Weak and strong anthropic principle

In summary, the conversation discusses the Weak Anthropic Principle (WAP) and the Strong Anthropic Principle (SAP), which both suggest that the physical properties of the universe are favorable for life. The WAP proposes that this is due to a selection effect, while the SAP suggests a more specific reason for the values of physical parameters. One example of the SAP is Smolin's Cosmological Natural Selection (CNS) theory, which suggests that universes are born out of black holes and evolve to maximize the production of black holes. However, the existence of other universes and the validity of the SAP are still in doubt, and some argue that the SAP is unscientific and better suited for religious beliefs.
  • #1
werner heisenberg
Can somebody post the diferences. To me they seem to be the same
 
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  • #2
The Weak Anthropic Principle (WAP) simply says the physical properties of the universe are propitious for life somewhere within it.

The Strong Anthropic Principle (SAP) says the physical properties of the universe must be propitious for life somewhere within it, that is there is some unspecified 'law' or reason why the various physical parameters have the values they do, and why this set of values are propitious for life.

One explanation for the AP is that the are many, or even an infinite number, of universes and we are in this one because of a selection effect; we could be in no other. This is the WAP.

However if the SAP is true then if there were many universes every universe would be propitious for life.

As we cannot observe, and may never be able to observe, these other universes the scientific status of these explanations is somewhat in doubt.

One example of the SAP is Smolin's Cosmological Natural Selection (CNS) theory, which suggests that universes are born out of the singularities at the centres of black holes and each new universe copies the physical attributes of its progenitor but changes them slightly. The universes then evolve to maximise the number of black holes they spawn, and these maximal conditions just happen to be also those that are propitious for life. After a certain number of iterations almost every universe would therefore be propitious and so here we are!

However the fact that CNS requires the conditions that maximise the spawning of BHs should be also those that are propitious for life seems to be a bit of a coincidence. As the AP reflects on the 'coincidental' habitability of this universe it seems to me that for CNS to replace one coincidence with another does not really achieve anything.

Garth
 
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  • #3
Garth said:
The Strong Anthropic Principle (SAP) says the physical properties of the universe must be propitious for life somewhere within it, that is there is some unspecified 'law' or reason why the various physical parameters have the values they do, and why this set of values are propitious for life.

So if life has a number of places it can arise, for example billions of galaxies, would this also be an example of the strong Anthropic Principle?

Garth said:
One example of the SAP is Smolin's Cosmological Natural Selection (CNS) theory

Just out of curiosity, doesn’t Smolin argue that the Athropic Principle is unfalsifiable, and that CNS is an example of a falsifiable multiverse theory? Whether or not this is still Athropic Reasoning is unclear.
 
  • #4
Vast said:
So if life has a number of places it can arise, for example billions of galaxies, would this also be an example of the strong Anthropic Principle?

If there were only one universe, I think we would be forced to resort to the SAP, regardless of the number of galaxies, because the subspace of conceivable laws of physics that don't produce galaxies at all is much larger than that for those that do. It's true that this universe has billions of galaxies in which life could potentially form, but if you change the fundamental parameters of our universe by a significant amount, it's likely that none of them will be able to produce life (in fact, the galaxies may not even form).
 
  • #5
I see, the number of galaxies is irrelevant if there is only one universe. In which case I would consider Smolin’s CNS to be closer to the WAP analogous to evolution where an emergent property comes about over a series of generations. In this light the SAP would seem to represent an intelligent design or creator, is this correct?
 
  • #6
Vast said:
In this light the SAP would seem to represent an intelligent design or creator, is this correct?

That would be one example of the SAP, yes. I suppose one could also subscribe to the notion that the universe is just "here for us" and bypass the deity entirely.
 
  • #7
Certainly if our universe was the only one the SAP would be true but I think there cannot be a way of working this out. And until somedoby shows me the oposite I do not feel like joining the SAP
 
  • #8
werner Heisenberg said:
Certainly if our universe was the only one the SAP would be true but I think there cannot be a way of working this out. And until somedoby shows me the oposite I do not feel like joining the SAP

I don't think anyone's trying to convince you that you should. The SAP is extremely unscientific.
 
  • #9
That 's what I was trying to say. Is fits better in a religious myth
 
  • #10
werner Heisenberg said:
That 's what I was trying to say. Is fits better in a religious myth
It all depends on what you mean by the Anthropic Principle itself and what it is used for.

My favourite definition of the AP is Stephen Hawking's: "The world is as it is because we are", because it is so succinct.

The WAP can be used to argue for the multiverse
The idea of a multiverse – an ensemble of universes or universe domains – has received increasing attention in cosmology, both as the outcome of the originating process that generated our own universe, and as an explanation for why our universe appears to be fine-tuned for life and consciousness.
or, simply as a recognition that things could not be otherwise if we are around to recognise it.

The problem with all these other universes is we cannot observe them, and may never be able to do so. Therefore belief in their existence is as much an act of faith as belief in a creating Deity.

The SAP may be taken as an argument for the existence of such a Deity however, the cause that makes the set of physical constants propitious for life may equally well be a natural cause.

As I said above Smolin's CNS is one such natural explanation why the anthropic 'coincidences' are so, they are the result of the natural selection for maximising a universe's black hole production.

My caveat to Smolin's argument against the AP coincidences is to point out that if, the conditions that maximise BH production are also those that are propitious for life then, that itself seems to be a bit of a coincidence!

Garth
 
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  • #11
I can think in a universe born from every singularity. To me maybe appears more interesting this Wheeler thought about large amounts of parallel universes, without contact, with different constants... Well as it is imposible to prove its existence right now it all about believing it or not. Anyway I hope we will be able to discover if we are really alone or if there is life somewhere else in this or another universe. The only way is harnessing the space-time and I guess we won't be here when this has been one
 
  • #12
I'm confident the WAP is the most unfalsifiable conjecture imaginable. But I don't see it as being predictive, merely a logical test of validity. I would argue that any observation that leads to the conclusion it is impossible to make such an observation has fatal flaws. Either the observation or interpretation must be incorrect.
 
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  • #13
Chronos said:
I'm confident the WAP is the most unfalsifiable conjecture imaginable. But I don't see it as being predictive, merely a logical test of validity. I would argue that any observation that leads to the conclusion it is impossible to make such an observation has fatal flaws. Either the observation or interpretation must be incorrect.
Yes the WAP is unfalsifiable in the sense that 'things' could not be otherwise; to our minds it is self evident because it is consistent with the existence of such minds.

Garth
 
  • #14
The other option is that 'God' [I don't mean the ' ' negatively, I like her immensely] has selectively shielded us from every observation that contraindicates our existence. I resist that argument. She is vain, has a great sense of humor, and is amused seeing us flop around on the grass like beached salmon. But, deep down, she likes us... every once in awhile, she whispers a word of wisdom to those willing to listen.
 
  • #15
Chronos said:
The other option is that 'God' [I don't mean the ' ' negatively, I like her immensely] has selectively shielded us from every observation that contraindicates our existence. I resist that argument.

I hope I’m reading that right, because when you use "she" in this particular context it sounds as if we’re an unplanned pregnancy. :biggrin:

Religious dogma would be the first to resist such ideas that life was anything but special, it takes away their sense of self importance, their uniqueness. But likewise I see no reason why this should be the case.

Perhaps Emergence is a better way of explaining physical properties?
 
  • #16
Agreed, all physical properties are emergent from 'first principles', IMO.
 
  • #17
http://www.religion-online.org/showarticle.asp?title=2917 by Philip Clayton an associate professor of philosophy at Sonoma State University in Sonoma, California.
Emergence, in contrast, suggests a very different model of the God-world relationship. In this model God sets in motion a process of ongoing creativity.

Did you hear about the right-wing fundamentalist who went to heaven? He found that not only was God black, but she was Jewish!

We can't go on like this or the thread will be moved!

Garth
 
  • #18
Another emergence model is Tipler’s Omega Point Theory, where he puts forward his model for an evolving God as a scientific theory. http://www.middx.org.uk/gordo/ellis3.html" [Broken] G. F. R. Ellis and W. R. Stoeger offer a critique to his theory.

his theory involves major errors in attribution, in the use of language, in understanding the character of knowledge relative to reality, in logic and consistency, and in the justifiability of fundamental assumptions.
 
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1. What is the difference between the weak and strong anthropic principle?

The weak anthropic principle states that the universe must be compatible with our existence, while the strong anthropic principle goes further and suggests that the universe was specifically designed for our existence.

2. How are the anthropic principles used in scientific theories?

The anthropic principles are often used to explain why certain physical constants in the universe have values that allow for the existence of life. For example, the fine-tuning of the cosmological constant is often explained by the anthropic principle.

3. Are the anthropic principles testable?

No, the anthropic principles are philosophical concepts and cannot be tested directly. However, they can be used to make predictions and guide scientific theories.

4. Do the anthropic principles suggest that there is a purpose or meaning to our existence?

The anthropic principles do not necessarily imply a purpose or meaning to our existence. They simply suggest that our existence is a result of the conditions and parameters of the universe.

5. Are the anthropic principles widely accepted in the scientific community?

The anthropic principles are still a topic of debate and are not universally accepted in the scientific community. Some scientists find them useful in explaining certain aspects of the universe, while others view them as untestable and unscientific.

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