Three photons from the same gamma ray burst, recorded in 2009 by the Fermi telescope and recently analyzed by Robert Nemiroff and colleagues, have demonstrated that spacetime is smooth below the Planck length.
Brian Dodson gives an explanation you can follow without a Physics PhD in Quantum spacetime more like foam rubber than beer foam.
According to the Michigan Tech group, spacetime is free of major irregularities on size scales below about 525 Planck lengths in size.
A highly speculative image suggesting how a universe composed of quantum foam might appear at the Planck length (Image: Shutterstock)
Or knuckle dusters on a Bug Eyed Monster!.
This bloke at the Fermilab campus is doing some almost garage scale science on this topic. If your garage has a source of light speed sub atomic particles that is.
It is somehow more inspiring when the science is kind of basic and "hammer and spanner" like this, rather than the CERN level of complexity and expense. Maybe i am old fashioned that way.