Galaxies, along with their underlying dark matter halos, constitute the building blocks of structure in the Universe. Of all fundamental forces, gravity is the dominant one that drives the evolution of structures from small density seeds at early times to the galaxies we see today. The interactions among myriads of stars, or dark matter particles, in a gravitating structure produce a system with fascinating connotations to thermodynamics, with some analogies and some fundamental differences. Ignacio Ferreras presents a concise introduction to extragalactic astrophysics, with emphasis on stellar dynamics, and the growth of density fluctuations in an expanding Universe. Additional chapters are devoted to smaller systems (stellar clusters) and larger ones (galaxy clusters). Fundamentals of Galaxy Dynamics, Formation and Evolution is written for advanced undergraduates and beginning postgraduate students, providing a useful tool to get up to speed in a starting research career. Some of the derivations for the most important results are presented in detail to enable students appreciate the beauty of maths as a tool to understand the workings of galaxies. Each chapter includes a set of problems to help the student advance with the material.
The smooth operation and success of the Terrain Exercise are almost entirely dependent on the Director's ability and tactical knowledge, the care he takes in selecting the ground, preparing the problem, and his preparation for the Terrain Exercise. The subsequent special situations must occur in a logical order. The Director must have in mind a solution to the problem's various situations and must become familiar with all of its phases so that he can provide a reasonable answer to any question that may be posed. He must be careful not to overly criticize the students when they make mistakes or have bad attitudes.
The Dead Sea Scrolls were discovered more than 60 years ago in seaside caves near an ancient settlement called Qumran. The conventional wisdom is that a breakaway Jewish sect called the Essenes—thought to have occupied Qumran during the first centuries B.C. and A.D.—wrote all the parchment and papyrus scrolls. The Dead Sea Scrolls, in the narrow sense of Qumran Caves Scrolls are a collection of some 981 different texts discovered between 1946 and 1956 in eleven caves in the immediate vicinity of the ancient settlement at Khirbet Qumran in the West Bank, The caves are located about two kilometres (1.2 miles) inland from the northwest shore of the Dead Sea, from which they derive their name. The consensus is that the Qumran Caves Scrolls date from the last three centuries BCE and the first century CE. Bronze coins found at the same sites form a series beginning with John Hyrcanus (135–104 BCE) and continuing until the First Jewish–Roman War (66–73 CE), supporting the radiocarbon and paleographic dating of the scrolls. Manuscripts from additional Judean desert sites go back as far as the eighth century BCE to as late as the 11th century CE. The texts are of great historical, religious, and linguistic significance because they include the third oldest known surviving manuscripts of works later included in the Hebrew Bible canon, along with deuterocanonical and extra-biblical manuscripts which preserve evidence of the diversity of religious thought in late Second Temple Judaism. Biblical text older than the Dead Sea Scrolls has been discovered only in two silver scroll-shaped amulets containing portions of the Priestly Blessing from the Book of Numbers, excavated in Jerusalem at Ketef Hinnom and dated c. 600 BCE. A burnt piece of Leviticus dating from the 6th century CE analyzed in 2015 was found to be the fourth-oldest piece of the Torah known to exist. Most of the texts are written in Hebrew, with some in Aramaic (in different regional dialects, including Nabataean), and a few in Greek. If discoveries from the Judean desert are included, Latin (from Masada) and Arabic (from Khirbet al-Mird) can also be added. Most texts are written on parchment, some on papyrus and one on copper. The scrolls have traditionally been identified with the ancient Jewish sect called the Essenes, although some recent interpretations have challenged this association and argue that the scrolls were penned by priests in Jerusalem, Zadokites or other unknown Jewish groups. Due to the poor condition of some of the scrolls, not all of them have been identified. Those that have been identified can be divided into three general groups: - Some 40% of them are copies of texts from the Hebrew Scriptures. - Approximately another 30% of them are texts from the Second Temple Period which ultimately were not canonized in the Hebrew Bible, like the Book of Enoch, the Book of Jubilees, the Book of Tobit, the Wisdom of Sirach, Psalms 152–155, etc. - The remaining roughly 30% of them are sectarian manuscripts of previously unknown documents that shed light on the rules and beliefs of a particular group (sect) or groups within greater Judaism, like the Community Rule, the War Scroll, the Pesher on Habakkuk and The Rule of the Blessing.
'This significantly expanded and revised fourth edition of what has always been the best English translation of the Scrolls has become a combination of two books: Vermes has replaced nearly all of the original Introduction with an abridged version of the corresponding material from The Dead Sea Scrolls: Qumran in Perspective... He has also added new translations of material that has been published since the last edition appeared in 1975... By far still the best edition of the scrolls in English.' James R Mueller, Religious Studies Review>
This updated edition of the bestselling guidebook helps middle and high school science teachers reach English learners in their classrooms. The guide offers practical guidance, powerful and concrete strategies, and sample lesson scenarios that can be implemented immediately in any science class. It includes rubrics to help teachers identify the most important language skills at five ELD levels; practical guidance and tips from the field; seven scaffolding strategies for differentiating instruction; seven tools to promote academic language and scientific discourse; assessment techniques and accommodations to lower communication barriers for English learners; and two integrated lesson scenarios demonstrating how to combine and embed these various strategies, tools, techniques, and approaches. The volume is designed for teachers who have had limited preparation for teaching science in classrooms where some students are also English learners.
