Capturing Primordial Starlight

Edwin Hubble at 100-Inch

 By 1936, Edwin Hubble was a dozen years into his search for distant galaxies. At that time, he could see out to several hundreds of millions of light-years, using the great 100-inch telescope atop California’s Mount Wilson. But even then the smudges on his photographic plates were dim, fuzzy, and next to impossible to identify.

“There,” wrote Hubble in his classic book The Realm of the Nebulae, “we measure shadows and…search among ghostly errors of measurement for landmarks that are scarcely substantial.”

Ever since, astronomers have struggled to trace the evolution of galaxies back through space-time—not just hundreds of millions of light-years but billions. For decades, all that astronomers could say with surety were that distant galaxies and clusters looked a bit “bluer,” a sign of heightened star formation as hoards of young, massive stars, flush with energy, put out more blue light.

Quasars, the brilliant cores of newborn galaxies, had long been sighted at great distances, but astronomers questioned whether they could truly understand the early universe by studying only its most active members.

But thanks to key technological breakthroughs over the last two decades—among them, the Hubble Space Telescope, the opening of giant telescopes in Hawaii and South America, and advances in telescopic detectors—more typical primordial galaxies are now being found, and at greater and greater distances.




UDFy-38135539 (circled in red) lurks within the Ultra Deep Field


The current record holder was recently discovered by a European team of astronomers using the European Southern Observatory’s Very Large Telescope (VLT) in Chile. It’s but a speck in the image, but a sensitive spectrograph allowed the observers to peg its distance. It’s more than 13 billion light-years from Earth and has been christened UDFy-38135539. That’s a mouthful for us but helpful to astronomers: the UDF stands for Ultra Deep Field (a region located in the southern-hemisphere constellation Fornax that was first closely imaged by the Hubble Telescope) and the number pegs its precise position on the sky.

The photons from this distant object started their journey when the universe was only 600 million years old. This was a time when a great fog of hydrogen gas, in which the universe was bathed, was just beginning to break up—cleared out by the fierce ultraviolet light emitted by newborn galaxies. The VLT likely sighted the new record holder through a break in the clouds, a lucky event for the astronomers and for us.  Through this fortuitous window, we get to see a bit of primordial starlight.

Picture Credits: (top) Huntington Library; (bottom) European Southern Observatory

All the King's Men

I've had many inquiries about the cover of my latest book.  It shows Einstein and company during a visit to the top of California's Mount Wilson on 29 January 1931. It was the one and only time Einstein made the trip. The group is standing in front of the dome of the observatory's historic 100-inch telescope, the instrument Edwin Hubble used to make his major discoveries.

Everyone wants to know, who are those other people? Here's the scoop (as far as I know it): The tall man right behind Einstein's hair and above the short guy in front of him is Hubble. The short guy is Walther Meyer, Einstein's assistant. The man in the hat, slightly leaning in the center, is astronomer Walter Adams, then head of the Mount Wilson Observatory. The stiff-looking man on the right with the distinguished chapeau is William Campbell, who at the time was directing Lick Observatory (Mount Wilson's competitor to the north). The other men, I believe, are professors from Caltech. (If anyone knows who they are, please contact me.) I feel sorry for the man in the very back who is viewed only as a forehead, a lost opportunity at being seen with the world's most famous scientist. What I love best is the old car in the background.

I was happy to learn recently that Vintage Books will be using the same cover for my paperback, coming out in March. I can't imagine any other depiction that captures the topic and the era so well.

Visualizing Hubble

I was just introduced today to an intriguing website called Many Eyes, run by IBM. You can check it out at http://manyeyes.alphaworks.ibm.com/manyeyes. Or just type "many eyes" into a search engine to get there.

One of the site's many features is giving you the ability to turn text into an image. I downloaded the preface to my latest book The Day We Found the Universe, for example, and chose to display it as a "wordle," which shows how frequently words appear in your text by the size of each word. You can even tweak these word "clouds" with different fonts, layouts, and color schemes. Here's how mine came out:

It's fascinating how well the central themes of my book just pop out, as if by magic. Edwin Hubble would certainly have liked the outcome.

Galaxies and Nebulae and Clusters, Oh My!

After being rejuvenated from its space shuttle servicing mission last May, the 19-year-old Hubble Space Telescope is officially back in business. Engineers had spent the last three months focusing, testing, and calibrating. But now it’s back to photographing the universe like never before. Yesterday, NASA released the first stunning snapshots from the upgraded scope. They include a remarkable butterfly-shaped nebula (top left), a galaxy cluster as crowded as a subway in rush hour (bottom left), and a roiling stellar nursery (bottom right). Full details can be obtained by going to http://www.spacetelescope.org/news/html/heic0910.html.

As a nod to astronomer Edwin Hubble, I wish they had photographed NGC 2261 again as well, a comet-shaped cloud of gas located in the direction of the Monoceros constellation (left). While working on his doctoral thesis at Yerkes Observatory in Wisconsin around 1914, Hubble took a picture of this nebula and compared it with photographs taken earlier at other observatories. He noticed that his recent photo displayed distinct differences from previous ones, which proved that certain faint nebulae could change over time. It was his first major discovery. Today, this object, located within the Milky Way, is known as Hubble’s variable, a reflection nebula made of gas and fine dust fanning out from the star R Monocerotis. It's about one light-year across and lies about 2,500 light-years away.

NGC 2261 always held a fond place in Hubble’s heart. Soon after he arrived at the Mount Wilson Observatory as a staff astronomer in 1919, he got his first crack at the newly opened 100-inch telescope, what he called his “magic mirror.” It was on Christmas Eve, and he couldn’t have asked for a more fitting holiday present. The atmosphere was almost at its best, and it was also dark-sky time, the Moon having just set in the west. His best photograph of the night came when he aimed the giant scope at his variable nebula. From that point on, it became his observational “mascot.”

Later in his observing life, 1949, Hubble had the honor of being the first scheduled observer on the giant 200-inch Hale Telescope situated on California’s Palomar mountain. Needless to say, he got started by imaging his good luck charm, NGC 2261. Perhaps, Hubble Space Telescope astronomers should consider adopting this intriguing nebula as their mascot, too. Who knows, the luck might rub off. (Though from the look of these photos, maybe they don't need it.)

Two, Four, Six, Eight, Who Do We Appreciate

An interesting event happened last May, but I only recently learned of it, thanks to Michael Long, a trustee of the Mount Wilson Institute. When the space shuttle Atlantis went into space last May to repair the Hubble Space Telescope, it took along a very special memento: a century-old basketball that Edwin Hubble used in 1909 while a star player for the University of Chicago. Hubble and his fellow Maroons scored a winning 18-12 victory over Indiana University with the ball. Astronaut John Grunsfeld, also a Chicago alumnus (a PhD in 1988) made the arrangements to take it on the flight with him. On his two previous space telescope missions, Grunsfeld flew with the eyepiece of a telescope that Hubble had peered through at Yerkes Observatory in Wisconsin and the cover of Hubble's doctoral dissertation.



Hubble, Class of 1910, had been awarded a scholarship to attend the university partly due to his superb athletic skills. He participated in track (though seldom winning) but did far better in basketball, as his exceptional height for the day, six feet two inches, gave him an advantage playing center. He and his teammates were national champions in 1909. They swept through the Big Ten season and won the national title by defeating the University of Pennsylvania in two games.

Above image: Hubble's winning 1909 basketball aboard the space shuttle Atlantis last May (John Grunsfeld)

Hi-Ho, Hubble, Away!

After being interviewed recently on a national radio program, I was surprised and thrilled to be contacted by a not-so-distant relative of Edwin Hubble.

Vickie Kalthoff of Chesterfield, Missouri, e-mailed that her grandfather, Ralph James, and Hubble’s mother Virginia were first cousins (both distant relations to the famous outlaw Jesse James). In fact, Vickie's brother was born in the same house that Hubble was born in Marshfield, Missouri, a town that celebrates its most famous resident with a replica of the Hubble Space Telescope on the courthouse grounds. She recalls the superb nighttime sky there in the 1940s and 1950s: “I would stand outside at night, and I felt as if I were floating in the Milky Way.”


Vickie’s grandfather once drove from Kansas to California just to meet the great astronomer, and she wondered what Hubble thought about her “cowboy” gramps. I thought about that, too. While a Rhodes scholar at Oxford University in his youth, Hubble completely reinvented himself. He adopted a British accent that he maintained the rest of his life, dressed like a dandy, and could often be arrogant and standoffish to his fellow astronomers. He married into a rich Los Angeles family and throughout his life seemed intent on erasing his Midwestern roots.

In fact, Hubble rarely saw his mother and siblings, who remained in the Midwest. But Vickie told of one particular visit. Her mother and aunts were present when Hubble returned to the family ranch and got on a horse backwards. “They never forgot that,” says Vickie, “but I am sure he was teasing them.”

Above image: Replica of the Hubble Space Telescope on the courthouse grounds of Marshfield, Missouri. (Credit: freepages.genealogy.rootsweb.ancestry.com)

You're Not the Center of the Universe, You Know

My Op-Ed published in the Washington Post, July 19, 2009

Walk into an open field on a clear, moonless night. Overhead, sparkling stars sprinkle the sky. All of them seem equidistant from you―and no one else―and you are lulled into imagining yourself at the center of the universe.

For nearly 500 years, astronomers have struggled to break that illusion. Our petty standing in the cosmos is a scientific fact, if not a visceral experience. Earth zips at nearly 67,000 miles an hour around the sun, which in turn completes one lap around the Milky Way every 220 million years, meaning that the last time we were in this neck of the galaxy, dinosaurs were getting ready to rule the planet. Still, as you look skyward in that pitch-black field, Earth seems to be at the heart of all creation.

We could blame Aristotle. So authoritative was his pronouncement of an Earth-centered universe in the 4th century B.C. that few challenged the idea for nearly two millennia. Over time, the urge to better explain the universe's behavior gave rise to new models. In 1543, Nicolaus Copernicus boldly placed the sun at the center of the universe, shoving the Earth into motion. The radiant sun was at last in its proper perch, "as if resting on a kingly throne," he wrote.

Copernicus was not disturbed at all by a moving Earth but was troubled by a rotating sky. The Polish mathematician and astronomer, though, knew quite well the consequences of challenging conventional notions. In the preface to his great work, "On the Revolutions of the Heavenly Spheres," he predicted that "as soon as certain people learn that in these books of mine . . . I attribute certain motions to the terrestrial globe, they will immediately shout to have me and my opinion hooted off the stage."

That fate fell upon Galileo, who starting in 1609 gathered the crucial evidence supporting Copernicus's heliocentric vision. In 1633 he was brought before the Inquisition and eventually put under house arrest for daring to oppose an Earth relaxing at the universe's center.

By the time of Newton, decades later, such hostility had faded. For one, Sir Isaac's physics could at last explain why we aren't thrown off the planet as the Earth rotates and orbits the sun. But even though Copernicus moved Earth from the hub of the solar system, its inhabitants remained confident that they retained a privileged place at the center of the Milky Way, the sole galaxy. Homo sapiens is an egotistical species; we resist being kicked out of a prime spot in the cosmic scheme of things.

That confidence, though, withered as astronomy underwent a spectacular transformation starting in the 19th century, an era teeming with technological innovation. Prominent industrialists, enriched by the Gilded Age, provided the money that allowed dreamers to construct the powerful telescopes they had long desired.

With one of those new instruments atop California's Mount Wilson, Harlow Shapley resized the Milky Way. He discovered in 1918 that it was 10 times larger than previously thought and, along the way, he relocated the sun and its planets into the galaxy's suburbs. The sun resides roughly 30,000 light-years from the galactic center, more than halfway to the Milky Way's edge. "The solar system is off center, and consequently, man is too," Shapley liked to say.

But Shapley did not take the next step; he, too, fell victim to cosmic pride. Despite the growing evidence that the Milky Way was not alone in the universe, he held fast to his beloved Big Galaxy model: Our galaxy remained at center stage. We lived in a solitary, star-filled oasis suspended in a darkness of unknown depth.

Shapley's vision was demolished in 1924, when Edwin Hubble proved that the cosmos is populated with myriad galaxies as far as the telescopic eye can see. The Milky Way suddenly became a bit player in a much larger drama.

The history of astronomy is a continuing extension of the Copernican principle, moving us farther and farther from the front row. It's a principle of irrelevance that involves not only our position in space and time but also the contents of the universe. In recent decades, astronomers have learned that a hidden ocean of cosmic matter―comprising about 85 percent of the universe's mass―surrounds us, possibly elementary particles yet to be discovered. The stuff of stars, planets and us is but the flotsam in this enveloping sea.

More startling―and taking the Copernican principle to its finale―our universe may not be the only one. As physicists attempt to construct a theory that unifies all the forces of nature, one theme repeatedly arises: that additional cosmic realms may be lurking in other dimensions. We could be part of the multiverse; the Big Bang might have occurred when universes outside our dimensional borders bumped into one another.

The main response to this astounding theory has been to bury our heads in terra firma. Yet such a wider perspective offers some succor, allowing our earthly concerns to shed away. Hubble knew this. During a visit to the astronomer's home, the English poet Edith Sitwell was shown slides depicting the many galaxies that cannot be seen with the naked eye. "How terrifying!" she exclaimed. To which Hubble replied: "Only at first―when you are not used to them. Afterwards, they give one comfort. For then you know that there is nothing to worry about―nothing at all."

Granted, the hugeness of the cosmos is difficult to perceive and, as Sitwell expressed, horrifying to ponder. A character in Thomas Hardy's 19th century novel "Two on a Tower" gives splendid voice to this apprehension: "There is a size at which dignity begins; further on there is a size at which grandeur begins; . . . further on, a size at which ghastliness begins," says astronomer Swithin St. Cleeve. "That size faintly approaches the size of the stellar universe."

Indeed, our cosmic address is getting excruciatingly long: Planet No. 3, Solar System, Orion Spur on the Sagittarius Spiral Arm, Milky Way, Local Cluster, Virgo Supercluster, Universe, Multiverse.

It's time for earthlings to acknowledge our minor-league status and collectively grasp the magnificent vastness that engulfs us all. While a widespread recognition of Earth's humble station is unlikely to end conflict here, fully comprehending our planet's infinitesimal place in the universe might be a modest step toward diminishing our hubris. Earth is but a speck, the cosmic equivalent of a subatomic particle hovering within an immensity spanning billions of light-years.

And we can still savor our cleverness in figuring this out.

Image Credits: (top) Sagittarius Star Cloud (Hubble Heritage); (lower) Imagined Multiverse (Nature)

Hubble Redux

History can often be lazy. Not historians. They go after details with a vengeance. But over time we tend to remember historic tales in easy bites. Take Edwin Hubble, for example, namesake of the popular space telescope newly refurbished by the space shuttle astronauts. It's often related that Hubble went to the world's largest and best-equipped telescope in 1923—the 100-inch reflector atop Mount Wilson in California—and, voila, revealed a cosmos populated with myriad galaxies spread over space as far as the young astronomer could peer. But that is not the case at all.

In reality, Hubble's discoveries did not arrive in one eureka moment, but only after years of contentious debates over conjectures and measurements that were fiercely disputed. That was one reason for my interest in delving more deeply into this story, a rich saga published in my latest book The Day We Found the Universe. It shows how the avenue of science is more often filled with twists, turns, and detours than unobstructed straightaways.

Here are some surprises to be found within the book's pages:

• Hubble didn’t really discover the expanding universe: The first person to observe that galaxies were racing away from us was Vesto Slipher at the Lowell Observatory in Arizona, an astronomer now largely forgotten. He first noticed the effect in 1913, sixteen years before Hubble’s historic observations. Slipher didn’t know at the time it was due to a universe expanding, but he did suggest the galaxies might be “scattering” in some way.
• Hubble was a scientific cad: In 1929 Hubble pegged how the galaxies move outward but failed to note in his famous paper that half his data—the velocities—were Vesto Slipher’s measurements. There was no citation, no acknowledgment—a serious breach of scientific protocol. Slipher deserves half the credit. Privately, Slipher was bitter but too humble and reserved to demand his share of the glory.
• The so-called “discoverer” of the expanding universe never liked the idea: For the rest of his life, Hubble had serious doubts about a universe expanding. He told a Los Angeles Times reporter, “It is difficult to believe that the velocities are real—that all matter is actually scattering away from our region of space.” In his scientific papers, he always referred to the galaxies’ “apparent” velocities, worried that a new law of physics might sneak in and change the interpretation.
• A woman made the discovery of the modern universe possible: Henrietta Leavitt, working at the Harvard College Observatory, came upon astronomy’s celestial Rosetta Stone in 1912, which allowed Edwin Hubble twelve years later to prove that the Milky Way was not alone but just one of a multitude of galaxies. She found a new cosmic yardstick, based on blinking stars called Cepheid variables, to determine distances to far-off celestial objects, a task that was formerly impossible to carry out. She might have earned a Nobel prize for this work, if she had not died of stomach cancer at the age of 53.
• Edwin Hubble was not much liked by his colleagues: Hubble, often arrogant and standoffish, rarely hung out with his fellow astronomers. One called him a “stuffed shirt.” Hubble preferred to socialize with the actors and writers in nearby Hollywood, the aristocrats of southern California. While a Rhodes scholar at Oxford University, he completely reinvented himself: he adopted a British accent that he maintained for the rest of his life, dressed like a dandy, and began to add dubious credentials to his résumé (like saying he once practiced law, which he never did). Hubble’s affectation for wearing jodhpurs, leather puttees, and a beret while observing, or going around and saying “Bah Jove,” was simply too much for the other astronomers to bear.
• Not Hubble, not Einstein, but a Belgian priest first discovered how the cosmos truly operates: Both a theorist and a Jesuit priest, Georges Lemaître predicted in 1927—two years before Hubble measured it—that space-time was moving outward, with the galaxies going along for the ride. Here was the reason for Slipher's fleeing galaxies. Lemaître even estimated a rate of expansion close to the one that Hubble would later calculate. Since the young priest published this astonishing news in an obscure journal, no one noticed—no one at all.
• The Hubble Space Telescope could have had another name: Three men had a good chance at proving the universe was filled with other galaxies, beyond the borders of the Milky Way, years before Hubble. Each had the opportunity and the expertise. But James Keeler at the Lick Observatory prematurely died in 1900 at the age of 42; Heber Curtis, also at Lick, took a promotion, taking himself out of the race; and Harvard astronomer Harlow Shapley was mulishly wedded to a flawed vision of the cosmos, a blunder he regretted for the rest of his life.

Above photos, from top to bottom: (1) Edwin Hubble; (2) Vesto Slipher; (3) Henrietta Leavitt; (4) Georges Lemaître