Introduction

As my home city, Melbourne, is based by a very large, roughly spherial natural harbour, Port Phillip Bay it makes it a perfect place to test the whether the Earth is flat or spherical. In particular my skills as a drone phototrapher and the amazing improvments to the camera equipped on the DJI Mavic Pro 4 make it possible to test a varieity of claims made by flat earth advocates.

Test Series

In this test series I went to number of locations around Port Phillip Bay that had a clear line of sight to Melbourne as show below. The distances shown on the map are from the shoot location to Australia 108. The tallest building in Melbourne.

There I got down on the beach and setup the drone as close to the waters edge as I could, typically a few meters.

Then I launched the drone and took photos at a variety of heights, 0 meters, 5 meters, 20 meters, 50 meters, 100 meters and 150 meters. At the height of 5 meters and 150 meters I took photos at a variety of different zoom levels. Also I took a video of the drone descending from 150 meters high back down to launch. The intent was to vary a number of variables that then be used to test various claims.

I'm afraid the air over the bay was rather murky on this day, but you can see the buildings outlines clearly.

Distance

This first set of photos is the ones taken at the base line height of 5 meters. They start from the closest location at Mornington and progressively get further away as I move around the bay.

As you get further away you can clearly see that more and more of the city is hidden from view. Also note that how the sinking appearance gets more pronounced as you approach Rye, with Rosebud only being 2.2 kilometers closer than Rye. This is consistent with how the expected drop gets more pronounced as you get further away if the earth is spherical.

Height

The next set of photos is the ones taken at Rye at increasing heights. Rye is the furthest distance from Melbourne and display the greatest amount of hiding.

As we get higher we can see more and more of the buildings being uncovered. Also at the lowest height of 5m, you can see from the texture of the water covering the building its relatively close compared to the higher photos.

Zooming in

One of the frequent claims made by flat earth advocates is that the sinking effect when viewing ships, cities etc. from a long distance is due to perspective. That as the object in question gets further away, it becomes harder to discern the details of the object from the ground and that gives the appearance of the object sinking.

Well all the photos shown so far have been zoomed in. So what does Melbourne look like if you don't zoom in.

Here is a photo taken at Rosebud with no zoom.

Can't see Melbourne? Its there in the center of the image. You might have to look closely.

To help get you an idea of what detail is visible I've cropped the photo.

The buildings are very washed out and you can barely see them. But you can start to see the flat earth advocates point. As there is very little detail in the photo its reasonable to surmise that the apparent missing bottom of the image is actually there but you cant make it out. And if you use a camera with a zoom feature, a P100 with a 125 times zoom is often quoted, then the missing detail will come back into view.

Well my drone can't do a 125 times zoom but It can do a 13.5 and 32.5 times zoom. So lets see 13.5 times zoom and compare it with the photo taken at 150 meters high with the same 13.5 times zoom

Well you can know see the buildings a lot more clearly. However by comparing the low photo with the high photo you can see there is still lots of missing height.

Lets push it to 32.5 times zoom.

Again more details in the low photos, but barely any missing height has returned, if any.

Height Overlay

To get an even clearer perspective on whether zooming in can reveal the missing building height I came up with an image editing process where we combine a low photo with a high photo.

The murkiness of the photos in the test series I've been using so far make it tricky to use it, so I'm going to switch to a set of photos I took at Leopold on a different date. These photos were taken on a clear day, just on sunset. The buildings reflected the setting sun which made them clearly stand out.

Here are the low and high photos using 32.5 zoom.

Next I took the low photo, and using an image editor overlaid the high photo so the parts of the buildings visible in both photos lined up and the high photo buildings showed through.

This photo makes it unambiguously clear that the bays surface is covering the lower parts of the building, and no amount of zooming in is going to reveal the bottom of the buildings. Its clearly shows that the bays surface must in some way bend down between Leopold and Melbourne.