Understanding Mach's Principle: 2 Objects & Zero Observation

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Discussion Overview

The discussion centers around Mach's principle, particularly in a hypothetical scenario involving only two objects in the universe and the implications of observation. Participants explore philosophical and conceptual aspects of observation, existence, and the nature of objects in relation to Mach's principle.

Discussion Character

  • Exploratory
  • Conceptual clarification
  • Debate/contested

Main Points Raised

  • One participant expresses confusion about Mach's principle, suggesting that with only two objects, observation is impossible due to the absence of photons.
  • Another participant argues that even with photons present, observation is contingent on the observer's existence, referencing the state of being before birth as an example.
  • A third participant questions the use of "we" in the context of observation, prompting a discussion about the necessity of an observer.
  • There is a suggestion that photons do not qualify as "somebodies" necessary for observation, as they are modes of a field rather than conscious entities.
  • One participant reflects on the philosophical implications of observation, noting that a structureless particle cannot perceive motion without a reference point, implying that at least three bodies are needed for meaningful observation.
  • A later reply mentions a book, "The End of Time" by Julian Barbour, as a resource for those interested in the philosophical reflections related to real physics.

Areas of Agreement / Disagreement

Participants express differing views on the nature of observation and the implications of Mach's principle, indicating that multiple competing perspectives remain without consensus.

Contextual Notes

Participants highlight limitations in understanding Mach's principle and the conditions under which observation can occur, suggesting that the discussion is dependent on definitions of observation and the nature of objects.

mersecske
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I don't understand the Mach's principle completely.

In the base situation when there are only two objects in the Universe.
I think there is no question, because we cannot observe anything,
since there are no photons etc. in the Universe.
 
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Well, even when there are photons, but you are not there - you will not be able to observe anything. For instance before you are born. That does not mean that the universe does not make sense and you can't discuss what happens when when you are not there.
 
Its not about me or you
 
You wrote "because we cannot observe anything". Whom did you have in mind writing "we"?
 
Somebody on the object.
 
So, you need "somebodies". Photons, as far as we know, are not "somebodies". Photons are modes of a quantized electromagnetic field.
 
mersecske said:
I don't understand the Mach's principle completely.

In the base situation when there are only two objects in the Universe.
I think there is no question, because we cannot observe anything,
since there are no photons etc. in the Universe.

What about Mach's principle do you not understand? It's not obvious from your three sentences what you are asking.
 
I have never read Mach but only read of Mach indirectly. This is not the Mach's principle I know of, but it sounds like the sort of thing he would have enunciated.

For the purposes of philosophical argument it is permissible to take a naive view of e.g. vision, and imagine like you do before knowing any physics, that stuff is just there and you can see it. You would have to know what a 'body' is. A structureless particle even if conscious cannot see another object move. It needs a third object in order to see it move with respect to. Or it needs to be a body with a structure of its own - well that is really a particular example of the former case. It cannot have any experience (e.g. of something moving) unless it has a memory or a means of recording a past situation and comparing with present. Three bodies in the Universe is a minimum and even that is pushing it!

If you are interested in this sort of reflection but in connection with real physics there is a book called "The end of time" by Julian Barbour plus, I just saw, a website and stuff on the web..
 

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