Why The Prime Meridian Isn't At 0º

  • Published on: 05 January 2015
  • http://tomscott.com - http://twitter.com/tomscott - If you travel to Greenwich, stand on the famous Prime Meridian Line -- which is marked with a physical line and a sculpture at the Royal Observatory -- and look at your GPS, it won't read 0° longitude. It'll be slightly out. Who's right? And why?

    Many thanks to my lovely cameraman Tom Morris (http://tommorris.org), who dealt with the cold wind admirably!
  • Runtime : 3:14
  • tomscott tom scott things you might not know Greenwich (City/Town/Village) greenwich meridian Prime Meridian (Invention) Royal Observatory Greenwich (Astronomical Observatory) Greenwich (Location) Global Positioning System (Industry) Location (Literature Subject) Johns Hopkins University (College/University) Applied Physics Laboratory (Spacecraft Manufacturer) george airy astronomer royal wgs84 ellipsoid spheroid GPS Navigation Device (Consumer Product)


  • POVgames
    POVgames   10 hours ago

    didn’t know this guy was a round earther, what a shame

  • Adam Haj
    Adam Haj   1 days ago

    So in pictures of earth the earth looks perfectly spherical because the atmosphere acts as a liquid in zero gravity and makes it look spherical?

  • Dan Li
    Dan Li   4 days ago

    I like that the video is is about spheroids and is 3.14 minutes long.

  • Zhuang Zhuang Sun
    Zhuang Zhuang Sun   6 days ago

    1:05I thought you were gonna say "unfortunately, the world isn't the UK"

  • Frankie Teague
    Frankie Teague   3 weeks ago

    So...I would imagine, if you stand between the two lines, you dont exist?

  • J M
    J M   3 weeks ago

    Title:British People: Wait, that’s illegal

  • Gary Cooper
    Gary Cooper   3 weeks ago

    It’s weird to hear you speaking of the Greenwich meridian as the division between the eastern and western hemispheres. In terms of longitude numbers it is, of course, but in school I was always taught that the Western Hemisphere comprises the Americas, while the Eastern Hemisphere is Europe, Africa, Asia, and Australia. By that standard, all of Great Britain is in the Eastern Hemisphere.

  • Zoyx
    Zoyx   3 weeks ago

    I see the problem. We are using a spheroid on a flat earth.

  • Moderately Pissed Off

    So the British won't adopt the new standard because it's inconvenient? I'll remember that next time a Brit makes a joke about Americans still using English units of measurement.

  • Venky Wank
    Venky Wank   1 months ago

    I came back to watch this video in September 2019 reminiscing about the unique wonderful quirky strange amazing crazy stuff that took place in the past decade... The twenteens have been memorable 😊

  • George Emil
    George Emil   1 months ago

    The only plausible explanation is the shift of tectonic plates. So what if the Earth is lumpy? Imaginary lines can go straight through mountains and hills.

  • US
    US   1 months ago

    The UK invented maps and time. Thats why all the maps and clocks are centered on them ( ͡° ͜ʖ ͡°)

  • dasten123
    dasten123   1 months ago

    Brilliant video! Super interesting!

  • Violeta Sampedro
    Violeta Sampedro   1 months ago

    Hey, I've got a question, does that affect the Equator too? Because when I went to Ecuador I remember the half world monument (I don't think that's the proper translation, it's Monumento de la Mitad del Mumdo in Spanish) was slightly off.

  • JesusJuenger
    JesusJuenger   1 months ago

    Tom Scott is everything the show "QI" should have been -- interesting facts, instead of the boring technical pedantry it became.

  • Ľuboš Rybanský
    Ľuboš Rybanský   1 months ago

    2:51 Wrong! According to the fixed point theorem there has to be at least one point on the surface that isn't moving relative to the coordinate system (I mean sure, the earth is spinning - the whole thing is moving around in space, but other than that).

  • Kennedy McLeod
    Kennedy McLeod   1 months ago

    This problem is particularly evident in Fiji where charts can be 1/4 mile off in places. While I was sailing those waters, islands, coral reefs and passes would not be where charted. Fortunately one can overlay the area with Google Earth downloads and correct the navigation problem locally. There is a formula for this correction.

  • Steven Pilling
    Steven Pilling   1 months ago

    Things change over time and both Greenwich and Annapolis are slowly moving tectonically. However, Greenwich will always define the Prime Meridian; if not physically, then symbolically.

  • pmailkeey
    pmailkeey   1 months ago

    Anyway, never mind spheroids, GB, Fr & US et al have a position from Greenwich - that is INACCURATE compared to GPS standards. WSG84 (the currently accepted GPS standard) just averages all the errors out of the systems previously erroneously measured - so we now have a consistent system that's just a little out all over the place !

  • pmailkeey
    pmailkeey   1 months ago

    No Tom, Greenwich is NOT moving. It's as silly as saying the end of your tape measure is moving. Clearly it's not, it remains at zero. Everything else around you might be moving.

  • Daniel Zylberkan
    Daniel Zylberkan   2 months ago

    I just found about Tom and all I have to say is that he's really good at this YouTube thing

  • Tygearianus
    Tygearianus   2 months ago

    My right foot is always in the left and my left is always in the right. The rest of you are doing it wrong

  • Lee Elliott
    Lee Elliott   2 months ago

    I was in Quito Ecuador and visited the monument that supposedly is on the equator. However, when later comparing the monument's location to Google maps, it turned out that Google located the equator several hundred meters to the south. That means that the demonstration showing water swirling one way down the drain at a location just above the equator and another swirling the other way just below the equator is most likely a scam. But, its for the tourists, so who cares.As for the difference in England, keep in mind they use the Sat-Nav system while Americans use GPS.

  • Philip Leitch
    Philip Leitch   2 months ago

    When working with Geographic Information Systems these different "spheres" (ellipsoids) are called projections, so that images, streets and infrastructure with known locations are "known" (recorded) by one projection and can be displayed (projected) onto a different shape.

  • Happymonday
    Happymonday   2 months ago

    Why is it called a spheroid when the earth is a square? 🤔

  • Tupacabra
    Tupacabra   2 months ago

    Is it Greenwich or Grinnich?

  • Chriseurosong
    Chriseurosong   2 months ago

    So GPS is wrong. The Prime Meridian was fixed before satellites. And if tectonic plates move... well, using the zero-degree frame of reference, the Greenwich plate is fixed but everything else moves relatively.

  • Peter Harris
    Peter Harris   3 months ago

    next time I go to aberdeen I'll compare some notes

  • Thulasi Das
    Thulasi Das   3 months ago

    But how did you decide 0 degree meridian is where it is? Just 250 years ago the 0 meridian was running through Ujjain in India, which was quoted by ptolemy! When did they shift it to Greenwich?