When it comes to the dimensions of spacetime, what you see may be what you get.
Using observations from the collision of two neutron stars that made headlines in 2017 (SN: 11/11/17, p. 6), scientists found no evidence of gravity leaking into hidden dimensions. The number of observed large spatial dimensions — kilometer-scale or bigger — is still limited to the three we know and love, the researchers report January 24 at arXiv.org.
Just as insects floating on a pond may be unaware of what’s above or below the water’s surface, our 3-D world might be part of a higher-dimensional universe that we can’t directly observe. However, says astrophysicist David Spergel of Princeton University, a coauthor of the new study, “gravity might be able to explore those other dimensions.”