A Historical Perspective on Cancer

It is proposed that cancer results from the breakdown of universal control mechanisms which developed in mutual association as part of the historical process that brought individual cells together into multi-cellular communities. By systematically comparing the genomes of uni-celled with multi-celled organisms, one might be able to identify the most promising sites for intervention aimed at restoring the damaged control mechanisms and thereby arresting the cancer.Comment: 3 pages, plainTeX, no figure

Two Topics concerning Black Holes: Extremality of the Energy, Fractality of the Horizon

We treat two aspects of the physics of stationary black holes. First we prove that the proportionality, d(energy) ~ d(area) for arbitrary perturbations (``extended first law''), follows directly from an extremality theorem drawn from earlier work. Second we consider quantum fluctuations in the shape of the horizon, concluding heuristically that they exhibit a fractal character, with order lambda fluctuations occurring on all scales lambda below M^{1/3} in natural units.Comment: 18 pages, plainTeX, 2 postscript figures (Figures for automatic inclusion are in a separate file which you should receive with the .tex file. For instructions on decoding and including them (or omitting them to avoid error messages if your system can't handle them) see the box at the beginning of the tex file for this paper.

Is the spacetime metric Euclidean rather than Lorentzian?

My answer to the question in the title is "No". In support of this point of view, we analyze some examples of saddle-point methods, especially as applied to quantum "tunneling" in nonrelativistic particle mechanics and in cosmology. Along the way we explore some of the interrelationships among different ways of thinking about path-integrals and saddle-point approximations to them.Comment: plainTeX, 21 pages, 1 figure (in color). A few minor corrections and some re-wording. A previous version erroneously gave Re(f(z)) rather than Im(f(z)) (Thanks to Adam Brown for this correction.) Most current version is available at http://www.perimeterinstitute.ca/personal/rsorkin/some.papers/134.tunneling.pdf (or wherever my home-page may be