At a glance

• Researchers have reported evidence consistent with a “primordial” black hole — an object that could have formed in the first fractions of a second after the Big Bang.
• If confirmed, it would be among the oldest known black holes, predating the first stars and galaxies.
• Such a finding would shed light on how supermassive black holes appeared so quickly in the early universe and could even inform theories of dark matter and inflation.

What does “less than one second after the Big Bang” actually mean?

Cosmologists measure cosmic age from the moment of the Big Bang. The interval around one second after that moment was a special epoch: the universe was still a hot, dense plasma, protons and neutrons were forming light nuclei, and neutrinos were decoupling from matter. There were no stars yet — those appeared hundreds of millions of years later. A black hole originating at this time would therefore not be the remnant of a star; instead, it would be what physicists call a primordial black hole (PBH), born directly from extreme density fluctuations in the very early universe.

Why are primordial black holes a big deal?

• Seeding supermassive black holes: Telescopes like JWST have found surprisingly massive black holes in galaxies less than a billion years after the Big Bang. PBHs could have provided the “head start” seeds that rapidly grew into these giants.
• Dark matter candidate: If PBHs exist in the right mass ranges and abundances, they could account for some fraction of the universe’s dark matter.
• Window on the first instants: PBHs encode information about conditions during inflation and reheating, scales far beyond what we can probe in particle accelerators.

How can scientists find a black hole from the universe’s first second?

Black holes do not emit light, but their gravity leaves fingerprints that observatories can detect. Evidence consistent with a primordial origin can arise in several ways:

• Gravitational lensing: A compact, massive object crossing our line of sight can briefly magnify the light of a distant star, quasar, or galaxy — a phenomenon called microlensing. The duration and shape of the brightening event constrain the lens’s mass and size.
• Gravitational waves: Mergers of black holes with unusual masses or mass ratios, detected by LIGO–Virgo–KAGRA, could hint at a primordial population distinct from black holes formed by dying stars.
• Cosmic backgrounds: An excess or pattern in the cosmic infrared or microwave background, or in the nanohertz gravitational-wave background seen by pulsar timing arrays, can be compared with models that include PBHs.
• Early-universe counts: If we infer black holes that appear too early or too massive to be explained by normal stellar evolution, a primordial origin becomes a strong candidate.

The reported discovery highlighted by Yahoo News Canada points to one or more of these signatures producing a mass and age estimate that are most naturally explained if the object formed almost instantaneously after the Big Bang.

How do researchers estimate “age” for such an object?

Scientists do not watch a black hole aging directly. Instead, they infer when it must have formed by combining:

• Redshift of the background source being lensed (to know the cosmic time window involved).
• Mass and compactness of the lens, derived from the lensing light curve or image distortions.
• Population models, which predict how many stellar-remnant black holes should exist along the line of sight compared with a hypothetical primordial population.
• Consistency checks against constraints from big bang nucleosynthesis and the cosmic microwave background, which limit how many PBHs of different masses can exist without conflicting with observed element abundances and radiation patterns.

When these pieces align, a primordial-formation scenario — potentially within a fraction of a second after the Big Bang — emerges as the simplest explanation.

What this could mean for cosmology

• New constraints on inflation: A confirmed PBH reveals the amplitude of density fluctuations on extremely small scales, sharpening or ruling out families of inflationary models.
• Pathways to rapid growth: If PBHs provided the seeds, simulations of galaxy formation can more naturally reproduce the supermassive black holes seen in the first billion years.
• Dark matter mapping: Even if PBHs are only a minority of dark matter, pinning down their abundance constrains what the rest must be.

Reasons for healthy skepticism

Extraordinary claims demand extraordinary evidence. Several caveats often apply:

• Lensing degeneracies: Different lens masses, distances, and velocities can produce similar brightening curves. Robust modeling and independent cross-checks are essential.
• Astrophysical impostors: Stellar remnants (black holes, neutron stars, or even binary stars) within our galaxy or a foreground galaxy can mimic primordial signatures.
• Selection effects: Surveys are more likely to notice unusual, high-magnification events; correcting for this bias is nontrivial.
• Consistency with early-universe physics: A PBH population must not overproduce gamma rays, disrupt light-element abundances, or violate microwave-background limits.

Because of these challenges, teams typically seek multiple, independent observations before declaring a definitive primordial origin.

What to watch next

• Follow-up observations: Repeat monitoring of the same field to catch additional lensing events attributable to the same object or population.
• High-resolution imaging: JWST, HST, Euclid, and the upcoming Roman Space Telescope can resolve lensed arcs and pinpoint compact lenses.
• Time-domain surveys: The Vera C. Rubin Observatory (LSST) will provide an unprecedented catalog of microlensing events across the sky.
• Gravitational-wave catalogs: As LIGO–Virgo–KAGRA resume operations and next-gen detectors come online, the mass spectrum and spins of merging black holes will test PBH scenarios.
• Pulsar timing arrays: Continued measurements by NANOGrav and partners will refine the nanohertz gravitational-wave background that could include a PBH component.

Quick primer: timeline of the very early universe

• 10^-36 to 10^-32 s: Cosmic inflation (hypothesized) rapidly expands space.
• 10^-12 to 10^-6 s: Quarks bind into protons and neutrons as the universe cools.
• ~1 s: Neutrinos decouple; conditions allow light nuclei to begin forming (big bang nucleosynthesis).
• ~380,000 years: Atoms form; the universe becomes transparent; the cosmic microwave background is released.
• ~100–500 million years: First stars and galaxies ignite; stellar black holes begin to form.

A black hole created “less than one second” after the Big Bang would therefore belong to a fundamentally different class than black holes born from collapsed stars.

Bottom line

The report covered by Yahoo News Canada points to a candidate black hole whose properties are best explained if it formed in the universe’s first heartbeat — well before stars or galaxies existed. If subsequent observations confirm a primordial origin, the object would provide a rare, powerful probe of physics at energies and timescales otherwise far beyond reach, reshaping our understanding of how the universe began and how its earliest structures emerged.