- #1
Gerinski
- 323
- 15
What I mean by this question is the following: If, just for example, we define the surface region of a star as that where the matter undergoes a phase transition from plasma to radiation, then that boundary has an objective physical meaning (let's not bother with the fact that the transition is not definite and there are flares and fluctuations and so on, that's not my point).
On the other hand, if we define the surface of the star, again as just an example, by the region where its radiation falls below the visible spectrum and becomes infrared, the 'visible diameter of the star for us humans', then that description is subjective, any living being with infrared vision would say that the diameter of the star is larger than what we humans say, and any living being with vision shifted the other way might say that the star diameter is smaller.
TX!
On the other hand, if we define the surface of the star, again as just an example, by the region where its radiation falls below the visible spectrum and becomes infrared, the 'visible diameter of the star for us humans', then that description is subjective, any living being with infrared vision would say that the diameter of the star is larger than what we humans say, and any living being with vision shifted the other way might say that the star diameter is smaller.
TX!