Prime meridian

[BrilloPad]

Greenwich Meridian line is actually 334 ft east...near a rubbish bin - Telegraph

Why not go back to the original base line Ordnance Survey Blog Heathrow Airport honours the work of Major General William Roy - Ordnance Survey Blog ?

[meridian]

Well, right now the meridian is a bit further west of London.

[NickFitz]

The Telegraph's "science reporting" is a joke nowadays. "Now scientists have explained…" == "A mate told me about this well-known fact, which I would already have been aware of if I was an actual science correspondent rather than an arts graduate who got dumped on the science desk because I was cheaper than somebody who knows what they're talking about, so I phoned up Greenwich and they confirmed that my mate was correct, and explained why. As the explanation was received by me just now, I shall write it up as 'Now scientists have explained…' and bingo! it looks as if somehow it's news."

[expat]

It's not as simple as that. Zeity is right that it comes from the US GPS definition, the real origin for GPS is not 0° but 90° West. They chose that because it actually runs through the continental US. That seems fair enough, when we made most of the world's maps we got to choose, now they put the satellites up there so they get to choose.

But also it depends on the coordinate frame used. There is no unique method of mapping a point on the Earth's surface to Lat+Long coordinates, and the modern one puts Greenwich's marker a bit off.

Indeed if you kept Greenwich = 0° then it would be the GPS origin that is a bit off from 90°.