We report the draft genome of the black cottonwood tree, Populus trichocarpa. Integration of shotgun sequence assembly with genetic mapping enabled chromosome-scale reconstruction of the genome. More than 45,000 putative protein-coding genes were identified. Analysis of the assembled genome revealed a whole-genome duplication event; about 8000 pairs of… (More)
We review a striking array of recent experiments and their theoretical interpretations on the superfluid transition in 4 He in the presence of a heat flux Q. We define and evaluate a new set of critical point exponents. The statics and dynamics of the superfluid-normal interface are discussed, with special attention to the role of gravity. If Q is in the… (More)
The article that follows was written in 1994, and first appeared in The American Scholar (vol. 63 p. 527). In the three years since then much has happened, but little has changed. There have been reports of increasingly reliable production of excess heat, and of the detection of 4 He residue, and much more. Nevertheless, the most remarkable fact remains… (More)
Theoretical and experimental studies have been conducted of the transmission of phonons in sapphire and their reflection at a crystal-vacuum interface. The effects of crystal anisotropy on the reflection process, not previously noted in the literature, are discussed in detail. The heat-pulse technique has been used to obtain high-resolution time-of-flight… (More)
We present the first experimental evidence that the heat capacity of superfluid 4 He, at temperatures very close to the lambda point T l , is enhanced by a constant heat flux Q. The heat capacity at constant Q, C Q , is predicted to diverge at a temperature T c ͑Q͒ , T l at which superflow becomes unstable. In agreement with previous measurements, we find… (More)
We review a striking array of recent experiments, and their theoretical interpretations, on the superfluid transition in 4 He in the presence of a heat flux, Q. We define and evaluate a new set of critical point exponents. The statics and dynamics of the superfluid-normal interface are discussed, with special attention to the role of gravity. If Q is in the… (More)
Knowledge has killed the sun, making it a ball of gas with spots… The world of reason and science… this is the dry and sterile world the abstracted mind inhabits. A public that does not understand how science works can, all too easily, fall prey to those ignoramuses… who make fun of what they do not understand, or to the sloganeers who proclaim scientists… (More)
We discuss aspects of the theory of critical phenomena and explore the superfluid transition in 4 He. We review some of the recent experimental and theoretical work on helium in nonequilibrium conditions and summarize some future space experiments that might shed light on disagreements between theory and experiment.