A few weeks ago, on an afternoon in London, I took in the Thames and then headed a few miles down river to Greenwich and the Royal Observatory, a prime attraction for map nerds around the world. Unfortunately, my visit was untimely, and the observatory was closing up for the day when we got there.
The Royal Observatory in Greenwich is THE home to Prime Meridian and Greenwich Mean Time (GMT), so I hope you’ll forgive me the terrible puns in the last paragraph. A telescope at the Royal Observatory precisely defines the Prime Meridian – the line of longitude at 0o 0′ 0″ from which all east-west distances are measured. Fittingly, the observatory is home to the extraordinarily precise chronometers which solved the “longitude problem” in the first place. “By international decree, the official starting point for each new day, year and millennium (at the stroke of midnight GMT as measured from the Prime Meridian)” occurs at the Royal Observatory.
Our view of the telescope building at the Royal Observatory
During the Observatory’s open hours, visitors can see the telescopes, historical exhibits, a planetarium, and a famous line on the pavement that separates the eastern and western hemisphere. Visitors arriving too late in the day to get inside are, however, still rewarded for the climb up the hill from the river. A green laser light shines forth along the meridian, streaming out of the observatory and across the Thames and London.
The green laser demarcating the Prime Meridian, issuing forth from a building on the grounds of the Royal Observatory. The pavement marking seen by daylight visitors is in the courtyard in front of this building.
As the sky darkens toward night, there’s a stunning panorama of lit up London to enjoy. [Click on the image below for a much larger view.]
The view from the Royal Observatory, not long after sunset. From the left, you can see the Observatory building, and central London in the distance. Straight ahead is the Canary Wharf financial district and to the right is the O2 Millenium Dome. Just to the left of the O2 cuts the Prime Meridian, though you can’t see it in this picture. Click to very much embiggen.
As, arguably, the start of time and the center of space, it was totally worthwhile to visit the Royal Observatory – even in the dark. But Greenwich is a place that deserves more time and light than I could give it on this trip, so I’ll be back to take in the sights of this special place on some future journey.
The green laser light emanating from the Royal Observatory marks the path of the Prime Meridian as it encircles the world. My arms encircle my world – my daughter – who turned 6 years old today.
Nice plan for content warnings on Mastodon and the Fediverse. Now you need a Mastodon/Fediverse button on this blog.