Paul Bernays Lectures 2013
Robert B. Laughlin, Stanford University, USA
Professor Robert B. Laughlin is the Anne T. and Robert M. Bass Professor of Physics and Applied Physics at Stanford University. Macroscopical quantum phenomena belong to his main field of research. In 1998 he received the Nobel Prize for Physics for his contribution to the theoretical explanation of the fractional quantum Hall effect. In his popular scientific books he also deals with epistemological questions concerning the future and the knowledge strategy of physics ("A Different Universe: Reinventing Physics from the Bottom Down") as well as with political and social questions concerning the energy future ("Powering the Future: How We Will (Eventually) Solve the Energy Crisis and Fuel the Civilization of Tomorrow").
Programme
Lecture 1: A different universe
Tuesday, 10 September 2013, 5.00 p.m.
Abstract
It sometimes seems obvious that the universe should be ruled by law-relationships among measured quantities that are always accurately true -but it actually isn't. It's a miracule that only look obvious because of one's cultural and religious prejudices, specificially the idea from Greek stoic philosophy that Nature, Logic and God should all be the same thing. The power of this idea makes it notoriously difficult for us to ask where law might come from. But it turns out that many of the most useful laws -rigidity of solids, for example, the electrical properties of metals or the rules of heat- definitely do come from somewhere. They are organizational, and they emerge from chaos as the system size grows larger the way political consensus might, or the way a Monet painting does as one steps away. The growing body of experimental evidence accumulated in the last 60 years has demonstrated explicitly that many engineering laws fail when the system size gets small. But there is also accumulating evidence at the level of big science that ALL physical laws known to science may be in this category, including those of Newton (which emerge from quantum mechanics) and those of the empty vacuum of space-time. This observation has the disturbing implication that entire idea of fundamental law, and the search for the theory of everything based on it, may be ideological, and thus not science at all.
Lecture 2: The meter stick of life
Wednesday, 11 September 2013, 2.15 p.m.
Abstract
It is not known how living things measure their lengths. They clearly do so, for organisms have characteristic sizes and shapes that are the same down to very small details. But it is a conundum nonetheless because the experimental means at our disposal are not very good at addressing this question. Elementary mass action in chemistry is very good for making clocks, but not so good at making lengths, especially ones that can be tuned and scaled proportionately as an organism grows. In this talk I shall discuss the various options available for dealing with this problem, including Turing reaction-diffusion, none of which is completely satisfactory. One's inability to write down equations that describe how cells do this highly quantitative thing is not an unimportant detail of interest only to physicists but unambiguous evidence that at least one important idea is missing.
Lecture 3: Bond current antiferromagnetism
Wednesday, 11 September 2013, 4.30 p.m.
Abstract
In this talk I will review the growing body of evidence that a previously unknown order parameter, bond antiferromagnetism, is present in cuprate superconductors in a glassy form and is responsibile for much of their perplexing behavior, including particularly their pseudogap, doping asymmetry, weak spin polarization and violenty varying superfluid density. I shall argue that bond-current order competes with d-wave superconductivity in the cuprates the same way structural phase transitions compete with s-wave superconductivity in conventional metals, the ordered bond antiferromagnet being essentially a crystal of d-wave Cooper pairs. Its relevance to the cuprates is thus mainly as an impediment to achieving higher superconducting transition temperatures. However, it has wider relevance to engineering through oxide resistive memory, a vastly more important phenomenon presently of great interest to electronics manufacturers on account of its potential to replace flash memory.