Einstein’s gravity endures despite a dark energy puzzle

An analysis upholds general relativity but hints dark energy may vary over time 

A telescope instrument is pointed at a starry sky.

Scientists mapped galaxies with the Dark Energy Spectroscopic Instrument at the Mayall telescope (shown) at Kitt Peak National Observatory in Arizona.

T. Slovinský, KPNO/AURA/NSF, NOIRLab

Scientists could be wrong about dark energy.