A semantic ‘engine’ for universal translation

Having dedicated prior research to identifying a range of methods for detecting the hierarchical layers of language, which also incorporates unsupervised learning toolkits and a Corpus that represents the entire ‘Human Chorus’, this paper outlines the concepts behind providing the last piece in the jigsaw. This particular piece, which ultimately will provide the ability to decipher meaning without an exhaustive crib or primer, poses the perplexing problem of dealing with the seemingly arbitrary nature of this linguistic ‘veneer’. Techniques that, if perfected, will also have a profound impact on developing a universal translator for everyday translation issues and cryptopalaeography.     

Improvements in the re-flight of spaceflight experiments on plant tropisms

In order to effectively study phototropism, the directed growth in response to light, we performed a series of experiments in microgravity to better understand light response without the “complications” of a 1-g stimulus. These experiments were named TROPI (for tropisms) and were performed on the European Modular Cultivation System (EMCS), a laboratory facility on the International Space Station (ISS). TROPI-1 was performed in 2006, and while it was a successful experiment, there were a number of technical difficulties. We had the opportunity to perform TROPI-2 in 2010 and were able to optimize experimental conditions as well as to extend the studies of phototropism to fractional gravity created by the EMCS centrifuge. This paper focuses on how the technical improvements in TROPI-2 allowed for a better experiment with increased scientific return. Major modifications in TROPI-2 compared to TROPI-1 included the use of spaceflight hardware that was off-gassed for a longer period and reduced seed storage (less than 2 months) in hardware. These changes resulted in increased seed germination and more vigorous growth of seedlings. While phototropism in response to red illumination was observed in hypocotyls of seedlings grown in microgravity during TROPI-1, there was a greater magnitude of red-light-based phototropic curvature in TROPI-2. Direct downlinking of digital images from the ISS in TROPI-2, rather than the use of analog tapes in TROPI-1, resulted in better quality images and simplified data analyses. In TROPI-2, improved cryo-procedures and the use of the GLACIER freezer during transport of samples back to Earth maintained the low temperature necessary to obtain good-quality RNA required for use in gene profiling studies.     

Iron: Whence it came,where it went

Determinations of the abundances of iron and related elements in the photosphere, chromosphere and corona of the Sun and in solar and galactic cosmic rays are reviewed and compared with abundances derived from meteoritic data. Observed Solar System abundances are found to be in accord with predictions of nucleosynthesis under either hydrostatic or explosive conditions but cannot yet be used to define these processes uniquely.Distribution of iron among planets and meteorites can probably be adequately modelled by condensation and fractionation under equilibrium conditions above about 700 K but below that temperature it is likely that inhibited solid state diffusion perturbed attainment of equilibrium. Pertinent factors which are presently unknown include the mechanism responsible for metal-silicate fractionation, the grain size achieved by metallic iron in the nebula and whether iron-bearing silicate formed prior to accretion.Dedicated to Professor Harold C. UreyPublication Number 1560-Institute of Geophysics and Planetary Physics, University of California, Los Angeles.     

EXOSAT observations of the contact binary VW Cephei

EXOSAT observations of the contact binary VW Cephei on 19th March 1984 are presented. The L1-telescope with CMA+thick Lexan filter was used. The observations cover one orbital revolution showing an asymmetrical X-ray light curve. This can be modelled by an active neck, connecting the two stars, and with enhanced coronal regions on the primary star. Nearly simultaneous IUE observations are also presented. The observations form a part of the program to observe contact binaries with EXOSAT.     

Status of space commercialization in the USA

This article considers the status of space commercialization in the USA and suggests that recent developments present a pessimistic picture. What progress there has been is in settling in for the long-run task of building the research base and infrastructure required for the realization of space-based commercial activities.     

Fields and plasmas in the outer solar system

The most significant information about fields and plasmas in the outer solar system, based on observations by Pioneer 10 and 11 investigations, is reviewed. The characteristic evolution of solar wind streams beyond 1 AU has been observed. The region within which the velocity increases continuously near 1 AU is replaced at larger distances by a thick interaction region with abrupt jumps in the solar wind speed at the leading and trailing edges. These abrupt increases, accompanied by corresponding jumps in the field magnitude and in the solar wind density and temperature, consist typically of a forward and a reverse shock. The existence of two distinct corotating regions, separated by sharp boundaries, is a characteristic feature of the interplanetary medium in the outer solar system. Within the interaction regions, compression effects are dominant and the field strength, plasma density, plasma temperature and the level of fluctuations are enhanced. Within the intervening quiet regions, rarefaction effects dominate and the field magnitude, solar wind density and fluctuation level are very low. These changes in the structure of interplanetary space have significant consequences for the many energetic particles propagating through the medium. The interaction regions control the access to the inner solar system of relativistic electrons from Jupiter's magnetosphere. The interaction regions and shocks appear to be associated with an acceleration of solar protons to MeV energies. Flare-generated shocks are observed to be propagating through the outer solar system with constant speed, implying that the previously recognized deceleration of flare shocks takes place principally near the Sun. Radial gradients in the solar wind and interplanetary field parameters have been determined. The solar wind speed is nearly constant between 1 and 5 AU with only a slight deceleration of 30 km s⁺¹ on the average. The proton flux follows an r ⁺² dependence reasonably well, however, the proton density shows a larger departure from this dependence. The proton temperature decreases steadily from 1 to 5 AU and the solar wind protons are slightly hotter than anticipated for an adiabatic expansion. The radial component of the interplanetary field falls off like r ⁺² and, on the average, the magnitude and spiral angle also agree reasonably well with theory. However, there is evidence, principally within quiet regions, of a significant departure of the azimuthal field component and the field magnitude from simple theoretical models. Pioneer 11 has obtained information up to heliographic latitudes of 16°. Observations of the interplanetary sector structure show that the polarity of the field becomes gradually more positive, corresponding to outward-directed fields at the Sun, and at the highest latitudes the sector structure disappears. These results confirm a prior suspicion that magnetic sectors are associated with an interplanetary current sheet surrounding the Sun which is inclined slightly to the solar equator.Proceedings of the Symposium on Solar Terrestrial Physics held in Innsbruck, May–June 1978.     

The Magnetometer Instrument on MESSENGER

The Magnetometer (MAG) on the MErcury Surface, Space ENvironment, GEochemistry, and Ranging (MESSENGER) mission is a low-noise, tri-axial, fluxgate instrument with its sensor mounted on a 3.6-m-long boom. The boom was deployed on March 8, 2005. The primary MAG science objectives are to determine the structure of Mercury’s intrinsic magnetic field and infer its origin. Mariner 10 observations indicate a planetary moment in the range 170 to 350 nT R _M³ (where R _M is Mercury’s mean radius). The uncertainties in the dipole moment are associated with the Mariner 10 trajectory and variability of the measured field. By orbiting Mercury, MESSENGER will significantly improve the determination of dipole and higher-order moments. The latter are essential to understanding the thermal history of the planet. MAG has a coarse range, ±51,300 nT full scale (1.6-nT resolution), for pre-flight testing, and a fine range, ±1,530 nT full scale (0.047-nT resolution), for Mercury operation. A magnetic cleanliness program was followed to minimize variable and static spacecraft-generated fields at the sensor. Observations during and after boom deployment indicate that the fixed residual field is less than a few nT at the location of the sensor, and initial observations indicate that the variable field is below 0.05 nT at least above about 3 Hz. Analog signals from the three axes are low-pass filtered (10-Hz cutoff) and sampled simultaneously by three 20-bit analog-to-digital converters every 50 ms. To accommodate variable telemetry rates, MAG provides 11 output rates from 0.01 s⁻¹ to 20 s⁻¹. Continuous measurement of fluctuations is provided with a digital 1–10 Hz bandpass filter. This fluctuation level is used to trigger high-time-resolution sampling in eight-minute segments to record events of interest when continuous high-rate sampling is not possible. The MAG instrument will provide accurate characterization of the intrinsic planetary field, magnetospheric structure, and dynamics of Mercury’s solar wind interaction.     

Effect of variable solid phase thermal properties on propellant combustion

Mathematical models derived for describing the combustion of solid rocket propellants have in the past assumed that the thermal properties, specific heat, and thermal conductivity are constant throughout the solid phase portion of the combustion zone. The values for specific heat and thermal conductivity can vary as much as 50–100 percent for the temperatures in the solid phase combustion wave, values from about 250 to 1100 K. Thus, the variation in solid phase properties due to the temperature variation in the solid phase have significant effects on the burning rate, the temperature sensitivity and the pressure coupled response. The paper is concerned with predicting the effect of the variable solid phase properties on the combustion properties. Parametric calculations were made to illustrate the effect of the magnitude of the variation of solid phase properties with temperature. The results indicate that significant differences exist between the values for the combustion parameters calculated using variable thermal properties as compared to those calculated using constant thermal properties.     

Turning space tourism into commercial reality

On 7 June 2006 the Royal Aeronautical Society (RAeS) hosted a one-day conference entitled ‘Space Tourism: From Lofty Dreams to Commercial Reality’ in London. The conference brought together parties interested in the future of passenger flights into space, presenting perspectives on the evolution of the private spaceflight industry over the next decade, with the goal of stimulating enthusiasm for the creation of a profitable industry and affordable space travel for a mass, global market. The conference chairman reports on its outcomes.