The discussion centers around the relationship between light and spacetime, specifically questioning whether light can exist independently of spacetime. Participants explore theoretical implications, the nature of light propagation, and the effects of different reference frames on the speed of light.
Participants express differing views on the relationship between light and spacetime, with no consensus on whether light can exist independently of spacetime. Additionally, there is disagreement regarding the constancy of the speed of light in non-inertial frames.
Participants reference various theoretical frameworks, including Special Relativity and Newtonian mechanics, but do not resolve the implications of these frameworks on the original question. The discussion includes assumptions about the nature of reference frames and the definitions of light propagation.
Does the way you think of it affect any quantitative predictions? If not, it's not a physics question.aditya ver.2.0 said:...or can light be thought ...
The old idea that light propagates in a medium implies that there is just one particular Inertial Reference Frame (IRF) in which light propagates at a constant speed called "c". If that were true then we wouldn't call it spacetime, it would just be space, and time would be independent of space. But theories based on those ideas end up being rather cumbersome and confusing. On the other hand, Special Relativity asserts that light propagates at c in any and every IRF, no matter what the relative speeds are between those IRF's and that is a much simpler concept and still comports with everything we can measure about light, space and time.aditya ver.2.0 said:Since the medium in which light propagates is space time, would light be able to exist if spacetime did not exist?
Rather than thinking of Special Relativity as a problem, it is a simple solution to what would otherwise be an intractable problem in thinking about light, space and time.aditya ver.2.0 said:Is this like one of those chicken/egg problems, or can light be thought of as a legitimately independent entity?
Isn't the speed of light constant in non-inertial frameoo)ghwellsjr said:The old idea that light propagates in a medium implies that there is just one particular Inertial Reference Frame (IRF) in which light propagates at a constant speed called "c". If that were true then we wouldn't call it spacetime, it would just be space, and time would be independent of space. But theories based on those ideas end up being rather cumbersome and confusing. On the other hand, Special Relativity asserts that light propagates at c in any and every IRF, no matter what the relative speeds are between those IRF's and that is a much simpler concept and still comports with everything we can measure about light, space and time.Rather than thinking of Special Relativity as a problem, it is a simple solution to what would otherwise be an intractable problem in thinking about light, space and time.
The speed of light is constant in the non-inertial frames I make using the radar method but other people make non-inertial frames in which the speed of light is not constant. There's no standard way (no rules) to make a non-inertial frame so you can do it any way you like. For example, in the coordinate system defined by GPS, the speed of light is not constant.aditya ver.2.0 said:Isn't the speed of light constant in non-inertial frameoo)
Not in general, no.aditya ver.2.0 said:Isn't the speed of light constant in non-inertial frameoo)
aditya ver.2.0 said:Isn't the speed of light constant in non-inertial frame