The original version of this story appeared in Quanta Magazine.
Nearly a century ago, Edwin Hubble discovered that the universe is getting larger. Modern measurements of how fast it is expanding disagree, however, suggesting that our understanding of the laws of physics might be off. Everyone expected the sharp vision of the James Webb Space Telescope to bring the answer into focus. But a long-awaited analysis of the telescope’s observations released late Monday evening once again gleans conflicting expansion rates from different types of data, while homing in on possible sources of error at the heart of the conflict.
Two rival teams have led the effort to measure the cosmic expansion