Morphological and compositional evidence for biotic precipitation of marine barite

Barite formation in the surface oceans is generally assumed to be dominated by abiotic precipitation. Acceptance of this pathway is largely the result of the absence of a pelagic marine organism known to precipitate the ovoid to rounded-rectangular barite crystals typically observed in marine waters and sediments. Barite crystals observed in net-tow particles and on substrates retrieved from the seafloor (both in the central North Pacific) were examined by scanning electron microscopy and energy dispersive X-ray spectrometry. Three distinct crystalline forms of barite were observed: ovoid and hexagonal crystals several microns in diameter, and aggregates of submicron-sized crystals. Ovoid and hexagonal-type crystals contained between 0 and 26 mole percent SrSO4. The microcrystalline barite contained no detectable Sr (\u3c0.05 percent). Hexagonal-type crystals were precipitated by an unusual benthic foraminifera. Comparison of the morphology and composition of the barite crystals observed in this study to crystals precipitated by a variety of biotic and abiotic processes suggests a biotic origin for the ovoid barite crystals, the most common form of barite observed in this region

The influence of a changing bacterial community on trace metal scavenging in a deep-sea particle plume

An extensive set of particle samples was collected from the extended (nonbuoyant) hydrothermal plume, the distal remnant plume, and the adjacent waters in a transect across the Southern Juan de Fuca Ridge. Bacterial capsules comprised the primary species of particulate Mn. However, the data also showed significant shifts in the relative abundance of distinctive subpopulations of this bacterial community, as expressed by several consistently recurring capsule morphologies. The data are discussed with respect to distance from plume origins (relative plume age), total bacterial numbers, experimentally determined scavenging rate constants and total particulate and dissolved Mn. The relative distribution of one morph (Fibrous) corresponded (r = .825, p \u3c 0.001) to that of the scavenging rate constant, k1 (Cowen et al., 1990) for dissolved Mn onto particles. The greatest Mn deposits (by a factor of over 10×) were associated with this same morph, which was also the numerically dominant capsule morph at the off-axis stations where total particulate Mn plume values were highest. The disequilibrium in the particle population and the geochemical cycle of Mn in an evolving hydrothermal vent plume is reflected in the distribution coefficients for Mn (KD), which increase with distance from vent origins. The potential influence that changing subpopulations of bacteria may exert on the overall scavenging behavior of Mn in this evolving natural particle population is emphasized

P1_4 Starship UK, the Hardest of Brexits?

In this paper we estimated the amount of energy and mass of fuel required to move the landmass of the United Kingdom, including the crust down to a depth of 24 km, into a “stable” circular Low Earth Orbit. We also compared various launch vehicles in terms of how much they can carry to orbit, and thus how many would be required and how much this would cost. It was found that 5.17X 10^26 J of energy would be required, or  7.06X10^14 Falcon 9 launchers, %at a cost of\\ £2.69X 10^22,which would take 1.48 Tera-years to save for.

P1_8 Magcargo, I Don't Choose You!

In this paper we estimate the Basal Metabolic Rate (BMR) of Magcargo, the "Lava Pokemon" from the popular Pokemon video game series, and from there estimate the caloric intake necessary to maintain its extremely high internal temperature of 10, 000 C. We then calculate approximately how much heat energy a Magcargo would leak to its surroundings in the Pokemon world. It was found that it would have an impossibly high BMR of 3.94×10^733 W, which would require Magcargo to ingest 1.18×10^733 Calories each second. Additionally, it would emit thermal radiation with a Luminosiy of 1.27×10^9 W

P1_5 The View Of The Sun From Alien Worlds

In this paper, we estimate whether the planets of the Solar System would be detectable by a theoretical extraterrestrial civilisation with a level of technology similar to present day Earth. We found that Jupiter, Earth, and Venus could have been detected already, while Saturn, Uranus and Neptune would be detectable in the future. Mars and Mercury are considered undetectable

P1_6 "Let the old gods flow through me one last time!

This paper investigates whether the Bifrost, a magical beam of light that the Asguardians use to travel between realms, can act as a spaceship transporting the Hulk across space by looking at the time and energy required to send him back to Earth in Marvels; Infinity War. We calculated that at 0.999 c the Hulk would take 2.52 ± 0.14 million years with a kinetic energy of 1.01x1021 J and a total energy of 23.5x1021 J