Several new and broader views on
computation in Nature and by Nature, and on its limitations and barriers are presented and analysed briefly. Quantum information precessing, global network information
processing and cosmology-based information processing theories are seen as three extreme, but well-founded approaches to computation
by Nature. It is also emphasized that a search for barriers and limitations in information processing as well as attempts
to overcome their barriers or to shift limitations, can have deep impacts on science, especially if they are accompanied by
a search for limitations and barriers also in communication and security. It is demonstrated that a search for barriers in
communications brings a lot of interesting and deep outcomes.
Computational and communication complexity is shown to play an important role in evaluating various approaches to get through
barriers that current physical theories impose. It is also argued that a search for barriers and limitations concerning feasibility
in information processing and physical worlds are of equal or maybe even of larger importance than those to overcome the Church-Turing
barrier and some communication barriers. It is also emphasized that relations between information processing in the real and
virtual worlds, or between physical and information worlds, are likely very deep and more complex than realized. All that
has even broader sense than usually realized because we are witnessing a radical shift in the main characterization of the
current science in general. A shift from so called Galilean science dominated by mathematics, to the Informatics (based) science - an informatics methodology based science and technology.
Keywords Frontiers and barriers of information processing - Information processing by nature - Quantum information processing - Feasibility - Security - Church-Turing barrier
This is an extended version of a paper (Thies et al. 2006) that appeared in the 12th International Meeting on DNA Computing, June, 2006.