The Speed of Light Exhibits
Click here for the Speed of Light
Speed of Light Brochure
One of the most famous experiments in
all human endeavor is the measurement and understanding of the Speed of Light.
Albert Einstein's Theory of General Relativity establishes that nothing can go
faster than the Speed of Light. In science fiction stories, people
routinely travel faster than light to reach distant stars and planets that are
so far away, humans could never reach them. If humans are to reach for the
stars, we must develop new understandings of natures laws.
The OISC is dedicated to inspiring
young people to study science as we move into the 21st century of possibilities.
To that end, we installed our first
Speed of Light Exhibit at the Irvine Civic Center in Oct. 2004.
Speed of Light Exhibit at Irvine
Civic Center - October 2004 Reception
We are now preparing for our second
exhibit to be at the UC Irvine Beall Center for Art + Technology in July 2008
SOL Exhibit @ The Beall Center - Outline
Find out how you can be part of this project and help us into
the future by downloading the Speed of
Light Project Overview and then contact the OISC.
We are also sponsoring an
Art Competition to help promote this exhibit.
Some History of:
The Michelson Speed of Light Experiment at the Irvine Ranch
(scroll down to the bottom for links to posters used in the
Oct. 2004 Irvine Civic Center Exhibit)
C = 186,282.3960 miles per second, plus or minus 3.6 feet per second
C = 299,792.4562 kilometers per second, plus or minus 1.1 meters per second
Albert Michelson was known as finest experimental physicist alive
At the heart of the experiment (pictured in the shack and graphic above), an
arc light was bounced off a rapidly rotating set of mirrors, back and forth down
a mile-long tube and home, to the mirrors, which by then would have moved
slightly. If the speed of the mirror, the angle of the bounce and the length of
the tube are known, it is possible to calculate the speed of light.
Above, Albert Einstein and Albert Michelson met at Mount Wilson in 1931, just
before Michelson's death. From left to right are Milton Humason, Edwin Hubble,
Charles St. John, Michelson, Einstein, W.W. Campbell and Walter S. Adams.
if rebuilt on its old site today, the Irvine Ranch speed of light experiment would run
through an industrial park, in what is now the city of Irvine, near Newport
Corporation, a world leader in the optics and laser indusrty.
In 1887, Michelson and Edward Morely used the interferometer to find out how
light waves moved through the theoretical "ether" in the universe. According to
the principals of classical physics, the movement of the earth through this
mysterious substance affected the speeds of light rays moving through it.
Michelson and Morely used the interferometer to bounce light waves out and back
at right angles, expecting to see one of the beams lag behind.
Instead, the beams returned at exactly the same time. In years to come, these
findings would be cited as one of the first proofs this mysterious ether did not
exist, that the speed of light was a constant, and that classical physics was
not enough to explain the physical universe.
While Michelson and Morely were testing the "ether drift," Einstein had begun to
speak of clocks that moved backward, mass that was not constant and light made
up of things called "photons." For scientists, these heresies were as profound
as those of Copernicus, the first to suggest that the earth was an orbiting
planet, and not the center of the universe.
The drama surrounding Michelson's experiments was heightened by this atmosphere
of turmoil. Although his work helped trigger a revolution in the study of
physics, Michelson never decided which side he was on, according to his
His daughter, Dorothy Michelson Livingston, wrote that Michelson never gave up
his belief in "ether," even though he accepted Einstein's work.
In 1930, that belief may have helped bring Michelson to Santa Ana, for his last
and most ambitious test.
Athelie Clark, the oldest living member of the family that once owned the
gigantic Irvine Ranch, remembers a day in the late 1920s when Michelson came to
At the table in the opulent dining room of James Irvine's Victorian home sat
Michelson, James Irvine Sr., James Irvine Jr. and the scientist Robert Millikan.
Clark sat and listened, understanding little of what was being said.
"I remember being told that he was a very famous man who was looking for a site
for an important experiment," said Clark, now 85.
"His hair was gray and unruly. He seemed extremely gracious to me."
"Gracious" was one of the nicer words used to describe Michelson's manner.
Throughout his career, as honors piled up, he had earned a reputation as both
brilliant and unstable. He was an accomplished tennis player. an excellent
painter and violinist, and so good at billiards that opponents complained that
his knowledge of physics gave him an unfair advantage.. His few close friends
described him as extremely loyal, fond of practical jokes, and quite cool under
Yet Morely, Michelson's early partner, said he feared that Michelson had
suffered a "softening of the brain" early in his career, after Michelson was
hospitalized for exhaustion in the 1880s. Michelson's first wife tried to have
the scientist committed. One of his maids sued unsuccessfully for assault.
Dorothy Michelson Livingston wrote that her father often worked for days without
sleeping or eating, that he sat alone at meals so his thinking would not be
disturbed, that in turns he could be arrogant, distant, imperious and rude. A
messy divorce made front-page headlines for weeks. The physicist also suffered
from recurring nightmares, including one in which he rode a motorcycle up an
"Americans have this obsession with mad scientists, and Michelson
fit the image," said UCLA physicist Wuerker. "He was the most famous American
scientist of his day. Anything he did was news."
Mad or not, he was definitely prodigious.
In 1907 when Michelson won the Nobel Prize for physics, his career was only
getting started. He beat off several challenges to his findings and honed his
earlier work. In 1920, he was the first to measure the diameter of a star,
called Betelgeuse, an achievement hailed in The New York Times as
In 1926, the most spectacular of Michelson's experiments split the night sky
between Mount Wilson and Mount Baldy** (See the bottom of
With mirrors, turbines, his interferometer and an arc light, he measured the
speed of light to within two miles per second of its currently accepted speed.
Horace Babcock, the emeritus director of the Mount Wilson observatory, remembers
visiting the experiment as a child, seeing the light shooting out of the cracks
in the shack where Michelson was at work.
Michelson wasn't satisfied with the results of the Mt. Wilson experiment. For
one thing, he worried that "shimmers" of air between the mountains might have
fouled his results. He also didn't trust the work of the United States Geodetic
Survey team, which had measured the distance between peaks.
He wanted to repeat the test in a vacuum to measure a more precise speed and,
perhaps, show the presence of the "ether."
Clark says Michelson settled on the Orange County site for the experiment after
lunch in the Irvine family home, when James Irvine Jr. took the physicist for a
drive in the family Packard. Michelson liked the low, flat bean field on the
north end of the ranch, near what is now the Marine helicopter base. The
agreed to donate the use of the land.
The project took shape quickly. Michelson's assistants built a metal shack to
hold the turbines, the arc light and other equipment from Mount Wilson and a
network of tubing, metal pipes, wires, plugs and switches. From the shack, they
built a mile-long tube of 3-foot-diameter, corrugated steel pipes sealed
airtight by layers of steel, cloth, inner tubes and rubber paint. Inside the
tubes were a series of mirrors, each on a motorized balancing machine.
In the center of the shack was the interferometer, which Michelson sometimes
called his "she devil." At the heart of the machine, a wheel covered with
finely-honed mirrors spun at exactly 512 revolutions per second. When light
struck this wheel, it bounced back and forth through the tunnel, eventually
returning to the spot it had started from. By then the mirror would have changed
its angle slightly, reflecting the light at an angle. By knowing the distance
the light had traveled, the speed of the mirror and the angle of the bounce,
Michelson could calculate the speed of light.
Clark remembers that the shack was "absolutely spotless" inside. While the
experiment was running, her father often would drive house guests over to look
at the shack- when he wasn't driving them to the other side of the ranch, where
battle scenes were being shot for the film "All Quiet on the Western Front."
Once, towards the end of the experiment, she says Michelson asked her to come
inside, to look through a window that showed the length of the tube.
"It was very dark," she said. "I looked in the window and saw a long, dark hole
that disappeared into nothing. There were little tiny sparks shooting back and
forth. I'd never seen anything like it."
Michelson's last experiment did not go smoothly. On the day of his arrival, the
pump being used to suck air out of the pipe broke down, halting the project.
Leaks in the pipe were a regular problem, and fears of an earthquake were
persistent. Michelson and his assistants fought over details.
His daughter described one of those fights, in which an assistant drove to
Pasadena and called the physicist to the lobby of the Hotel Maryland. The two
men stood in the lobby arguing with each other, wearing pajamas, scribbling
diagrams on the back of a Chinese laundry ticket, until Michelson noticed that a
crowd had gathered.
Michelson himself was not well. His health had begun to deteriorate years
before, in what his doctor referred to as the "vile climate of Chicago," where
Michelson had taught. His bladder was removed in 1929. The train trip to
California exhausted him. His heart was weak and his circulation was slow. As
the Orange County experiment progressed, he began to spend more and more time in
bed, alert but physically weak.
Michelson got out of bed in April, 1931, when Einstein came to visit.
Michelson's daughter remembers sitting between them at dinner, seeing that
neither could keep his hair combed, and struggling to keep from laughing. The
two men attended banquets together, and talked to each other privately.
At the end of April, Michelson's doctor confined him to his house, after
suffering what the papers said was a nervous breakdown. In
early May, his assistants brought him early data from the tests. On May 9,
Michelson suffered a stroke, followed by a cerebral hemorrhage. After lingering
in a coma for several hours, he died.
The Register of Orange County, California ran the obituary on page 1.
Why would a dying man attempt an experiment as ambitious as Michelson's in
R.S. Shankland, a leading historian of physics, believes Michelson came to Santa
Ana to look one last time for the ether that had been so central to the science
of his youth.
The final report on the Irvine Ranch experiments was published in 1933. The
findings were extremely close to those accepted today, but many physicists
consider the results of the tests on Mount Wilson more accurate. Some of the
metal tubing now is used as drainage pipes at the Mount Wilson observatory.
There are markings at the site of the test, and though a nearby street was named
in Michelson. s honor, it is commonly mispronounced. The Irvine Company has been
sold and resold. James Irvine's mansion burned to the ground and was abandoned.
If the vacuum tube were rebuilt on its old site today, it would run through the
parking lot of a Home Club and the lobbies of two manufacturing firms on
Armstrong Avenue in Irvine.
Wuerker, a UCLA physicist, thinks Michelson's work in Orange County is worth
more than that. For one thing, he says, Michelson can be thought of as the man
who gave this country a scientific tradition, on the day he won the Nobel Prize.
Even though Michelson's work here is not widely recognized, Orange County has
become a hotbed for experimental physics. At the University of California,
Irvine, this work is helping push physics beyond the edge of Einstein's world.
And in several of those experiments, UCI scientists are investigating incredibly
small particles that move near the speed of light. These particles have no
affect on the speed of light, but they do appear everywhere, invisible and
mysterious, like an ether.
US Naval Academy - Nimitz Library - Albert Michelson Career & Influence
Click here for Title Posters
Click here for Michelson Posters
Click here for Speed of Light
Theme Poster Layout info
Click here for details of the
The information on this page was found at
**An error about Michelson's
measurement of the velocity of light in 1926 (as described above) was reported
by Don Nicholson of the OSSC .
The measurement was made between
Mount Wilson and Lookout Mountain, not Mount Baldy.
The piers on which the retro
reflector were mounted are still in place on Lookout Mountain.