Discussion Overview
The discussion revolves around the concept of pressure in gases when there are no container walls. Participants explore the relationship between pressure, particle momentum, and intermolecular collisions, questioning how pressure can exist without a defined surface to measure it against.
Discussion Character
- Exploratory
- Technical explanation
- Debate/contested
Main Points Raised
- One participant suggests that pressure is defined by changes in particle momentum and questions how pressure can exist without walls to facilitate these changes.
- Another participant proposes that wall-less pressure could be attributed to intermolecular collisions, asserting that pressure cannot exist without such collisions.
- A different viewpoint questions the necessity of a wall for measuring pressure, suggesting that collisions among particles themselves could serve as a reference surface.
- One participant emphasizes the calculation of pressure as a function of kinetic energy density, derived from momentum changes, and discusses the implications of particle density and collisions in gases.
- There is a mention of using statistical mechanics to derive the perfect gas law, indicating a potential resource for deeper understanding.
- Another participant introduces calculations related to the number of collisions per unit area and time, as well as mean free length, to further explore the concept of pressure without walls.
Areas of Agreement / Disagreement
Participants generally agree that there can be no pressure without change of momentum, but there is disagreement on the necessity of walls for measuring pressure. Some argue that pressure can be understood through particle collisions alone, while others maintain that walls provide a clearer framework for calculation.
Contextual Notes
Participants express various assumptions regarding the nature of pressure, including the dependence on particle interactions and the implications of using walls as reference points. The discussion includes unresolved mathematical steps related to calculating pressure and collision rates.