If latitude is how far you are from the equator, why is longitude how far away we are from a town in the UK?

Thumbnail only barely related.

Resources

https://www.ordnancesurvey.co.uk/newsroom/blog/ordnance-datum-newlyn-100-years-old-today

https://www.sea.museum/2016/06/08/where-on-earth-are-you-a-beginners-guide-to-longitude/

https://journal.hautehorlogerie.org/en/the-marine-chronometer-invention-and-rivalry-on-the-high-seas/

https://www.britannica.com/technology/chronometer

https://www.rmg.co.uk/stories/topics/greenwich-mean-time-gmt