The term "20th-century physicists" refers to the numerous influential scientists who made significant contributions to the field of physics during the 1900s. This period was marked by groundbreaking discoveries and the development of new theories that fundamentally changed our understanding of the universe. Some key figures from the 20th century include: 1. **Albert Einstein**: Best known for his theories of special relativity and general relativity, which revolutionized the understanding of space, time, and gravity.

The term "21st-century physicists" refers to the scientists and researchers who are actively engaged in the field of physics in the 21st century. This includes individuals working across various subfields, such as particle physics, condensed matter physics, astrophysics, quantum mechanics, and more. Key attributes and developments characterizing 21st-century physicists include: 1. **Interdisciplinary Research**: Many physicists today collaborate across disciplines, integrating concepts from chemistry, biology, and engineering.

The Fellows of the American Physical Society (APS) is an honorary designation bestowed by the APS to recognize outstanding contributions to physics. The fellowship honors members who have made significant advancements in the field, demonstrated excellence in research, or made notable contributions to the education and public understanding of physics. Each year, nominations for fellowship are made by existing APS members, and the selection is made by the APS Fellowship Committee.

The 18th century was a significant period in the history of physics and science in general, marked by advances in various fields, including mechanics, thermodynamics, and electricity. Some notable physicists and thinkers of this time include: 1. **Isaac Newton (1643-1727)**: Although he is primarily associated with the 17th century, his works continued to influence 18th-century physics profoundly. His laws of motion and universal gravitation laid the foundation for classical mechanics.

The term "European physicists" generally refers to physicists who conduct research or work in the field of physics within Europe. This can include a wide range of individuals from various countries in Europe who are involved in different branches of physics, such as theoretical physics, experimental physics, astrophysics, condensed matter physics, and more. European physicists have made significant contributions to the field and have been involved in many landmark discoveries and advancements.

Physicists have emerged from various countries and time periods, contributing to the development of physics as a science. Below is a summary of notable physicists categorized by their nationality and the century in which they were most active: ### 17th Century - **Galileo Galilei** (Italy) - Often called the "father of modern science," he made significant contributions to motion and astronomy.

The ASA Gold Medal is an award presented by the American Statistical Association (ASA) to honor individuals for their outstanding contributions to the field of statistics. It recognizes significant achievements in statistical science, including methodological development, applications, and leadership in the discipline. The award is typically given to individuals who have made notable advancements or innovations in statistics, influencing the field through research, teaching, or public service.

"North American physicists" broadly refers to physicists who are based in or are citizens of countries in North America, primarily the United States, Canada, and Mexico. These scientists engage in research and education in various fields of physics, including but not limited to, condensed matter physics, particle physics, astrophysics, and applied physics. North American physicists often work in academic institutions, research laboratories, and industry, contributing to advancements in scientific knowledge, technology, and education.

Cultural heritage at risk from climate change refers to the threats that climate-related impacts pose to sites, structures, traditions, and practices that hold historical, cultural, or artistic significance. This risk can manifest in various ways: 1. **Physical Damage to Sites**: Extreme weather events, rising sea levels, and increased temperatures can lead to the deterioration of buildings, monuments, archaeological sites, and landscapes.

"South American physicists" refers to physicists who are from South America or are working in South American countries. The continent has a number of prominent physicists who contribute to various fields of physics, including theoretical physics, experimental physics, and applied physics. Some notable South American physicists include: 1. **César D. Laing** - Known for his work in theoretical physics, particularly in statistical mechanics.

An acoustician is a professional who studies and applies the principles of acoustics, which is the science of sound. This can encompass various fields, including engineering, architecture, music, and environmental science. Acousticians may work on a range of projects, such as: 1. **Architectural Acoustics**: Designing spaces like concert halls, theaters, and auditoriums to optimize sound quality and manage noise.