“Chaos Is Hard to Predict”

It is hard to predict the future: the evolving nature of threats and vulnerabilities.

This paper describes the evolving nature of threats and vulnerabilities associated with biological disasters with animal origins, and introduces some of the pitfalls and opportunities associated with anticipating future threats. Evolving threats and vulnerabilities include continued deforestation and encroachment on virgin habitats, the effects of globalisation on trade and transportation, the ...

Climate change. Why is it hard to predict the future of ice sheets?

(IPCC) (1) highlights the improved accuracy of measurements of current sea-level rise, as well as greater certainty in the projected impacts of global warming on non-polar glaciers and thermal expansion of the oceans. These advances heighten confidence in projections of the most predictable components of sea-level rise, but the IPCC's projections specifically exclude the contribution that could...

Still alluring and hard to predict at 100.

Birthdays are always a time for introspection and, given the number of fingers humans generally have, a one hundredth birthday is especially so. Almost exactly a century ago, in April 1911, the laboratory run by Heike Kamerlingh Onnes at the University of Leiden discovered a sudden transition to zero resistance in high-purity mercury on cooling through 4.2 K. At the time, Onnes was basking in t...

Walk-Time Nested If-Conversion of Hard-to-Predict Branches

Clique is hard to approximate within n

We prove that, unless any problem in NP can be solved in probabilistic polynomial time, for any ǫ > 0, the size of the largest clique in a graph with n nodes is hard to approximate in polynomial time within a factor n. This is done by constructing, for any δ > 0, a probabilistically checkable proof for NP which uses logarithmic randomness and δ amortized free bits.