Two well-regarded measurements for the expansion rate of the universe disagree, leaving cosmologists very puzzled. It may be that something large has been overlooked in our theory of the Big Bang. This discrepancy is called the Hubble tension and it has led to a very interesting conversation within the cosmology community.

I begin my introductory astronomy course with a unit on critical thinking that focuses on, among other things, the differences between the "scientific method" as frequently presented in textbooks and actual scientific practice. One particular classroom activity uses a simple dice game to simulate observation of a natural phenomenon and…

The chronic underrepresentation of Native and indigenous peoples in STEM fields (Fig. 1) has been a longstanding issue in the United States, despite concentrated efforts by many local and national groups, including the Society for Advancement of Chicanos/Hispanics and Native Americans in Science (SACNAS) and the American Indian Science and…

In his "The Making of the Atomic Bomb," Richard Rhodes remarks of the July 16, 1945, Trinity atomic bomb test in New Mexico that "had astronomers been watching they could have seen it reflected from the moon, literal moonshine," an allusion to Ernest Rutherford's famous dismissal of the prospect of atomic energy. Investigating…

Presents the history of the discovery of pulsars, observations that have been made on pulsar radiation, and theories that have been presented for its presence and origin. Illustrations using pulsar's properties are presented in mechanics, electromagnetic radiation and thermodynamics. (DS)

Discusses a number of possible explanations for the Christmas Star as described in the Bible. (SL)

Following a short review of the history of cosmic-ray astrophysics and a discussion of the accumulated data, pointing to the need for isotope measurement, the theory of heavy-element nucleosynthesis is reviewed to provide a basis for the interpretation of the cosmic-ray data. (Author/JN)

Provides a chronicle of the work of Miss Leavitt in the field of variable stars during the early part of the 20th century. (CP)

Discusses a joint research program between several high school teachers and solar system astronomers in which data were collected on photoelectric observations of asteroids and minor planets via astronomical telescopes. (MLH)

The second of two parts (part 1 in v20 n4, p222, Apr 1982) focuses on experimental techniques used to study cosmic-ray isotopic composition, experimental results, and comparison between cosmic-ray source matter and solar-system material. Several models for nucleosynthesis and evolution of cosmic-source matter are also discussed. (Author/JN)

Discussed are two current physics research areas. Solar cell efficiencies are discussed relating to present and future conversion efficiencies. Topics discussed in Astrophysics include the observation of astronomical bodies at different wavelengths, in terms of electromagnetic spectrum, tools of astronomy, compact stars, pulsars X-ray binaries,…

The difference in time between the emission and reception of light is called the "lookback" time. This article explores implications of lookback time and explains some of the puzzling questions posed by the scientific observation of cosmic history. Provides several pictures and diagrams. (YP)

Detection of neutrino decay may have profound consequences for both particle physics and cosmology, providing a deep connection between physics of the very large and physics of the very small. Describes this link and discusses the nature and status of the search for decaying neutrinos. (Author/JN)