Days.
And deep time.
What changes when space expands?
What does a clock actually measure?
Let’s make the assumptions visible.
Gerald Schroeder proposes a connection between Genesis’ creation days and cosmic expansion. Here we check a simple numerical conversion, explore unequal-day allocations, and compare both with the clock used in standard cosmology.
The arithmetic is testable. A physical interpretation needs more than a numerical match. This is an examination of a proposal, not a proof of a six-day physical age.
Read Schroeder’s public explanation ↗Space grows.
Light carries the stretch.
Move through history. Follow one slice of space. Then compare the rhythm of light sent from an earlier universe.
An illustrative early-star epoch at redshift 20. Star formation began over a range of times, not at one instant.
One rhythm, a longer arrival interval.
Hold the emission epoch fixed, then move the history slider forward. A short pulse interval and a light wavelength stretch by the same scale-factor ratio.
Both pulse rows share one time scale up to 4.25×. Larger reception intervals are compressed to fit; their true ratio remains in the labels. The local clock is never slowed. A short-signal relation does not convert the universe’s entire age into days.
The Earth and universe
have different ages.
The universe is about 13.8 billion years old. Earth formed about 4.54 billion years ago. One comes from cosmological inference; the other from geological and meteoritic evidence. NASA ↗ · USGS ↗
Same linear scale. Earth forms roughly 9.26 billion years after the Big Bang. Its geological age and the universe’s age are different measurements.
Light arrives
stretched in time.
For nearby-in-time emissions from a comoving source, the ratio of received to emitted intervals is the ratio of scale factors. This is observed cosmological time dilation. Wright’s cosmology FAQ ↗
a measures the universe’s relative size; z measures redshift. The relation assumes that a changes negligibly over each short emission interval.
Stretch the signal.
Imagine three flashes emitted one second apart. Change the redshift to see their arrival spacing. The source’s own clock still ticks normally.
This compares short emission and reception intervals connected by light. It does not divide the universe’s entire lifetime by one expansion factor.
What would
five and a half days require?
Schroeder’s public article uses a trillion-fold factor and a 5.5-day count. Treat that global factor as a hypothesis and first check its units and arithmetic. The original book has not been independently reproduced here; this appendix checks the public explanation and a clearly labelled teaching model. Author’s explanation ↗
Y is years, D is days, and K is an assumed dimensionless conversion factor. One Julian year is 365.25 SI days throughout the calculations.
Can billions become days?
Yes, arithmetically, if you choose a large enough conversion factor. Try the trillion-fold factor, then see what is required to match your target exactly.
Using K = 10¹², 5.5 days corresponds to 15.06 billion years. A constant-factor conversion is an assumption; redshift alone does not establish this global clock.
At K = 10¹², 13.8 billion years becomes 5.04 days. Conversely, 5.5 days becomes 15.06 billion years. To match 13.8 billion years to 5.5 days exactly requires K ≈ 0.9164 × 10¹².
That last value is calculated from the desired answer. Independent physics would need to establish the factor and its applicability to this whole interval before it could count as a prediction.
A shorter next day.
A chosen rule.
An unequal-day picture is easy to visualize. Here is a geometric allocation: each day receives q times the years assigned to the previous day. This is our illustrative model, normalized to the reference age.
Six days. Unequal slices.
Here the next day holds a chosen fraction of the previous day’s years. The total is deliberately normalized to 13.8 billion years. Changing the fraction redraws the story’s distribution while preserving that total.
This is a geometric teaching model, not a reconstruction of every equation in Schroeder’s books. The shrinking-day rule and normalization are choices; the Friedmann equations do not derive them. Fractional days are interpolated linearly within each slice.
This allocation and the constant-factor calculator are different models. Their 5.5-day results need not agree. Neither model establishes the sequence of physical events described in Genesis.
Let the universe expand.
Keep track of the clock.
For a spatially flat FLRW universe, a clock moving with the cosmic flow has no comoving spatial displacement. Its proper time equals cosmic time. Wright’s tutorial ↗
A model age follows by integrating the expansion history, rather than applying one redshift factor to the entire lifetime. The interactive example uses radiation, matter, and a cosmological constant, with parameters close to Planck’s base ΛCDM inference. Planck 2018 parameters ↗
Follow a physical clock.
In a homogeneous expanding universe, clocks moving with the cosmic flow measure cosmic time. Adjust the expansion model and watch its inferred age change.
Flat radiation + matter + Λ illustration. Ωᵣ = 0.000092; ΩΛ = 1 − Ωₘ − Ωᵣ. Reference H₀ and Ωₘ follow Planck 2018. Sliders explore assumptions, not new fits to observations. Early particle transitions, inflation and neutrino-mass evolution are omitted.
Expansion stretches signals; it does not turn this clock’s billions of years into six days.
A useful comparison.
An unproven identification.
Cosmic expansion stretches observed light signals. Standard cosmology and geological dating support billion-year ages.
A chosen conversion or day-allocation rule can map billions of years onto a few labelled days.
Identifying those labels with literal Genesis days needs independently justified clock definitions, evolution, initial conditions, and an account of the sequence of events.
Mathematics can reveal what follows from assumptions. It cannot, by a fitted ratio alone, establish that those assumptions describe creation.
Take the mathematics
with you.
- Gerald Schroeder, The Age of the Universe. Primary source for the interpretation examined here. Not a consensus physics reference.
- NASA, What is the Universe? Approximate universe age and planetary context.
- USGS, Age of the Earth. Radiometric and meteoritic basis for 4.54 billion years.
- Planck Collaboration, 2018 results VI. Model-dependent H₀ and Ωₘ reference values.
- David W. Hogg, Distance measures in cosmology. Definitions and cosmological age integrals.
- Ned Wright, Cosmology Tutorial, Part 2. Cosmic proper time and comoving observers.
The historical timeline and this optional interpretation remain separate. All interactive controls update immediately; there is no motion required to read a graph.