On September 14, 2015 at 09:50:45 UTC the two detectors of the Laser Interferometer Gravitational-Wave Observatory simultaneously observed a transient gravitational-wave signal. The signal sweeps upwards in frequency from 35 to 250 Hz with a peak gravitational-wave strain of 1.0×10(-21). It matches the waveform predicted by general relativity for the inspiral and merger of a pair of black holes and the ringdown of the resulting single black hole. The signal was observed with a matched-filter signal-to-noise ratio of 24 and a false alarm rate estimated to be less than 1 event per 203,000 years, equivalent to a significance greater than 5.1σ. The source lies at a luminosity distance of 410(-180)(+160)  Mpc corresponding to a redshift z=0.09(-0.04)(+0.03). In the source frame, the initial black hole masses are 36(-4)(+5)M⊙ and 29(-4)(+4)M⊙, and the final black hole mass is 62(-4)(+4)M⊙, with 3.0(-0.5)(+0.5)M⊙c(2) radiated in gravitational waves. All uncertainties define 90% credible intervals. These observations demonstrate the existence of binary stellar-mass black hole systems. This is the first direct detection of gravitational waves and the first observation of a binary black hole merger.

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The Observation of Gravitational Waves from a Binary Black Hole Merger

The task of quantizing general relativity raises serious questions about the meaning of the present formulation and interpretation of quantum mechanics when applied to so fundamental a structure as the space-time geometry itself. This paper seeks to clarify the foundations of quantum mechanics. It presents a reformulation of quantum theory in a form believed suitable for application to general relativity. The aim is not to deny or contradict the conventional formulation of quantum theory, which has demonstrated its usefulness in an overwhelming variety of problems, but rather to supply a new, more general and complete formulation, from which the conventional interpretation can be deduced. The relationship of this new formulation to the older formulation is therefore that of a metatheory to a theory, that is, it is an underlying theory in which the nature and consistency, as well as the realm of applicability, of the older theory can be investigated and clarified.

"relative State" Formulation of Quantum Mechanics

Terrestrial net primary production (NPP) quantifies the amount of atmospheric carbon fixed by plants and accumulated as biomass. Previous studies have shown that climate constraints were relaxing with increasing temperature and solar radiation, allowing an upward trend in NPP from 1982 through 1999. The past decade (2000 to 2009) has been the warmest since instrumental measurements began, which could imply continued increases in NPP; however, our estimates suggest a reduction in the global NPP of 0.55 petagrams of carbon. Large-scale droughts have reduced regional NPP, and a drying trend in the Southern Hemisphere has decreased NPP in that area, counteracting the increased NPP over the Northern Hemisphere. A continued decline in NPP would not only weaken the terrestrial carbon sink, but it would also intensify future competition between food demand and proposed biofuel production.

Drought-Induced Reduction in Global Terrestrial Net Primary Production from 2000 Through 2009

Annalen der Physik

A clutch of '-isms' characterises the approach to consciousness which David Chalmers defends: dualism, epiphenomenalism, functionalism, anti-reductionism, and -probably -panpsychism. (The author would no doubt want 'naturalism' included in the list as well, but as we shall see, Chalmers' predilection to describe his theory as 'scientific' stretches credibility.) While the book does not, as far as I can see, move consciousness research significantly forward, Chalmers succeeds admirably in clarifying the philosophical terrain around and within each of these '-isms' and in questioning the usual assumptions which suggest some of them are mutually exclusive. Because nearly all of what follows is highly critical, I want to be explicit about one thing: I do not think this is a bad book. Throughout, most discussions keep to a very high standard; it's just that they include fatal flaws.

The conscious mind: In search of a fundamental theory

1 Overview 2 The physics of coordinate transformations 3 The relativity principle and the fable of Albert Keinstein 4 The trailblazers 5 Einstein's principle-theory route to the Lorentz transformations 6 Variations on the Einstein theme 7 Unconventional voices on special relativity 8 What is special relativity? 9 The view from general relativity APPENDICES A Einstein on general covariance B Special relativity and quantum theory

Physical Relativity: Space-Time Structure from a Dynamical Perspective

It is argued that Minkowski space-time cannot serve as the deep structure within a “constructive” version of the special theory of relativity, contrary to widespread opinion in the philosophical community. This paper is dedicated to the memory of Jeeva Anandan.

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Minkowski space-time: A glorious non-entity

The quantum theory of de Broglie and Bohm solves the measurement problem, but the hypothetical corpuscles play no role in the argument. The solution finds a more natural home in the Everett interpretation.

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Solving the measurement problem: de Broglie-Bohm loses out to Everett

The Shaky Game: Einstein, Realism and the Quantum Theory

This paper investigates what the source of time-asymmetry is in thermodynamics, and comments on the question whether a time-symmetric formulation of the Second Law is possible.

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Harvey R. Brown

Papers

Physical Relativity: Space-Time Structure from a Dynamical Perspective

Minkowski space-time: A glorious non-entity

Solving the measurement problem: de Broglie-Bohm loses out to Everett

The Shaky Game: Einstein, Realism and the Quantum Theory

The Origins of Time-asymmetry in Thermodynamics: The Minus First Law