In his latest book 'Farewell to Reality', Jim Baggott suggests that the Anthropological Principle, even in its 'weak' rendition, is not a valid scientific area of enquiry.
Do you agree?
The weak AP has given rise to many attempted explanations over the years - it spurred multiverse theories, for instance - yet as of now no one has a inkling as to how to resolve it.
Is not JB's suggestion a case of, if you can't solve a scientific riddle, then just simply declare it as non-scientific? And, would not declaring it a purely philosophical or theological issue, as JB suggests, simply displace the issue one step over without bringing it any closer to resolution?
I personally believe that the AP is an artifact of thinking the law of nature as fixed and this automatically lead to a fine tuning problem. Many philosophers and physicists have speculated that the laws of nature as everything else in Nature have gradually been created which mean that there are multiple layers of meta-laws with different phase transitions.
Yes, I agree. For me, the anthropic principle is something like cosmological rasism. Sooner or alter it will disappear, as the dominance of "white man" did on Earth. It's an unfalsifiable illusion, thus not scientific at all. There is no real need to think of humans, or just of "intelligent life", as of the central part of the Universe, its necessary building block..
Marek, not sure if I quite see your point. You seem to be talking of the strong AP, the talk here is of the weak AP.
The inescapable maths is, it is extremely unlikely for any Universe to be fine-tuned to end up being bio-friendly to the extent that our Universe is - to be there, there must be a chain of extremely unlikely events. This level of fine tuning is akin to winning a lottery several hundred times in a row.
Surely, the reason why it is so is a valid area of scientific investigation ? And you can't cast stones at those who came up with all kinds of scenarios to explain it?
I personally believe that the AP is an artifact of thinking the law of nature as fixed and this automatically lead to a fine tuning problem. Many philosophers and physicists have speculated that the laws of nature as everything else in Nature have gradually been created which mean that there are multiple layers of meta-laws with different phase transitions.
Chris, if fine-tuning has extremely small probability - so whaṭ? The probability of hitting a given point in a rectangle, using another point as a projectile is equal to zero, exactly. Yet this event may happen. The event with arbitrarily small, but non-zero, probability is therefore infinitely more likely to occur. It just happened.
And, of course, the Universe was by no means bio-friendly for many years after the Big Bang. AP, weak or strong, seems only good for theologicians. In my humble opinion. Some scientists even call it a tautology and it is probably the best name (or foundation) for AP.
The number \pi is also very fine-tuned - yet nobody has ever tried to relate it either to humans or to any other form of intelligent life. Why?
Marek, that's fair enough, and your points are well made, but that still does not mean that asking the question and looking into it is illegitimate ...
Looking into π or into √2 at once illuminates why their values are what they are.
Generally speaking, 'it just happened' does not seem very satisfactory. Of course the Universe was extremely bio-unfriendly for eons, but it remains that the far and away huge majority of possible conceivable universes are bio unfriendly, period.
Looking into why such a chain of unlikely events leading up to our Universe occurred in the first place looks like a valid scientific enquiry - if a person won the lottery 20 times in a row, would not it surely be wholly legitimate grounds for a thorough enquiry, rather than for a shrug and a dismissal by saying that it just happened ?
Chris,
look at the lives of roughly 6 billion humans living today. Each one of them is different from others, thus the probability of the sequence of events in life of any given individual is negligibly small, less than 10^{-9}. Yet every individual's life is not only possible, it indeed is occurring now, it's a fact. The same is true, even to greater extent, in relation to insects. But we are not inclined to speak about "insect's principle" - why?
Wikipedia:
http://en.wikipedia.org/wiki/Anthropic_principle
The phrase "anthropic principle" first appeared in Brandon Carter's contribution to a 1973 Kraków symposium honouring Copernicus's 500th birthday. Carter, a theoretical astrophysicist, articulated the Anthropic Principle in reaction to the Copernican Principle, which states that humans do not occupy a privileged position in the Universe. As Carter said: "Although our situation is not necessarily central, it is inevitably privileged to some extent."[14] Specifically, Carter disagreed with using the Copernican principle to justify the Perfect Cosmological Principle, which states that all large regions and times in the universe must be statistically identical. The latter principle underlay the steady-state theory, which had recently been falsified by the 1965 discovery of the cosmic microwave background radiation. This discovery was unequivocal evidence that the universe has changed radically over time (for example, via the Big Bang).
Carter defined two forms of the Anthropic Principle, a "weak" one which referred only to anthropic selection of privileged spacetime locations in the universe, and a more controversial "strong" form which addressed the values of the fundamental constants of physics.
Roger Penrose explained the weak form as follows:
"The argument can be used to explain why the conditions happen to be just right for the existence of (intelligent) life on the earth at the present time. For if they were not just right, then we should not have found ourselves to be here now, but somewhere else, at some other appropriate time. This principle was used very effectively by Brandon Carter and Robert Dicke to resolve an issue that had puzzled physicists for a good many years. The issue concerned various striking numerical relations that are observed to hold between the physical constants (the gravitational constant, the mass of the proton, the age of the universe, etc.). A puzzling aspect of this was that some of the relations hold only at the present epoch in the earth's history, so we appear, coincidentally, to be living at a very special time (give or take a few million years!). This was later explained, by Carter and Dicke, by the fact that this epoch coincided with the lifetime of what are called main-sequence stars, such as the sun. At any other epoch, so the argument ran, there would be no intelligent life around in order to measure the physical constants in question — so the coincidence had to hold, simply because there would be intelligent life around only at the particular time that the coincidence did hold!"
—The Emperor's New Mind, Chapter 10
Marek- I agree with Chris. The unique life of one individual out of nearly 10^10 makes exactly the point of the weak anthropic principle. The physical laws (force strengths) of our universe are so unlikely that there must be an infinity of other universes with different values in order to make our own existence more likely. If the gravitational constant, for example, can in principle have any value between 0 and infinity then any particular value is not just unlikely, it has a probability of zero. But in the infinity of universes there will be a (smaller) infinity in which G has a value, probably within
Stephen,
Our existence is not more or less likely. It is sure. We do exist regardless of existence of any other potential universe(s), with or without intelligent form of life there.
Marek
Indeed, against apparently enormous odds, we do exist. But if there is an infinity of other universes, amongst which there must be a much smaller infinity of universes identical to our own and a larger infinity of universes very similar, but not quite identical to, ours then our existence is not at all improbable but inevitable.
If I understand correctly, the finite number of other universes does not suffice? This is highly speculative, if not suspected, for me.
If those other universes do exist but are separate from our Universe, then how could they possibly influence our Universe? Mathematically but not physically? Unbelievable.
It changes nothing about the universe if we know it. It was also there without us and it still will be when we are gone. We are simply too insignificant. A small planet of a little sun at the edge of a small galaxy, in the middle of nowhere. We are not important to the universe. So we need no AP, whether the strong one, nor the weak one.
I have read only the book of Barrow and Tipler and found it fascinating. It does not prove the existence of God or anything like that, nevertheless it is not against it ... Interestingly the book was written by admittedly non-religios scientists, and some of their conclusions have nothing to do with theology.
Hans Küng in his seminal book "Does God Exist" demonstrated that although there is no rigorous proof this assumption is not against human reason.
I will never try to prove anyone the existence of God. I have quite personal reason to believe in Him as He manifested Himself in Jesus - but I do not find these reasons compelling. It is an existential decision, not a logical conclusion.
Wilfried,
You and me are part of the universe, and this part of the universe that we are seems to be interested to itself and this seem to be central to this kind of part to be interested in what it is and thus where it is coming from. Now when we look at the evolution of the universe along the theoretical framework of physics as they exist today provide a cosmic lotterie answer. It is not the type of answer we like. What we like are answer that make it probable for us to be here. The multiverse scenarios are solving the problem by saying it is probable given the enormous among of draw that occured previous to our local big bang in the cosmic lotterie. I simply do not like the cosmic lotterie idea altogheter.
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