Boffins crystallize space-time.
“As mind-boggling as the concept may be for most of us, these researchers were able to harness the properties of crystal formation to devise a clock that operates in 4 dimensions, needs no power source and will keep time even after the universe as we know it comes to an end.”
There is some pretty heavy physics concepts here but the above quote is a fairly simple explanation of what Berkley has done here.
Up till now crystals have been made with 3 or less dimensional structures, taking it up to include time gives us a quantum ground state clock that will last literally forever.