The amount of Earth’s surface we can see at once from a location in space depends on our distance to the Earth. The closer the observer, the smaller the amount of visible Earth’s surface. Conversely, the farther the observer, the larger the amount of Earth’s surface visible to them. But no matter how far the observer, they would not be able to see the entire hemisphere.
Flat-Earthers discovered that there are the differences in the sizes of continents in the different images of the Earth, and used the fact as ‘evidence’ of misconduct. They are wrong. Such differences in continent sizes are present because the images show the Earth from different distances and different field of view.
The two images flat-Earthers bring up often are the Blue Marble 2002 and 2012, which shows North America with different sizes relative to the Earth.
To illustrate how such a phenomenon might happen, we can use a globe and a camera with a zoom lens:
- The upper picture was taken using a 70-200mm telephoto lens at 200mm. The field of view is ±11°. The distance to the object is ±2.6 meter.
- The lower picture was taken using a 16-35mm wide-angle lens at 16mm. The field of view is ±98°. The distance to the object is ±27 cm.
Both pictures were taken using the same Canon 5D Mark III camera and using the same globe.
Anyone can do the same experiment using a camera and a globe or even another spherical object like a basketball or a football, and would easily get the same result. Any camera that can zoom is sufficient, including most camera phones.
To better illustrate this phenomenon, we can also use the simulation here: The True Face of the Earth, Camera Distance matters.
- The True Face of the Earth, Camera Distance Matters – Walter Bislin
- Debunked: “Blue Marble” Photos show a Changing Earth – Metabunk