Undergrad Theoretically, can perfectly flat spacetime exist in the Universe?

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SUMMARY

The discussion centers on the theoretical possibility of achieving perfectly flat spacetime in the presence of mass and energy, as dictated by general relativity. It concludes that while a perfectly spherical shell of matter can create a locally flat spacetime, it requires an idealized scenario that is unattainable in reality due to the Heisenberg Uncertainty Principle and the inherent imperfections of physical objects. The conversation emphasizes that perfect flatness is a mathematical concept rather than a physical reality, as any actual region will exhibit some curvature due to external mass distributions.

PREREQUISITES
  • Understanding of general relativity principles
  • Familiarity with the Heisenberg Uncertainty Principle
  • Knowledge of spherical symmetry in physics
  • Basic concepts of gravitational waves and their properties
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  • Research the implications of the Heisenberg Uncertainty Principle on spacetime geometry
  • Study the properties of gravitational waves and their interaction with matter
  • Explore the concept of spherical symmetry in general relativity
  • Investigate the theoretical frameworks for quantum gravity
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This discussion is beneficial for physicists, students of theoretical physics, and anyone interested in the complexities of spacetime geometry and gravitational wave interactions.

  • #31
Alien101 said:
Perfect flatness would require absolutely nothing in the entire universe
This is not correct. As already discussed in this thread, a spherical shell of matter in an otherwise empty universe has flat spacetime in the cavity inside.

You still can't have perfectly flat spacetime in the real universe, but your claim misses a case.
 
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  • #32
This thread is now closed since the OP question has been well addressed.
 

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