There is, I think, something ethereal about i —the square root of minus one. I remember first hearing about it at school. It seemed an odd beast at that time—an intruder hovering on the edge of reality.

Usually familiarity dulls this sense of the bizarre, but in the case of i it was the reverse: over the years the sense of its surreal nature intensified. It seemed that it was impossible to write mathematics that described the real world in …

I and i

Deposits of clastic carbonate-dominated (calciclastic) sedimentary slope systems in the rock record have been identified mostly as linearly-consistent carbonate apron deposits, even though most ancient clastic carbonate slope deposits fit the submarine fan systems better. Calciclastic submarine fans are consequently rarely described and are poorly understood. Subsequently, very little is known especially in mud-dominated calciclastic submarine fan systems. Presented in this study are a sedimentological core and petrographic characterisation of samples from eleven boreholes from the Lower Carboniferous of Bowland Basin (Northwest England) that reveals a >250 m thick calciturbidite complex deposited in a calciclastic submarine fan setting. Seven facies are recognised from core and thin section characterisation and are grouped into three carbonate turbidite sequences. They include: 1) Calciturbidites, comprising mostly of highto low-density, wavy-laminated bioclast-rich facies; 2) low-density densite mudstones which are characterised by planar laminated and unlaminated muddominated facies; and 3) Calcidebrites which are muddy or hyper-concentrated debrisflow deposits occurring as poorly-sorted, chaotic, mud-supported floatstones. These

Phd by thesis

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 $1.0 \times 10^{-21}$. 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 5.1 {\sigma}. The source lies at a luminosity distance of $410^{+160}_{-180}$ Mpc corresponding to a redshift $z = 0.09^{+0.03}_{-0.04}$. In the source frame, the initial black hole masses are $36^{+5}_{-4} M_\odot$ and $29^{+4}_{-4} M_\odot$, and the final black hole mass is $62^{+4}_{-4} M_\odot$, with $3.0^{+0.5}_{-0.5} M_\odot c^2$ 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.

https://physics.aps.org/featured-article-pdf/10.1103/PhysRevLett.116.061102

Observation of Gravitational Waves from a Binary Black Hole Merger

Quantum networks provide opportunities and challenges across a range of intellectual and technical frontiers, including quantum computation, communication and metrology. The realization of quantum networks composed of many nodes and channels requires new scientific capabilities for generating and characterizing quantum coherence and entanglement. Fundamental to this endeavour are quantum interconnects, which convert quantum states from one physical system to those of another in a reversible manner. Such quantum connectivity in networks can be achieved by the optical interactions of single photons and atoms, allowing the distribution of entanglement across the network and the teleportation of quantum states between nodes.

The quantum internet

Meeting the Universe Halfway is an ambitious book with far-reaching implications for numerous fields in the natural sciences, social sciences, and humanities. In this volume, Karen Barad, theoretical physicist and feminist theorist, elaborates her theory of agential realism. Offering an account of the world as a whole rather than as composed of separate natural and social realms, agential realism is at once a new epistemology, ontology, and ethics. The starting point for Barad’s analysis is the philosophical framework of quantum physicist Niels Bohr. Barad extends and partially revises Bohr’s philosophical views in light of current scholarship in physics, science studies, and the philosophy of science as well as feminist, poststructuralist, and other critical social theories. In the process, she significantly reworks understandings of space, time, matter, causality, agency, subjectivity, and objectivity.

In an agential realist account, the world is made of entanglements of “social” and “natural” agencies, where the distinction between the two emerges out of specific intra-actions. Intra-activity is an inexhaustible dynamism that configures and reconfigures relations of space-time-matter. In explaining intra-activity, Barad reveals questions about how nature and culture interact and change over time to be fundamentally misguided. And she reframes understanding of the nature of scientific and political practices and their “interrelationship.” Thus she pays particular attention to the responsible practice of science, and she emphasizes changes in the understanding of political practices, critically reworking Judith Butler’s influential theory of performativity. Finally, Barad uses agential realism to produce a new interpretation of quantum physics, demonstrating that agential realism is more than a means of reflecting on science; it can be used to actually do science.

Meeting the Universe Halfway: Quantum Physics and the Entanglement of Matter and Meaning

Ymipulstmg circulnr Rydberg atoms one by one i n a microwave superconducting cavity is a universal tool to generate entanglement. Two separated atom8 have heen prepared in an EPR statell] by using the resonant interaction with a single photon[Z]. In the non-resonant regime, we prepare quantum supelpositions involving coherent field states with different phases. Those sulmpositions can he considered as small laboratory versions of the famous Schrdingor cat coherently suspended between life and death. The progressive decoherence of these states has been observed, sheding light on the elusive quantum--classical boundary. The setup can also be turned into simple quantum information processing devices such as elementary quantum memarie [4], or quantum gates. By cumbininpng these various elements, i t become feasible to prepare Fock states of the cavity field containing up to 4 photoria 151. The realizahan of s controlled-Not gate will provide an extremely sensitive tool to perform an ideal QND measurement of the photon number in the cavity [6] as well as to charactewe completely the cavity field by measurement of the Wigner distribution [7]. I t also opens the w&y to the generationnew entanghi states involving either 3 atoms or t m different fields stored in two different cavities mildng together the strangeness of Schriidinger's ear. m t h the one af non-locality

Quantum Electrodynamic Shifts of Rydberg Energy Levels

Laser-induced fluorescence study of the reactions of fluorine atoms with iodomethane and iodotrifluoromethane

http://ieeexplore.ieee.org/iel5/8035/22193/01034344.pdf

Role of the Absolutephase in Photoionization with Fewcycle Laser Pulses

Multiple-charged optical vortex solitons (OVSs) are generated in a thermal nonlinear medium with saturation. The respective soliton constants are found to be linearly proportional to the topological charges. The linear stability analysis and the numerical simulations indicate a rich variety of instability scenaria depending on the type of perturbation. The saturation of the nonlinearity is shown to be able to slow down the decay of multiple charged dark beams at an intermediate evolution stage and to prevent their ultimate decay into charge-one OVSs. This concept is experimentally verified by the experimental observation of a partial decay of a triple- charged optical vortex beam.

/pdf/multiple-charged-optical-vortex-solitons-existence-and-1nciqkzapk.pdf

Multiple-charged optical vortex solitons: existence and stability in saturable Kerr-type nonlinear media

Surface scattering experiments with atomic or molecular beams yield important information on the dynamics of adsorption, desorption and chemical reactions at solid surfaces. As long as only atoms are involved the measurement of the angular distribution and momentum change of the scattered particles provide sufficient insight in the scattering dynamics. However, when molecules are scattered additional information on the change of internal energy is necessary. Recently the possibility to probe the internal state distribution of molecules with high sensitivity by the use of laser light has been successfully used in a number of surface scattering experiments [1–14]. Applying the laser-induced-fluorescence or the multiphoton-ionization technique, these studies have so far mainly concentrated on the determination of rotational state distributions of molecules scattered or desorbed from solid surfaces. In most cases the state populations of molecules leaving the surfaces can formally be described by a Boltzmann distribution with a rotational temperature Trot. However, the rotational temperature is frequently smaller than the surface temperature, even if the molecules had a very long residence time (≧ 10−4 s) on the surface.

Herbert Walther

Papers

Quantum Electrodynamic Shifts of Rydberg Energy Levels

Laser-induced fluorescence study of the reactions of fluorine atoms with iodomethane and iodotrifluoromethane

Role of the Absolutephase in Photoionization with Fewcycle Laser Pulses

Multiple-charged optical vortex solitons: existence and stability in saturable Kerr-type nonlinear media

Scattering of NO Molecules from Surfaces