Physical sciences articles within Nature

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  • Letter |

    Long duration γ-ray bursts mark the explosive death of some massive stars and are a rare sub-class of type Ibc supernovae. To date, central-engine-driven supernovae have been discovered exclusively through their γ-ray emission, yet it is expected that a larger population goes undetected. The discovery of luminous radio emission from the seemingly ordinary type Ibc supernova SN 2009bb, which requires a substantial relativistic outflow powered by a central engine, is now reported.

    • A. M. Soderberg
    • , S. Chakraborti
    •  & M. A. P. Torres
  • Letter |

    In the study of high-transition-temperature (high-Tc) copper oxide superconductors, a fundamental question is what symmetries are broken when the pseudogap phase sets in below a temperature T*. A large in-plane anisotropy of the Nernst effect is now observed in a high-Tc copper oxide superconductor that sets in precisely at T* throughout the doping phase diagram. It is concluded that the pseudogap phase is an electronic state that strongly breaks four-fold rotational symmetry.

    • R. Daou
    • , J. Chang
    •  & Louis Taillefer
  • News Feature |

    The surprising discovery of methane in Mars's atmosphere could be a sign of life there. Researchers are now working out how to find its source, reports Katharine Sanderson.

    • Katharine Sanderson
  • Letter |

    The transformation of petroleum-derived feedstocks into useful chemicals often requires controllable cleavage of C–H or C–C bonds. There are many examples of achieving this through the oxidative addition of C–H bonds to metal centres, but analogous transformations of C–C bonds are rare. Here, using a tungsten centre and exploiting the formation of an unusual chelating ligand, a strong C–C bond is cleaved; other metal centres with suitable ancillary ligands could perform the same function.

    • Aaron Sattler
    •  & Gerard Parkin
  • News and Views Q&A |

    The race is on to build a computer that exploits quantum mechanics. Such a machine could solve problems in physics, mathematics and cryptography that were once thought intractable, revolutionizing information technology and illuminating the foundations of physics. But when?

    • Emanuel Knill
  • News & Views |

    As a rule of thumb, carbon–carbon bonds are not easily broken. But a tungsten complex has been found to break a particularly strong carbon–carbon bond, opening up fresh opportunities for organic synthesis.

    • Alan S. Goldman
  • News & Views |

    A probabilistic analysis of climate variation during the period AD 1050–1800 refines available estimates of the influence of temperature change on the concentration of carbon dioxide in the atmosphere.

    • Hugues Goosse
  • News Feature |

    Scientists are struggling to make sense of the expanding scientific literature. Corie Lok asks whether computational tools can do the hard work for them.

    • Corie Lok
  • Letter |

    Type Ic supernovae have drawn attention since 1998 owing to their sparse association with long duration γ-ray bursts (GRBs). Although the GRB central engine generates ultra-relativistic jets, no relativistic outflows have yet been found in type Ib/c supernovae explosions. Here, radio observations reveal a mildly relativistic expansion in a nearby type Ic supernova, SN 2007gr.

    • Z. Paragi
    • , G. B. Taylor
    •  & B. Paczyński
  • Letter |

    In the search to reduce our dependency on fossil-fuel energy, new plastic materials that are less dependent on petroleum are being developed, with water-based gels — hydrogels — representing one possible solution. Here, a mixture of water, 3% clay and a tiny amount of a special organic binder is shown to form a transparent hydrogel that can be moulded into shape-persistent, free-standing objects and that rapidly and completely self-heals when damaged.

    • Qigang Wang
    • , Justin L. Mynar
    •  & Takuzo Aida
  • Letter |

    Although deformation twinning in crystals controls the mechanical behaviour of many materials, its size-dependence has not been explored. Using micro-compression and in situ nano-compression experiments, the stress required for deformation twinning is now found to increase drastically with decreasing sample size of a titanium alloy single crystal, until the sample size is reduced to one micrometre; below this point, deformation twinning is replaced by dislocation plasticity.

    • Qian Yu
    • , Zhi-Wei Shan
    •  & Evan Ma
  • Letter |

    Telescopic measurements of asteroids' colours rarely match laboratory reflectance spectra of meteorites owing to a 'space weathering' process that rapidly reddens asteroid surfaces. 'Unweathered' asteroids, however, with spectra matching ordinary chondrite meteorites, are seen only among small bodies with orbits that cross inside the orbits of Mars and Earth. Such unweathered asteroids are now shown to have experienced orbital intersections closer than the Earth–Moon distance within the past half-million years.

    • Richard P. Binzel
    • , Alessandro Morbidelli
    •  & Alan T. Tokunaga
  • News & Views |

    The use of magnetic fields to assemble particles into membranes provides a powerful tool for exploring the physics of self-assembly and a practical method for synthesizing functional materials.

    • Jack F. Douglas
  • News & Views |

    Springtime ozone levels in the lower atmosphere over western North America are rising. The source of this pollution may be Asia, a finding that reaffirms the need for international air-quality control.

    • Kathy Law
  • News & Views |

    Asteroids are weakly bound piles of rubble, and if one comes close to Earth, tides can cause the object to undergo landslides and structural rearrangement. The outcome of this encounter is a body with meteorite-like colours.

    • Clark R. Chapman
  • News Feature |

    Like any other field, research on climate change has some fundamental gaps, although not the ones typically claimed by sceptics. Quirin Schiermeier takes a hard look at some of the biggest problem areas.

    • Quirin Schiermeier
  • Letter |

    The close binary Algol system contains a radio-bright KIV sub-giant star in a very close and rapid orbit with a main sequence B8 star. Evidence points to the existence of an extended, complex coronal magnetosphere originating at the cooler K subgiant, but the detailed morphology of the subgiant's corona and its possible interaction with its companion are unknown. Multi-epoch radio imaging of the Algol system now reveals a large coronal loop suggestive of a persistent asymmetric magnetic field structure aligned between the two stars.

    • W. M. Peterson
    • , R. L. Mutel
    •  & W. M. Goss
  • Letter |

    The properties of 'dwarf' galaxies have long challenged the cold dark matter (CDM) model of galaxy formation, as the properties of most observed dwarf galaxies contrast with models based on the dominance of CDM. Here, hydrodynamical simulations (assuming the presence of CDM) are reported in which the analogues of dwarf galaxies — bulgeless and with shallow central dark-matter profiles — arise naturally.

    • F. Governato
    • , C. Brook
    •  & P. Madau
  • Letter |

    Phytochromes regulate numerous photoresponses in plants and microorganisms through their ability to photointerconvert between a red-light-absorbing, ground state (Pf) and a far-red-light-absorbing, photoactivated state (Pfr). The structures of several phytochromes as Pf have been determined previously; here, the three-dimensional solution structure of the bilin-binding domain as Pfr is described. The results shed light on the structural basis for photoconversion to the activated Pfr form.

    • Andrew T. Ulijasz
    • , Gabriel Cornilescu
    •  & Richard D. Vierstra
  • Editorial |

    Manufacturers of computer systems should welcome researchers' efforts to find flaws.

  • News & Views |

    Windy weather is forecast where stars are forming. Numerical simulations show that these winds can reshape dwarf galaxies, reconciling their properties with the prevailing theory of galaxy formation.

    • Marla Geha
  • News |

    Collaboration launches effort to track marine nutrients.

    • Mark Schrope
  • Letter |

    The amplitude of the magnetic field near the Galactic Centre has been uncertain by two orders of magnitude for several decades. A compilation of previous data now reveals a downward break in the region's non-thermal radio spectrum; this requires that the Galactic Centre field be at least ∼50 microgauss on 400 parsec scales, with evidence supporting a field of 100 microgauss. This would imply that over 10% of the Galaxy's magnetic energy is contained in only around 0.05% (or less) of its volume.

    • Roland M. Crocker
    • , David I. Jones
    •  & Raymond J. Protheroe
  • Letter |

    From earthquakes to hard drives, frictional motion and its strength are involved in a wide range of phenomena. The strength of an interface that divides two sliding bodies is determined by both the real contact area and the contacts' shear strength. By continuous measurements of the concurrent local evolution of the real contact area and the corresponding interface motion from the first microseconds when contact detachment occurs, frictional strength is now characterized from short to long timescales.

    • Oded Ben-David
    • , Shmuel M. Rubinstein
    •  & Jay Fineberg
  • Letter |

    The Dirac equation successfully merges quantum mechanics with special relativity. It predicts some peculiar effects such as 'Zitterbewegung', an unexpected quivering motion of a free relativistic quantum particle. This and other predicted phenomena are key fundamental examples for understanding relativistic quantum effects, but are difficult to observe in real particles. Here, using a single trapped ion set to behave as a free relativistic quantum particle, a quantum simulation of the one-dimensional Dirac equation is demonstrated.

    • R. Gerritsma
    • , G. Kirchmair
    •  & C. F. Roos
  • Letter |

    Existing models of type Ia supernovae generally explain their observed properties, with the exception of the sub-luminous 1991bg-like supernovae. It has long been suspected that the merger of two white dwarfs could give rise to a type Ia event, but simulations so far have failed to produce an explosion. Here, a simulation of the merger of two equal-mass white dwarfs is presented that leads to a sub-luminous explosion; it requires a single common-envelope phase and component masses of about 0.9 solar masses.

    • Rüdiger Pakmor
    • , Markus Kromer
    •  & Wolfgang Hillebrandt