Jump to content

Horizon Dip Measurements: Difference between revisions

From Flerf Wiki
← Older edit
Dave (talk | contribs)
45 edits
No edit summary
Dave (talk | contribs)
45 edits
No edit summary
 
(23 intermediate revisions by the same user not shown)
Line 1: Line 1:
The horizon dip measurement is the angle between the horizontal (the line perpendicular to the vertical at a specific point) and the apparent horizon.
The horizon dip measurement is the angle between the horizontal (the line perpendicular to the vertical at a specific point) and the apparent horizon.


On a globe, you would expect this angle to increase with increasing altitude, because the horizon would drop away with the curve. In fact, we can calculate the expected dip of the horizon for any altitude using this formula:
On a globe, we would expect this angle to increase with increasing altitude, because the horizon would drop away with the curve.


<math>
On a flat earth, we would expect the horizon to always "rise to eye level".
\text{Dip} = \sqrt{\frac{2h}{R}}
</math>


Where:</br>
This page is a gallery of photos showing the measured dip of the horizon from horizontal.
h = the height or altitude of the observation </br>
R = the radius of the earth (6,378 km)


Here is a table of the expected dip of the horizon for various altitudes:
= Instructions =


{| class="wikitable"
If you want to submit your own image, email dip@mctoon.net Please include the following details with your submission:
| Altitude
| Dip
|-
| 10,000 km || drop1
|}


On a flat earth, if the plane is infinite, you would expect no drop of the horizon with increasing altitude. You would just be able to better resolve distant points because of the greater angular resolution between them. If the plan is finite, there would be slight dip of the apparent horizon from the horizontal, but not nearly as much as on the globe. We can calculate this expected dip for any altitude as well.
1.  A clearly visible horizon (ideally, no clouds at, or near the horizon)


Measurements will be forthcoming.
2.  An instrumented graphic overlay showing true horizontal
 
3.  The name of the device generating the graphic overlay
 
3.  Altitude at time of photo
 
4.  Image Source/Credit.  Please indicate if you want to be credited and how.  We do not wish to dox anyone but we do want to appropriately give credit where it is due.
 
= Gallery =
 
'''Note:'''</br>Some photos are cropped due to the size limit for uploaded files.
 
<div class="dip">
 
{{Dip
|image=File:Theodolite-app-flatslugbrains-.jpg
|Source/Credit= Globular EPIC Bikini @FlatSlugbrains on Twitter
|altitude=11074 m
|dip=3.3°
|device=Theodolite
}}
 
{{Dip
|image=File:Tyler.jpg
|Source/Credit= @Tylerthepilot_ on Twitter
|altitude=35820 m
|dip=4.8°
|device=Theodolite
}}
 
{{Dip
|image=File:Moon.jpg
|Source/Credit=McToon
|altitude=35091 ft
|dip=~4°
|device=Theodolite
}}
 
{{Dip
|image=File:Theodolite-app-dwolfman54-.webp
|Source/Credit=@dwolfman54 on Twitter
|altitude=33709 ft
|dip=>2°
|device=Theodolite
}}
 
{{Dip
|image=File:Theodolite-app-bk.webp
|Source/Credit=BK, flight from Newcastle to Brisbane, in Australia:
|altitude=36706 ft
|dip=~2°
|device=Theodolite
}}
 
{{Dip
|image=File:Screenshot 2024-12-16 at 10.35.21 PM.png
|Source/Credit=Wolfie6020
|altitude=46000 ft
|dip=
|device=cockpit display
}}
 
</div>
 
[[Category:Science data]]

Latest revision as of 19:05, 26 December 2024

The horizon dip measurement is the angle between the horizontal (the line perpendicular to the vertical at a specific point) and the apparent horizon.

On a globe, we would expect this angle to increase with increasing altitude, because the horizon would drop away with the curve.

On a flat earth, we would expect the horizon to always "rise to eye level".

This page is a gallery of photos showing the measured dip of the horizon from horizontal.

Instructions

If you want to submit your own image, email dip@mctoon.net Please include the following details with your submission:

1. A clearly visible horizon (ideally, no clouds at, or near the horizon)

2. An instrumented graphic overlay showing true horizontal

3. The name of the device generating the graphic overlay

3. Altitude at time of photo

4. Image Source/Credit. Please indicate if you want to be credited and how. We do not wish to dox anyone but we do want to appropriately give credit where it is due.

Gallery

Note:
Some photos are cropped due to the size limit for uploaded files.

Source/Credit Globular EPIC Bikini @FlatSlugbrains on Twitter
Altitude 11074 m
Dip 3.3°
Device Theodolite
Source/Credit @Tylerthepilot_ on Twitter
Altitude 35820 m
Dip 4.8°
Device Theodolite
Source/Credit McToon
Altitude 35091 ft
Dip ~4°
Device Theodolite
Source/Credit @dwolfman54 on Twitter
Altitude 33709 ft
Dip >2°
Device Theodolite
Source/Credit BK, flight from Newcastle to Brisbane, in Australia:
Altitude 36706 ft
Dip ~2°
Device Theodolite
Source/Credit Wolfie6020
Altitude 46000 ft
Dip
Device cockpit display
Retrieved from "https://www.flerf.info/index.php?title=Horizon_Dip_Measurements&oldid=1494"