Did Hubble Steal Credit From Lemaître's Discovery?

The first time I knew the name Hubble, it belonged to a telescope, not a man — the one circling far above the Earth, sending back images of galaxies too distant to see any other way. I learned there was a person attached to that name only later, after I'd already fallen for the night sky on my own. And the more I read about him, the more the disappointment crept in.

Somewhere along the way, I'd been handed a story about one man discovering that the universe expands. The story, it turns out, leaves out most of the people who did the actual work.

Here's who actually calculated the universe's expansion first, and why the man who got the credit almost certainly didn't steal it, even though the popular version makes it sound that way. It involves a Belgian priest, a French-language journal almost nobody read, and missing pages that took eighty years to explain.

Georges Lemaître Did the Math in 1927, Two Years Before Hubble

The disappointment starts with a man named Georges Lemaître, two years before Hubble's name ever entered the story.

Lemaître was a Belgian physicist and a Catholic priest working through Einstein's general relativity equations. He wasn't even the first to notice that the math allowed for a universe that isn't fixed in size.

A mathematician named Alexander Friedmann had already found non-static solutions to Einstein's equations back in 1922. What Lemaître did in 1927 was different: he tested the idea against real telescope data.

He published his results in French, in a Belgian journal not widely read outside Belgium. His velocity data came from Vesto Slipher, an astronomer at Lowell Observatory, by way of a 1925 compilation from fellow astronomer Gustaf Strömberg. His distance figures came from Hubble's own estimates from the year before.

Working through 42 nebulae, Lemaître calculated the expansion rate at 625 kilometers per second per megaparsec. In a footnote, he ran the numbers a second way and landed on two more figures, 575 and 670, depending on how the data were grouped.

Both scientists reached similar conclusions from much of the same underlying data, working independently of each other.

Lemaître wasn't guessing at a philosophy of the cosmos. He was working with the data he had. I still wonder how different this whole argument would look if he had simply written it in English.

What Hubble's Famous 1929 Paper Actually Said

Hubble's own paper is more modest than the myth built on top of it.

In 1929, Hubble published "A Relation between Distance and Radial Velocity among Extra-Galactic Nebulae" in the Proceedings of the National Academy of Sciences. The paper compared distance and velocity for 24 galaxies, a small sample by modern standards, and found that the farther away a galaxy sat, the faster it appeared to be moving away.

For distance, Hubble did his own work. For velocity, he leaned on someone else's numbers.

Most of the recession-velocity figures in Hubble's paper came from Vesto Slipher's spectroscopy, the same data Lemaître had used two years earlier. Some of the key observations were carried out by Milton Humason, Hubble's observing partner at Mount Wilson.

Here's the part the popular version skips. Science historians note that Hubble was cautious about what the pattern meant. Some go further: a 2011 paper by astronomers Michael Way and Harry Nussbaumer argues Hubble never fully embraced the idea of an expanding universe, and doubted it for the rest of his career.

The more I read of Hubble's original paper, the more it feels like a careful observation waiting for an explanation, not proof of anything.

Credit doesn't always track cleanly with achievement, it turns out. NASA found that out again decades later, when its newest space telescope ran into its own naming fight.

The Missing 1931 Pages That Fueled the Theft Rumor

Here's where the theft accusation actually earns its teeth.

In 1931, Lemaître's 1927 paper was finally translated into English and published in the Monthly Notices of the Royal Astronomical Society, four years after the French original and two years after Hubble had already become famous for a similar result. Two pages were missing from the English version, including the section where Lemaître calculated 625 and the footnote with 575 and 670.

For decades, that gap looked exactly like what everyone assumed: someone protecting Hubble's priority by quietly trimming the competition's numbers from the record. It's a good story, and I'll admit I went looking for the villain in it.

The letter doesn't cooperate. Lemaître wrote to William Marshall Smart, the astronomer who arranged the English translation, on March 9, 1931. The letter came to light and was studied closely in research reported by Nature in 2011, backed by the Royal Astronomical Society's own archives.

In it, Lemaître himself asked that some of his 1927 calculations be left out of the English version. His stated reason: by 1931, he considered those figures outdated.

Edwin Hubble did not steal the expanding universe from Georges Lemaître.

Maybe the least satisfying part of this whole mystery is how ordinary the real explanation turns out to be. No cover-up, no editor with a grudge — just a scientist deciding his own four-year-old numbers weren't worth reprinting, a choice that would end up costing him more credit than he could have guessed.

The Names This Story Keeps Leaving Out

Lemaître isn't even the only name this story tends to drop.

Vesto Slipher spent from the 1910s onward measuring the spectra of one faint nebula after another, quietly building the pile of redshift data that both Lemaître and Hubble would later lean on. I find Slipher's part of this story the hardest to sit with — years of patient measurement, and his name mostly shows up as a footnote to other people's equations. Milton Humason spent long nights at Mount Wilson exposing photographic plates for hours at a stretch to capture the spectra of galaxies too dim for a quick look.

In 1931, he and Hubble published an expanded version of the distance-velocity study together, built on a larger sample than either man had used alone.

This kind of erasure runs through the history of science, and it happens even more often to the women who did comparable work without comparable recognition.

Maybe science history just likes a single hero standing at a chalkboard better than a crowded room. The actual history usually is a crowded room, and most of the people in it never make the chalkboard.

In 2018, the International Astronomical Union tried to correct part of this by formally recommending a new name for the relationship between galaxy distance and velocity: the Hubble–Lemaître law. The resolution wasn't a ruling that Hubble had done anything wrong, and it didn't erase his name from anywhere.

Lemaître did the math first. It took ninety-one years for his name to share the sentence.

Almost a Century Later, the Expansion Rate Still Doesn't Add Up

The argument over the exact number never really ended. It just got a much bigger budget.

I would have thought that with a space telescope and a satellite involved, instead of a priest with a slide rule, this would be settled by now. It isn't.

Cosmologists call the current disagreement the Hubble tension: teams using different methods keep landing on different numbers.

In 2022, the SH0ES team, combining data from the Hubble Space Telescope and the Gaia satellite, measured the expansion rate at 73.04 kilometers per second per megaparsec. The Planck satellite's 2020 analysis of the universe's earliest light, using the standard cosmological model, puts the same number at 67.4.

73.04. 67.4. Neither number has moved yet.

Nobody has settled which measurement is wrong, or whether either one is. It might be a calibration problem still working its way out of the data. It might be a sign the standard model is missing something. The argument, for now, stays open.

The name outlived the argument in more ways than one. By the time I learned an astronomer was attached to the word "Hubble," it already belonged to a law, a constant, and a space telescope with a complicated origin story worth its own read. All three carry a name that, on the evidence here, was never quite as solitary an achievement as it sounds.

Source / Year	Estimated Expansion Rate	Method
Georges Lemaître, 1927	625 km/s/Mpc (footnote: 575 and 670)	42 nebulae; Slipher's redshifts via Strömberg (1925), Hubble's 1926 distances
Planck Collaboration, 2020	67.4 ± 0.5 km/s/Mpc	Cosmic microwave background analysis, flat ΛCDM model
SH0ES Team, 2022	73.04 ± 1.04 km/s/Mpc	Distance ladder using Hubble Space Telescope and Gaia data

Hubble's own colleagues didn't always think kindly of him, either. He turns up in letters and recollections as prickly, difficult to work with, not an easy man to have in the room. None of that makes the theft story true.

But it does leave a harder question sitting where the easy one used to be: was Edwin Hubble really the singular genius the textbooks remember, or did the rest of us just find it easier to build one hero than to credit a crowded observatory full of them?

Frequently asked questions

What is the Hubble-Lemaître law?

The Hubble-Lemaître law describes how a galaxy's distance from Earth relates to how fast it appears to be moving away, expressed as v = H0 × d for relatively nearby galaxies. The value H0, called the Hubble constant, is currently estimated between about 67 and 73 kilometers per second per megaparsec, depending on the measurement method.

Why is it sometimes called the Hubble-Lemaître law instead of just Hubble's law?

In 2018, the International Astronomical Union recommended crediting Georges Lemaître alongside Hubble in the law's name. Because the recommendation isn't a binding rule, both "Hubble's law" and "Hubble-Lemaître law" remain in common use today.

Does the Hubble tension mean the Big Bang theory is wrong?

No. The Hubble tension refers to a disagreement between two ways of measuring the universe's expansion rate, not evidence against the Big Bang itself. Scientists have not yet determined whether the gap comes from a calibration issue or points to new physics.

Sources and References

This article is for educational and informational purposes only. Sources are linked where available. Readers are encouraged to consult primary sources for further research.

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