Discussion Overview
The discussion revolves around the measurement of vacuum in the universe, specifically addressing the concept of "absolute vacuum" and the pressures involved in creating deep vacuums on Earth. Participants explore the implications of these pressures on spacecraft and compare them to atmospheric conditions experienced by high-flying aircraft.
Discussion Character
- Exploratory
- Technical explanation
- Debate/contested
Main Points Raised
- One participant notes that the deepest vacuum achieved on Earth is about 1000 molecules per cm3, requiring immense energy to reach a pressure of 400 billion bars.
- Another participant explains that spacecraft can withstand the pressure difference because their internal pressure can be at normal atmospheric levels, which is similar to conditions faced by high-flying airplanes.
- A different viewpoint suggests that the stress on a vessel's skin is proportional to the difference between internal and external pressures, questioning the relevance of the 400 billion bars figure in relation to molecular density.
- One participant emphasizes that achieving ultra-deep vacuums is more about the purity of the process rather than the energy required, expressing uncertainty about the comparison of billions of bars to absolute vacuum.
- A participant provides a link to a previous discussion on vacuums that may offer additional insights.
Areas of Agreement / Disagreement
Participants express differing views on the relationship between pressure, molecular density, and the concept of absolute vacuum. There is no consensus on the significance of the 400 billion bars figure or its connection to the molecular count.
Contextual Notes
Participants mention various assumptions regarding pressure measurements and the definitions of vacuum, but these remain unresolved within the discussion.