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**Flat Earth Theory / Latitude and longitude - please enlighten me**

« **on:**June 01, 2020, 10:03:35 AM »

I've read a number of posts where latitude and longitude are dismissed by FErs because they are based on a globe earth.

I'd like to unpick this and ask what the actual objections are.

Fundamentally (if you live in the northern hemisphere), your latitude is easily determined. It's simply the altitude of Polaris from your location. It's not an absolute value in miles, km or light years, because to determine that you'd need to know how far away Polaris is and in times past, that wasn't possible to determine. What we do instead is measure the angle from the horizon to the star, because that's easily done and doesn't require you to know any distances.

Longitude is based on time. When was the sun due south at your location compared to when it was due south in Greenwich UK? If that's +1 hour and the sun moves at 15 degrees per hour, then your longitude is 15W.

Both of these are determined easily from the positions and movements of celestial bodies and can be measured with simple instruments (if you consider an accurate timepiece to be a simple instrument).

Neither of these values rely on any preconceived assumption about the shape of the earth.

There is an issue of course if you want to calculate the distance between two points given by latitude/longitude, because that involves spherical geometry and includes an assumption about the shape of the earth.

So is that it? Are latitude/longitude OK by themselves, but the distances are not? What are the actual objections?

I'd like to unpick this and ask what the actual objections are.

Fundamentally (if you live in the northern hemisphere), your latitude is easily determined. It's simply the altitude of Polaris from your location. It's not an absolute value in miles, km or light years, because to determine that you'd need to know how far away Polaris is and in times past, that wasn't possible to determine. What we do instead is measure the angle from the horizon to the star, because that's easily done and doesn't require you to know any distances.

Longitude is based on time. When was the sun due south at your location compared to when it was due south in Greenwich UK? If that's +1 hour and the sun moves at 15 degrees per hour, then your longitude is 15W.

Both of these are determined easily from the positions and movements of celestial bodies and can be measured with simple instruments (if you consider an accurate timepiece to be a simple instrument).

Neither of these values rely on any preconceived assumption about the shape of the earth.

There is an issue of course if you want to calculate the distance between two points given by latitude/longitude, because that involves spherical geometry and includes an assumption about the shape of the earth.

So is that it? Are latitude/longitude OK by themselves, but the distances are not? What are the actual objections?