JWST’s Newfound Galaxies Are the Oldest Ever Seen

Scientific American, April 13, 2023. By Jonathan O’Callaghan, edited by Lee Billings.

Key Takeaways

• JADES-GS-z13-0 is the most distant confirmed galaxy, at redshift 13.2 — roughly 320 million years after the Big Bang.
• They formed faster than models predicted, and some show star-formation rates comparable to the Milky Way despite being far smaller, which pressures existing accounts of galaxy formation and dark matter.
• “You go from nothing to these fully formed galaxies in the blink of an eye.” — Pieter van Dokkum, Yale.
• “The vast majority of these galaxies are being confirmed.” — Steven Finkelstein, UT Austin. The finding is not a measurement artifact.
• “We’ve been waiting decades for this.” — Emma Curtis-Lake, Hertfordshire.

Connections

• Saved against Super Uno Pluribus as the largest-scale case of structure appearing sooner and more completely than the theory of its assembly allows.
• ⚠️ The analogy has a hard limit. “Faster than models predicted” is a statement about the models, not about causation. The defensible borrowing is narrow: theories of assembly consistently underestimate how quickly complex structure appears.