Dark Ages Research Articles

Research on the Notation of French Guitar and Lute in the Renaissance and Baroque Periods

After the long and dark Middle Ages, Europe ushered in the Renaissance of ideological and cultural prosperity. Under the influence of humanism, secular music began to be valued and some church music also began to be secularized, and thus the guitar instrument ushered in its first heyday. With the development of instrumental music, a notation method, which is suitable for musical instruments, gradually began to appear, also known as "sign spectrum". Besides, guitar instruments use a lot of musical notation. Even in the baroque period when the staff is mature, some French lute and baroque guitar solo works still use this notation. This notation was recorded in different ways in various parts of Europe during the Renaissance and Baroque periods, but it can be roughly divided into Italian notation and French notation. This paper will focus on the analysis of French notation.

Pottery from Tell Khaiber: A Craft Tradition of the First Sealand Dynasty By Daniel Calderbank (Archaeology of Ancient Iraq 1). Ludlow: Moonrise Press 2021. Pp. xii + 282. £ 35. ISBN 978-1-910169-02-5 (cloth).

<i>Pottery from Tell Khaiber: A Craft Tradition of the First Sealand Dynasty</i> By Daniel Calderbank (Archaeology of Ancient Iraq 1). Ludlow: Moonrise Press 2021. Pp. xii + 282. £ 35. ISBN 978-1-910169-02-5 (cloth).

Moral Cosmopolitanism and the Challenge of Global Terrorism

The world is bedevilled by terrorism. Of the most recent treats and challenges that the world faces there seem to be none bigger than terrorism. There is hardly a week that passes when you do not hear of terrorist attacks in one place of the order. Terrorist attacks have been perpetuated in places like Syria, Iraq, Afghanistan, Nigeria, Somalia, Yemen, and Pakistan, the United States, Britain, Canada, France, Italy and so forth. The effects and impact of terrorism are incalculable. Thousands of lives and properties have been lost to terrorism. If terrorism is not mitigated or stopped it has the capacity to plunge the world into a new dark age. The paper examines the reality, effects, and causes of terrorism. It uses critical analytic and evaluative methods to examine terrorism from the lens of moral cosmopolitanism. The paper proposes that the idea of moral cosmopolitanism that affirms the common humanity of all humans and obligates each human to come to the help of others, even strangers can help to combat global terrorism. The paper finds that there is need to educate, conscientize, and persuade global terrorists with the value of moral cosmopolitanism. If this can be done it will greatly help in mitigating global terrorist attacks.

Antenna beam characterization for the global 21-cm experiment LEDA and its impact on signal model parameter reconstruction

ABSTRACT Cosmic dawn, the onset of star formation in the early universe, can in principle be studied via the 21-cm transition of neutral hydrogen, for which a sky-averaged absorption signal, redshifted to MHz frequencies, is predicted to be O(10–100) mK. Detection requires separation of the 21-cm signal from bright chromatic foreground emission due to Galactic structure, and the characterization of how it couples to instrumental response. In this work, we present characterization of antenna gain patterns for the Large-aperture Experiment to detect the Dark Ages (LEDA) via simulations, assessing the effects of the antenna ground-plane geometries used, and measured soil properties. We then investigate the impact of beam pattern uncertainties on the reconstruction of a Gaussian absorption feature. Assuming the pattern is known and correcting for the chromaticity of the instrument, the foregrounds can be modelled with a log-polynomial, and the 21-cm signal identified with high accuracy. However, uncertainties on the soil properties lead to percentage changes in the chromaticity that can bias the signal recovery. The bias can be up to a factor of two in amplitude and up to few per cent in the frequency location. These effects do not appear to be mitigated by larger ground planes, conversely gain patterns with larger ground planes exhibit more complex frequency structure, significantly compromising the parameter reconstruction. Our results, consistent with findings from other antenna design studies, emphasize the importance of chromatic response and suggest caution in assuming log-polynomial foreground models in global signal experiments.

K. C. F. Krause: The Combinatorian as Logician

In a time which it is not amiss to term “the Dark Ages of logic”, Karl Christian Friedrich Krause stayed not only true to logic but actually did something for its advancement. Besides making systematic use of Venn-diagrams long before Venn, Krause — once more taking his inspiration from Leibniz — propounded what appears to be the first completely symbolic systematic representation of logical forms, strongly suggestive of the powerful symbolic languages that have become the mainstay of logic since the beginning of the 20th century. However, Krause’s limits in logic are also clearly visible: Krause’s method in logic is, in the main, not axiomatic; it is combinatorial (in other words, it consists in systematically producing finite lists of logical laws, following some organizational principle). More importantly, Krause remained entirely within the confines of traditional syllogistics (his flirt with “quantification of the predicate” notwithstanding), neglecting propositional logic and, of course, first-order relational terms.

The first molecules in the intergalactic medium and halos of the Dark Ages and Cosmic Dawn

We study the formation and destruction of the first molecules at the epochs of the Dark Ages and Cosmic Dawn to evaluate the luminosity of the protogalaxy clumps (halos) in the molecular lines. The cosmological recombination is described using the RecFast model of an effective three-level atom, while the chemistry of the molecules is examined using the relevant basic kinetic equations. We then studied the effect of collisional and radiative excitation of molecules on the intensity of molecular emission in both warm and hot halos. Using the Planck data on the reionization of the intergalactic medium at z ∼ 6−8, we evaluated the upper limits of the light energy density for four models of thermal light from the first sources that appeared in the Cosmic Dawn epoch. Assuming that in the halos, the light energy density may essentially be even higher, we estimated the impact of the light from the first sources (the first light) on the formation and destruction of the first molecules in them as well as between them. We show that the molecules H2 and HD are destroyed by photodissociation processes shortly before the full reionization in the inter-halo medium, in the medium of both types of halos and for all models of the first light. At the same time, the number density of helium hydride ions, HeH+, shows essentially more complicated dependences on the kinetic temperature of halos and the models of the first light. These features characterizing the abundance of molecules also determine the intensity of the halos luminescence during their evolution. Furthermore, we calculated the evolution of the brightness temperature of the individual halo in the rotational lines of H2, HD and HeH+ molecules relative to the temperature of the cosmic microwave background at redshifts corresponding to the Dark Ages and Cosmic Dawn epochs. It does not exceed the microkelvin, but its detection may be an important source of information about the physical processes taking place at the beginning of the formation of the first stars and galaxies at the epochs of the Dark Ages and Cosmic Dawn.

Signature of primordial non-Gaussianity on the 21 cm power spectrum from dark ages

Abstract We study the signature of primordial non-Gaussianity imprinted on the power spectrum of the 21 cm line differential brightness temperature during dark ages. Employing the perturbative treatment of gravitational clustering, we quantitatively estimate the effects of the non-Gaussian and one-loop corrections on the 21 cm power spectrum. The potential impact of the use of the 21 cm power spectrum for the constraint on local-type primordial non-Gaussianity is investigated based on the Fisher matrix analysis. Our results show that the 21 cm power spectrum for an array with a baseline of several tens of kilometers can constrain the primordial non-Gaussianity to a level severer than that from cosmic microwave background measurements, and its constraining power is stronger than that of the 21 cm bispectrum, while in the ultimate situation the 21 cm bispectrum eventually becomes more powerful.

A Brief History of Liberal Education in Ancient and Medieval Europe－Focusing on the Formation and Evolution of Liberal Arts

This paper examined the history of liberal education in ancient and medieval Europe, focusing on the formation and evolution of liberal arts using materials concerning the history of education, history of university, history of philosophy, and history of science. The elementary form of liberal education emerged at Greece in the fourth century BC. The philosophers’ tradition and the orators’ tradition made two approaches to liberal education. Greek scholarship was accepted in the form of encyclopedic publications in the Roman era, and &lt;i&gt;Disciplinarium libri novem&lt;/i&gt;, the first work which contained the idea of liberal arts, was written in the first century BC. In the early medieval ages, so called dark ages, secular scholarship maintained its existence through the medium of liberal arts. In the fifth century, liberal arts became actualized into the seven liberal arts through &lt;i&gt;De nuptiis Philologiae et Mercurii&lt;/i&gt;. Since the sixth century, the seven liberal arts were divided into trivium and quadrivium. In the Renaissance of the twelfth century, ancient writings were extensively translated including Aristotelian works, and the attempt to relate Greek philosophies and the seven liberal arts was tried. Circa 1250, some universities were set up in the major cities of Europe, and medieval universities were mostly organized with the faculties of arts, theology, law, and medicine. Since the late thirteenth century, the arts faculty extended the scope of liberal arts by adding three philosophies to the existing seven liberal arts: natural philosophy, metaphysics and ethics. Based on the above examination, this paper showed that the scope of liberal arts was not fixed but continuously changed, and that humanities and science were not separated in ancient and medieval Europe.

A Dystopian Future: Social Oppression and Religious Extremism in Margaret Atwood's The Handmaid's Tale

Many literary research papers have dealt with the work of Margaret Atwood's The Handmaid's Tale (1985) as a feminist work. However, nearly few studies combine social oppression with religious extremism. To bridge this gap, the present study aims at exploring the use of totalitarian theocracy of terror to oppress its citizens in the name of religion. In other words, it explicates the way religion is used to brutally suppress and exploit people in general and vulnerable women in particular. To meet this objective, the study adopted the qualitative descriptive method to describe how religion is used as a contradictory controlling means in Gilead discourse. It also adopted the Foucault theory in analyzing the data of the study, illustrating the means of terror in the novel, and identifying the features of the Gileadean regime. The study has concluded that the plight of women does not happen in a vacuum. It is a result and a reflection of people's past and present times. It is the extremist religious discourse that almost always contributes to violence and oppression. Finally, the Republic of Gilead highlights a common point between the dark and modern ages where the female citizens lived under the oppressive patriarchal government.

Exploring the cosmic dawn and epoch of reionization with the 21 cm line

Abstract The dark age of the Universe, when no luminous object existed, ended with the birth of the first stars, galaxies, and black holes. This epoch is called cosmic dawn. Cosmic reionization is the major transition of the intergalactic medium in the Universe driven by ionizing photons emitted from luminous objects. Although the epoch through the dark ages to reionization is a milestone in the Universe, our knowledge of it is not yet sufficient. The cosmic 21 cm signal, which is emitted from neutral hydrogen, is expected to open a new window into this epoch. In this review paper, we first introduce the basic physics of the 21 cm line and how the first stars impact on the 21 cm line signal. Next, we briefly summarize how we extract astrophysical information from the 21 cm line signal by means of statistical and machine-learning approaches. We also discuss the synergy between the 21 cm line signal and other emission lines. Finally, we summarize the current status of 21 cm experiments.

대교약졸(大巧若拙)의 의미 고찰 – 철농 이기우(鐵農李基雨)의 전각예술(篆刻藝術)을 중심으로 –

Taoist doctrine had a great influence on Chinese art, and as a result, East Asian art appreciated the value of “Inaction nature(無爲自然)”. Inaction nature(無 爲自然) is related to Laozi's “Conforms to naturalness(道法自然)”, which is the doctrine that connects with Laozi's “The Greatest Skill Seems to Be Clumsy(大巧 若拙)”, it aims for poor beauty of “Inaction(無爲)” that goes beyond outstanding techniques. Laozi pursued the greatest skill that matched the nature of Tao and it is the skill of Tao(道之巧). Jol(拙) means ‘clumsy’ that is natural without any decoration. In order to ‘seem to be clumsy’, a skilled technique of “What the heart wishes one's hands accomplish(得心應手)” is required. Lee, Ki-woo(1921-1993) was a modern Korean calligrapher and engraver. He studied to Muho Lee Han-bok and Wichang Oh Se-chang, and tried to promote the artistry of engraving and calligraphy in the dark age of culture. By combining modern aesthetics on the foundation of “Clumsy and plain(古拙素朴)”, he boldly pioneered not only calligraphy but also the field of engraving, which was like a wasteland. He expanded the world of engraving indefinitely not only with stone engraving but also with various media. This paper sheds light on Lee Ki-woo‘s view of art, which was rose to the level of “What the heart wishes one's hands accomplish(得心應手)” and pursued “Purifying the heart(心齋)” and “sitting oblivion(坐忘)” and then reached to the level of “The Greatest Skill Seems to Be Clumsy(大巧若拙)”. I hope that this paper could be a cornerstone for restarting research on Lee Ki-woo, which has been sluggish.

The Dark Ages' 21-cm trispectrum

We investigate tomography of 21-cm brightness temperature fluctuations during the Dark Ages as a probe for constraining primordial non-Gaussianity. We expand the 21-cm brightness temperature up to cubic order in perturbation theory and improve previous models of the signal by including the effect of the free electron fraction. Using modified standard perturbation theory methods that include baryonic pressure effects we derive an improved secondary bispectrum and for the first time derive the secondary trispectrum of 21-cm brightness temperature fluctuations. We then forecast the amount of information available from the Dark Ages to constrain primordial non-Gaussianity, including the imprints of massive particle exchange during inflation and we determine how much signal is lost due to secondary non-Gaussianity. We find that although secondary non-Gaussianity swamps the primordial signal, primordial non-Gaussianity can still be extracted with signal-to-noise ratios that surpass current and future CMB experiments by several orders of magnitude, depending on the experimental setup. Furthermore, we conclude that for the bi- and trispectra of massive particle exchange marginalizing over other primordial shapes affects signal-to-noise ratios more severely than secondary shapes. Baryonic pressure effects turn out to have a negligible impact on our forecasts, even at scales close to the Jeans scale. The results of this work reinforce the prospects of 21-cm brightness temperature fluctuations from the Dark Ages as the ultimate probe for primordial non-Gaussianity.

Late Holocene vegetation dynamics and monsoonal climatic changes in Jammu, India

Knowledge of the Holocene Indian Summer Monsoon (ISM) variability is important for understanding the spatio-temporal dynamics of the ISM precipitation. In this study, a Late Holocene pollen proxy record of the changes in the ISM intensity from a 1.8 m deep lacustrine sedimentary deposit in Jammu District (Jammu and Kashmir State) in India is presented. The results show that between ~3205 and 2485 cal yr BP, mixed broad-leaved/conifer forests occurred in the region under a warm and humid climate, probably indicating high monsoon precipitation. Subsequently, the conifers, such as Pinus sp., Cedrus sp., Abies sp., Picea sp. and Larix sp. increased comparatively and show dominance over the existing broad-leaved taxa between ~2485 and 1585 cal yr BP under a cool and dry climate with reduced monsoon precipitation. The climate further deteriorated (towards attaining aridity under reduced monsoon condition) during ~1585 to 865 cal yr BP, which coincides with the Dark Ages Cold Period (DACP: CE/AD 400–765; 1185–1550 cal yr BP). Since ~865 cal yr BP (CE/AD 1085 onwards) to Present, the broad-leaved taxa, such as Alnus sp., Betula sp., Ulmus sp., Carpinus sp., Corylus sp. and Quercus sp. started expanding and showed their dominance over the conifers, indicating a warm and humid climate in the region with increased monsoon precipitation. This phase partly corresponds with the Medieval Climatic Anomaly (MCA) between CE/AD 950 and 1300. Thus, the ISM rainfall intensity is linked with some of the global climatic trends in the present study.

Centennial-scale linkages between the Indian Summer Monsoon and the solar irradiation from the Gulf of Khambhat (Western India)

The Indian Summer Monsoon (ISM) is a major driver of the summer precipitation across the Indian subcontinent affecting a vast population. Yet, the limited chronological extent of the instrumental records accompanied with the control of the climatic variables on the ISM, has hampered the efforts to document the climate change for the last two millennia. The present multiproxy study reports a high-resolution sedimentary record from the Gulf of Khambhat region (Western India) which represents two alternating climatic phases representing relatively arid and humid climatic conditions that coincides with the widely reported Dark Ages Cold Period (DACP) (AD 680 – AD 920) and Medieval Warm Period (MWP) (AD 920 to ∼ AD 1400). This variability of the ISM, further tends to be modulated by the solar forcings, with the periods of solar minima coinciding well with the episodes of the reduced monsoonal strength and vice-versa. The difference in timing of DACP and MWP in the North Atlantic Region (NAR) and the present study, hints at the linkage between the ISM and NAR via an atmospheric route, driven by the solar variability.

Sensitivities on nonspinning and spinning primordial black hole dark matter with global 21-cm troughs

Detection of the global 21 cm signal arising from neutral hydrogen can revolutionize our understanding of the standard evolution of the Universe after recombination. In addition, it can also be an excellent probe of dark matter (DM). Among all the DM candidates, primordial black holes (PBHs) are one of the most well motivated. Hawking emission from low-mass PBHs can have a substantial effect on the thermal and ionization history of the early Universe, and that in turn can have an imprint on the global 21 cm signal. Recently EDGES has claimed a global 21 cm signal, though SARAS 3 has rejected that claim. In this work, we investigate the sensitivities on nonspinning and spinning PBHs arising from an EDGES-like measurement of the global 21 cm signal, and find that the sensitivities will be competitive with those arising from other astrophysical observables. We show that the sensitivities can be significantly strengthened depending on various uncertain astrophysical parameters. Besides, we also derive projections on the PBH density from the absorption trough expected during the Dark Ages. Our work shows that the near future unambiguous detection of the global 21 cm absorption troughs can be an excellent probe of PBH DM.

The Royal Texts of the History of Abyssinia During the Reign of Emperor Amda Seyon (1314-1344): Translation and Analytic Study

Researchers divide Ethiopian history into two main eras, the first of which begins in the fourth century AD with the entry of Christianity into Ethiopia during the era of King Ezana (1). The history of this period depends on a group of inscriptions and excavations. Some historical news continues until the end of the fifth century AD, almost until the era of Caleb and his campaigns to southern Arabia, then Ethiopia enters its dark ages, which extended until the middle of the thirteenth century AD, through which we do not receive any documents, manuscripts or inscriptions that tell what happened in those days. The historical period, except for some scattered news about the Agawi dynasty that ruled Ethiopia from the tenth century until the thirteenth century AD.

The persistent lake level decreasing induced Phragmites peatland development in the Bosten Lake (Northwest China) during the Medieval Warm Period

Northwest China (NW China) falls within Arid Central Asia (ACA) and has a climate dominated by westerly winds, a fragile ecosystem, and a high sensitivity to climate change. Paleoenvironmental reconstructions of this region can assist in understanding the general processes contributing to environmental variation in such arid areas. This study examined a dated sedimentary core containing both peat and lacustrine deposits obtained from the shore of the Bosten Lake, NW China. The study aimed to reconstruct paleoenvironmental variations over the last 3,000 years and to explore the possible drivers of peatland development over the last millennium. An examination of grain size and δ13C was conducted to investigate lake level variation. The results showed that the lake level of the Bosten Lake declined gradually between 2,905 and 480 cal yr BP and increased thereafter, consistent with other records of the Bosten Lake. At a centennial timescale, the lake level was high under a wet climate during the Dark Age Cold Period (DACP), whereas it decreased significantly during the Medieval Warm Period (MWP). The inferred “cold and wet” and “warm and dry” patterns indicated climatic characteristics of a “westerlies-dominated climatic regime”. In addition, the persistent decreasing lake level during the MWP resulted in Phragmites peatland initiation and development along the shores of the Bosten Lake.

PH modifies the oxidative potential and peroxide content of biomass burning HULIS under dark aging

Humic-like substances (HULIS) account for a major redox-active fraction of biomass burning organic aerosols (BBOA). During atmospheric transport, fresh acidic BB-HULIS in droplets and humid aerosols are subject to neutralization and pH-modified aging process. In this study, solutions containing HULIS isolated from wood smoldering emissions were first adjusted with NaOH and NH3 to pH values in the range of 3.6–9.0 and then aged under oxic dark conditions. Evolution of HULIS oxidative potential (OP) and total peroxide content (equivalent H2O2 concentration, H2O2eq) were measured together with the changes in solution absorbance and chemical composition. Notable immediate responses such as peroxide generation, HULIS autoxidation, and an increase in OP and light absorption were observed under alkaline conditions. Initial H2O2eq, OP, and absorption increased exponentially with pH, regardless of the alkaline species added. Dark aging further oxidized the HULIS and led to pH-dependent toxic and chemical changes, exhibiting an alkaline-facilitated initial increase followed by a decrease of OP and H2O2eq. Although highly correlated with HULIS OP, the contributions of H2O2eq to OP are minor but increased both with solution pH and dark aging time. Alkalinity-assisted autoxidation of phenolic compounds and quinoids with concomitant formation of H2O2 and other alkalinity-favored peroxide oxidation reactions are proposed here for explaining the observed HULIS OP and chemical changes in the dark. Our findings suggest that alkaline neutralization of fresh BB-HULIS represents a previously overlooked peroxide source and pathway for modifying aerosol redox-activity and composition. Additionally, these findings imply that the lung fluid neutral environment can modify the OP and peroxide content of inhaled BB-HULIS. The results also suggest that common separation protocols of HULIS using base extraction methods should be treated with caution when evaluating and comparing their composition, absorption, and relative toxicity.

Prospective scenarios for offshore private banking firms serving Brazilians in 2040

Objective: This article aims to explore potential future scenarios for the offshore Private Banking industry serving Brazilian individuals, considering the increasing competition. Methods: The research employs the Prospective Scenarios approach, including a Delphi panel with industry’s experts in two rounds of interviews. Results: The results indicated a consensus among the participants regarding two driving forces for the offshore Private Banking Industry: Regulation and Educational Challenges. The work builds four prospective scenarios for 2040: The Sky is the limit; Swimming against the Tide; The Dark Ages; and Too Much Openness Misses the Optimal Point. Conclusions: The research concludes that Private Banking firms should closely monitor the main regulations that can impact their business. In addition, offshore Private Banking firms should invest in educating potential investors in Brazil, especially the rising affluent segment and the millennials demographic group, leveraging all the technological resources at their disposal. Both scholars and practitioners might also replicate the methodology used of prospective scenarios using Delphi (Lima, 2014; Skulmoski, Hartman &amp; Krahn, 2007) method to other sectors.

New probe of the high-redshift Universe: Nulling CMB lensing with interloper-free line intensity mapping pair lensing

Intermediate redshifts between galaxy surveys and the cosmic microwave background (CMB) remain unexplored territory. Line intensity mapping (LIM) offers a way to probe the $z\gtrsim 1$ Universe, including the epoch of reionization and the dark ages. Via exact nulling of the lensing kernel, we show that LIM lensing, in combination with galaxy (resp., CMB) lensing, can uniquely probe the $z\gtrsim 1$ (resp., pre-reionization) Universe. However, LIM foregrounds are a key hurdle to this futuristic technique. While continuum foregrounds can be controlled by discarding modes perpendicular to the line of sight (low $k_\parallel$ modes), interloper foregrounds haven't been addressed in the context of LIM lensing. In this paper, we quantify the interloper bias to LIM lensing for the first time, and derive a ''LIM-pair'' estimator which avoids it exactly after cross-correlating with CMB lensing. This new quadratic lensing estimator works by combining two intensity maps in different lines, from the same redshift, whose interlopers are uncorrelated. As a result, this foreground avoidance method is robust to even large changes in the amplitude of the interloper power and non-Gaussianity. The cross-spectrum of the LIM-pair estimator with CMB lensing is thus robust to the currently large theoretical uncertainties in LIM modeling at high redshift.