading off with Zeno's paradox (obviously not alphabetically arranged).

Ancient Antecedents

In contemplating the overthrow of Newtonian mechanics, it is useful to reexamine some of the thought overthrown by Newton.
Buddhist Doctrines of Momentariness and Subjective Idealism in the Nyaya-sutras
Some strains of Buddhism contemplated time as a succession of moments, rather than a continuous stream.
Zeno and the Paradox of Motion
Three thousand years old and still a thorn in the side of both philosophy and physics.
The Atomism of Democritus
The antecedent of Zeno's arguments.
Aquinus and Big Bang Cosmology
An interesting review of traditional church doctrine in light of Big Bang doctrines and the discovery that the universe is expanding.
Catholic Encyclopedia: Cosmology
A good survey of the roots of inquiry, from a theological perspective.

Science with a Religious Bent (Mostly Christian)

Christian Physics
"I believe that to study physics in the most God-honouring way involves seeing it as an integral part of the whole human experience. Yes, physics has to be taught as physics, but one needs to consider its wider applications and implications."
Alex Patterson Master Index

Thoughtful essays on a variety of topics, including physics, evolution, and spirituality.

Scriptural Physics
This website offers very readable and thought-provoking articles about physics, scriptural methods, and problem-solving techniques. I sense a kindred spirit here.
The Edgar Cayce Books World Database: The Physics of Angels
I like quasi-scientific discussions of traditional theological concepts, and I've always had a soft spot for Edgar Cayce. (The Edgar Cayce Foundation does not restrict itself to subjects directly related to the prophet's work, and this example does not rely on Cayce's readings.) Let the Californians worry about UFOs; I prefer to contemplate angels.
Mike Levin's Web Page, including Mike Levin's Philosophy and Religion Page & Mike Levin's Science Page
Levin is a biology post-doc in the Boston area. He has collected a wide range of material on scientific and philosophical subjects.
Evangelical Resources Focused on Science
Reasons to Believe
Founded by Hugh Ross, lists many resources examining science from a Christian perspective.
Virtual Particles or Virtual Religion
Tends to shout at the reader. The point is that there is much we do not know or understand, and so scientific atheism is not an honest option.
This has been a hot topic for more than 100 years. Given my own devotion to digital physics I am not concerned with creationism as a doctrine, but at the least these pages poke some well-deserved holes in the new theology of science.
Phillip E. Johnson

I've been reading Johnson recently.  He has a marvelous sense of God and a deep understanding of Christianity.  His writings on science and religion are perhaps the most perceptive analyses of the conflict you will ever read.   Everyone should take the time to read one of his short books in order to understand the debate on school curriculums that is rolling across the country.

Creation Research Society
The Pascal Centre for Advanced Studies in Faith and Science
"The Pascal Centre promotes constructive relations between Christian faith and the natural sciences by means of education, outreach and research in the light of Scripture." Affliliated with Redeemer College, a private non-denominational Christian liberal arts university in Ancaster, Ontario, Canada.
Journals and Societies
American Scientific Affiliation and its journal Perspectives on Science & Christian Faith
Science & Christian Belief
A scholarly journal "exploring God's work in creation, encouraging concern for the environment, applying biblical principles to science and technology".
John Templeton Foundation
This is the granddaddy of foundations interested in science and religion. It received a special mention from Stephen Jay Gould in his railings against syncretism. The whole purpose of the Templeton Foundation is to promote dialog between and among scientists and persons of faith -- not necessarily traditional faiths.
Institute for Theological Encounter with Science & Technology
"An organization committed to ongoing dialog among contemporary thinkers, assessing developments in science and technology for their theological implications and to apply religious values to scientific processes."
Science & Spirit Magazine
"Science & Spirit magazine reports on cutting-edge science, balanced with the wisdom of a world of faiths."
The Center for Faith and Science Exchange
A program of The Boston Theological Institute. The Center's purpose is "to promote interdisciplinary dialogue, with the sharing of knowledge, metaphors, and values; to study and resolve the historical misunderstandings that have resulted in cultural division between the religious and scientific communities; and to promote a prophetic vision of change in which religious leaders are better informed about science and more responsive to the challenges of faithful living in a technological age, and in which the scientific community recognizes human spiritual experience."
Christians in Science
Christians in Science is "a professional Christian group for all who are concerned about science/faith issues." Based in the UK.
Christian Students in Science
Christian Students in Science is a subgroup of Christians in Science.

Alternative Physics, New Age & Eastern

From California:
The McFarlane Collection
Thomas J. McFarlane is a physicist, mathematician and member of a patent firm in Palo Alto, California. McFarlane has a deep interest in the meaning of all of this information.
Center for Integral Science
Sacred Science Title Page
McFarlane Home Page

Reasonable and knowledgeable exposition of QM, and a good sense of why it's important to the rest of us. "In the vision that inspires these essays, the link between physics and spirituality is found in the depths of mathematics. Just as mind mediates between body and soul, so mathematics mediates between physics and metaphysics. Although the essays begin with physics and progress through mathematics to metaphysics, a central vision ties the essays together."

Quantum Mechanics and Reality
McFarlane's treatise on the wonders of QM. Included in the Sacred Science site, but worthy of special mention.
The Sarfatti Group
Jack Sarfatti is a prophet of the New Age new reality, highly regarded in some circles. A bit quirky at times, and jealous of his place in the vanguard. Often difficult to tell when he is kidding and when he is serious. Trumpets the "post-quantum self-deterministic physics."
The Center for Theology & the Natural Sciences (CTNS)
An affiliate of the Graduate Theological Union (GTU) in Berkeley, California, and relatively mainstream in its outlook (for California). "The mission of CTNS is to promote the creative mutual interaction between contemporary theology and the natural sciences. . .. It focuses primarily on the relation between contemporary physics, cosmology, technology, environmental studies, evolutionary and molecular biology and Christian theology and ethics."
From the rest of the world:
Common Grounds between Buddhism, Quantum Physics and Baha'i Faith
A posting from the Baha'i Library. "The heart of all religions is the relationship of the individual with Ultimate Reality. For centuries no concept of God or Creator existed in Buddhism with the same meaning as in most Western religions. According to Buddhism, Ultimate Reality is viewed as "Empty Void." This idea of the "Empty Void" is a rich and productive one conveying an extensive variety of meanings. There are some interesting relationships between these Buddhist ideas and concepts in quantum physics and the Baha'i Faith.
Paradigm Challenge - Wave/Particle Duality
A thoughtful attempt by John K. N. Murphy, New Zealand physicist and electrical engineer, to resolve the wave/particle duality on the basis of relativistic time dilation. "[W]hen you project the 'existence' of a photon into a 'photon's frame of reference' then what you see is that the photon experiences no time when it moves from its start point to its end point. . . . [This may be] an illusion that arises because that which is simultaneous in the photon's frame is not simultaneous in any other observer's frame of reference. It is an artifact of the way time occurs across space.'
The Swedish Association for New Physics
The pickings are slim, but some interesting links. Again, what is the fascination with UFOs?
The Computer Inside You
"This [web-published] book proposes in detail an old idea: that the universe is a virtual reality generated by an underlying network of computing elements. In particular, this book uses this reality model to explain the otherwise unexplained: ESP, afterlife, mind, UFOs and their occupants, organic development, and such." The author, Kurt Johmann, is a software developer with a PhD in computer science. Although I can't fathom the fascination with UFO's and the like (Johmann lives in Florida, not California), the basic idea is straight Cellular Automata computer simulation.
The New Universal Consciousness
D.G. Leahy's exposition of mathematical physics with his insight into certain universal constants, i.e., the number 82944.

Lists of Links and Resources

Cramster physics help

"Cramster is a global study community comprised of students and teachers helping each other understand how to solve problems for mathematically-based subjects (e.g. Physics, Calculus, Stats, Chemistry, ME, EE, CS, etc). Cramster provides access to various types of study material (e.g. textbook solutions, topic notes, sample problems, practice exams) created by us, indexed from the web, or contributed by our members. As an online study group, Cramster fosters social learning through the Cramster Answer Board where members ask and answer questions moderated by Cramster Subject Matter Experts."

Arnold Sikkema: Christian Links
Arnold Sikkema: Science and Faith Links and Resources
The Center for Theology & the Natural Sciences - Bibliography
Atomic Physics Links
Collected by Marcus Larson, D.V.M. "This existence is but a small part of what we really are."

QPT collects and digests philosophical models of quantum mechanics.  QM's experimental paradoxes are described and interpreted in a broad range of historical and contemporary efforts.

Collections of Quotations

Miscellenia: Quotables
Mike Levin's pages also have good collections of quotations on science, religion, and science-and religion.
A Dictionary of Scientific Quotations
Physics Time Line
A chronology of scientific discovery. Interesting reading, and a good source of historical dates. Phil Gibbs' Weburbia site used to post a host of interesting material, including the Heretic's Hall, a wide-ranging collection of alternative thinking in physics. For some unkown reason, the good stuff is presently unavailable (5/31/00).


James Clerk Maxwell and the Christian Proposition
A profile of the scientist and his faith.
Niels Bohr
Biographical data on the great Dane.


Help for physics pocket computer:conversions
Conversion of units - Script
"This Javascript program makes possible the conversion between a large number of different units." Quite useful.
Quantum Fog
Simulation software (Mac) demonstrating the double slit experiment, EPR phenomena, and the like.
Java Ripples

Paul Halstad's java simulation of wave action.  Includes single- double- and triple-slit set ups, and many others.  Change the set up and see how the wave(s) behave.  Excellent visualization tool, I use it myself.

3. Technical Papers - Recent and of Interest

The e-print service of arXiv.org is a wealth of data.  I don't know what I would do without it.  Caveat that e-print means the paper has not necessarily been peer-reviewed, so there is a non-negligible chance that the author is completely wrong, off his rocker, or even demonstrably lunatic.  On the other hand, submissions are only accepted from usually-reliable sources, i.e., the author must have a university or research affiliation.  Most of the stuff is in the process of submission to standard peer-reviewed journals, and many papers have already been accepted.  

Find your own diamonds at http://www.arxiv.org


A. Suarez (Center for Quantum Philosophy, Zurich).  "Classical Demons and Quantum Angels: On 't Hooft's deterministic Quantum Mechanics."  (May 27, 2007) http://www.arxiv.org/pdf/0705.3974 

In 2006, John Conway and Simon Kochen began a new philosophical discussion of the free will implications of determinism in physics (http://www.arxiv.org/quant-ph/0604079) which has proved quite fertile.  Gerard 't Hooft, in particular, rose to defend strict determinism and the logical conclusion that free will is an illusion.  In this paper, Antoine Suarez critiques this view by focusing on just two experiments implying that "the Quantum World requires causes acting freely from outside space-time."  

G. Scarcelli, Y. Zhou and Y. Shih (Dep't of Physics, Univ. of Maryland). "Random Delayed-Choice Quantum Eraser via Two-Photon Imaging." (Dec. 22, 2005) http://arxiv.org/abs/quant-ph/0512207

[RR:  This is an excellent companion to the Kim experiment, noted with commentary on this site.] 


We report on a delayed-choice quantum eraser experiment based on a two-photon imaging scheme using entangled photon pairs. After the detection of a photon which passed through a double-slit, a random delayed choice is made to erase or not erase the which-path information by the measurement of its distant entangled twin; the particle-like and wave-like behavior of the photon are then recorded simultaneously and respectively by one set of joint detection devices. Unlike all previous experiments the present work takes advantage of two-photon imaging. The complete which-path information of a photon is transferred to its distant entangled twin through a "ghost" image. The choice is made on the Fourier transform plane of the ghost image between reading "complete information" or "partial information" of the double-path.

Karl Svozil (Institut fur Theoretische Physik, University of Technology Vienna),
Computational Universes, pre-print, submitted to Chaos, Solitons & Fractals (May 12, 2003).

Suspicions that the world might be some sort of a machine or algorithm existing ``in the mind'' of some symbolic number cruncher have lingered from antiquity. Although popular at times, the most radical forms of this idea never reached mainstream. Modern developments in physics and computer science have lent support to the thesis, but empirical evidence is needed before it can begin to replace our contemporary world view. 


Karl Svozil, "Finite Automata Models of Quantum Systems: Conceptual Status and Outlook," prepared for the Sixth International Conference on Developments in Language Theory, Kyoto, Japan, September 18-21, 2002 http://www.arxiv.org/PS_cache/quant-ph/pdf/0209/0209089.pdf

Since Edward Moore, finite automata theory has been inspired by physics, in particular by quantum complementarity. We review automaton complementarity, reversible automata and the connections to generalized urn models. Recent developments in quantum information theory may have appropriate formalizations in the automaton context.
Quote with interesting phrasing:
"[E]very physical feature, in particular of a physical system, should correspond to a feature of an appropriate computational model.  This is by no means trivial . . .."  (Emphasis in the original.)
Compare, e.g., E. Fredkin, Finite Nature, http://www.digitalphilosophy.org/finite_nature.htm :
"8.      What cannot be programmed cannot be physics.  This is a very important idea."
The paper concludes that we may profitably investigate "the 'intrinsic physical properties' of virtual realities in general, and computer games in particular.  Complementarity and the other discussed features are robust and occur in many different computational contexts, in particular if one is interested in the intrinsic 'look and feel' of computer animated worlds."
N.D. Mermin, "Copenhagen Computation:  How I learned to stop worrying and love Bohr" (May 16, 2003).  [Skip past section 1, and stay with it through section 3].
More information at
N.D. Mermin, "From Cbits to Qbits: Teaching computer scientists quantum mechanics" (July 11, 2002).

From the abstract to "Copenhagen Computation, etc.":
"I inadvertently reinvented the Copenhagen interpretation in the course of constructing a simple, straightforward, and transparent introduction to quantum mechanics for computer scientists."

From the abstract to "From Cbits to Qbits, etc.":
"A strategy is suggested for teaching mathematically literate students, with no background in physics, just enough quantum mechanics for them to understand and develop algorithms in quantum computation and quantum information theory."
From the introduction to "From Cbits to Qbits, etc.":
"[Q]uantum mechanics . . . provides dramatic proof that the abstract analysis of computation cannot be divorced from the physical means available for its execution. Computer scientists of the future ought to learn quantum mechanics.

Mermin describes QM with diagrams, using the computer concepts of (among others) memory registers and logic gates.  The gates themselves are presented as "black boxes," so this is not a how-to manual for building a quantum computer with real wires.  Nevertheless, it was quite helpful to me as a framework for how one might describe the "algorithm of QM."


Nick Bostrom (Dept of Philosophy, Yale) 
(July 2002; forthcoming in Philosophical Quarterly)


This paper argues that at least one of the following propositions is true: 
(1) the human species is very likely to go extinct before reaching a “posthuman” stage; 
(2) any posthuman civilization is extremely unlikely to run a significant number of simulations of their evolutionary history (or variations thereof); 
(3) we are almost certainly living in a computer simulation. 

It follows that the belief that there is a significant chance that we will one day become posthumans who run ancestor-simulations is false, unless we are currently living in a simulation. A number of other consequences of this result are also discussed.

The Role of the Observer in the Quantum Experiment
Bruce Rosenblum and Fred Kuttner
Revised December 12, 2001
Department of Physics, University of California, Santa Cruz, California 95064

A goal of most interpretations of quantum mechanics is to avoid the apparent intrusion of the observer into the measurement process. Such intrusion is usually seen to arise because observation somehow selects a single actuality from among the many possibilities represented by the wavefunction. The issue is typically treated in terms of the mathematical formulation of the quantum theory. We attempt to address a different manifestation of the quantum measurement problem in a theory-neutral manner. With a version of the two-slit experiment, we demonstrate that an enigma arises directly from the results of experiments. Assuming that no observable physical phenomena exist beyond those predicted by the theory, we argue that no interpretation of the quantum theory can avoid a measurement problem involving the observer.

This paper now summarized at the BottomLayer,


Wave-particle Duality of C60

Markus Arndt , Olaf Nairz, Julian Voss-Andreae, Claudia Keller, Gerbrand van der Zouw, and Anton Zeilinger

M. Arndt, et al., "Wave-particle duality of C60" Nature 401, 680-682 (1999).  Summarized at "Fullerine Diffraction" http://www.univie.ac.at/qfp/research/matterwave/c60/.

"It is intriguing that C60 can almost be considered to be a body obeying classical physics in view of its many excited internal degrees of freedom. Leaving the source, it has as much as 7 eV of internal energy stored in 174 vibrational modes, and highly excited rotational states with quantum numbers greater than 100. Fullerenes can emit and absorb blackbody radiation very much like a solid and they can no longer be treated as a simple few level system."

Physics as Information Theory

A. Grinbaum, "Elements of information-theoretic derivation of the formalism of quantum theory" (June 11, 2003)

A recent survey/synthesis of three approaches to the concept that physics is a science of information and not of "things."  Anton Zeilinger's views are compared to the information theoretic approaches of Carlo Rovelli and Christopher Fuchs.  

From p. 6:
"We are guided by the computer metaphor. Indeed, the strategic task is to give a reformulation of quantum theory in information-theoretic terms.  A theory that operates with the notion of information can be compared to software as opposed to a theory that operates with the notion of energy which can be compared to hardware."

V. Jacques, E. Wu, F. Grosshans, F. Treussart, P. Grangier, A. Aspect, J-F Roch, "Experimental realization of Wheeler's delayed-choice GedankenExperiment" (Oct. 31, 2006), e-print http://www.arxiv.org/abs/quant-ph/0610241

The quantum "mystery which cannot go away" (in Feynman's words) of wave-particle duality is illustrated in a striking way by Wheeler's delayed-choice GedankenExperiment. In this experiment, the configuration of a two-path interferometer is chosen after a single-photon pulse has entered it : either the interferometer is closed (the two paths are recombined) and the interference is observed, or the interferometer remains open and the path followed by the photon is measured. We report an almost ideal realization of that GedankenExperiment, where the light pulses are true single photons, allowing unambiguous which-way measurements, and the interferometer, which has two spatially separated paths, produces high visibility interference. The choice between measuring either the 'open' or 'closed' configuration is made by a quantum random number generator, and is space-like separated -- in the relativistic sense -- from the entering of the photon into the interferometer. Measurements in the closed configuration show interference with a visibility of 94%, while measurements in the open configuration allow us to determine the followed path with an error probability lower than 1%.

A Free Plug for

The Beer that Made Quantum Mechanics Famous

Carlsberg Breweries in Copenhagen, Denmark. 
Did you ever wonder why the standard explanation of quantum mechanics is called the "Copenhagen Interpretation"?

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