Amino acids on the rampant primordial Earth: Electric discharges and the hot salty ocean

For more than 50 years scientists who study prebiotic chemistry have been dealing with chemical evolution as it could have possibly taken place on the primordial Earth. Since we will never know what processes have really taken place around 3.8 to 4 billion years ago we can only come up with plausible reaction pathways that work well in an early Earth scenario as indicated by geochemists. In our work we have investigated the plausibility of one particularly important branch of prebiotic chemistry, the formation of amino acids, by electric discharge in a neutral atmosphere composed of carbon dioxide, nitrogen, and water vapour above liquid water. We have found yields of various amino acids under different temperature conditions, with and without sodium chloride in a simulated primordial lake or ocean within extremely short reaction times compared to the timespan available for prebiotic evolution.     

Sonochemistry on primordial Earth--its potential role in prebiotic molecular evolution

Sonochemical processes are known to occur in nature and have occurred ever since there was liquid water on Earth. We advance a hypothesis that complex carbonaceous compounds, the probable precursors of life, were produced from simple primordial molecules by sonochemical processes in breaking waves of primordial seas or oceans. Our calculations show that these processes were much more common on Earth than other pathways, suggested for the formation of prebiotic complex carbonaceous compounds. The high occurrence rate of sonochemical events in breaking sea waves and the qualitative difference between sonochemical processes and other shock phenomena might have enabled formation of a variety of complex carbonaceous compounds, including amino acids, nucleotides and nucleosides, the precursors of RNA or DNA.     

Prebiological evolution and the physics of the origin of life

The basic tenet of the heterotrophic theory of the origin of life is that the maintenance and reproduction of the first living systems depended primarily on prebiotically synthesized organic molecules. It is unlikely that any single mechanism can account for the wide range of organic compounds that may have accumulated on the primitive Earth, suggesting that the prebiotic soup was formed by contributions from endogenous syntheses in reducing environments, metal sulphide-mediated synthesis in deep-sea vents, and exogenous sources such as comets, meteorites and interplanetary dust. The wide range of experimental conditions under which amino acids and nucleobases can be synthesized suggests that the abiotic syntheses of these monomers did not take place under a narrow range defined by highly selective reaction conditions, but rather under a wide variety of settings. The robustness of this type of chemistry is supported by the occurrence of most of these biochemical compounds in the Murchison meteorite. These results lend strong credence to the hypothesis that the emergence of life was the outcome of a long, but not necessarily slow, evolutionary processes. The origin of life may be best understood in terms of the dynamics and evolution of sets of chemical replicating entities. Whether such entities were enclosed within membranes is not yet clear, but given the prebiotic availability of amphiphilic compounds this may have well been the case. This scheme is not at odds with the theoretical models of self-organized emerging systems, but what is known of biology suggest that the essential traits of living systems could have not emerged in the absence of genetic material able to store, express and, upon replication, transmit to its progeny information capable of undergoing evolutionary change. How such genetic polymer first evolved is a central issue in origin-of-life studies.     

The Correspondence of Isaac Newton,Volume V, 1709–1713, edited by A. Rupert Hall and L. Tilling

This report reviews the recent progress that has been made toward understanding the necessary-for-life chemistry that took place on the prebiotic Earth, and that led to the appearance of the ht living cells. This understanding is based on the simulation, in the laboratory, of conditions analogous to those presumed (on geological and astronomical evidence), to have been present on the primitive Earth. Such research has led to the production of many of the classes of compounds that are key constituents of our contemporary biology. It has also led to the knowledge that abiogenetically produced organic compounds have an intrinsic tendency to assume the forms and the aggregations that are found in living cells. The report concludes with a summary of the exciting new finds of ‘biological’ molecules in interstellar space.     

Eruptive events in the solar atmosphere: new insights from theory and 3-D numerical modelling

Ejections of magnetised plasma from the Sun, commonly known as coronal mass ejections (CMEs), are one of the most stunning manifestations of solar activity. These ejections play a leading role in the Sun–Earth connection, because of their large-scale, energetics and direct impact on the space environment near the Earth. As CMEs evolve in the solar corona and interplanetary space they drive shock waves, which act as powerful accelerators of charged particles in the inner solar system. Some of these particles, known as solar energetic particles (SEPs), can strike our planet, and in doing so they can disrupt satellites and knock out power systems on the ground, among other effects. These particles, along with the intensive X-ray radiation from solar flares, also endanger human life in outer space. That is why it is important for space scientists to understand and predict the ever changing environmental conditions in outer space due to solar eruptive events – the so-called space weather. To enable the development of accurate space weather forecast, in the past three decades solar scientists have been challenged to provide an improved understanding of the physical causes of the CME phenomenon and its numerous effects. This paper summarises the most recent advances from theory and modelling in understanding the origin and evolution of solar eruptive events and related phenomena.     

Constraint Closure Drove Major Transitions in the Origins of Life

Life is an epiphenomenon for which origins are of tremendous interest to explain. We provide a framework for doing so based on the thermodynamic concept of work cycles. These cycles can create their own closure events, and thereby provide a mechanism for engendering novelty. We note that three significant such events led to life as we know it on Earth: (1) the advent of collective autocatalytic sets (CASs) of small molecules; (2) the advent of CASs of reproducing informational polymers; and (3) the advent of CASs of polymerase replicases. Each step could occur only when the boundary conditions of the system fostered constraints that fundamentally changed the phase space. With the realization that these successive events are required for innovative forms of life, we may now be able to focus more clearly on the question of life’s abundance in the universe.     

Phantom energy: dark energy with w <--1 causes a cosmic doomsday

We explore the consequences that follow if the dark energy is phantom energy, in which the sum of the pressure and energy density is negative. The positive phantom-energy density becomes infinite in finite time, overcoming all other forms of matter, such that the gravitational repulsion rapidly brings our brief epoch of cosmic structure to a close. The phantom energy rips apart the Milky Way, solar system, Earth, and ultimately the molecules, atoms, nuclei, and nucleons of which we are composed, before the death of the Universe in a "big rip."     

寻找另一个地球

系外行星尤其是宜居行星的搜寻与刻画,是天文学研究的热点前沿问题。寻找另一个地球,是回答“生命如何起源?”,“人类是否孤独?”等重大科学问题的关键。文章结合理论和观测,对现有的行星形成演化理论和系外行星探测方法做了简要介绍,并说明现有的探测技术很难探测到“另一个地球”。此外,主流的探测方法,如视向速度法、凌星法,都是通过恒星变化探测行星,属于间接探测。未来的系外行星刻画需要直接获取来自行星的光子,因此直接成像是未来系外行星探测的趋势。合成孔径光干涉成像法可以同时实现高对比度和高空间分辨率,未来可用于对“另一个地球”的直接成像。中国提出的“觅音”计划,有望首次实现系外行星的光干涉成像,在寻找“另一个地球”上取得重大突破。     

Dust in the planetary system: Dust interactions in space plasmas of the solar system

Cosmic dust particles are small solid objects observed in the solar planetary system and in many astronomical objects like the surrounding of stars, the interstellar and even the intergalactic medium. In the solar system the dust is best observed and most often found within the region of the orbits of terrestrial planets where the dust interactions and dynamics are observed directly from spacecraft. Dust is observed in space near Earth and also enters the atmosphere of the Earth where it takes part in physical and chemical processes. Hence space offers a laboratory to study dust–plasma interactions and dust dynamics. A recent example is the observation of nanodust of sizes smaller than 10 nm. We outline the theoretical considerations on which our knowledge of dust electric charges in space plasmas are founded. We discuss the dynamics of the dust particles and show how the small charged particles are accelerated by the solar wind that carries a magnetic field. Finally, as examples for the space observation of cosmic dust interactions, we describe the first detection of fast nanodust in the solar wind near Earth orbit and the first bi-static observations of PMSE, the radar echoes that are observed in the Earth ionosphere in the presence of charged dust.     

Biomolecular self-assembly under extreme Martian mimetic conditions

The recent discovery of subsurface water on Mars has challenged our understanding of the natural limits of life. The presence of magnesium perchlorate (Mg(ClO₄)₂) on the Martian surface raises the possibility that it may also be present in this subsurface lake. Given that the subsurface lakes on Earth, such as Lake Vostok and Lake Whillans, are capable of harbouring surprising amounts of life, these new findings raise interesting possibilities for how biomolecules might self-assemble in this environment on Mars. Here we investigate the self-association and hydration of the amino acid glycine in aqueous Mg(ClO₄)₂ at 25°C and ?20°C using neutron diffraction with hydrogen isotope substitution and subsequent analysis with empirical potential structure refinement to yield a simulated box of atoms consistent with the scattering data. We find that although the highly chaotropic properties of Mg(ClO₄)₂ disrupt the hydration and hydrogen bonding ability of the amino acid, as well as the bulk water structure, glycine molecules are nonetheless still able to self-associate. This occurs more readily at lower temperature, where clusters of up to three molecules are observed, allowing us to speculate that the formation of biological molecules is possible in the Martian environment.     

Über die Ablenkung des Lichtes im Schwarzschild-Raum

On the Deflection of Light in Schwarzschild-Space A trigonometric approximation formula for the paths of light in Schwarzschild-Space is derived. A formula for the deflection angle at the Earth is given. Then we describe and calculate an experiment, where angles change the value by 1/2 · 1.75′ without a solar eclipse being necessary.     

Katz Fractal Dimension of Geoelectric Field during Severe Geomagnetic Storms

We are concerned with the time series resulting from the computed local horizontal geoelectric field, obtained with the aid of a 1-D layered Earth model based on local geomagnetic field measurements, for the full solar magnetic cycle of 1996–2019, covering the two consecutive solar activity cycles 23 and 24. To our best knowledge, for the first time, the roughness of severe geomagnetic storms is considered by using a monofractal time series analysis of the Earth electric field. We show that during severe geomagnetic storms the Katz fractal dimension of the geoelectric field grows rapidly.     

Experimental quantum simulation of Avian Compass in a nuclear magnetic resonance system

Avian magnetoreception is the capacity for avians to sense the direction of the Earth’s magnetic field. Discovered more than forty years ago, it has attracted intensive studies over the years. One promising model for describing this capacity in avians is the widely used reference-and-probe model where radical pairs within the eyes of bird combines to form singlet and triplet quantum states. The yield depends on the angle between the Earth’s magnetic field and the molecules’ axis, hence the relative value of yield of the singlet state or triplet state enables avians to sense the direction. Here we report the experimental demonstration of avian magnetoreception in a nuclear magnetic resonance quantum information processor. It is shown clearly from the experiment that the yield of the singlet state attains maximum when it is normal to the Earth’s magnetic field, and the experimental results agree with theory very well.     

Forecasting Earth's magnetopause, magnetosheath, and bow shock

The magnetopause and bow shock are two of the most important discontinuities in near Earth space, separating three distinct plasma regimes: the solar wind, magnetosheath, and the magnetosphere. Both discontinuities are sensitive to the solar wind conditions. They change their shape and location in space in response to upstream solar wind variations. Prediction of the location of a satellite relative to these two boundaries helps satellite operators to be prepared for major changes in plasma condition. The physical conditions near the magnetopause are useful information for magnetospheric models. Over the past decades, our observational knowledge and physical understanding of these regions have been advanced significantly. We have developed the capability of prediction. The location of the magnetopause and its dependence on the upstream conditions can be relatively accurately predicted. Prediction models have been tested extensively. The success rate is extremely high and the false-alarm rate is relatively low. A magnetosheath prediction model has been developed and tested. Some of the magnetosheath quantities can often be predicted fairly accurately. Others may have slightly larger errors. Further tests and scientific investigations of the causes of these errors are under way. Our ability to predict the location of the bow shock is very limited. More research is needed     

Terrestrial Seismic Activity and Neutrons from the Surface of the Earth Associated with Lunar and Solar Tides

drastic increase in the flux of thermal neutrons of secondary cosmic radiation coming from the Earth was observed in the Pamir Mountains during the solar eclipse of July 22, 1990. In the following years, such phenomena were observed on each new moon and each full moon, when lunar and solar tides combine to produce an exceptionally high resultant tide. Tidal forces may serve as a trigger for the release of the deepearth seismic energy in a certain region. This directed our attention to the search for a temporal correlation between earthquakes and new and full moons, which may help identify a new type of seismic activity precursor. Such a correlation was found in the circum-Pacific belt and the adjacent regions at latitudes above 40° N and 10° S. The results of daytime measurements of the thermal neutron flux from the surface of the Earth in the Western Pamirs (Moskvin Glade, 4200 m above sea level) on August 1–14, 1994, are reported in the present study. Since these days were quiet in terms of weather and heliophysical and geophysical activity, the intensity of neutrons of secondary cosmic radiation was expected to remain almost constant. However, twofold (or even larger) intraday variations of the neutron count rate were observed on August 1–14, 1994. These quiet measurement conditions rule out the possibility that these bursts were associated with certain known extraterrestrial factors. It has been demonstrated that the observed neutron-intensity peaks were produced by lunar and solar tides. These results confirm that tidal forces play a prominent part in the generation of neutron fluxes from the surface of the Earth. The Astronomical Yearbook for 1994 published by the Russian Academy of Sciences was used in the present study.     

Characterising dye-sensitised solar cells

In today's society there is a vast and in many cases not fully appreciated dependence on electrical power for everyday life. Furthermore, with growing energy and environmental concerns arising due to fossil fuel depletion and climate change/global warming, ever increasing attention is being given to alternative and/or renewable sources of energy such as biomass, hydropower, geothermal, wind and solar energy. Devices such as photovoltaic cells are therefore of enormous importance. The more widely used and commercially available silicon (semiconductor) based cells currently have the greatest reported efficiencies and have received considerable attention. However the manufacturing of these cells is complex and expensive due to the cost and difficulty of producing and processing pure silicon. One alternative technology being explored is the development of dye-sensitised solar cells (DSSCs) or Grätzel cells. In this paper we report on our current work to develop simple test equipment and optoelectronic models describing the performance and behaviours of DSSCs. We describe some of the background to our work and also some of our initial experimental results. Based on these results we aim to characterise the opto-electrical properties and bulk characteristics of simple dye-sensitised solar cells and then to proceed to test new cell compositions.     

Evolution of protein synthesis in a lattice model of replicators

The traditional chemical-kinetics approach to the study of prebiotic evolution cannot explain the evolution of protein synthesis in a homogeneous population of self-replicating molecules, because the invasion of a resident population of simpler, template-directed replicators by mutant protein-assisted replicators is deemed impossible. Approaching this problem in a spatial cellular automaton framework, we argue here that in such a setting evolution of protein synthesis is a likely event. In addition, we show that the onset of invasion may be viewed as a nonequilibrium phase transition, that can be characterized quantitatively by a set of critical exponents.     

On the fictitious nonlinearity of the surface impedance of the Earth’s crust

The observations of Alfvén oscillations of the magnetosphere are used to study the Earth’s crust and upper mantle by the magnetotelluric sounding method. The sounding procedure involves the measurement of the horizontal components of the electromagnetic field at a given point on the ground, the calculation of the surface impedance, and the determination of the conductivity of rocks from these data. It has been shown that the anharmonicity of the oscillations of the magnetosphere in combination with the nonlocality of the boundary condition on the ground gives rise to the amplitude dependence of the impedance calculated using the classical magnetotelluric sounding method. This apparent nonlinearity of the impedance can be manifested in the sounding of the Earth’s interior with intense electromagnetic pulsations, which appear when the Earth’s magnetosphere is embedded in the highspeed solar wind flow.     

Electrospray deposition in vacuum

We have used the established technique of electrospray in developing a portable vacuum electrospray system which can deposit, in vacuo, dissolved molecules onto a sample which may then be analysed by UHV techniques. As an initial test of the system we have analysed silicon samples with an electrosprayed layer of poly(ethylene) oxide (PEO) using atomic force microscopy (AFM). The polymer forms different structures depending on the voltage applied to the emitter, and solution composition. The system is part of our ongoing effort to deposit other materials such as nanoparticles, and large dye molecules for developing molecular dye sensitised solar cells.