fredag 18 september 2015

Ripples in the Fabric of Space and Time?

The code word of modern physics is:
  • fabric of space and time
  • observe gravitational waves—ripples in the fabric of space and time. 
If we dare to ask what the meaning of "fabric of space and time" may be, we get the following illuminating lesson by leading physicists:
  • First of all, space-time is not a fabric. Space and time are not tangible 'things' in the same way that water and air are. It is incorrect to think of them as a 'medium' at all. 
  • No physicist or astronomer versed in these issues considers space-time to be a truly physical medium, however, that is the way in which our minds prefer to conceptualize this concept, and has done so since the 19th century. 
  • We really do not know what space-time is, other than two clues afforded by quantum mechanics and general relativity.
  • Space-time does not claim existence in its own right, but only as a structural quality of the [gravitational] field. (Einstein)
  • Space and time coordinates are just four out of many degrees of freedom we need, to specify a self-consistent theory. What we are going to have [in any future Theory of Everything] is not so much a new view of space and time, but a de-emphasis of space and time. (Steven Weinberg)
  • In the theory of gravity, you can't really separate the structure of space and time from the particles which are associated with the force of gravity [ such as gravitons]. The notion of a string is inseparable from the space and time in which it moves. (Michael Greene)
The punch line of this educational experience is presented in this way: 
  • So, the question about what happens to space-time when a particle moves through it at near the speed of light is answered by saying that this is the wrong question to ask. Just because the brain can construct a question doesn't mean that the question has a physical answer!
We understand that LIGO in its search for "ripples in the fabric of space and time" is studying "the wrong question" and thus can be viewed as a study into the ""fabric of fantasy" which has become such a fundamental part of modern physics demanding full devotion by the sharpest brains of modern physicists (see also here ):

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