What is it like to stand on both the Eastern and Western Hemispheres?

The answer is... nothing special. But when in London, you have to visit the Royal Observatory Greenwich, the birthplace of time as we know it. Since Greenwich is in the suburbs of London, public transportation is a bit inconvenient, so we went there on the day we rented a car to visit the White Cliffs of Dover. · The Royal Observatory Greenwich was founded in 1675 to meet the need for determining longitude at sea. It became famous in 1884 when the International Meridian Conference was held in Washington, D.C. The conference decided that the meridian passing through the Airy Transit Circle at the Royal Observatory Greenwich would be the standard reference meridian for global time and longitude measurement, known as the Prime Meridian, or the 0° longitude line. · To be honest, the Royal Observatory Greenwich is much smaller than I imagined, and you can see the end of it at a glance. This is not surprising, as the observatory was relocated to Herstmonceux Castle in Sussex, on the southeast coast of England, in 1948. What we see today is the old site, which is now part of the National Maritime Museum. · ✅ The main building of the observatory is small, a museum displaying astronomical history, including early telescopes, clocks from various countries, globes, armillary spheres, many of which were made in China, and the process of many astronomical discoveries. What impressed me most was a wooden long telescope tube in the octagonal room upstairs, which is said to still be usable, but the view through the telescope didn't seem real to me. · ✅ Next to the museum is a small dark room with a long line. Inside, it is pitch black, but with the help of the explanation, I understood that the room uses optical principles to observe the Queen's House and the National Maritime Museum below the hill, and you can even see people on the street clearly. · ✅ Next to the small dark room is an observation deck, located on the high ground of Greenwich Park, with a great view of the National Maritime Museum, the River Thames, and Canary Wharf, London's second financial center, behind the river. · ✅ Of course, the most popular attraction here is the 0° longitude line embedded in the ground. People love to take photos with their feet on either side of the line, as this is the only place where you can truly stand on both the Eastern and Western Hemispheres, even though the line is man-made, haha~