Journal Club

"An Upper Palaeolithic Proto-writing System and Phenological Calendar"

Fatima Kayanikhoo (NCAC, Warsaw)

In at least 400 European caves such as Lascaux, Chauvet and Altamira, Upper Palaeolithic Homo sapiens groups drew, painted and engraved non-figurative signs from at least ∼42,000 BP and figurative images (notably animals) from at least 37,000 BP. Since their discovery ∼150 years ago, the purpose or meaning of European Upper Palaeolithic non-figurative signs has eluded researchers. Despite this, specialists assume that they were notational in some way. Using a database of images spanning the European Upper Palaeolithic, we suggest how three of the most frequently occurring signs—the line <|>, the dot <•>, and the —functioned as units of communication. We demonstrate that when found in close association with images of animals the line <|> and dot <•> constitute numbers denoting months, and form constituent parts of a local phenological/meteorological calendar beginning in spring and recording time from this point in lunar months. We also demonstrate that the sign, one of the most frequently occurring signs in Palaeolithic non-figurative art, has the meaning . The position of the within a sequence of marks denotes month of parturition, an ordinal representation of number in contrast to the cardinal representation used in tallies. Our data indicate that the purpose of this system of associating animals with calendar information was to record and convey seasonal behavioural information about specific prey taxa in the geographical regions of concern. We suggest a specific way in which the pairing of numbers with animal subjects constituted a complete unit of meaning—a notational system combined with its subject—that provides us with a specific insight into what one set of notational marks means. It gives us our first specific reading of European Upper Palaeolithic communication, the first known writing in the history of Homo sapiens.

20000-year Ice Age drawings mystery
An Upper Palaeolithic Proto-writing System and Phenological Calendar
https://doi.org/10.1017/S0959774322000415

"Perpendicular arms, triangle or circle: the new shapes of gravitational wave detectors"

Lami Suleiman (NCAC, Warsaw)

The third generation of Gravitational Wave detectors includes the space based triangular detector LISA and the two ground based detectors Cosmic Explorer and Einstein telescope. If Cosmic Explorer is a brute force improvement on the LIGO/Virgo perpendicular arms configuration, Einstein telescope is exploring much more “exotic” features for signal improvement. For this Journal Club, I will first discuss the underground and triangle shape configurations in discussion for Einstein Telescope. Then, I will present two papers that propose the detection of Gravitational Waves in LHC like particles accelerators.

Articles for the discussion:

• “Detection of gravitational waves in circular particle accelerators” Phys. Rev. D 102, 122006 (2020) Rao Suvrat, Brüggen Marcus, Liske Jochen
• “Erratum: Detection of gravitational waves in circular particle accelerators” Phys. Rev. D 102, 122006 (2020)
• “Detection of gravitational waves in circular particle accelerators II. Response analysis and parameter estimation using synthetic data” eprint arXiv:2301.08331

"Neutron star planets: Atmospheric processes and irradiation"

Amedeo Romagnolo (NCAC, Warsaw)

Of the roughly 3000 neutron stars known, only a handful have sub-stellar companions. The most famous of these are the low-mass planets around the millisecond pulsar B1257+12. New evidence indicates that observational biases could still hide a wide variety of planetary systems around most neutron stars. We consider the environment and physical processes relevant to neutron star planets, in particular the effect of X-ray irradiation and the relativistic pulsar wind on the planetary atmosphere. We discuss the survival time of planet atmospheres and the planetary surface conditions around different classes of neutron stars, and define a neutron star habitable zone based on the presence of liquid water and retention of an atmosphere. Depending on as-yet poorly constrained aspects of the pulsar wind, both Super-Earths around B1257+12 could lie within its habitable zone.

Patruno, A., & Kama, M. (2017) Astronomy & Astrophysics, Volume 608

"A unified model for tidal disruptions events"

Angelos Karakonstantakis (NCAC, Warsaw)

1. Dai, L., McKinney, J., Roth, N., Ramirez-Ruiz, E., & Miller, M. (2018). ApJL, 859(2), L20.
2. Thomsen, L., Kwan, T., Dai, L., Wu, S., Roth, N., & Ramirez-Ruiz, E. (2022). Dynamical Unification of Tidal Disruption Events. ApJL, 937(2), L28.