An illustration of the first stars turning on in the Universe. Without metals to cool down the clumps of gas that lead to the formation of the first stars, only the largest clumps within a large-mass cloud will wind up becoming stars: fewer in number but greater in mass than today’s stars. Although there’s plenty of light-blocking matter surrounding them, some longer-wavelength light (when first emitted) can still escape into the Universe beyond. (Credit: NASA / WMAP Science Team)
With several seemingly incompatible observations, cosmology faces many puzzles. Could early, supermassive stars be the unified solution?
In most scientific fields, one of the most exciting things we can encounter is data — high-quality, robust data — that doesn’t align neatly with the expectations of our currently leading theories. Since the late 1990s, our leading theory of the Universe has been known as either the “ΛCDM” or “concordance” cosmology, where our Universe:
began with a period of cosmic inflation that preceded and set up the hot Big Bang,
then the hot Big Bang occurred, creating a dense, hot, mostly uniform Universe,
containing normal matter and radiation, but dominated by dark matter and dark energy,
which gravitated, expanded, and cooled,
forming the light elements, neutral atoms, stars, galaxies, and black holes,
and giving rise to the Universe as we observe it today.
Today, that concordance picture looks like a Universe presently expanding at a rate of ~70 km/s/Mpc, made of around 70% dark energy as a cosmological constant and 25% dark matter as…
