Human Journey

Hubble v. Slipher: Putting Due Credit in Perspective

“If I have seen further, it is only by standing on the shoulders of giants.”

Most people familiar with this phrase attribute it to Sir Isaac Newton, who included it in a letter to fellow Brit researcher Robert Hooke in the late 1600s.


The remark is often taken as Newton tipping his voluminous wig to the scientists whose work served as the basis of his eventual breakthroughs in math, optics, and gravitational laws of motion.

Irony alert: It seems Newton pinched the quote from a 12th century writer called John of Salisbury.

There’s something about human nature that makes us want every story to have a hero—or at least a main character driving the action—even when we know for a fact that most important events are driven by teams, who themselves are building their work on the years of toil compiled by previous teams of experts.

There’s also nothing that seems to get a scientist riled up more than someone else getting public accolades for work in which they think they deserve the glory.

It’s such a point of honor in the community that even scientists not involved in the competing projects will continue to bicker years after the dueling heroes have died.

A case-in-point exploded right before my eyes Wednesday night during a press screening of a new documentary about telescopes at the [sniff, now over] American Astronomical Society meeting in Long Beach.

The PBS doc, called 400 Years of the Telescope, is a pretty straightforward telling of how the device first got applied to astronomy, what scopes have shown us since Galileo’s time, and what the future holds for building newer, larger instruments for scanning the skies.

Writer/director Kris Koenig shared with us Galileo’s Astronomical Ale (“theoretically the best beer in the universe!”) and then aired some clips from his show at a small reception Wednesday night.

Unfortunately for him, one of the segments pretty much directly and singularly credits astronomer Edwin Hubble with discovering the expansion of the universe.

Meh, you might say. That’s what started a scientific cat fight? Seems like a pretty innocent statement, especially since Hubble must have done something pretty cool career-wise… Isn’t that why we named a great big space telescope after him?


—Image courtesy NASA

To understand why the subject is touchy, let me get even more geeky for a moment…

Telescopes have played a big role in helping us revise our models of how the universe works. But many of these steps were pretty big mind-blowers for people of the time, akin to folks today finding out that mice built the Earth to be a giant organic computer.

It was Galileo’s use of a telescope to watch planetary motions that provided solid proof for Nicolaus Copernicus’s sun-centered model of the cosmos, dethroning Earth as the center of everything—and eventually landing Galileo in house arrest until his death.

Telescopes also gave a long line of astronomers the resolution required to see that some bright spots in the sky look more like clouds than single points of light. A few of these so-called nebulae were even seen to have structure—spirals and ellipses and rings, o my!

As far back as the 1700s English astronomer Thomas Wright suggested that nebulae are actually other Milky Ways outside our own galaxy.

Hubble, in fact, was the one to put the nail in that coffin in the 1920s when he used the largest telescope of his time to see individual stars within nebulae, including some from a gently pulsing class of stars that allow astronomers to calculate their distances from Earth.

What he saw proved to the world that these nebulae are too far out to be part of our home galaxy, and must be galaxies themselves.


—Image courtesy Robert Williams and the Hubble Deep Field Team (STScI) and NASA

And here’s where things get sticky.

Hubble measured the distances of many galaxies with a high degree of precision. Meanwhile, several astronomers—including one Vesto Slipher of the Lowell Observatory in Arizona—were measuring how fast those galaxies were moving away from us, a value known to astronomers as redshift.

Combining his data on distances with Slipher’s data on the same galaxies’ redshifts, Hubble and colleague Milton Humason calculated that galaxy distance was proportional to speed. In other words, the universe is not only vast, it’s expanding.

This was a game-changer for astronomy, which for most of human history rested on the notion that the universe is a static, unmoving kind of place.

To some experts, the work is good enough to pile praise on Hubble for all eternity, the hero of the story of universal expansion. But to a few members of the AAS screening audience, at least, Hubble was just that guy who found the last puzzle piece under the couch and stuck it in to complete the picture.

Many other “giants” contributed to the discovery, most notably Slipher, who gets no love at all in this particular documentary.

Tempers flared, names and dates flew around the room like shrapnel, and the poor director was stuck repeating his safety line: “Everything in the film was reviewed by a panel of 12 notable astronomers.”

Regardless of how you come down on the issue, Slipher may eventually get some public visibility, as human nature also seems to love a good “rise of the underdog” story. Many more people these days seem to know of Rosalind Franklin being a key player in the Watson and Crick DNA breakthrough, so I think there’s hope.

Or maybe everyone just needs a trip to the Total Perspective Vortex. That’d show ’em.

  • jack

    Thank you for another essential article. Where else could anyone get that kind of information in such a complete way of writing? I have a presentation incoming week, and I am on the lookout for such information.
    mbt shoes online
    mbt sandals
    mbt sandals sale

About the Blog

Researchers, conservationists, and others share stories, insights and ideas about Our Changing Planet, Wildlife & Wild Spaces, and The Human Journey. More than 50,000 comments have been added to 10,000 posts. Explore the list alongside to dive deeper into some of the most popular categories of the National Geographic Society’s conversation platform Voices.

Opinions are those of the blogger and/or the blogger’s organization, and not necessarily those of the National Geographic Society. Posters of blogs and comments are required to observe National Geographic’s community rules and other terms of service.

Voices director: David Braun (

Social Media