Wednesday, August 29, 2007

A tiresome business

Lewis Hamilton's tyre failure in last Sunday's Turkish Grand Prix was, it appears, caused by 'chunking'. Formula One tyres are a complex and fascinating business. With the addition of this hitherto unreported phenomenon, there are at least three ways in which the performance of an F1 tyre can deteriorate:

  • Graining. This is a consequence of the grooves cut into the tyres, by regulation, to reduce the size of the contact patches. Cutting grooves into a tyre creates separate blocks of rubber, and the shoulders of each block are unsupported on one side. Under braking and cornering forces, the blocks of rubber experience a type of leverage, and, under shear forces, the shoulders of each block are ripped away, creating grains of rubber. These grains roll across the surface of the contact patches, reducing the grip of the tyre. The process continues until the blocks of rubber have been eroded to the point where the leverage upon the shorter blocks is insufficient to create any more grains.
  • Blistering. This occurs when the carcass of the tyre (i.e., the interior of the tyre) overheats, causing patches on the surface to overheat. The rubber peels away at the blister points.
  • Chunking. This occurs when small bits of rubber deposited on the track surface (called 'marbles', and not the same as the grains which cause graining), are picked up by a passing tyre, chemically adhere to the tyre, and then harden.
Each of these phenomena are quite separate from the deterioration in tyre performance which takes place due to simple tyre wear!

Liverpool v Toulouse

Yesterday, of course, was Anfield. And, in particular, the Kop.

Arriving early, and after a short walk across Stanley Park, I found myself in the Liverpool club shop. Astonishingly, I also found myself quite unable to resist buying and wearing a Liverpool shirt. It felt good, though, and at £39.99, it was obviously a snip.

There was then opportunity for a quick drink in The Albert, just adjacent to the ground, which was packed with fans clad in similar scarlet attire. I saw a couple of girls in Steven Gerrard number 8 shirts, and it struck me, as last year, that there is something incredibly arousing about a girl wearing a Steven Gerrard shirt. Like a girl, but also like Stephen Gerrard, at the same time.

Standing in place in the minutes prior to kick-off, the enormous Liverpool flag appeared (as if by magic), and, pulled by the fans beneath, descended over the top, and down the face of the Kop. There was a rousing tribute to the murdered 11-year old, Rhys Jones, whose mother was in attendance, and then 'You'll Never Walk Alone' was delivered with familiar gusto.

The Kop offered a fabulous view of the game. The seating therein, however, is crazy: I spent the first 15 minutes with my right knee jammed against the seat in front, and my right foot off the ground. The Kop rises to its feet, however, when Liverpool mount an attack, so the game is spent getting up, then sitting down, then getting up, then sitting down, etc. etc.

Most impressive player in the match was Yossi Benayoun, who was full of skillful flicks, tricks and eye-of-the-needle passes. A couple of late goals from Dirk Kuyt made him look good, but, like Crouch, he squandered a number of other excellent opportunities.

Tuesday, August 28, 2007


Today I go to Anfield, where Liverpool, oxymoronically, hope To-win against Toulouse. I shall be in the Spion Kop, where, I'm sure, my fellow Kopites will also be nodding their heads sagaciously at the irony of the encounter.

Last November I went to Anfield to see the first ever league 'clash' between Liverpool and my home town of Reading. A number of impressions have stayed with me from that day: the blazing emerald green of the pitch as I emerged from the stairs into the grandstand; the pies-and-larger-shop tucked away in a concrete recess within the ageing stadium; the tightly enclosed geometry of Anfield; the row of terraced housing behind the stadium; the emotional overload of singing 'You'll Never Walk Again', with the sound reverberating off the stadium roof. That day I saw Stevie G, Carra, and even God came on as a substitute. Today, alas, none of them will be there.

Monday, August 27, 2007

The aesthetics of landscape and architecture

Is aesthetic appreciation merely fetishistic behaviour, a type of learnt imagination, or is it grounded in something objective, which is shared amongst humanity, something which is perhaps a remnant or a by-product of some evolutionary instinct?

John Barrow argues that "the fact that our ancestors spent very long periods in tropical savannah habitats leads us to expect that some of our emotional responses to such an environment may possess adaptive features. Instinctive aesthetic reactions to the world could not have evolved if, on average, they contributed negatively to survival...

"The savannah landscape is an environment with many reliable cues for safe and fruitful human habitation. These cues are widely reproduced in our parklands and recreation areas. There is scattered tree cover, which offers shade and escape from ferocious predators, interspersed with grasses; yet there are long vistas with frequent undulations that allow good views, orientation and way-finding...The most distinctive unpredictability about savannah life is the availability of water. Here, one recognises the importance of cues like cloud formation, changes in temperature and weather outlook, and seasonal variations in the colour and vitality of plant life, together with the water levels in rivers and streams. Sensitivity to these environmental indicators has a clear adaptive advantage over insensitivity. The presence of tress, greenery, and water offers an instant evaluation of the suitability of a potential habitat. These primary indicators, together with a sense of the openness of the terrain, its prospects for shelter, and the furtive viewing of others, are valuable sensitivities that signal whether further exploration or settlement can safely ensue...We recognise, also, the encouragement to exploration that is created by the mysterious element in the terrain: the path that leads out of sight or behind a hill.

"There is a clear adaptive advantage to be gained by choosing environments that offer places of security and clear unimpeded views of the terrain...These combinations remain an innate preference: their attractiveness informs many of our aesthetic preferences, from landscape architecture to painting. Extensive views and cosy inglenooks; daunting castles; the tree-house, the 'Little House on the Prairie'; the mysterious door in the wall of the secret garden: so many of the classically seductive landscape scenes combine symbols of refuge and safety, with the prospect of uninterrupted panoramic views; or the enticement to explore, tempered by verdant pastures and water. These comfortable, pastoral scenes appeal to out instinctive sensibilities because of the selective advantages that such attractions first held for our ancient forebears...

"Our aesthetic preferences are a fusion of instinct and experience. We would expect that, in the absence of experience and special influence, our innate sensitivities for these life-supporting features of natural scences would remain. Indeed, simple landscapes and still-life scenes are usually preferred by those with no special interest in art. A taste for the avant-garde or the abstract is a fruit of experience overriding instinct. Even then, what appeals in man-made art is the symbolic play, or counterplay, on those same adaptive features that have for so long informed traditional artistic images," (The Artful Universe, p91-95).

Barrow cites studies which show that younger children prefer images of savannah landscapes, whilst older teenagers, with experience of, say, deciduous woodland or rainforest environments, often like these landscapes just as much.

Is this approach capable of explaining why many of us have a shared appreciation of what constitutes a beautiful building, or a beautiful car? Certainly, experience, learning, and social conditioning can be shared, so a common aesthetic reaction to something doesn't necessarily entail that it must be rooted in evolutionary instinct. But perhaps there are other, common cognitive sensitivities, which are not learnt, which have developed through evolution, and which produce common aesthetic reactions, but which are not rooted in the specific cues of the savannah landscape itself.

Lee Smolin argues that what makes a scene beautiful is a variety of harmonious structure on different length scales. Describing the city of Verona, he recalls that

"From a tower or garden overlooking the city one sees the great curves of the river Adige, in the albows of which are nestled the different parts of the city, built in different eras, by what were almost different civilizations. And what is most striking is the way the same red tile roofs cover such a variety of shapes and sizes of buildings, from the medieval churches and palazzi to the modern stores and office buildings. Descending, one comes to streets that curve gracefully, with the rhythmic patterns made by the balconies and windows blending harmoniously the styles of houses built over ten different centuries, until one stands before a door or gazes on a medieval wall, and sees there the carvings and the frescoes made by artisans long passed. And then one goes through the door into a gallery or a boutique to see what strange tastes the modern inhabitants of this ancient place now fancy.

"Imagine, by contrast, those man-made landscapes that we find most ugly, the suburban deserts with every house simple and similar, the American shopping center, the great monoliths of soviet architecture, or the unfortunate office towers and hotels based on economized postmodern styles. Certainly, what most of these lack is a variety of interest and harmony occurring over a large range of scales, so that so many of them look like models or computer images of themselves. In most of these the planners have taken care only of how things look on one scale, so that with one glance one takes in all that is to be seen there," (The Life of the Cosmos, p162-163).

A sensitivity to size and shape on a variety of different length-scales, could well be a favourable evolutionary trait, which promotes the aesthetic appreciation of landscapes and cityscapes quite distinct from that provided by the savannah. Such a sensitivity would be innate, and would have initially developed in the savannah environment, but would be independent of the specific cues of the savannah landscape.

Wednesday, August 22, 2007

Inventions week - Day 4

Scything relentlessly through the golden fields of mental chaff, and reaping a ripe harvest of swollen noogony, here are today's ideas:

  • Yakultiated tap-water: Chlorine was introduced into the water supply some decades ago when it was established that chlorine is good for our teeth. Shortly afterwards, all dentists went out of business. In a similar vein, it has recently been established that Yakult replenishes the good bacteria in our tummies, improving digestive well-being. Hence, to enhance the gastrointestinal health of the nation, Yakult should be injected into the water supply.

  • Seismic broadband: The Earth's crust and mantle is a much under-used communications medium. Tightly focused seismic waves could be used to rapidly transmit signals from one part of the world's surface to another. The digital encoding of information in seismic waves will enable broadband communication channels to be developed through the interior of the planet. A global seismic communications network will provide a back-up system in the event of satellite communications being disabled by electromagnetic pulse devices.

Wednesday, August 15, 2007

Inventions week - Day 3

Dredging the fertile subconscious effluent of the human mind once more, and sending enough neural traffic across the corpus callosum to cause a bridge collapse in Minneapolis, here are today's ideas:

  • Bullshit dosemeters. Epidemiological studies indicate that bullshit can have deleterious health effects if delivered in sufficiently high doses. Measured in multiples of the basic bullshit unit, the Pr, the average annual background bullshit dose in the UK is 2.4 mPr. Occupational doses can, however, reach 1Pr. There is therefore a need for the people working in such hazardous occupations to be equipped with bullshit dosemeters. Made out of scepticinium-fluoride crystals, these dosemeters can measure bullshit by the amount of smelly energy deposited in the crystal per unit mass.

  • TV news bulletins for adults. This would be TV news free from continuously scrolling banners and 'breaking news' graphics. This form of news broadcast would attach no value whatsoever to a live report that contains only nugatory information. Expert analysis would be favoured over vapid cliche and condescension.

Tuesday, August 14, 2007

Inventions week - Day 2

Pushing the fecundity envelope of the human mind once more, here are today's ideas:

  • The umbrella-ella-ella-ella. Normal, single canopy umbrellas clearly don't work in anything other than light rain and the absence of wind. One's legs are exposed to precipitation if one is engaging in bipedal locomotion, and in a strong wind, the umbrella is wildly unstable. I propose, therefore, a gyroscopically-stabilised, quadruple canopy umbrella. The greater surface area of the umbrella-ella-ella-ella protects all parts of the body, and the gyros prevent excessive perturbation of the ella axes.
  • The colour piano. Existing pianos are monochromatically keyed, and topologically linear. I propose, therefore, that two sets of piano octaves be curved into semi-circles, and joined end-to-end, to form a circle. The keys can then be colour-coded as in the Munsell colour circle, so that the colours of keys on opposite sides of the circle are complementary; i.e., adding the two colours together produces a shade of grey. The phase of the notes on opposite sides of the piano can then be offset by 180 degrees, so that if opposite notes are played, the sound waves interfere destructively, producing silence. This piano is ideal for duets.
  • Rainfall energy production. Energy from falling rain is wasted as sound energy, (and a little heat energy). Hydrovoltaic cells should be installed on rooftops, roads, and across the open countryside. These cells absorb the impact energy of falling raindrops, and convert it into electricity.

Monday, August 13, 2007

From the notebooks of Lazarus Long

The great Dawkins returns tonight with a new TV series, The enemies of reason. The targets this time are irrational 'new age' superstitions such as astrology. I feel Dawkins might have enjoyed the company of Lazarus Long, one of Robert A. Heinlein's personae:

What are the facts? Again and again and again --- what are the facts? Shun wishful thinking, ignore divine revelation, forget what "the stars foretell", avoid opinion, Care not what the neighbors think, never mind the unguessable "verdict of history" --- what are the facts, and to how many decimal places? You pilot always in to an unknown future; facts are your only chance. Get the facts! -- Lazarus Long

The most preposterous motion that H. sapiens has ever dreamed up it that the Lord God of Creation, Shaper and Ruler of all the Universes, wants the saccharine adoration of His creatures, can be swayed by prayers, and becomes petulant if He does not receive this flattery. Yet this absurd fantasy, without a shred of evidence to bolster it, pays all the expenses of the oldest, largest and least productive industry in all history. -- Lazarus Long

"God split himself into a myriad parts so that he might have friends". This may not be true, but it sounds good -- and is no sillier than any other theology. -- Lazarus Long

To be "matter of fact" about the world is to blunder into fantasy --- and dull fantasy at that, as the real world is strange and wonderful. -- Lazarus Long

Freedom begins when you tell Mrs Grundy to go fly a kite. -- Lazarus Long

Political tags -- such as royalist, communist, democrat, populist, fascist, liberal, conservative, and so forth -- are never basic criteria. The human race divides politically into those who want people to be controlled and those who have no such desire. The former are idealists acting from highest motives for the greatest good of the greatest number. The latter are surly curmudgeons, suspicious and lacking in altruism. But they are more comfortable neighbors than the other sort. -- Lazarus Long

Inventions week - Day 1

In honour of the well-known Simpsons episode where Homer attempts to emulate Thomas Edison, I have decided to spend the week developing my own inventions. Here's some ideas for starters:

  • Panty-pads for men. Why should women be the only people to have comfort and confidence all month long? Men want to go roller-blading in the park without any embarrassing stains as well.
  • Golf-course pulleys. Have you seen all the effort expended on golf courses to carry or pull a heavy bag of golf-clubs around the course? This is all quite needless. There should be a system of ropes criss-crossing each fairway. You simply hook your golf-bag onto one of the ropes, and, via a remote-control Bluetooth system, it is winched down the fairway alongside you. A bit like a ski-lift, but for golf-bags.
  • Dark bulbs. Thomas Edison famously didn't invent the light bulb, but he also failed to invent the dark bulb. There are many situations during the daylight hours when there is simply too much light. In such circumstances, it would be extremely helpful to simply switch on a dark bulb. These are made out of lithium flouride crystals with a negative coefficient of opacity. Such crystals are not merely opaque to the passage of light, they positively suck light out of the surrounding space.

Saturday, August 11, 2007

Symmetries in Physics

The status and implications of symmetry in physics is of great philosophical interest, and this collection of papers from 2003 provides a decent insight into the issues engaging contemporary philosophers of physics. As a service to the impoverished, I here reproduce the contents, with hyperlinks to those articles freely downloadable.

1. Introduction
Part I. Continuous Symmetries:
2. Classic texts: extracts from Weyl and Wigner
3. On the significance of continuous symmetry to the foundations of physics, C. Martin
4. The philosophical roots of the gauge principle: Weyl and transcendental phenomenological idealism, T. Ryckman
5. Symmetries and Noether’s theorems, K. A. Brading and H. R. Brown
6. General covariance, gauge theories, and the Kretschmann objection, J. Norton
7. The interpretation of gauge symmetry, M. Redhead
8. Tracking down gauge: an ode to the constrained Hamiltonian formalism, J. Earman
9. Time-dependent symmetries: the link between gauge symmetries and indeterminism, D. Wallace
10. A fourth way to the Aharanov-Bohm effect, A. Nounou

Part II. Discrete Symmetries:
11. Classic texts: extracts from Lebniz, Kant and Black
12. Understanding permutation symmetry, S. French and D. Rickles
13. Quarticles and the identity of discernibles, N. Huggett
14. Handedness, parity violation, and the reality of space, O. Pooley
15. Mirror symmetry: what is it for a relational space to be orientable? N. Huggett
16. Physics and Leibniz’s principles, S. Saunders

Part III. Symmetry Breaking:
17: Classic texts: extracts from Curie and Weyl
18. Cross-fertilization in theoretical physics: the case of condensed matter and particle physics, G. Jona-Lasinio
19. On the meaning of symmetry breaking, E. Castellani
20. Rough guide to spontaneous symmetry breaking, J. Earman
21. Spontaneous symmetry breaking: theoretical arguments and philosophical problems, M. Morrison

Part IV. General Interpretative Issues:
22. Classic texts: extracts from Wigner
23. Symmetry as a guide to superfluous theoretical structure, J. Ismael and B. van Fraassen
24. Notes on symmetries, G. Belot
25. Symmetry, objectivity, and design, P. Kosso
26. Symmetry and equivalence, E. Castellani.

Friday, August 10, 2007

The structural foundations of quantum gravity

Oxford University Press published this excellent collection of papers on the foundations of quantum gravity last year. As a service to those less well-endowed (financially), I here reproduce the contents, with hyperlinks to those articles which are freely-downloadable.

1. Quantum Gravity Meets Structuralism: Interweaving Relations in the Foundations of Physics, D. P. Rickles and S. R. D. French
2. Structural Realism and Quantum Gravity, T. Y. Cao
3. Structure, Individuality, and Quantum Gravity, J. Stachel
4. Points, Particles, and Structural Realism, O. Pooley
5. Holism and Structuralism in Classical and Quantum GR, M. Dorato and M. Pauri
6. Time and Structure in Canonical Gravity, D. P. Rickles
7. The Case for Background Independence, L. Smolin
8. Quantum Quandaries: A Category-Theoretic Perspective, J. C. Baez

Tuesday, August 07, 2007

The Future of Theoretical Physics and Cosmology

This rather imposing collection of papers, published a few years back to celebrate Stephen Hawking's 60th birthday, will reduce your disposable income by £50. Hence, as a service to the destitute, I here provide a list of contents with hyperlinks to all the freely downloadable articles.

1. Introduction;
Part I. Popular Symposium:
2. Our complex cosmos and its future, Martin J. Rees
3. Theories of everything and Hawking’s wave function of the Universe, Jame B. Hartle
4. The problem of space-time singularities: implications for quantum gravity? Roger Penrose
5. Warping spacetime, Kip Thorne
6. 60 years in a nutshell, Stephen W. Hawking

Part II. Spacetime Singularities:
7. Cosmological perturbations and singularities, George F. R. Ellis
8. The quantum physics of chronology protection, Matt Visser
9. Energy dominance and the Hawking–Ellis vacuum conservation theorem, Brandon Carter
10. On the instability of extra space dimensions, Roger Penrose

Part III. Black Holes:
11. Black hole uniqueness and the inner horizon stability problem, Werner Israel
12. Black holes in the real universe and their prospects as probes of relativistic gravity, Martin J. Rees
13. Primordial black holes, Bernard Carr
14. Black hole pair creation, Simon F. Ross
15. Black holes at accelerators, Steven Giddings

Part IV. Hawking Radiation:
16. Black holes and string theory, Malcolm Perry
17. M theory and black hole quantum mechanics, Joe Polchinski
18. Playing with black strings, Gary Horowitz
19. Twenty years of debate with Stephen, Leonard Susskind

Part V. Quantum Gravity:
20. Euclidean quantum gravity: the view from 2002, Gary Gibbons
21. Zeta functions, anomalies and stable branes, Ian Moss
22. Some reflections on the status of conventional quantum theory when applied to quantum gravity, Chris Isham
23. Quantum geometry and its ramifications, Abhay Ashtekar
24. Topology change in quantum gravity, Fay Dowker

Part VI. M Theory and Beyond:
25. The past and future of string theory, Edward Witten
26. String theory, David Gross
27. A brief description of string theory, Michael Green
28. The story of M, Paul Townsend
29. Gauged supergravity and holographic field theory, Nick Warner
30. 57 varieties in a NUTshell, Chris Pope

Part VII. de Sitter Space:
31. Adventures in de Sitter space, Raphael Bousso
32. de Sitter space in non-critical string theory, Andrew Strominger
33. Supergravity, M theory and cosmology, Renata Kallosh

Part VIII. Quantum Cosmology:
34. The state of the universe, James B. Hartle
35. Quantum cosmology, Don Page
36. Quantum cosmology and eternal inflation, A. Vilenkin
37. Probability in the deterministic theory known as quantum mechanics, Bryce de Witt
38. The interpretation of quantum cosmology and the problem of time, J. Halliwell
39. What local supersymmetry can do for quantum cosmology, Peter D’Eath

Part IX. Cosmology:
40. Inflation and cosmological perturbations, Alan Guth
41. The future of cosmology: observational and computational prospects, Paul Shellard
42. The ekpyrotic universe and its cyclic extension, Neil Turok
43. Inflationary theory versus the ekpyrotic/cyclic scenario, Andrei Linde
44. Brane (new) worlds, Pierre Binetruy

Science and Ultimate Reality

A few years ago, John Barrow edited an excellent collection of papers entitled Science and Ultimate Reality: Quantum theory, Cosmology, and Complexity. It will, however, set you back £50, so to continue the trend established yesterday, I here provide the list of contents with hyperlinks to those papers which can be freely downloaded.

Part I. An Overview of the Contributions of John Archibald Wheeler:
1. John Archibald Wheeler and the clash of ideas, Paul C. W. Davies

Part II. An Historian’s Tribute to John Archibald Wheeler and Scientific Speculation Through the Ages:
2. The heritage of Heraclitus: John Archibald Wheeler and the itch to speculate, Jaroslav Pelikan

Part III. Quantum Reality - Theory:
3. Why is nature described by quantum theory? Lucien Hardy
4. Thought experiments in honor of John Wheeler, Freeman J. Dyson
5. It from qubit, David Deutsch
6. The wave function: it or bit?, H. Dieter Zeh
7. Quantum Darwinism and envariance, Wojciech H. Zurek
8. Using qubits to learn about it, Juan Pablo Paz
9. Quantum gravity as an ordinary gauge theory, Juan M. Maldacena
10. The Everett interpretation of quantum mechanics, Bryce S. DeWitt

Part IV. Quantum Reality - Experiment:
11. Why the quantum? It from bit? A participatory universe? Three far-reaching, visionary questions from John Archibald Wheeler and how they inspired a quantum experimentalist, Anton Zeilinger
12. Speakable and unspeakable, past and future, Aephraim M. Steinberg
13. Conceptual tensions between quantum mechanics and general relativity: are there experimental consequences? Raymond Y. Chiao
14. Breeding non-local Schrödinger cats: a thought experiment to explore the quantum classical boundary, Serge Haroche
15. Quantum erasing the nature of reality - or, perhaps, the reality of nature? Paul G. Kwiat and Berthold-Georg Englert
16. Quantum feedback and the quantum-classical transition, Hideo Mabuchi
17. What quantum computers may tell us about quantum mechanics, Christopher R. Monroe

Part V. Big Questions in Cosmology:
18. Cosmic inflation and the arrow of time, Andreas Albrecht
19. Cosmology and immutability, John D. Barrow
20. Quantum cosmology, inflation, and the anthropic principle, Andrei Linde
21. Parallel universes, Max Tegmark
22. Quantum theories of gravity: results and prospects, Lee Smolin
23. A genuinely evolving universe, Joao Magueijo
24. Planck-scale models of the universe, Fotini G. Markopoulou
25. Implications of additional spatial dimensions to questions in cosmology, Lisa Randall

Part VI. Emergence, Life, and Related Topics:
26. Emergence: us from it, Philip D. Clayton
27. True complexity and its associated ontology, George F. R. Ellis
28. The three origins: cosmos, life and mind, Marcelo Gleiser
29. Autonomous agents, Stuart A. Kauffman
30. To see a world in a grain of sand, Shou-Cheng Zhang

Monday, August 06, 2007

Universe or Multiverse?

In our universe, Cambridge University Press have recently published this weighty tome on the subject of multiverse physics. At £45, it's rather expensive for what is basically a collection of conference papers, most of which are re-hashed versions of material already published by the respective authors. Moreover, most of the articles, or the papers from which they are derived, can be freely downloaded from the internet. Hence, as a service to the impecunious, I here provide links to all these papers with the list of contents from the book.

Part I. Overviews:
1. Introduction and overview, Bernard Carr
2. Living in the multiverse, Steven Weinberg
3. Enlightenment, knowledge, ignorance, temptation, Frank Wilczek

Part II. Cosmology and Astrophysics:
4. Cosmology and the multiverse, Martin J. Rees
5. The anthropic principle revisited, Bernard Carr
6. Cosmology from the top down, S. W. Hawking
7. The multiverse hierarchy, Max Tegmark
8. The inflationary universe, Andrei Linde
9. A model of anthropic reasoning addressing the dark to ordinary matter coincidence, Frank Wilczek
10. Anthropic predictions: the case of the cosmological constant, Alexander Vilenkin
11. The definition and classification of universes, James D. Bjorken
12. M/string theory and anthropic reasoning, Renata Kallosh
13. The anthropic principle, dark energy and the LHC, Savas Dimopoulos and Scott Thomas

Part III. Particle Physics and Quantum Theory:
14. Quarks, electrons and atoms in closely related universes, Craig J. Hogan
15. The fine-tuning problems of particle physics and anthropic mechanisms, John F. Donoghue
16. The anthropic landscape of string theory, Leonard Susskind
17. Cosmology and the many-worlds interpretation of quantum mechanics, V. F. Mukhanov
18. Anthropic reasoning and quantum cosmology, James. B. Hartle
19. Micro-anthropic principle for quantum theory, Brandon Carter

Part IV. More General Philosophical Issues:
20. Scientific alternatives to the anthropic principle, Lee Smolin
21. Making predictions in a multiverse: conundrums, dangers, coincidences, Anthony Aguirre
22. Multiverses: description, uniqueness and testing, George Ellis
23. Predictions and tests of multiverse theories, Don N. Page
24. Observation selection theory and cosmological fine-tuning, Nick Bostrom
25. Are anthropic arguments, involving multiverses and beyond, legitimate? William R. Stoeger
26. The multiverse hypothesis: a theistic perspective, Robin Collins
27. Living in a simulated universe, John D. Barrow
28. Universes galore: where will it all end? Paul Davies.

Friday, August 03, 2007


There is such beautiful poetry in science. Consider the following passage by Pamela J. Gunter Smith, (Pam to her friends):

Vomiting is a complex multifaceted event that requires the coordinated response of neural, respiratory, and gastrointestinal centers. It occurs in response to a variety of stimuli, including local irritation and distention of the gut, introduction of various drugs and hormones into the systemic circulation, psychogenic stimuli, and exposure to ionizing radiation. The sequence of events involved in vomiting are as follows. Indications that vomiting is imminent are those of widespread autonomic discharge: hypersalivation, tachypnea, and dilation of the pupils. Events leading to the expulsion of gastric contents are initiated by slow and deep inspiration against a closed glottis. This reduces the intra-thoracic pressure below atmospheric pressure. The abdominal muscles contract strongly, raising the intra-abdominal pressure; the resulting pressure gradient forces the gastric contents into the esophagus. If the hypopharyngeal sphincter is closed, the contents do not enter the mouth but return to the stomach. These events produce the retching that generally precedes vomiting. But if the sphincter is opened (by drawing the larynx and the hyoid bone forward), the gastric contents are expelled into the mouth. Thus, expulsion of the gastric contents is a passive process that does not involve active contractions of the body of the stomach.

Wednesday, August 01, 2007

A strange loop

Martin Gardner reviews Douglas Hofstadter's recent book, I Am a Strange Loop, in Notices of the AMS, and makes some rather odd claims towards the end. He asserts that:

1) "No philosopher or scientist living today has the foggiest notion of how consciousness, and its inseparable companion free will, emerge, as they surely do, from a material brain."

2) "No computer of the sort we know how to build—that is, one made with wires and switches—will ever cross a threshold to become aware of what it is doing. No chess program, however advanced, will know it is playing chess anymore than a washing machine knows it is washing clothes. Today’s most powerful computers differ from an abacus only in their power to obey more complicated algorithms, to twiddle ones and zeroes at incredible speeds."

3) "It is the height of hubris to suppose that evolution has stopped improving brains."

These sorts of claims are extremely popular, but quite irrational. The mind is related to the brain in the same way that software is related to hardware. The mind-brain relationship is no more lacking an explanation than the relationship between software and hardware. It may be difficult to imagine how a computer program can emerge from the voltage levels of the electronic components and circuitry in a computer, but that doesn't mean that there isn't an explanation.

It might be argued that the software-hardware analogy is not relevantly similar, because software cannot be conscious or self-conscious, but that is simply question-begging. To argue that a computer, "made with wires and switches", cannot be conscious like a brain made of dendrites and nerve cells, is, in effect, to suggest that there is something bizarrely unique about the carbon-based dendrites and nerve cells of the brain, which makes it the only type of cognitive system capable of being conscious.

Consciousness of the external world is simply the representation by one physical system of its environment; self-consciousness is merely reflexive representation; and so-called 'free will' is nothing but a special type of deterministic process, a decision-making process, running upon the hardware of the brain. Of course evolution hasn't stopped improving brains, but that is irrelevant to the issue at hand. Hubris is, however, a most appropriate concept here: the notion that our species of mammal wields a unique type of causative power, called free will, is the ultimate in deluded hubris.