4) Here are the final letters by Leonard Susskind' and Lee Smolin in their email debate re the Anthropic Principle.

Smolin: ... My main point is that string theory will have much more explanatory power if the dominant mode of reproduction is through black holes, as is the case in the original version of CNS. This is the key point I would hope to convince Susskind and his colleagues about, because I am sure that the case they want to make is very much weakened if they rely on the Anthropic Principle (AP) and eternal inflation. ...

Susskind: ... Finally let me quote a remark of Smolin's that I find revealing. He says "It was worry about the possibility that string theory would lead to the present situation, which Susskind has so ably described in his recent papers, that led me to invent the Cosmological Natural Selection (CNS) idea and to write my first book. My motive, then as now, is to prevent a split in the community of theoretical physicists in which different groups of smart people believe different things, with no recourse to come to consensus by rational argument from the evidence." First of all, preventing a "split in the community of theoretical physicists" is an absurdly ridiculous reason for putting forward a scientific hypothesis.

But what I find especially mystifying is Smolin's tendency to set himself up as an arbiter of good and bad science. Among the people who feel that the anthropic principle deserves to be taken seriously, are some very famous physicists and cosmologists with extraordinary histories of scientific accomplishment. They include Steven Weinberg [2], Joseph Polchinski [3], Andrei Linde [4], and Sir Martin Rees [5]. These people are not fools, nor do they need to be told what constitutes good science. ...    more »

3) Here's Leonard Susskind's #2 to Lee Smolin #2:

...The issue here is not whether the usual phenomenological inflation was of the eternal kind although that is relevant. Eternal inflation taking place in any false vacuum minimum on the landscape would favor [in Smolin's sense] the maximum cosmological constant. But for the sake of argument I will agree to ignore eternal inflation as a reproduction mechanism.

The question of how many black holes are formed is somewhat ambiguous. What if two black holes coalesce to form a single one. Does that count as one black hole or two? Strictly speaking, given that black holes are defined by the global geometry, it is only one black hole. What happens if all the stars in the galaxy eventually fall into the central black hole? That severely diminishes the counting. So we better assume that the bigger the black hole, the more babies it will have. Perhaps one huge black hole spawns more offspring than 10^22 stellar black holes.

That raises the question of what exactly is a black hole? One of the deepest lessons that we have learned over the past decade is that there is no fundamental difference between elementary particles and black holes. As repeatedly emphasized by 't Hooft [10][11][12], black holes are the natural extension of the elementary particle spectrum. This is especially clear in string theory where black holes are simply highly excited string states. Does that mean that we should count every particle as a black hole? ...   more »

We have here at the sciy an article Appreciating Arabic Science that predates Newton written by Jim Al-Khalili. Speaking of an early Muslim biologist it says the following: “…what surprises many even more is that a ninth-century Iraqi zoologist by the name of al-Jahith developed a rudimentary theory of natural selection a thousand years before Darwin. In his Book of Animals, Jahith speculates on how environmental factors can affect the characteristics of species, forcing them to adapt and then pass on those new traits to future generations.” Here I am presenting, by way of introduction, the work of this scientist belonging to the early Islamic period, the Dawn of its Golden Age. It is being reproduced from my book Narad’s Arrival at Madra in which there is a chapter dealing with scientific theories of evolution. The chapter has relevance in the book, even as the sage in his song presents the occult-spiritual aspects of the long story of evolution; he is on his way from his heavenly abode in Paradise to king Aswapati’s palace in Madra and is absorbed in meditative thought of the subject. I am also including two other connected pieces which may be relevant here. ...   more »