What is action at a distance in physics?

Action at a distance is the physics concept that an object can be directly influenced and have its motion affected by another object without physical contact between them. Historically, it served as the earliest scientific model for gravity and electricity, seen in frameworks like Newton's law of universal gravitation and Coulomb's law. Although 19th- and 20th-century field models and modern physics generally replaced it with field theories, alternative action at a distance models also arose.

What we know

• Action at a distance is defined as spatially nonlocal causation, where an object is directly influenced by another that is not adjacent to it. [1]
• Coulomb's law and Newton's law of universal gravitation are based on the concept of action at a distance. [2]
• Historically, action at a distance was the earliest scientific model for gravity and electricity. [2]
• Under modern understandings, the four fundamental interactions in physics are not described by action at a distance. [2]

Where to go next

• what caused itHow did field models replace action at a distance?
• a case in pointWhat are Newton's law of universal gravitation and Coulomb's law?
• the bigger pictureHow do physical fields work in modern physics?
• compared withWhat is the role of action in quantum mechanics and general relativity?
• whenHow did ancient philosophy influence seventeenth-century physical thought?
• an unexpected connectionHow does Mary Hesse's philosophy book connect ancient thought to modern physics?The book Forces and Fields examines ancient Greek science and antique philosophy while also addressing modern physics concepts like wave-particle duality and the uncertainty principle.

Sources

• [1]action at a distance (Wikidata Q1407429) · CC0 1.0
• [2]Action at a distance · CC BY-SA 4.0
• [3]Action (physics) · CC BY-SA 4.0
• [4]Forces and Fields · CC BY-SA 4.0
• [5]History of variational principles in physics · CC BY-SA 4.0