25.3.2011

Michal Krizek (Institute of Mathematics, Academy of Sciences, Prague)

Dark Energy and the Anthropic Principle

Summary:
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The Hubble constant is split into two terms H=H1+H2, where H1 is a decreasing
function due to the Big Bang and the subsequent gravitational interaction that
slows the expansion of the Universe and H2 is an increasing function that
corresponds to dark energy which accelerates this expansion. For T = 13.7 Gyr
we prove that H2(T) > 5 m/(yr AU).  This is a quite large number and thus the
impact of dark energy, which is spread almost everywhere uniformly, should be
observable not on only large scales, but also in our Solar system. In
particular, we show that Earth, Mars and other planets were closer to the Sun
4.5 Gyr ago. The recession speed ~5.3 m/yr of the Earth from the Sun seems to
be just the right amount for there to be an almost constant influx of solar
energy from the origin of life on Earth up to the present over which time the
Sun's luminosity has increased approximately linearly. This presents further
support for the Anthropic Principle. Namely, the existence of dark energy
guarantees very stable conditions for the development of intelligent life on
Earth over a period of 3.5 Gyr.