Scientists always say that we stand on the shoulders of giants.

In the observatory and the people that worked here, they are the giants.

Langley was a cutting edge scientist of his time.

He did major work when he was here at the Allegheny Observatory, both in astrophysics and in in aerodynamics.

That's a big that's a big accomplishment.

Without John Brashear, the astronomers and the scientists of his time would not have been able to do the very fine measurements that they were able to do.

This was a man who worked very hard to get it perfect, and that's what they needed.

This is the story of tenacious and ingenious minds, and perhaps the most surprising of all places for the study of the skies.

With little formal education and few resources, they defied the odds.

Through sheer determination, they found ways to change our world.

And how we view the universe.

And now, “Undaunted: The Forgotten Giants of the Allegheny Observatory.

This program was made possible by support from the Buhl Foundation, the Richard King Mellon Foundation, the Pittsburgh Foundation, the University of Pittsburgh.

Others support provided by.

You know, what is astronomy?

When we think about it?

Classically, it's looking up at the night sky, either with your eyes or with a telescope.

But there's a limit to how much you can ever know if those are the only tools you're equipped with.

At some point, you're going to be concerned with more than just where is the object, how fast is it moving and what color is it?

You're going to want to know what it's made of.

You're going to want to know where it's been.

How was it born?

How will it die?

These questions were only enabled with the birth of astrophysics, and the birth of astrophysics was enabled only by the application of spectroscopy, to the exercise of looking up.

The entire branch of physics called spectroscopy, where you take light and pass it through a prism, breaking it up into its component colors.

Turns out there's information embedded in those colors.

From those colors and features within them you can learn what the chemical composition of the sun is.

If it's a star, you can learn the chemical composition of the star.

You can learn how fast the star is rotating.

You can learn how fast the star is moving through space, either toward you or away from you.

You can know things like how strong the gravity is on the surface of the star.

And sure enough, you want to learn the physics of a black hole.

You get a spectrum of the light emanating from the vicinity of that black hole, and then you can start talking physics.

Without spectra, we know practically nothing about the physics of the universe.

With it, we know practically everything.

And that transition took place in the 19th century.

Where astronomy was reborn as astrophysics.

It was the fall of 1858, and throughout the world, a brilliant comet dominated the night sky.

This was Donatis Comet, named after its discoverer, Giovanni Donati.

The comet mesmerized virtually everyone, called by many the most beautiful comet on record.

And among the people who marveled at the nightly spectacle were the citizens of Allegheny City, Pennsylvania, a city across the Allegheny River from Pittsburgh.

Together, these two cities made up a powerful manufacturing and financial center.

This was the seat of the world's most profitable corporations.

And in the fall of 1858, three of Allegheny City's prominent citizens, Josiah King, Harvey Childs, and Professor Louis Bradley, were among those who gazed in awe at Donatis Comet.

What Bradley had been doing is taking his small telescope out onto the lawns during the nice weather, and just getting people interested.

People came by and looked, and then he began to talk to the right people about, well, you know you would see so much better if you had a bigger telescope.

These men met one evening in the winter of 1859 at the home of Professor Louis Bradley, and they were discussing how they might share their newfound interest in astronomy with their fellow citizens.

And so during the winter time of of 1859, they actually started talking about buying something bigger.

And that bigger was to buy an eight inch diameter reflector.

At first they were going to take this telescope and just like, move it from rooftop to rooftop.

These men were bold captains of industry men accustomed to both thinking big and doing big.

And as they talked, they convinced themselves that a 13 inch diameter telescope would be much better than an eight inch one.

And these men were indeed thinking big, for their 13 inch telescope would be the second largest refracting telescope one could buy in the United States in 1859.

So now that theyve thought about this very large scope, they need to think of a home.

So that means to look at an architect, talk to masons and carpenters, and actually build their observatory.

To get the extra money to build their new observatory building, these three men set out to recruit other wealthy citizens to form the Allegheny Telescope Association.

And so, as the month of February moves into the month of March, they invite a number of other friends, and the group grows from three to in the vicinity of 20 to 25.

And each gentleman is going to pledge or subscribe $100.

They collected donations from amongst their members, and commissioned the construction of a building that would house their world class telescope.

When Fitz came to town in 1861 with the telescope, we're on the cusp of the Civil War.

And then they decided in 1862, in January, they were going to have, like the grand opening.

They were going to have the special night when all the members and their families came and they were going to look through the telescope, or at least see it in its finished state.

But this was not to be.

Concerned that the Confederate Army might invade Pittsburgh, the Union Army dispatched Major General William T.H.

Brooks to organize the defenses of Pittsburgh.

By 1862, the Civil Wars on.

Many of them lost interest in astronomy because of the pressing needs of their businesses.

A number of these members actually went into service.

During those years of 1863, and 4 and 1865, the observatory is not used anyway, as they anticipated.

The Allegheny Observatory fell into a state of disrepair and began accumulating debt.

Members of the Allegheny Telescope Association began to lose interest in both astronomy and the observatory.

But this would be a boon to the Western University of Pennsylvania, the forerunner of today's University of Pittsburgh.

In the background is the chancellor of the Western University of Pennsylvania, who sees all this.

And he's thinking that, wouldn't it be nice if we could add an observatory to the university?

As what happened many times in its history, wealthy philanthropist William Thaw comes to the rescue of the Allegheny Observatory.

Coming from a prominent Pittsburgh family, Thaw made his fortune in banking and transportation, most notably the Pennsylvania Railroad.

Thaws are probably the wealthiest family in Pittsburgh, and while he attends to a lot of businesses, he has somehow developed a love for astronomy.

William Thaw organizes a fundraising campaign for the observatory.

He sees the opportunity to use the observatory for serious scientific research instead of just a pastime for the well-to-do.

And so, on the leadership of William Thaw, they have sort of a final fundraising.

They don't want to give away the observatory in its telescope with any debt remaining.

Despite having one of the world's largest telescopes, the Allegheny Observatory had never been a place of serious scientific research.

Thaw therefore wanted to place a trained astronomer in charge of the observatory.

The man he wanted was Samuel Pierpont Langley.

Langley was a really interesting fellow.

He was born outside Boston in 1834, attended the Boston Latin School the sort of the upper crust place to go to high school in Boston at the time.

As a child, Langley showed remarkable skill in mathematics.

He also developed an interest in astronomy.

And so Samuel Langley and his younger brother John learned how to make telescopes.

But unlike a lot of his classmates, he did not decide to go to Harvard or to any college.

His younger brother, John, was in the Civil War and was wounded, in fact, and once John is fairly well recovered, the two of them take off on a grand tour of Europe.

Only instead of going to the churches and the museums and so on.

They go to the observatories.

Upon his return to America, Langley learned that the Harvard College Observatory was expanding.

Impressed with Langley's enthusiasm and knowledge about telescopes, observatory director Joseph Winlock hired him as an assistant.

Langley quickly developed a reputation for being gifted in both mathematics and astronomy.

His reputation began to grow.

Langley soon received an invitation from William Thaw to move to Pittsburgh to become the director of the Allegheny Observatory.

And and when he came to Pittsburgh and he looked at what he had.

He had an observatory that no one had taken care of for a number of years.

He said, well, what do we have in the in the observatory for me to do work on?

We have essentially a table about the size of a card table and three chairs.

He's got no library, he's got no research tools.

And so he approaches the, the trustees about, well, how much money, how much of a budget goes along with this observatory.

And they said that there isn't any.

In his travels in Europe, Langley had learned how the Royal Greenwich Observatory provided a time service to mariners based on star time.

Knowing time to an extremely high precision was crucial for maritime navigation.

The observatory used astronomical observations to maintain an extremely precise master clock.

Each day, at exactly 1 p.m., the observatory would broadcast the time by dropping a red ball from high atop a mast visible for many miles.

The Royal Navy ships in the Thames River would know to synchronize their chronometers to this time signal, before they set off for distant lands.

And at that moment that he saw it, he thought it was real interesting, and he had no idea that it has later application in life for him.

But he he saw it and he learned it, and he understood how it worked.

In the mid-19th century, railroads were a new technology in America.

Companies built railroads faster than they could conceive of the consequences.

And by the 1870s, thousands of miles of railroad track crisscrossed the entire eastern half of North America.

Every town along the way used its own local time, and this time was often based on a large clock in the town square, and this clock was usually set to the noon sun.

Prior to the introduction of standard time on the railroads, railroads basically followed their own time zones that each individual carrier had adopted.

In many cases, there were as many as 53 different zones that were used by various railroad companies simultaneously.

Train scheduling was often chaotic, and this sometimes led to calamity.

From the 1850s through the 1880s, many people died in railroad accidents simply from the lack of a standardized railroad time system.

One of the worst accidents encountered by railroads was on the Boston and Worcester Railroad in August of 1853, in which two trains that were running opposite of one another basically missed their connection by a few minutes and ran head on into one another, and this resulted in over 14 casualties.

And later on, the conductor was convicted of manslaughter on the basis that his timepiece, his clock, was as much as 14 minutes off.

At that time, it was well known that mechanical clocks tend to drift over time.

A sundial is also not very accurate.

Since the Earth's orbit is elliptical.

The position of the high noon sun can never be used to derive an accurate time standard.

So as both a mathematician and an astronomer, Langley was well aware of these problems.

But he also knew that, unlike the sun, the stars always maintained their position relative to the Earth's rotation.

The time a star passes a known point in the night sky can be used as a reliable and precise indicator of time.

So Langley puts out a little proposal.

He does some fishing and he said, Mr.

Thaw, he says, you know, I think that this observatory is equipped to sell time.

With the right instruments here, the Allegheny Observatory can calculate time within a half second accuracy per month.

And Mr.

Thaw, being a railroad man, is interested in time.

Langley used the observed transit point of time stars to adjust a master clock kept in the observatory.

It was the time from this master clock that would then be broadcast to the railroad stations through the telegraph lines.

Langley's time service quickly established a standard time system for the entire east coast of North America.

Over 300 telegraph stations on the Pennsylvania Railroad alone subscribe to Langley's Allegheny Time service.

The Allegheny Time Service did not just enhance railroad safety.

It also generated much needed revenue for the observatory.

$3,400 a year was going to be the income from from selling this nebulous commodity called time, and that makes it possible for the Allegheny Observatory to survive on its own.

On November 18th, 1883, the railroad industry instituted Railway Standard Time that included five time zones spanning North America.

On that day, the Allegheny Observatory broadcast a noon time signal that synchronized railroad clocks across the U.S.

and Canada.

That time zone system continues to the present day.

Langley's main scientific interest when he started at the Allegheny Observatory was understanding the physics of the sun.

His first notable accomplishment was his detailed observations of sunspots.

But he wanted not only to observe the appearance of the sun, but also study the nature of the light coming from the sun.

This was truly a revolutionary approach to the conduct of astronomy.

At the time, astronomy was mostly observational, taking observations and doing these long abstract calculations about stellar positions and all of that kind of thing.

Langley was really much more interested in breaking new ground.

Langley was part of a new wave of astronomers who wanted to learn, what the light coming from celestial objects, could actually tell us about their physical properties.

We are all familiar with the colors of a rainbow.

A rainbow forms when sunlight passes through countless raindrops, with each raindrop acting like a tiny prism.

What we find is that features within the light spectrum tell a tale.

When an element is raised to a high temperature, as in a gas tube subjected to a high voltage, it emits light with strong intensities at specific wavelengths within the color spectrum.

Hydrogen, helium, nitrogen, oxygen.

Argon.

Each element gives off its own characteristic intensity peaks seen as lines within the light spectrum.

Spectral mission lines can be thought of as a sort of fingerprint for the light produced by an element.

By analyzing the emission lines in the light coming from the sun.

We can learn its chemical composition.

But if you look at how much of the entire range of light that exist is occupied by visible light, it's this tiny little slice light of wavelengths just longer than those of visible red light is called infrared light.

While we can't see infrared light, we can sense it as heat.

But since infrared light is invisible to the eye, how does one study its spectrum?

After months of experimenting, Langley invented an ingenious device that could measure the intensity of infrared light.

He called his device a Bolometer.

Langley's Bolometer was so sensitive that it could measure temperature to 1/100,000th of a degree.

With his new Bolometer, Langley was able to plot the infrared spectrum of light coming from the sun with astounding accuracy.

One of the first things he discovered is that water vapor in the Earth's atmosphere absorbs specific portions of infrared light from the sun's rays.

In 1896, Langley's discovery led Swedish scientists Fonti Arrhenius to further investigate warming of the Earth's surface by atmospheric absorption of the sun's energy.

The phenomenon soon became more widely known as the greenhouse effect.

Langley's discovery had laid the foundation for today's climate change research.

In 1887, Langley went on to publish a widely influential textbook in which he describes combining these new methods of traditional astronomy with physics.

He called this book The New Astronomy.

Langley's New Astronomy ushered in an entirely new field of scientific study, known today as astrophysics.

Langley's reputation as an innovative scientist began to grow.

He caught the attention of the Smithsonian Institution.

After the passing of the Smithsonian Secretary Spencer Baird, Langley was invited to take over the vacant position.

What that means in America in the late 19th century is that he is literally the unofficial chief scientist of the United States.

Langley really was on the top of the heap when he becomes secretary of the institution.

In the mid 1880s, Langley attended a meeting of the American Association for the Advancement of Science in Buffalo, New York, and one of the sessions that meeting was on flying machines, a subject which most people were still laughing at.

Regarded as impossible mechanical flight.

And he makes a decision really quickly that he's going to become involved in flying machine studies.

And he built these wonderful instruments.

A great hurling arm, many feet long, pivoted in the center.

You put test surfaces on the very end, and you swept them in a huge circle and tried to take measurements on the forces acting on those test surfaces.

And what he was he was working on was lift.

It's like what design of things will give lift.

So these are like like real primitive airfoils.

And he did that in the backyard of the observatory.

Langley's whirling table was the forerunner of the wind tunnels used today to test the aerodynamics of flight surfaces.

Based on the scientific data he collected, Langley worked out the mathematical equations of flight.

He published a textbook on the theory of mechanical flight in 1891.

The big finding is his decision that mechanical flight is not only possible, but it's easier than most people think it's going to be.

Langley went on to test his mathematical models in practice by building actual flying machines, which he called Aerodromes.

These were these were airplanes.

They had little steam powered engines in them, and they would fly by themselves.

He has one.

He flew it over the Potomac River.

I believe it traveled 4000ft.

That was the first time in human history that a fairly large scale flying machine powered by a prime mover, a steam engine, in this case, had made sustained flights of significant length.

So it proved to him that this model airplane would fly 4000ft.

Then can you make a bigger airplane with a bigger engine, and then put a man in the airplane too?

Langley, began thinking about how to construct an engine that would be powerful enough to sustain flight on a much larger Aerodrome.

He hired a mechanical engineer from Cornell University, Charles Manley, to design and build this new engine for him.

By 1903, Manley built a water cooled radial engine that developed 52 horsepower.

It was just an incredible engine, producing all that power for an all up weight of about 200 pounds.

Just the very best aeronautical engine of its time.

Unfortunately, Langley was putting all of his attention into the power plant and not enough attention into the flying machine itself.

Langley's plan was to make the first manned flying machine simply by scaling up his successful unmanned Aerodrome design.

His idea was to launch his Aerodrome with a catapult atop a houseboat in the Potomac River.

Langley hired his engine designer, Charles Manley, to serve as his Aerodrome pilot.

So the first trial is in October of 1903.

Manley is ready to go.

Down the catapult he goes and noses right into the water.

No one was quite sure what had gone wrong, but it was only the first trial after all.

Langley and his team modified the launch mechanism based on what they thought might have caused the failure.

They decided to try the launch again on December 8th, 1903.

So Manley climbs into the airplane, gives the signal down he goes, down the rail, and as he comes down the rail, the rear wings of the airplane, the bracing system, it just collapses.

When everything comes to rest, Charles Matthews Manley is underwater with the airplane on top of him, and he has to claw his way through snapped wires and broken wood and torn fabric.

And they finally get him back onto the houseboat and get his clothes off.

Wrap him in blankets.

He just turned the air blue, cussing everything and everybody in sight.

Langley had underestimated the stresses and loads that his Aerodrome would encounter with a catapult launch.

The structure of the machine just wasn't strong enough to do what he was going to ask it to do.

He was going to catapult it down this 40ft rail on top of a houseboat and, you know, 0 to 60 in 40ft, and the structure just wouldn't take it.

Just nine days later, on December 17th, the Wright brothers made their first flight at Kitty Hawk, North Carolina.

The Wright brothers were immediately celebrated as the inventors of flight.

Langley was devastated.

With his very conspicuous failure, he suddenly became the object of ridicule.

Langley really took it on the chin.

The Washington newspapers were just merciless.

It was really a very difficult time for him.

Despite his failures, Langley's scientific study of flight served as the foundation for early aeronautical engineering.

Years before their successful flights, the Wright brothers had gained valuable insight from Langley's textbook on the theory of mechanical flight.

Wilbur Orville Wright said that when they were first becoming interested in this thing between 1896 and 1899, the fact that somebody like Samuel Langley thought that the problem was soluble, that it was worth spending your time on, that the answer was really close, was an important factor in giving them confidence to enter the field.

In 1849, a traveling astronomer came to the town of Brownsville, Pennsylvania.

He would charge $0.05 a peek through his portable telescope.

His name was Squire Wampler.

Nathaniel Brashear brought his young grandson, John to peer through the telescope that night.

- And the peek that day was to take a look at Saturn and its rings.

And Brashear always said that that he was thrilled by that and said he never, never, ever forgot it.

In 1861, the now 21 year old John Brashear traveled to Pittsburgh in the hopes of establishing a career.

As was common in those days, John had no more than a grade school education.

It did not take him long, however, before he found work in the bustling steel mills of 19th century Pittsburgh.

His relatives thought that he had all of the skills to become a certified public accountant for the time.

Except that wasn't Brashear.

He's he's not interested in that.

He's interested in doing things with his hands.

He's a mechanic.

You give him a problem with tools and gears, and he solves them very easily.

He became a millwright very, very quickly, and that's not an easy thing to do.

So that shows you that Brashear was a talented individual to begin with.

At a boarding house, he met a Sunday school teacher named Phoebe Stewart.

They immediately fell in love.

With the help of Phoebe's sister and brother-in-law, young John and Phoebe eloped.

They built a home on Pittsburgh's South Side slopes overlooking the Monongahela River.

It was on a steep deer path named Holt Street.

John and Phoebe were fascinated by the night sky, and wished they could view the stars and planets through a telescope, as John remembered doing as a child.

But telescopes were expensive luxuries in those days.

So they decided they could learn to build one themselves.

Inside a small workshop attached to their house, they taught themselves how to grind and polish telescope lenses.

In his spare time, John read whatever textbooks he could find.

He was intensely interested in learning all he could about astronomy and everything related to it.

He even learned German so that he could understand the writings of German astronomers.

Every night late into the night, John and Phoebe gradually transformed their five inch diameter piece of glass into a piece of fine precision optics.

After two years, their lens was nearly finished.

And then he held it up to light to get a better a better look, to make sure it's perfect.

And something terrible happened, and he let it slip from his fingers and fell to the ground, and it broke.

And it's almost the unimaginable.

How many hundreds of hours were there?

And now it's on the floor and it has no value whatsoever.

He was he was just about ready to quit forever then.

And Phoebe, Phoebe came over, and she goes, well, there's no sense in crying over over this this glass well well get another one.

And and we're going to get started again.

The Brashears worked another two years on a second telescope lens.

John knew of Professor Langley's reputation as a great astronomer at the Allegheny Observatory, and so he decided to seek his opinion on the quality of the telescope lens he had made.

So he got up his courage one day and went to Langley and wanted to talk to him about him and show him what he was doing, and he showed Langley this lens that he made.

And Langley immediately understood from seeing what he did and from talking to the man, that Brashear was a very talented individual.

Langley does a rather tricky thing.

He gives Brashear a book.

He says, you know, here's a book on on making mirrors.

Mirrors are easier to make then lenses.

Langley had given Brashear a book on optics by the famous astrophysicist Henry Draper.

Brashear studied the book earnestly and then decided to make his own 12 inch mirror, as Langley had suggested.

The lens Brashear had made previously would have been for a type of telescope called a refractor.

A refracting telescope collects incoming light and focuses it through a lens, to a point where an eyepiece lens produces a visible image.

In contrast, a reflecting telescope collects light, simultaneously reflecting and focusing it off of a parabolic mirror.

The image is then reflected off a second mirror and viewed through an eyepiece lens.

Brashear began grinding a 12 inch parabolic glass mirror for a reflecting telescope, a process which took him another two years.

At the final stage, Brashear started to apply the reflective mirror coating on his parabolic glass.

No sooner than he began applying this mirror coating, then the heat from the process cracked the mirror in two.

Undaunted by failure this time Brashear started over.

And this time seeing how fragile these mirrors are, he began experimenting with better methods for coating them.

He improved on the existing method, and his new silvering process soon became the new standard for silvering telescope mirrors.

Brashear slowly began to build a worldwide reputation for making high quality scientific instruments.

Langley, knowing how valuable it would be to have a world class instrument maker virtually in his own backyard, introduced Brashear to his own wealthy benefactor, William Thaw.

So the next thing that happens is the in between man Mr.

Thaw begins to play a role, and he says, you know, for $7,000 or so, we can set your shop up and you can leave the south Side.

You can be close to Professor Langley, you could be close to the Allegheny Observatory.

While John Brashear built the reputation of being an extremely talented instrument maker, he was always thinking about engineering perfection rather than business.

He was always losing money, and Thaw even wrote to him one time and said, you know, Mr.

Brashear, you really have to learn a little bit more about business.

I understand that you're trying to give everybody an absolute perfect result here, but you have to figure in what it's costing you to do that.

William Thaw financed a factory for John Brashear.

He also tried to mentor John on how to run a proper, profitable business.

And so he comes up and he sets up a shop and he eventually brings his brothers.

By this time, his his daughters grown and married.

And who does she marry?

A man that could become an unbelievably good optician.

Jimmy McDowell.

So the whole familys involved in optics now.

We go from the mill workers into astronomy, into the things that astronomers need.

Brashear was definitely a perfectionist, so that if a really, really good optician would get a lens really, really, really good, Brashear would get it better.

He wanted it perfect.

Because of their reputation for high quality and precision, Brashears instruments were sought after all over the world.

One of the Brashear companys major contributions to science was the construction of the extremely precise optical components for the Michelson-Morley experiment of the late 1800s.

There are only a handful of experiments in physics that completely transformed physics.

At many people's top of the list would have to be the Michelson-Morley experiment.

In the 19th century, physicists thought that since sound waves travel through air, light waves must travel through some sort of medium as well.

They called this theoretical medium Aether.

The famous luminiferous Aether, this magical medium that was hypothesized to be what light required to move through the vacuum of space, just the way sound requires air to move from one place to another.

How else could waves of light move through the vacuum of space unless there was some medium there, some hypothetical medium?

Let's call it the Aether.

Aether, they theorized, is an invisible nothingness that permeates the universe.

Its only physical property is that it allows light to propagate through it.

But once precise measurements of the speed of light became possible, testing the predicted effects of Aether on the speed of light became possible as well.

The Earth orbits the sun at about 66,500mph.

If light travels through Aether, they reasoned, then as the earth moves through the Aether, the speed of light should be different, going with the Aether than perpendicular to it.

In an attempt to show the effects of Aether on the speed of light, Albert Michelson and Edward Morley conducted an experiment in 1887 and what is now Case Western Reserve University.

Michelson was an expert in optical experiments, and he thought that he could devise an experiment where one would be able to see the slight difference in the speed of light measured on the Earth.

If you measured it along the direction of the motion of the Earth and at right angles to it.

This should be a slight difference.

Compared to the speed of light, Earth is not moving that fast.

So if you're going to check the difference in the speed of light measured with the movement of the earth compared with transverse to it, you need a level of precision that was that no one had before.

The Michelson interferometer was just such an apparatus.

Michelson and Morley devised an apparatus that would detect minute differences in speed between two beams of light.

Light from one source is split into two directions through a half silvered mirror.

These beams are bounced between other mirrors and then recombined back into a single beam.

When two light beams combined, if their waves are completely synchronized, the peaks combine to make an even more intense peak.

If they are one half wavelength off, their peaks, combine and cancel out the intensity.

Slight differences in speed between two light waves will therefore produce a pattern based on the amount of interference between the two beams.

This is known as an interference pattern.

Examining the interference pattern from the two light beams sent out in different directions would clearly show if the speed of each light beam were different in different directions, but Michelson and Morley never detected such a difference.

Their results were inconsistent with the existence of Aether.

The scientific world didn't know what to make of it.

The famous scientists in Europe all Lord Reilly and Lord Kelvin and Lord Thompson were saying, hey, come on.

You must have done something wrong here.

There has to be an Aether.

And the whole thing didn't get resolved until many, many years later when Einstein came along.

Einsteins theory of special relativity proposed that the speed of light is always the same, regardless of the speed of the light source.

The results of the Michelson-Morley experiment were entirely consistent with Einstein's view of the universe.

And this served as the turning point in modern physics.

The Michelson-Morley experiment was an experimental advance in technology that transformed science not only physics, but science.

The important thing about this type of experiment is that there would be no way for them to to succeed.

There'd be no way for them to convince the scientific world that they had made a suitable measurement if they didn't have the right type of design and the right type of equipment.

They had to have extremely precise optical components, including all the mirrors and many mirrors involved in lenses and telescopes, and without those, they would never have been able to convince the scientific world that they had made a legitimate measurement.

They wouldn't even have seen the interference patterns that are required in this experiment if they didn't have superbly machined, superbly constructed optical components.

These components that made the Michelson-Morley experiment so successful were made in John Brashears workshop.

When Samuel Langley was developing his new astronomy.

He had a young protégé named James Keeler.

Under Langley's mentoring, Keeler himself quickly gained a reputation as one of the world's foremost spectroscopists.

Keeler was offered a position at California's Lick Observatory in 1887.

In 1891, after Samuel Langley's departure for the Smithsonian Institution, Keeler returned to the Allegheny Observatory to serve as its new director.

It was here Keeler made a major discovery in planetary science.

He used this telescope to work on the problem of what the rings of Saturn were composed of.

In 1610, Galileo became the first person to observe the rings around the planet Saturn.

Since then, astronomers had speculated on the nature of those rings.

Were they solid disks as they appear to be?

Or were they made up of countless tiny particles?

James Keeler thought he might be able to answer that question using spectroscopy.

And so Keeler's thinking, well, can you prove that with the light?

Can you look at Saturn and take the information that you get and then figure out the speed of the ring system and then determine whether or not you have a solid ring or a particular ring.

Keeler knew that if the rings of Saturn were solid, they would rotate around the planet like a phonograph record.

This means the outermost ring would have to travel much faster than the innermost one.

However, if the rings were particles, their motions would be like that of individual orbiting satellites.

In this case, the innermost ring would be traveling much faster than the outer one.

Keeler realized that to measure the speed of an object in space, he could use the principles of the Doppler effect, named after Christian Doppler in the early 19th century.

When a moving object makes a sound, the sound waves traveling in the direction of movement are compressed in time.

By knowing how much the pitch of a sound changes.

Doppler showed you can calculate the speed of the object, making that sound and toward you.

Or away from you.

It not only works for sound, it works for light.

You analyze the light, create its spectrum, look at features in the spectrum that have shifted.

In the case of light, we perceive its wavelength in terms of color.

An object moving away from the observer tends to have its spectrum shifted towards red.

The spectrum of an object moving toward an observer will tend to be shifted toward blue.

Keeler thought that he might be able to use these principles of the Doppler shift of light to measure the speed of Saturn's rings from edge to edge.

Using these principles, he was able to show that the inner rings were orbiting the planet faster than the outer rings, completely consistent with the calculated motion of orbiting particles.

So across the spectrum of the ring, it's slowest on the outside.

Fastest on the inside.

It's all particles.

In 1981, the Voyager II spacecraft made high resolution photographs of Saturn's rings and their particulate nature, confirming what Keeler had proved through earthbound spectroscopy in 1895.

As the coal and steel industries grew in the river valleys between the city of Allegheny and Pittsburgh in the late 19th century, so did the problem of smoke and soot.

So Keeler started to notice this.

He started to notice by the 1890s that his sky wasn't as good as it had been only a few years before.

Keeler had spent some time on the West Coast at the Lick Observatory.

One of their telescopes had a diameter of 36 inches.

And Keeler's now back in Pittsburgh, working with one that's just a little over one foot.

Maybe we need a new site.

We need a new observatory.

We got to have a big telescope.

The biggest champion of constructing a new observatory was John Brashear.

Keeler and Brashear selected a site for the new observatory, several miles away, on a hilltop that had once been a cornfield.

Following the model used for financing the first Allegheny Observatory, John Brashear began to approach a number of wealthy industrialists for subscriptions.

The list of contributors grew and included Andrew Carnegie, steel magnate Charles M Schwab, and industrialist Henry Clay Frick.

George Westinghouse donated an entire electrical generating plant for the observatory.

A lot of people are drawn to Brashear for some reason.

His personality is is magnetic, and so his he's able to raise money because he's working on a project that he loves, and he's able to translate the love for the project to these people that have the money and get them to be in love with the project too.

Groundbreaking for the new observatory took place in 1900.

Brashear stipulated that the observatory should be constructed to the highest architectural and artistic standards.

Two wealthy patrons, sisters Jennie and Matilda Smith, donated the money for marble hallways.

Legend has it around here I don't know if this is true or not, but the story is that the marble was raised to the height of the Smith sisters themselves.

The Smith sisters also paid for work by one of the leading stained glass artists of the time, Mary Elizabeth Tillinghast.

Tillinghast created a fitting tribute to this new observatory in the form of the Greek muse of astronomy, Urania.

In homage to the astronomers of ancient times, Urania embodies a number of symbolic motifs from classical mythology.

The opalescent glass forms Uranias long flowing robe.

She holds the celestial orb in one hand and with the other points towards the star cluster Hyades.

Behind her, in the moonlight are the ruins of the Acropolis, and to her left is the Lamp of Knowledge.

Beneath the window is a representation of the visible light spectrum, symbolizing the importance of spectroscopy in the observatory's history.

Just a few years after the construction of the new Allegheny Observatory was completed, John Brashear passed away at the age of 79.

The passing of John Brashear in 1920 led to an interest in the neighborhood and people to University of maybe having some kind of memorial to him.

And so Frank Vittor is hired to to make this a bronze sculpture of Brashear, but they installed the John Brashear statue in 1926, and he's been there just across from his his friend Urania, ever since.

The new Allegheny Observatory would have the third largest refracting telescope in the country.

The 30 inch Thaw Memorial Telescope would have such precise optical components that the observatory quickly gained a reputation for its ability to make accurate measurements of star position.

The accuracy of the instrument is sufficient.

That if an astronaut was standing on the moon holding a flashlight, we could see the flashlight with the CCD detector.

If he moved that flashlight from one hand to the other hand, put it over here.

The precision of the telescope is sufficient to actually record that movement.

That's on the order of 1,000th of an arc second.

One of the notable accomplishments of the Allegheny Observatory has been its star distance measurements, using the principles of parallax.

If you measure the position of a star in January and then measure its position again six months later in July, when the Earth is at the opposite side of its orbit, you can measure the apparent shift in its position.

Knowing the diameter of the Earth's orbit and the two measured angles to the star allows one to use basic trigonometry to calculate the distance to the star.

The key to these parallax measurements is the precision, to which one can measure star position angles at each point.

One of the main strengths of the 30 inch Thaw telescope at the Allegheny Observatory.

- The Allegheny Observatory Parallax Series, which was what Allegheny was famous for, was the most accurate in the world.

And in fact, star catalogs like the Yale Catalog of Stellar Parallax.

It's where they take all the parallaxs from all the universities and all the telescopes and put them together to get the best average values.

They gave the Allegheny Observatory telescope the highest rate of any telescope in the world at that time, and they could not find errors in them in the Allegheny results.

So they actually calibrated all the other observatories.

All of their parallaxs to the parallaxs produced with the Thaw telescope.

In more recent years, the Allegheny Observatory has been involved in the search for planets orbiting distant stars.

And searching for other planetary systems.

The major was half of what we did for for about 20 years was to look at nearby stars, to see if they had planets around them, and as a result, in fact, we were able to find a planetary system, we think, orbiting around Lalande 21185.

Another star that we looked at was Epsilon Eridani, which somebody had said, there seems to be a planet going around that star.

The Allegheny Observatory search for extrasolar planets starts by precisely mapping star positions over weeks, months or years.

If there is a massive planet orbiting the star, its gravitational pull makes the star appear to wobble over time.

If you could imagine you were looking down from the ceiling on polka dancers and they would swing across the floor as they went.

If one of those dancers was invisible, you could look at the dancers partner and still know that that dancer had a partner because of the motion.

And that's how we find double stars and planets around other stars.

The observatory serves as the eternal resting place for the two key people responsible for its existence, along with their families.

John Brashear with his wife, Phoebe.

And James Keeler with his son Henry and wife Cora.

The relationship between John Brashear and his wife, I think, can be seen by the fact that they share the same urn in the same part of the crypt together, even now.

To me, that's exactly the way their life was.

Theyre inseparable.

John Brashear was very clear about how he wanted the observatory used.

He wanted it to be both an institution of science and an institution where the public could come up and see the field of astronomy at work and understand better what astronomers do and what science does for the public.

For almost everybody that walks in the door here, you get the sense of the love and the care that went into this place.

And we all get this feeling of we have to take care of it.

We have to pass it on.

Whole, and entire and in good shape.

For many years, John and Phoebe Brashear shared a favorite poem, The Old Astronomer to his Pupil, published in 1872 by Sarah Williams.

Reach me down my Tycho Brahe.

I would know him when we meet, when I share my later science.

Sitting humbly at his feet.

He may know the law of all things.

Yet be ignorant of how we are working to completion.

Working on from then to now.

Pray remember that I leave you all my theory complete, lacking only certain data for your adding as is me.

And remember, men will scorn... - Some visitors today say that as they walk through the observatory.

It's as if they can still feel the presence of John and Phoebe Brashear.

They say it's as if John and Phoebe are still looking after their beloved observatory.

An observatory whose history encompasses both remarkable scientific achievements and remarkable personalities.

A history that is all but been forgotten.

Fate.

Though my soul may set in darkness, it will rise in perfect life.

I have loved the stars too fondly.

To be fearful of the night.