To test which of these models applies to our universe, one needs to extend redshift measurements to large distances, out to several Giga-light years. The most successful approach has been to use white dwarf supernovae (SN type Ia) as very luminous standard candles. One of the greatest surprises of modern astronomy is that the expansion of the universe must be accelerating! This implies there must be a positive, repulsive force that pushes galaxies apart, in opposition to gravity. We dub this force "dark energy."

Earth’s moon is quite distinct from other moons in the solar system, in being a comparable size to Earth. We explore the theory that a giant impact in the chaotic early solar system led to the Moon’s formation, and bombardment by ice-laden asteroids provided the abundant water we find on our planet. Further we find that Earth’s magnetic field shields us from solar wind protons, that protect our atmosphere from being stripped away. The icy moons of Jupiter and Saturn are the best targets for exploring if life exists elsewhere in the solar system.

This chapter characterizes the burden of suicidal behavior among adolescents using a sociological lens and a public health prevention approach. It describes the public health approach to preventing adolescent suicidal behavior. The public health approach includes assessing the problem; identifying causes or risk and protective factors; developing and evaluating programs; and implementing and disseminating findings. The chapter gives numbers on the extent of the problem among adolescents, describing the numbers, rates, and trends of fatal and nonfatal suicidal behavior among youth, then a summary of what is known about the community- and societal-level risk, and protective factors of the problem are presented, showing where sociology and public health complement each other. Lastly, the authors list several community- and societal-level prevention programs and the implications for what can be done to prevent adolescent suicidal behavior. Which types of suicidal behavior identified by Durkheim (i.e., anomic, egoistic, fatalistic, and altruistic) are addressed by modern prevention programs?

The close proximity of the Sun, and its extreme apparent brightness, makes it by far the most important star for lives here on Earth. In modern times we have access to powerful telescopes, both on the ground and in space, that observe and monitor the Sun over a wide range of wavelength bands. These vividly demonstrate that the Sun is in fact highly structured and variable over a wide range of spatial and temporal scales.

As a basis for interpreting observations of binary systems in terms of the orbital velocity of the component stars, we review the astrometric and spectrometric techniques used to measure the motion of stars through space. Nearby stars generally exhibit some systematic motion relative to the Sun, generally with components both transverse (i.e., perpendicular) to and along (parallel to) the observed line of sight.

What is the relationship between gender and mental health? What social forces shape this relationship? Evidence reveals that there are no differences by gender in overall rates of psychopathology, but gender predicts the types of psychopathology diagnosed and reported. Women suffer from higher rates of depression and anxiety (referred to as internalizing disorders), and men have higher rates of substance abuse and antisocial disorders (referred to as externalizing disorders). Sarah Rosenfield, Dena T. Smith, and Maleah Fekete concentrate on dominant gender conceptions – those held by groups in positions of power, which in the United States are primarily White and affluent. Focusing on the US adult population, the authors describe differences between men and women in power, responsibilities (i.e., different role positions), and personal characteristics that are relevant for mental health. For example, women earn less money, have jobs with less power and autonomy, and experience an overload of job and family demands more often than men. They have closer social ties, which bring more support but also more negative interactions. Women have personal characteristics of lower self-esteem and mastery than men. They are more nurturant and emotionally engaged, compared to men’s greater independence and assertiveness. Finally, gender predicts self-salience, that is, beliefs about the importance of the self versus others in social relations: women put others’ interests first more often, which promotes internalizing problems, while men tend to privilege the self more strongly, facilitating externalizing problems. It is important to note that most research on gender and mental health compares men and women while ignoring minority gender identities. It is also important to consider gender’s intersection with other social determinants of mental health such as socioeconomic status (SES), race, and ethnicity. The authors suggest that socializing practices encouraging high self-regard along with high regard for others improve mental health. What role can colleges play in encouraging high self-regard and regard for others for all students?

Our initial introduction of surface brightness characterized it as a flux confined within an observed solid angle. But actually the surface brightness is directly related to a more general and fundamental quantity known as the "specific intensity." The light we see from a star is the result of competition between thermal emission and absorption by material within the star.

The concept of accessed status lies at the intersection of two classic research traditions: stratification and social networks. Status is one of the most fundamental concepts that stratification sociologists contribute to social science and public discourse. From the social network perspective, status can be dichotomized into personal status (one’s own ranked positions) and accessed status (the ranked positions of one’s network members). In comparison to personal status, accessed status has been given much less attention (partly due to the lack of network data). Its theoretical meaning and role for well-being, mental well-being in particular, is actually relatively more complicated and intriguing, and appears to be puzzlingly double-edged (helpful and harmful). This chapter focuses on the relationship between accessed status and mental well-being. It first introduces accessed status and the external–internal well-being continuum and subsumes mental well-being within this continuum. It then describes a pair of competing theories (social capital versus social cost) on the double-edged role of accessed status and summarizes theoretical extensions and empirical efforts analyzing the diverse effects (direct, indirect, mediating, and interaction) of accessed status on mental well-being. It concludes with a discussion of future research directions and calls for more future efforts in the analysis of accessed status and well-being as well as network data collection. How is accessed status defined and measured? Where does mental well-being fall on the external–internal well-being continuum? Why does accessed status exhibit a more complex (both protective and harmful) association with mental well-being than with other types of well-being?

We now consider why stars shine with such extreme brightness. Over the long-term (i.e., millions of years), the enormous energy emitted comes from the energy generated (by nuclear fusion) in the stellar core, as discussed further in Chapter 18. But the more immediate reason stars shine is more direct, namely because their surfaces are so very hot. We explore the key physical laws governing such thermal radiation and how it depends on temperature.

This chapter reviews sociological theories and measurements of stratification and social class in the process of relating social inequality to mental disorder. Eaton and Muntaner argue that processes of stratification and periods of high vulnerability to mental disorder are related to different stages in the life course. Consequently, stratification and one’s place in the socioeconomic system have a complex relationship to the occurrence of mental disorder. Both individual and environmental factors must be taken into account. In general, researchers have found that socioeconomic position (SEP) is inversely related to mental disorder; that is, those in the “lower” classes experience higher rates of disorder. Two contrasting frameworks for understanding the relation of SEP to mental disorder are selection and drift on the one hand and social causation on the other hand. Selection refers to the idea that individuals who are predisposed to mental disorder have lower than expected educational and occupational attainment. Drift refers to the idea that those with mental disorders are likely to drift down the SEP ladder, after onset of the mental disorder, as they will have more trouble with employment and other means of attaining higher socioeconomic positions. In contrast, social causation explanations emphasize how the social experiences of members of different social classes influence their likelihood of becoming mentally ill or distressed. More research is needed on the specific ways in which social class affects mental disorder and how mental disorder affects the attainment of social status. Students should compare the selection and drift frameworks. Is it likely that an individual born of a wealthy family will drift down the socioeconomic ladder if they experience a mental health problem? Consider the role of stress and social resources in understanding the relationship between SEP and mental health.

Manning discusses the sociological approach to studying suicide and how it differs from biological and psychological approaches. After discussing the nature of suicide as human behavior, he addresses several social factors that predict and explain suicide, including social contagion, social integration, social mobility, and interpersonal conflict. Statistical and ethnographic evidence suggest these factors are important for shaping the frequency and distribution of suicide, and that sociological theory plays a crucial role in understanding self-destruction. How can we learn more about the impact of sociological variables on suicide? And how can taking account of them help us prevent suicide?

Most mental health care today takes place not in hospital settings, but rather in a range of community-based organizations. This chapter lays out the scope of contemporary mental health care and highlights major themes in sociological research in community care. While the average (non-office-based) specialty mental health care provider organization is private and nonprofit, public funds make up a large portion of the support for community mental health services. A range of workers provide services in community care, with psychiatrists continuing to play a prominent role in nonhospital settings and peer providers increasingly involved. Delivering services involves juggling competing demands from a variety of stakeholders, with calls for cost containment and accountability often crowding out other priorities and forcing adaptive responses from frontline workers. Community care is enmeshed in a complex social and policy context, in which mental health labels and mental health treatment help solve problems for policymakers and those from different sectors of society in addition to those receiving services. The arrival of COVID-19 changed the landscape of community mental health services, threatening resources and pushing much care online, exacerbating access issues for the most vulnerable. Students might discuss different settings and entry points of mental health care and how the experience of treatment might differ depending on where and how one enters care.