Can Quantum Gravity Explain Matter and Gravity as Separate Entities?

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SUMMARY

The discussion centers on the distinction between matter and gravity in the context of quantum gravity theories. In classical general relativity, matter is defined as localizable energy, while gravity is a field without localizable energy. Loop Quantum Gravity (LQG) maintains this distinction and does not attempt to explain matter, whereas string theory suggests that both matter and gravity originate from a more fundamental entity. However, the compatibility of string theory's matter with our universe remains uncertain.

PREREQUISITES
  • Understanding of classical general relativity concepts
  • Familiarity with Loop Quantum Gravity (LQG) principles
  • Knowledge of string theory fundamentals
  • Basic grasp of localizable energy and fields in physics
NEXT STEPS
  • Research the implications of Loop Quantum Gravity on matter and energy
  • Explore the foundational principles of string theory and its approach to gravity
  • Investigate the relationship between spin foams and lattice gauge theories
  • Examine current debates on the compatibility of string theory with observable universe matter
USEFUL FOR

Physicists, researchers in quantum gravity, and students of theoretical physics interested in the foundational aspects of matter and gravity.

wolram
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A mass in 3d space yet, sorry if this so pleb to be ignored.
 
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In classical general relativity, matter is that which has localizable energy, and includes stuff like light and dust, while gravity is the one field that does not have localizable energy. Matter and gravity are postulated to be fundamentally distinct, and gravity does not explain matter.

In Rovellian loop quantum gravity it is postulated that this distinction remains fundamental and so the theory does not seek to explain matter. LQG seems to be roughly ok with matter (spin foams are http://arxiv.org/abs/1103.6264" to some sorts of lattice gauge theories), but it may not have gravity.

In string theory it is postulated that both come from a more fundamental thing. String theory seems to have gravity, and is also roughly ok with matter, but we don't know if the matter in the theory matches that of our universe closely enough.
 
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