39,623 research outputs found
World prehistory from the margins: the role of coastlines in human evolution
Conventional accounts of world prehistory are dominated by land-based narratives progressing from scavenging and hunting of land mammals and gathering of plants to animal domestication and crop agriculture, and ultimately to urban civilisations supported by agricultural surpluses and trade. The use of coastlines and marine resources has been viewed as marginal, late in the sequence, or anomalous. This bias is primarily the result of three factors: the removal of most relevant evidence by sealevel change; the bad press given to coastal hunters and gatherers by 19th century ethnographers; and a belief in technological 'primitivism'. In this paper I will examine the case for treating coastal habitats as amongst the most attractive for human settlement, and coastlines and seaways not as barriers but as gateways to human movement and contact, from early hominid dispersals to the rise of the great coastal and riverine civilisations
Lorentz Violation and Gravity
In the last decade, a variety of high-precision experiments have searched for
miniscule violations of Lorentz symmetry. These searches are largely motivated
by the possibility of uncovering experimental signatures from a fundamental
unified theory. Experimental results are reported in the framework called the
Standard-Model Extension (SME), which describes general Lorentz violation for
each particle species in terms of its coefficients for Lorentz violation.
Recently, the role of gravitational experiments in probing the SME has been
explored in the literature. In this talk, I will summarize theoretical and
experimental aspects of these works. I will also discuss recent lunar laser
ranging and atom interferometer experiments, which place stringent constraints
on gravity coefficients for Lorentz violation.Comment: 5 pages, presented at the IAU Symposium No. 261: Relativity in
Fundamental Astronomy, Virginia Beach, VA, May 200
Exploring where Designers and Non-Designers meet within the Service Organisation: Considering the value designers bring to the service design process
Service design is sometimes thought of as the interface between the customer and the service provider, a design process that exists between design thinking and business practices. Service design consultancies working with service organisations are increasingly attempting to develop design thinking alongside business processes within the organisation, but if everyone becomes a ‘designer’ what value is placed on the design-trained service designer? What qualities, knowledge and skills does a designer offer that identifies them as a valuable business asset who has an integral place within the business process, rather than as someone brought in when the organisation wants to be seen to be ‘creative’ or ‘innovative.’ The process of design for services is well documented, however there is not much debate around whether the service designer needs to be design-trained, or of what benefits they would offer if they were. It is assumed that design tools and methods can be introduced and disseminated to non-designers, but if tools and methods are all it took to design services, what is the future for the ‘designer?’ From observations of students studying service design at postgraduate level and a comparative study with design and non-design staff within a service organisation, this paper aims to uncover the value and ‘craft’ of the designer within the context of the service design process
Gravity Couplings in the Standard-Model Extension
The Standard-Model Extension (SME) is an action-based expansion describing
general Lorentz violation for known matter and fields, including gravity. In
this talk, I will discuss the Lorentz-violating gravity couplings in the SME.
Toy models that match the SME expansion, including vector and two-tensor
models, are reviewed. Finally I discuss the status of experiments and
observations probing gravity coefficients for Lorentz violation.Comment: 5 pages, Presented at the Fifth Meeting on CPT and Lorentz Symmetry,
Bloomington, Indiana, June 28-July 2, 201
Lorentz-Violating Electromagnetostatics
In this talk, the stationary limit of Lorentz-violating electrodynamics is
discussed. As illustrated by some simple examples, the general solution
includes unconventional mixing of electrostatic and magnetostatic effects. I
discuss a high-sensitivity null-type measurement, exploiting Lorentz-violating
electromagnetostatic effects, that could improve existing limits on parity-odd
coefficients for Lorentz violation in the photon sector.Comment: 6 pages, presented at the Third Meeting on CPT and Lorentz Symmetry,
Bloomington, Indiana, August 200
Testing Lorentz Symmetry with Gravity
In this talk, results from the gravitational sector of the Standard-Model
Extension (SME) are discussed. The weak-field phenomenology of the resulting
modified gravitational field equations is explored. The application of the
results to a variety of modern gravity experiments, including lunar laser
ranging, Gravity Probe B, binary pulsars, and Earth-laboratory tests, shows
promising sensitivity to gravitational coefficients for Lorentz violation in
the SME.Comment: 7 pages, presented at the Fourth Meeting on CPT and Lorentz Symmetry,
Bloomington, Indiana, August 200
Integrating IR detector imaging systems
An integrating IR detector array for imaging is provided in a hybrid circuit with InSb mesa diodes in a linear array, a single J-FET preamplifier for readout, and a silicon integrated circuit multiplexer. Thin film conductors in a fan out pattern deposited on an Al2O3 substrate connect the diodes to the multiplexer, and thick film conductors also connect the reset switch and preamplifier to the multiplexer. Two phase clock pulses are applied with a logic return signal to the multiplexer through triax comprised of three thin film conductors deposited between layers. A lens focuses a scanned image onto the diode array for horizontal read out while a scanning mirror provides vertical scan
Lorentz-violating gravitoelectromagnetism
The well-known analogy between a special limit of General Relativity and
electromagnetism is explored in the context of the Lorentz-violating
Standard-Model Extension (SME). An analogy is developed for the minimal SME
that connects a limit of the CPT-even component of the electromagnetic sector
to the gravitational sector. We show that components of the post-newtonian
metric can be directly obtained from solutions to the electromagnetic sector.
The method is illustrated with specific examples including static and rotating
sources. Some unconventional effects that arise for Lorentz-violating
electrostatics and magnetostatics have an analog in Lorentz-violating
post-newtonian gravity. In particular, we show that even for static sources,
gravitomagnetic fields arise in the presence of Lorentz violation.Comment: 11 pages, 2 color figures, version accepted in Physical Review
Magnetic Matrix Memory System-Patent
Magnetic matrix memory system for nondestructive reading of information contained in matri
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