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.

Universe or Multiverse

Emesis

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.

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.