Treasure in Heaven: Economics and Christian Monasticism in Late Antiquity

In the 3rd century CE a new variety of Christian practice emerged to popularity that took a marked turn from traditional practice. It was an ascetic movement that led many people to deny themselves bodily pleasures, and even some to self-inflict pain. There were some who chose to live a solitary life in the desert or in caves, and others lived in monasteries or isolated on top of stone pillars. This movement encouraged individuals to sell all of their belongings and rely on others\u27 charity, or even God\u27s grace, to survive. While asceticism had previously existed in other cultures and religions, it did not exist on any large scale in Christianity for the first 200 years. But once it arrived on the scene, it developed rapidly and became uncontrollably popular. It was formalized as monastic practice and the practitioners were called monks

What has Athens to do with Mormonism?

In his lecture, Terryl Givens presents one with a new way to approach the prophecy of Enoch that was received by Joseph Smith. Contained in this short narrative is a new, innovative conception about God that differs greatly from traditional Christianity. This notion is that of a passible deity, a God that is susceptible to feeling and emotion. It is a God who weeps, a God who is vulnerable and suffers emotional pain. God, as defined by the Christian creeds, is one who lacks passions.1 Givens, in drawing attention to the passible deity, is illuminating just a small portion of a much larger tension that exists between Mormonism and traditional Christianity. The God of Mormonism is not just a slight modification of the God of the creeds. Traditionally Christians, who now will be referred to as orthodox, have endorsed a view of deity that is more or less in line with the God of Classical Theism, or the God of the philosophers. However, the difference between these two conceptions of God is much greater than this one attribute. The God of Mormonism has undergone such a vast transformation from the God of Classical Theism that it no longer resembles its predecessor. In this essay, I’m arguing that the God of Mormonism is not only different than the God of orthodox Christianity in terms of passibility, but is different in every other major characteristic

Ion Acceleration by Short Chirped Laser Pulses

Direct laser acceleration of ions by short frequency-chirped laser pulses is investigated theoretically. We demonstrate that intense beams of ions with a kinetic energy broadening of about 1 % can be generated. The chirping of the laser pulse allows the particles to gain kinetic energies of hundreds of MeVs, which is required for hadron cancer therapy, from pulses of energies of the order of 100 J. It is shown that few-cycle chirped pulses can accelerate ions more efficiently than long ones, i.e. higher ion kinetic energies are reached with the same amount of total electromagnetic pulse energy

Space Station Rapid Sample Return Revisited

Rapid feedback of experiment results helps investigators to fine tune experiments, shorten experiment cycle times, and reduce development costs for new products. A rapid sample return (RSR) system was studied early in the Phase B Space Station Preliminary Design effort as a means of providing rapid feedback to increase station experimental productivity and reduce mission costs. However sufficient justification for baselining a RSR concept was not found. RSR was deemed nonessential because the Space Station would be serviced by a NSTS flight every 45 days and the design included thorough onboard analytical capabilities. Efforts at cost reduction have since reduced habitable station volume by 50%, combining separate life science and materials science modules into a single U.S. Laboratory (USL) module. Volume allocated for USL analytical instrumentation was reduced as a result. This decrease in onboard instrumentation has since been followed by a substantial reduction of NSTS station support flights

High-quality multi-GeV electron bunches via cyclotron autoresonance

Autoresonance laser acceleration of electrons is theoretically investigated using circularly polarized focused Gaussian pulses. Many-particle simulations demonstrate feasibility of creating over 10-GeV electron bunches of ultra-high quality (relative energy spread of order 10^-4), suitable for fundamental high-energy particle physics research. The laser peak intensities and axial magnetic field strengths required are up to about 10^18 W/cm^2 (peak power ~10 PW) and 60 T, respectively. Gains exceeding 100 GeV are shown to be possible when weakly focused pulses from a 200-PW laser facility are used

Dense monoenergetic proton beams from chirped laser-plasma interaction

Interaction of a frequency-chirped laser pulse with single protons and a hydrogen plasma cell is studied analytically and by means of particle-in-cell simulations, respectively. Feasibility of generating ultra-intense (10^7 particles per bunch) and phase-space collimated beams of protons (energy spread of about 1 %) is demonstrated. Phase synchronization of the protons and the laser field, guaranteed by the appropriate chirping of the laser pulse, allows the particles to gain sufficient kinetic energy (around 250 MeV) required for such applications as hadron cancer therapy, from state-of-the-art laser systems of intensities of the order of 10^21 W/cm^2.Comment: 5 pages, 4 figure

Intense high-quality medical proton beams via laser fields

During the past decade, the interaction of high-intensity lasers with solid targets has attracted much interest, regarding its potential in accelerating charged particles. In spite of tremendous progress in laser-plasma based acceleration, it is still not clear which particle beam quality will be accessible within the upcoming multi petawatt (1 PW = 10$^{15}$ W) laser generation. Here, we show with simulations based on the coupled relativistic equations of motion that protons stemming from laser-plasma processes can be efficiently post-accelerated using crossed laser beams focused to spot radii of a few laser wavelengths. We demonstrate that the crossed beams produce monoenergetic accelerated protons with kinetic energies $> 200$ MeV, small energy spreads ($\approx$ 1$$) and high densities as required for hadron cancer therapy. To our knowledge, this is the first scheme allowing for this important application based on an all-optical set-up.Comment: 14 pages, 3 figures, 1 tabl