Can Quantum Gravity Explain Matter and Gravity as Separate Entities?

In summary, classical general relativity postulates that matter and gravity are fundamentally distinct, with matter being anything with localizable energy and gravity being the only field without localizable energy. Similarly, Rovellian loop quantum gravity also maintains this distinction and does not seek to explain matter. On the other hand, string theory postulates that both matter and gravity come from a more fundamental entity, with the theory seeming to have gravity and being somewhat compatible with matter, but it is uncertain if the matter in the theory is a close match to that of our universe.
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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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Related to Can Quantum Gravity Explain Matter and Gravity as Separate Entities?

1. Can quantum gravity explain the behavior of black holes?

Quantum gravity is a theory that attempts to reconcile the principles of quantum mechanics and general relativity. While it has been successful in explaining the behavior of subatomic particles, it has not yet been able to fully explain the phenomenon of black holes. However, it is an active area of research and there are ongoing efforts to develop a quantum theory of gravity that can better explain black holes.

2. How does quantum gravity relate to the unification of forces?

Quantum gravity is often seen as a key component in the unification of the four fundamental forces of nature: gravity, electromagnetism, strong nuclear force, and weak nuclear force. This is because it attempts to describe gravity in the same way that the other forces are described by quantum field theories. However, a complete unification of all forces has not yet been achieved.

3. Can quantum gravity explain the origin of the universe?

The origin of the universe is a complex and ongoing topic of study in cosmology and physics. While quantum gravity offers potential explanations for the early moments of the universe, it is not yet able to fully explain the origin of the universe. Theories such as the inflationary model and loop quantum cosmology incorporate elements of quantum gravity to try to explain the origin of the universe, but much more research is needed in this area.

4. Is quantum gravity necessary for understanding the behavior of particles at the Planck scale?

The Planck scale is the smallest scale at which our current understanding of physics breaks down. Quantum gravity is believed to be necessary for fully understanding the behavior of particles at this scale, as it incorporates both quantum mechanics and gravity. However, due to the immense energy and complexity involved, it is currently not possible to experimentally test this at the Planck scale.

5. Can quantum gravity explain the phenomenon of time?

Time is a fundamental aspect of our experience of the universe, but it is not yet fully understood by science. While quantum gravity offers potential explanations for the behavior of time at the smallest scales, it is still a topic of ongoing research and debate. The concept of time is also closely tied to theories of consciousness and the nature of reality, making it a complex and multifaceted topic.

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