estimation - Maximum Possible Information in the universe?

I remember hearing about this in one of the programs in discovery science. The physicist claimed that the maximum possible information in the universe is $10^{10^{123}}$ whereas the maximum possible information that can be known by man is $10^{10^{90}}$. Can anyone explain to me how can we arrive at such a specific number, and also how can information be represented by only numbers?

Answer

The number $10^{123}$ emerges as (roughly) the number of Planck areas contained within the boundary of the observable universe. If each Planck area can be (roughly) in two states, a total of $10^{123}$ yes/no questions suffice to describe the boundary of the universe and - via the (still speculative) holographic principle - the whole universe. In other words, if the universe is a hologram, about $10^{123}$ bits of information are needed to describe it.