Natalie Paquette, a theoretical physicist at the University of Washington, and a growing number of physicists are exploring the idea that space and time may not be fundamental, but rather emergent from more basic components. This idea comes from the hunt for a theory of quantum gravity, which aims to reconcile general relativity and quantum physics. String theory, the most popular candidate theory of quantum gravity, suggests that space and time are built from quantum entanglement. Loop quantum gravity, another theory, suggests that space and time are made up of discrete components. Both theories point towards an emergent nature of space and time. However, the lack of direct experimental data has made it challenging to test these theories, with scientists relying on cosmology and laboratory experiments to explore the true nature of space and time.
| Signal | Change | 10y horizon | Driving force |
|---|---|---|---|
| Physicists are increasingly converging on the idea that space and time may be emergent | Change from fundamental to emergent | A deeper understanding of the emergence of space and time | The search for a theory of quantum gravity |
| String theory suggests that space is built from quantum entanglement | Change from fundamental to emergent | Better understanding of how space emerges from entanglement | Exploring the AdS/CFT correspondence and finding a cosmological version |
| Loop quantum gravity suggests that space and time are made of discrete components | Change from smooth and continuous to discrete | Further development and exploration of loop quantum gravity | Understanding the collective behavior of spacetime “grains” |
| The lack of direct experimental data makes the search for a theory of quantum gravity difficult | Change from direct experimental data to reliance on cosmological observations and lab experiments | Cosmology may provide insight into quantum gravity | Testing the AdS/CFT correspondence through entangled systems of atoms |
| Questions about the true nature of space and time are ancient and continue to be asked | Change from ancient philosophy to current scientific inquiry | Continued exploration and reflection on the nature of space and time | Curiosity and the pursuit of knowledge |