Tuesday, 10 August 2010

The Weak Anthropic Principle

Barrow and Tipler offer this definition:

"The observed values of all physical and cosmological quantities are not equally probable but they take on values restricted by the requirement that there exist sites where carbon-based life can evolve and by the requirement that the Universe be old enough for it to have already done so"

Here's an example.

We observe that we exist at a point in the life of the universe where carbon is readily available (it wasn't this way earlier on).

But then this would have to be so - because if there wasn't any carbon then there wouldn't be any us.

1 comment:

  1. Yeah, that does seem a bit circular, self-defining.
    A bit like the Amp!
    "The constant current which will produce an attractive force of 2 × 10–7 newtons per metre of length between two straight, parallel conductors of infinite length and negligible circular cross section placed one metre apart in a vacuum"
    Obviously, the fairly random 2 × 10–7 N/M is derived from passing 1A through a wire, not someone measuring that attraction first and saying "that'll be called 1A then".
    The unit is thus only derived from itself as the primary measurement source, making it self-defining. Confusing, but that's what you get when you discover something first and define it later when you have already started using & measuring it / with it!