#### GFDream

• 1
##### How to explain?
« on: March 02, 2021, 05:05:29 PM »
Hello!
I was browsing on YouTube today and found this video:
In the video, a weather balloon was sent to 100K feet and we can clearly see some curvatures on the shape of Earth.

The video is a full uncropped 4 hours video from launch to landing.
I'm wondering what could explain this phenomenon?

Thanks.

#### stack

• 2068
##### Re: How to explain?
« Reply #1 on: March 02, 2021, 07:09:39 PM »
Hello!
I was browsing on YouTube today and found this video:
In the video, a weather balloon was sent to 100K feet and we can clearly see some curvatures on the shape of Earth.

The video is a full uncropped 4 hours video from launch to landing.
I'm wondering what could explain this phenomenon?

Thanks.

GoPros come stock with a fish-eye lens that creates curved distortions in various parts of the frame. As the horizon line moves around the frame you can see the curve change to almost flat:

Find a similar vid without a fish-eye lens and have a look at that.

#### scomato

• 74
##### Re: How to explain?
« Reply #2 on: March 04, 2021, 07:34:00 PM »
Hello!
I was browsing on YouTube today and found this video: https://www.yo utube.com/watch?v=9dfVtaZbuIQ
In the video, a weather balloon was sent to 100K feet and we can clearly see some curvatures on the shape of Earth.

The video is a full uncropped 4 hours video from launch to landing.
I'm wondering what could explain this phenomenon?

Thanks.

GoPros come stock with a fish-eye lens that creates curved distortions in various parts of the frame. As the horizon line moves around the frame you can see the curve change to almost flat:

Find a similar vid without a fish-eye lens and have a look at that.

How does the Fish Eye Lens effect explain this video? As you can see the Earth does not distort wildly due to a lens effect as it comes in and out of frame.

#### Clyde Frog

• 603
• [kʰlaɪ̯d fɹɒg]
##### Re: How to explain?
« Reply #3 on: March 04, 2021, 08:13:08 PM »
How does the Fish Eye Lens effect explain this video? As you can see the Earth does not distort wildly due to a lens effect as it comes in and out of frame.
That's not the video the OP asked about, and no one has yet made the claim you are demanding stack answers for. That's not really fair, is it?

Edit to also address the OP: If you take a look throughout the video you posted, there are times where the curvature not only appears to go away entirely, but times where it appears to horizon is concave. And times where the curvature is greatly exaggerated.
« Last Edit: March 04, 2021, 08:21:26 PM by Clyde Frog »

#### Grim4Reaper123

• 4
##### Re: How to explain?
« Reply #4 on: March 10, 2021, 09:43:48 AM »
How does the Fish Eye Lens effect explain this video? As you can see the Earth does not distort wildly due to a lens effect as it comes in and out of frame.
That's not the video the OP asked about, and no one has yet made the claim you are demanding stack answers for. That's not really fair, is it?
May I just ask - how is it not fair when someone brings relevant evidence to the discussion that is GE but it is fair when it is FE. This seems more unfair and a bit biased to GE.

#### Clyde Frog

• 603
• [kʰlaɪ̯d fɹɒg]
##### Re: How to explain?
« Reply #5 on: March 10, 2021, 01:20:16 PM »
How does the Fish Eye Lens effect explain this video? As you can see the Earth does not distort wildly due to a lens effect as it comes in and out of frame.
That's not the video the OP asked about, and no one has yet made the claim you are demanding stack answers for. That's not really fair, is it?
May I just ask - how is it not fair when someone brings relevant evidence to the discussion that is GE but it is fair when it is FE. This seems more unfair and a bit biased to GE.
What is with all the straw manning happening in this thread? Let's recap for a second.

1. OP posted a video saying it showed the Earth's curvature and asked for someone to explain how that could be.
2. It is then explained to the OP exactly how that could be.
3. Someone else entirely shows up with a red herring.
4. I point out that it's a red herring, not taking the time to also point out the fact that there are clear visual distortions in the goalpost-moving video (there are), but also point out that the initial video (you know, the one the thread is supposed to be about) also shows concave curvature on some frames, because lens distortion.
5. You show up to go back to the red herring comment to try and, I guess, justify it, and at the same time seem to imply that I would have no problem if it was an FE that wanted to move the goalposts.

Steps 3 and 5 in that chain of events don't make sense.

#### stevecanuck

• 271
##### Re: How to explain?
« Reply #6 on: March 10, 2021, 04:23:07 PM »
How does the Fish Eye Lens effect explain this video? As you can see the Earth does not distort wildly due to a lens effect as it comes in and out of frame.
That's not the video the OP asked about, and no one has yet made the claim you are demanding stack answers for. That's not really fair, is it?
May I just ask - how is it not fair when someone brings relevant evidence to the discussion that is GE but it is fair when it is FE. This seems more unfair and a bit biased to GE.
What is with all the straw manning happening in this thread? Let's recap for a second.

1. OP posted a video saying it showed the Earth's curvature and asked for someone to explain how that could be.
2. It is then explained to the OP exactly how that could be.
3. Someone else entirely shows up with a red herring.
4. I point out that it's a red herring, not taking the time to also point out the fact that there are clear visual distortions in the goalpost-moving video (there are), but also point out that the initial video (you know, the one the thread is supposed to be about) also shows concave curvature on some frames, because lens distortion.
5. You show up to go back to the red herring comment to try and, I guess, justify it, and at the same time seem to imply that I would have no problem if it was an FE that wanted to move the goalposts.

Steps 3 and 5 in that chain of events don't make sense.

I tried to show once that it's physically impossible to see three-dimensional curvature of a sphere by observing something round. Observable roundness could be due to the object being a flat circle. The only way to discerning whether it's flat or spherical is if our perspective allows our depth perception to tell us that the object is curving AWAY from us (like looking at a basketball).

But, nobody understood what I posted because nobody took the time to read it properly. They actually thought I was promoting FET.