Discussion Overview
The discussion revolves around the concept of center-of-mass in the context of Newtonian physics and special relativity (SR). Participants explore whether the determination of center-of-mass is instantaneous or affected by the speed of light, as well as the relationship between center-of-mass and center-of-gravity.
Discussion Character
- Exploratory
- Technical explanation
- Debate/contested
Main Points Raised
- Some participants assert that in Newtonian physics, the center-of-mass is determined by the instantaneous positions of particles, regardless of their relative motion.
- One participant believes that the determination of center-of-mass in special relativity is instantaneous, questioning how a delay could be conceptualized without knowing the point in question.
- Another participant argues that determining the center of mass does not involve any physical movement and thus should not be subject to light speed limitations.
- A participant raises a question about the distinction between center of mass and center of gravity, noting that gravity waves in general relativity (GR) travel at the speed of light.
- One participant mentions that the center of mass is frame-dependent in relativity, highlighting that observers may disagree on its location while agreeing on the center of momentum frame.
Areas of Agreement / Disagreement
Participants express differing views on whether the center-of-mass is determined instantaneously or subject to delays due to the speed of light. There is no consensus on the relationship between center-of-mass and center-of-gravity, nor on the implications of frame dependence in relativity.
Contextual Notes
Some limitations include the dependence on definitions of center-of-mass and center-of-gravity, as well as the unresolved implications of relativistic effects on the determination of center-of-mass.