Can someone explain me the anthropic principle. I don't get itl. The priciple sounds very non scientific.?

Question

I've read this priciple in a couple of books and they say sth like this,
"The Constants of our universe are what we observe them to be because, otherwise we would not be there to experience it."
Why should we be here in the first place? Why is it necessary for us to be here? This principle, to me, somehow indicates the presence of a creator.. who selected the present universe for life to exist.

Answer 1

The weak anthropic principle merely states the obvious: it should be no surprise that the universe supports life, because however unlikely it might be, if it didn't, we wouldn't be here to wonder about it.

The strong anthropic principle states that intelligence is an essential component of the universe, and that without someone to observe it, the universe would not exist.

The weak anthropic principle makes no assumptions about intent, as there could be googleplexes of uninhabitable universes for all we know. The various versions of the strong anthropic principle do tend towards mysticism or religion.

Answer 2

The Anthropic Principle has three theses, but only the Weak and the Strong Principles are discussed seriously by mainstream physicists, because the Final Principle is too unwarranted.

The Weak Principle merely states the obvious, that the observed physical conditions of the universe must allow the observers to exist. Were the universe inhospitable to us, we wouldn't exist to observe it. The Principle has a sense of redundancy in it. That's why sometimes it is criticized as a tautology.

The Strong Principle states that the universe must have the properties that allow life to develop. In other words, the development of life is the requirement of the universe. This is where the controversy begins.

The Anthropic Principle itself is void of wordings related to the supernatural, but is picked up by creationists to prove the existence of a deity. They claim the physical constants are fine-tuned for the establishment of life. They say it is very improbable that the constants happen to take up values that permit life, thus God must be behind it. But this receives much opposition from the scientific community.

Imagine you get four aces in a poker game. It is a highly unlikely hand. But do you need to account for it with miracles? Suppose you win the multi-million lottery. It is a very slim chance. But can you jump to the conclusion that God is partial to you?

There is no scientific evidence whatsoever to proof that our existence is necessary, that we are the ultimate purpose. We just happen to be here. If there are other universes with different configurations of physical properties, they may contain other life-forms. We may not be as special as it seems. Therefore, we cannot deduce that the universe is created for us. Instead, we should say that the physical conditions are as they are, so we have adapted to them.

Notice that creationists' anthropic reasoning is so strongly opposed by scientists because they are trying to introduce the supernatural into science. It doesn't mean that we cannot believe God created the universe for humanity in religion. Unlike science, religion doesn't need any proof, and is improvable.

Answer 3

I have gone through almost all answers. I have nothing to say anything in addition to these answers. But I would like to say something about your way of calling this non scientific. In physics the term 'principle' is used in various ways. Most of the time it is some definite derivable of experimental law. But many times we use it to mean theory, technique or most loosely to mean a way of looking at things. The method of science allows all this most respectfully. hence it will not be proper to call anthropic principle unscientific. It is as 'unscientific' as Newton's corpuscular theory was and as 'scientific' as modern quantum theory is!

Answer 4

Think about it this way: if there were a billion universes, and only one of those universes had just the right set of constants for life to emerge, then there would be 999,999,999 empty universes and one universe full of people wondering how they got so lucky.

We are in that one universe that happens to be able to support life. It seems phenomenally unlikely that we should be so lucky, but in this lottery you have to be a winner to notice that there's a game being played.

Answer 5

The anthropic principle states, that the Universe is what it is, and evolved in such way, that mankind appear. If the Universe had evolved in any other way, in which no inteligent creatures appear, "we would not be here to experience it".

Answer 6

In cosmology, the anthropic principle in its most basic form asserts the truism that any valid theory of the universe must be consistent with the existence of human beings and of organic chemistry, here and now in the universe.

In simple terms, the anthropic principle says, if a billion universes existed, with a multitude of laws of nature, then humans would only be aware of those in which humans could emerge, and (no matter how many versions of laws of nature existed) the laws of nature humans saw would only be the laws of nature of those universes in which humans as we know them could emerge. In other words, "If something must be true for us, as humans, to exist, then it is true because we exist." This is an effect known as selection bias.

Attempts to apply this principle to develop scientific explanations in cosmology have led to a little confusion and controversy.

The Anthropic Cosmological Principle
The most thorough extant study of the anthropic principle is the controversial book The Anthropic Cosmological Principle by John D. Barrow, a cosmologist, and Frank J. Tipler, a mathematical physicist. This book contains an extensive review of the relevant history of ideas, because its authors believe that the anthropic principle has important antecedents in the notions of intelligent design, the philosophies of Fichte, Hegel, Bergson, and Whitehead, and the omega point cosmology of Teilhard de Chardin. Barrow and Tipler carefully distinguish teleological reasoning from eutaxiological reasoning; the former asserts that order must have a consequent purpose; the latter asserts more modestly that order must have a planned cause. They attribute this important but nearly always overlooked distinction to Hicks (1883).

Barrow and Tipler set out in great detail the seemingly incredible coincidences that characterize our universe and that permit human beings to evolve in it. They then maintain that only the anthropic principle can make sense of this raft of coincidences. Everything from the energy states of the electron to the exact strength of the weak nuclear force seems tailored for us to exist. That our universe contains carbon-based life is contingent upon the values of several independent parameters, and were the value of any of those parameters to vary slightly, carbon-based life could not exist. While Barrow and Tipler (1986) is a primarily a work of theoretical physics, it also discusses a variety of related topics in chemistry and earth science.

In 1983, Brandon Carter, qualifying his 1974 paper, stated that the anthropic principle, in its original form, was meant only to caution astrophysicists and cosmologists about possible errors in the interpretation of astronomical and cosmological data if they failed to take into account constraints arising from the biological nature of the observer. Carter also warned that the inverse was true for evolutionary biologists; in interpreting the evolutionary record, one must take into account cosmological and astrophysical considerations. With this in mind, Carter concluded that, given the best estimates of the age of the universe (then about 15 billion years, now 13.7 billion years), the evolutionary chain probably can allow only one or two low probability links. A. Feoli and S. Rampone ("Is the Strong Anthropic Principle Too Weak," 1999) argue for a higher number of low probability links, given the size of our universe and the likely number of planets. The higher number of low probability links is less consistent with the claim that the emergence of life and its subsequent evolution requires intelligent design.

Recent work in observational cosmology and the theory of quantum gravity has led to renewed interest in the anthropic principle. Quantum gravity attempts to unify gravity with the other forces. While there have been a number of promising developments, all such theories suffer from the problem that the fundamental physical constants are unconstrained. The observational motivation comes from more precise estimates of quantities such as the matter density of the universe. Recent estimates of this density are about 0.3, while cosmological theory generally predicts a value indistinguishable from one.

There are alternatives to the anthropic principle, the most optimistic being that a Theory of everything will ultimately be discovered, uniting all forces in the universe and deriving from scratch all properties of all particles. Candidate "theories of everything" include M-Theory and various theories of quantum gravity, although all theories of this nature are currently deemed speculative. Another possibility is Lee Smolin's model of cosmological natural selection, also known as fecund universes, which proposes that universes have "offspring" which are more plentiful if they happen to have features common to our universe. Also see Gardner (2005) and his "selfish biocosm hypothesis."

Answer 7

wikipedia rules

Answer 8

I think therefore I am.