Greenwich Royal Observatory – Joel’s Journeys & Jaunts

This morning, I went to a nearby suburb of London, Greenwich, to journey to the beginning of space and time on Earth.

Because of the technical glitches I had with this journal yesterday, which I hope won’t arise again, by the time I posted the entry about the London Transport Museum and more that I saw in the afternoon, it was well past my normal bedtime. I managed to sleep in this morning, at least what counts as sleeping in for me.

It then took me a bit more than an hour to get to my first destination in Greenwich. The journey required an 11-minute Tube ride; a 10-minute DLR (Docklands Light Rail) ride; walks to, from, and between the two; and waits for the trains of each.

The point is, with my late start and the time to get there, I had time to visit only one sight before lunch. But what a sight it was. The Greenwich Royal Observatory.

Greenwich: The Beginning of Space and Time on Earth

Okay. “The beginning of space and time on Earth” might be too hyperbolic. But this is Greenwich. You know, the location of the Prime Meridian. Not just any meridian, but the Prime Meridian.

The prime meridian is zero longitude. Zero, i.e. nothing. Therefore, it’s the beginning of longitude—distance or, if you will, space—around the Earth.

And, not surprisingly, given that the Prime Meridian is here, Greenwich Mean Time is a time reference for the world. It’s the average time of day that the sun crosses the Prime Meridian over the course of the year. The time in time zones around the globe is set relative to that. So, one could argue, it’s the beginning of time on Earth.

(Yeah, like I said, the “beginning of space and time on Earth” is a stretch, but, damn it, I paid a guy on a street corner in London £50 for a five-day literary license. I’m damn well going to get my money’s worth.

The Royal Observatory in Greenwich is where the Prime Meridian was established. That imaginary line runs through the observatory.

Greenwich Royal Observatory

There is a planetarium beside the Greenwich Royal Observatory. I like planetariums, but I haven’t been into one for many years. I decided to go. The Royal Observatory decided otherwise.

When I arrived at the ticket desk (there’s a fee to visit the observatory), I asked about the planetarium. The ticket seller said, “Yes, we have one, but I can’t sell you a ticket to it. It closed only just recently for a two-year refurbishment.”

Of course it did.

She continued, “But there’s a one-hour guided tour of the observatory starting in just two minutes. It costs only £5 extra on top of the admission price. Would you like a ticket for that?”

I said yes and went on the tour. Sometimes I luck into timings. It’s astronomically rare, but this is an astronomical observatory. It happens.

There were about 20 or so people on the tour. We were each loaned an earpiece with the necessary electronics such that the guide, Paul, could speak into our ears without shouting.

Paul started in a courtyard just outside the original observatory and provided an introduction to the building (Flamsteed House), the work done there, and some of the astronomers who were there over the three and a half centuries since it was built in 1675.

King Charles II had Christopher Wren design Flamsteed House. The budget was tight. Paul gave a number for the budget, but I forgot what it was. However, I do remember that Paul said it was constructed for the same amount of money Wren spent building just the wooden model for one of his more famous buildings, St. Paul’s Cathedral in London. Flamsteed House is rather small, and to save money, Wren recycled construction material from other buildings to construct it.

Flamsteed House is so named because John Flamsteed (1675-1719) was the first “Astronomer Royal” there. There have since been some extensions and other buildings added to the Royal Observatory, but the complex and its buildings are still not large.

As I said, Paul gave his introductory remarks in a courtyard. He did so standing in front of something that was added only in 1977, for Queen Elizabeth’s Silver Jubilee. It’s a sundial.

But it’s not just any sundial. A plate of metal that’s arced on a single plane rests on a sculpted metal pedestal that, in turn, rests on a plainer stone pedestal. The plate is slanted up toward the sun.

On the arced plate, there are raised curved lines, each of which represents ten minutes. The curves of the lines accommodate the different heights of the sun in the sky at different times of the year.

But what shows the time on the plates, you ask? Dolphins do. That’s what. Two dolphin sculptures are mounted above the plate. The shadows their tails cast mark the time. Cool, right?

Moving inside …

Observations at the original observatory building were made through telescopes that looked out windows, not through the roof, which is opaque and can’t be opened. (A building was constructed much later with a roof that could be opened.) They used telescopes hinged on wooden quadrants that were permanently affixed to the floor. They could angle the telescopes up and down, but not side to side. They relied on the rotation of the Earth to shift the position they looked at in the sky.

The fixed telescopes were aligned on a meridian, an imaginary line that runs between the Earth’s two poles. As new astronomers succeeded former ones, they often built new, better telescopes. But rather than align them on the meridian of the preceding telescope, they left the old one in place for historical purposes and established a new meridian for their new telescope.

The telescopes are still in place for visitors to see.

In 1850, a telescope called the Airy Transit Circle, named after George Biddell Airy, the seventh Astronomer Royal, was installed. The meridian it operated on became the official Greenwich Meridian.

But that still wasn’t globally recognized as the Prime Meridian. Other important observatories around the world each had their own meridian that they considered to be the official one.

In 1884, there was a conference in Washington, DC, with representatives from several countries to choose an official Prime Meridian for the world. A Scottish Canadian engineer and inventor, Sir Sanford Fleming, agitated in favour of the Greenwich Meridian. He argued that most shippers in the world already used Greenwich Mean Time, so choosing the Greenwich Meridian made sense.

According to Paul, all of the countries agreed except for the French. They said that, because their observatory (I think it was in Paris, but I’m not sure) predated the Greenwich observatory, theirs should be the Prime Meridian.

The French finally conceded, but, according to one Paul, they did so only one condition: The British had to adopt the metric system. According to Paul, the British agreed. And, as Paul said with a huge smile on his face, “any day now…”

A straight, metal bar embedded in the courtyard marks the Prime Meridian.

It was all fascinating.

Navigating Time

One of the functions that the Greenwich Observatory used to perform was communicating time. There’s a large red ball mounted on a pole on the top of the observatory. At, I think it was five minutes to one in the afternoon, they raised the ball and then dropped it precisely at one. Ships in the nearby River Thames could see this and calibrate the time based on that.

It’s no longer necessary, but they still do the ball drop.

Accurate chronometers were critical for seafaring navigation when ships were out of sight of any landmarks. But there weren’t any chronometers that worked well on ships. The only ones with sufficient accuracy were pendulum-based. The rolling seas messed up the swings of pendulums.

Consequently, there were no good ways of navigating in the middle of oceans. Several ships were lost at sea, at an enormous cost. In I forget what year in the first half of the 18th century, I forget which king offered a £20,000 reward to anyone who could invent a chronometer that could operate precisely enough at sea to allow for accurate navigation.

Just to be clear, I’m talking about £20,000 early 18th-century pounds, not current pounds. The reward was an enormous fortune then.

An uneducated man named John Harrison came to the Greenwich Royal Observatory and told the Royal Astronomer at that time that he thought he could build such a device based on Isaac Newton’s Third Law of Motion. Even Newton himself had said that was impossible.

Despite Harrison not being formally educated, the Royal Astronomer listened to him and thought he might be able to do it. The astronomer convinced his colleagues to lend Harrison the money to build it because he’d easily be able to pay it back if he won the prize.

His design took advantage of components that had an equal and opposite reaction to the swaying of the motion at sea to compensate for it. He delivered his first model in 1736. It was good, but not good enough for the prize.

He then spent time working on an improved design. At some point, I forget if it was the next model, he made use of bi-metallic strips. If I remember correctly, that was the first use of them. The second model was better, but still not good enough.

The same was true with his third.

The fourth model wasn’t a pendulum-based clock at all, but a major upgrade on watches of the day. It won the prize. Harrison had spent a lot of years getting to that point. He died three years later.

When he took us into the clock/watch room, Paul said words to the effect, “Normally at this point I’d say, with great flourish, that these are all the original time pieces and the clocks are still functioning. But the first model needed refurbishing. So this is a replica that’s here until the original can come back. A very good replica, but a replica. But the other clocks are the originals.

“And these are old clocks. I’ve been here for three and a half years. I’ve often seen one of the clocks not working, but this is the first time I’ve seen two not working at the same time.”

The third model was running. The fourth model, the watch, couldn’t have worked. They’d pulled the guts out and displayed the face and works separately so people can see the latter.

You can probably tell that I was fascinated by the Greenwich Royal Observatory. There’s more I’ve forgotten than what I related here. If you ever have the chance, I highly recommend visiting the observatory and going on the guided tour.

Observatory Setting

The Greenwich Royal Observatory is situated on the top of a hill in a big, beautiful grass-and-trees park, Greenwich Park. Because the observatory is on a hill, there are some dramatic views of the skylines of Canary Wharf ahead and the City off to the left from its plateau. The park and the views aren’t sufficient reasons to make the trek out to Greenwich, a not-bad suburb on its own, but they do make for a nice bonus if you visit the Royal Observatory, which is indeed worth the journey.

Plus, I did more in Greenwich in the afternoon, but that’s fodder for another post.