What is Anthropic: Definition and 34 Discussions

The anthropic principle is a group of principles attempting to determine how statistically probable our observations of the universe are, given that we could only exist in a particular type of universe to start with. In other words, scientific observation of the universe would not even be possible if the laws of the universe had been incompatible with the development of sentient life. Proponents of the anthropic principle argue that it explains why this universe has the age and the fundamental physical constants necessary to accommodate conscious life, since if either had been different, we would not have been around to make observations. Anthropic reasoning is often used to deal with the notion that the universe seems to be fine tuned.There are many different formulations of the anthropic principle. Philosopher Nick Bostrom counts them at thirty, but the principles can be divided into "weak" and "strong" forms, depending on the types of cosmological claims they entail. The weak anthropic principle (WAP) such as the one defined by Brandon Carter, states that the universe's ostensible fine tuning is the result of selection bias (specifically survivorship bias). Most often such arguments draw upon some notion of the multiverse for there to be a statistical population of universes to select from. However, a single vast universe is sufficient for most forms of the WAP that do not specifically deal with fine tuning. The strong anthropic principle (SAP), as proposed by John D. Barrow and Frank Tipler, states that the universe is in some sense compelled to eventually have conscious and sapient life emerge within it.

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  1. S

    I Anthropic Principle: Exploring Logical Explanations

    And was confused on the implications. Is there a more logical explanation for this? I'm very confused on what's happening here
  2. Jim Kata

    I Participatory Anthropic Principle

    Consider the following thought experiment, two electrons are in an entangled state with a total angular momentum of zero. They split apart from each other some billion or so years ago and I observe one of the electrons right now. Before the observation, there is some probability that it will be...
  3. S

    Did Paul Dirac believe in multiple universes?

    Prominent physicist Paul Dirac proposed a hypothesis that indicated that constants and laws of physics would evolve with time into different constants and laws of nature (https://en.wikipedia.org/wiki/Dirac_large_numbers_hypothesis) This hypothesis was used by Robert Dicke...
  4. S

    Does Lawrence Krauss believe in the anthropic principle?

    Summary: Does Lawrence Krauss believe in the anthropic principle? I have read a lot of texts both indicating that physicist Lawrence Krauss is against the anthropic principle. But I have read several texts indicating that Lawrence Krauss believes that this principle is true and has developed...
  5. S

    I Did Wheeler consider Carter's anthropic multiverse?

    Physicist John Wheeler wrote an article called "Genesis and Observership" where he said near the end: "We have reviewed the evidence out of the big bang tat the universe did come into being and the evidence that not only space but all the structures and laws of physics are mutable. In the...
  6. S

    I Does the Strong Anthropic Principle have any equivalent specific model?

    The anthropic principle is a philosophical consideration that observations of the universe must be compatible with the conscious and sapient life that observes it. There are two main types of anthropic principle: Weak Anthropic Principle (WAP) and Strong Anthropic Principle (SAP) The Strong...
  7. A

    A Multiverse reduction in the new Hawking/Hertog model?

    Hawking and Hertog's new paper "A Smooth Exit from Eternal Inflation?" does away with the infinite multiverse of Hawking's previous theory and proposes a cosmology that predicts "a simpler and finite universe". But I can't figure out the extent of this reduction to a "simpler and finite"...
  8. W

    I What is the lower bound constraint for G in terms of anthropic principles?

    Martin Rees talks about the strength of G in his book Just Six Numbers and how it couldn't be much stronger than it is for life to evolve. However he seems to hint that it could be weaker without much problem. I am wondering if anyone knowns any papers on the lower bound constraint for G in...
  9. bcrowell

    I Anthropic Lower Limit on Cosmological Constant

    Piran et al., "Cosmic explosions, life in the Universe and the Cosmological Constant," http://arxiv.org/abs/1508.01034 I thought this was interesting. If I'm understanding correctly, the idea is that satellite galaxies such as the Magellanic Clouds have low metallicity, which causes them to...
  10. Buzz Bloom

    What can the Anthropic Principal predict?

    I am curious about how the Anthropic Principal could in principal be used to constrain possible values for physical constants. It seems plausible to me that quite a few physical constants are constrained to be within a few orders of magnitude of measured values, but that is just a guess. I...
  11. R

    Non anthropic decimal sequence origins?

    I am having difficulty trying to find any history in mathematics of the concept that the decimal number system is not just a product of human ingenuity. This anthropic assumption (and assumption is all that is) seems to have entirely precluded the contrary hypothesis that decimal sequence...
  12. Q

    Anthropic Principle and Infinitely Minute Variations

    Let's assume as per the anthropic principle, for the mere sake of argument alone, that the physical constants of the universe are indeed biased towards life and that any significant change would eradicate the possibility of any form of conscious life. For the sake of argument as well, let's...
  13. K

    Many Worlds + Anthropic Principle

    This might be interpreted by some to border on the fringes on pseudo-science, but I feel logic dictates that conclusion must be one of many possibilities according to the theories. Has anyone ever considered that the many worlds interpretation combined with the anthropic principle has some...
  14. A

    Simpler Anthropic Principle: the Computeric Principle

    I just read the Spacetime article on wikipedia which argues that the spatial and temporal dimensions (N=3, T=1) are special, since without them no life as we know it could ever exist. It is not clear to me however if a computer (or better an (in)finite Universal Turing Machine) could ever exist...
  15. Q

    Foundations of the anthropic principle

    What role does the anthropic principle play in modern cosmology? How can we justify it? (Is it merely good old common sense or does it have a mathematical formulation?) What does it succeed in explaining? Is it scientific? Is it necessary?
  16. 1

    Anthropic Principle: Opposition & Logic Explored

    What is everyone's opposition to the anthropic Principle? Is it not an application of deductive logic at it's purest level? We exist, therefore we must exist in a universe that allows for our existence. Seems to make perfect sense, or am I missing something crucial?
  17. S

    The MWI and the Anthropic Principle

    The MWI and the Anthropic "Principle" How is it that the MWI and the Anthropic "Principle, " which is especially distasteful, are regarded as compatible? It seems to me they are totally incompatible.
  18. C

    Anthropic principle and the time we find ourselves in

    Now, regarding the anthropic principle, I've been having the following thoughts. I have been considering the fact that we live in an age which is of the order of magnitude of the time it would take from the Big Bang until conditions of life can occur. It takes time for stars and planets to...
  19. Jonnyb42

    Anthropic Principle Interpretations

    Ok so I am writing a physics "research" paper over any topic we like. The one requirement is that the intro must be about the Anthropic Principle. I have searched it all over the internet and have found it hard to understand what the heck it is talking about. (I am not into this kind of thing...
  20. Holocene

    My take on the anthropic principle.

    We all know the general definition of the anthropic principle, but here's my "take" on it, if you will. Assume that life is super rare. Let's say that life is a near impossibility, but is still not ultimately precluded from occurring. Despite this, it seems to me, that any intelligent...
  21. S

    A Critique of Shortsighted Anthropic Principles

    a new paper in Physical Review Letters from a group of physicists at Case Western Reserve University argues that any connection between the laws of physics and the existence of life is likely to be an illusion stemming from our shortsighted definition of intelligent life. The paper implies...
  22. Chronos

    What's the trouble with anthropic reasoning?

    I couldn't help but notice this interesting paper. I'm guessing some lively discussion will be emergent on the blogs. http://arxiv.org/abs/astro-ph/0610330 What's the trouble with anthropic reasoning? Authors: Roberto Trotta (Oxford University), Glenn D. Starkman (Oxford University & Case...
  23. Robert100

    The anthropic principle(s) and the landscape

    In the thread on Peter Woit's new book, the conversation turned to the landscape currently predicted by string theory. This in turn led to me asking a question about Leonard Susskind, and his use of one form of the anthropic principle. Danger, Will Robinson! There are many versions of...
  24. W

    Weak and strong anthropic principle

    Can somebody post the diferences. To me they seem to be the same
  25. D

    Anthropic Multiverse Origin of Life

    "Quantum measurement by a self-replicating biomolecule was the key event that caused life to emerge." "Using the Many Worlds approach, peptide addition within the first (proto-) cell would have taken place, not in a classical universe, but within the multiverse of all possible states."...
  26. W

    Anthropic Principle musings and questions

    I just listened to a talk by Leonard Susskind on "Landscape" ideas. He obviously is a big believer in these ideas, and also clearly he knows much more physics than I do by an order of magnitude comparable to electromagnetism versus gravity:) So I'm interested in why people, especially...
  27. D

    The Anthropic Multiverse Origin of Life

    "Quantum measurement by a self-replicating biomolecule was the key event that caused life to emerge." Try to follow me on this: "Using the Many Worlds approach, peptide addition within the first (proto-) cell would have taken place, not in a classical universe, but within the multiverse...
  28. R

    The Anthropic Principal: Exploring Design Argument & Meaning

    Does the anthropic principal support the design argument and just what does it mean?
  29. M

    Bad Science and the Anthropic Cosmological Principle

    "Bad Science" and the Anthropic Cosmological Principle Many observers have noted that the physical laws, parameters and constants of our cosmos appear to be remarkably "fine tuned" in accordance with our existence. There are a number of suggestions that if certain parameters were to be...
  30. wolram

    Scientific alternative to the anthropic principle

    Scientific alternative to the anthropic principle by Baez http://arxiv.org/pdf/hep-th/0407213 To me this is an heroic paper
  31. K

    Answering the Anthropic Principle

    Hi! I don't really know if this is the right place to post this, but here's the question: It says that the universe is tuned so that we can exist. So if it were any different, we wouldn't be here to observe it. But why? I mean, there could still be life, maybe even more intelligent than us...
  32. R

    What's about a biological anthropic principle?

    Anthropic principle, in its different forms, is cause of discussion in Cosmology. My question here is restricted to Biology. Are conditions of life's origin and evolution restricted in so form that they allow the emergence of intelligent life? The great difference would be that a...
  33. T

    Anthropic Principle: Definition & Science

    What is Anthropic principle? And does it have to do anything with science?
  34. T

    The Weak vs Strong Anthropic Principle

    Which one do you believe is right the weak anthropic principle or the strong anthropic pricple. weak-one universe Strong-millions of universes, each with a differnt value for the constants.