The problem is this: we know the Universe is expanding, and we've been able to measure the expansion rate very well in recent years. Even given the puzzle of the Hubble tension, where fundamentally different methods yield answers that disagree at the 9% level, everyone agrees that the modern expansion rate of the Universe is somewhere between 67 and 74 km/s/Mpc.
This Hubble image features a trio of galaxies that appear to be very close together, but appearances can be deceiving. The large spiral galaxy at the bottom right is NGC 1356. The two apparently smaller spiral galaxies flanking it are LEDA 467699 ( top) and LEDA 95415 ( left).
"Building the world's largest digital camera will allow scientists to explore the cosmos in new ways and at a scale that will enable discoveries that should fundamentally change our understanding of the universe," said Aaron Roodman, deputy director of the Rubin Construction.
