Uploaded January 2019 | Updated September 2026, 3 weeks ago
Does the horizon really rise to eye level?
What does the math say for a globe?
tl;dr: They tried the test. Yep. It's a globe.
I had an error in the previous version, so here is the correction. Thanks to Walter Bislin for pointing that out.
jump ahead:
@0:10 Antonio Subirats suggests a test for flat-Earth vs Globe
@0:55 Bobby Shafto performs the test (spoiler alert... he got the globe result)
@1:00 Critical Think performs the test (spoiler alert... he got the globe result too)
@1:38 Deriving the equations for the horizon dip on a globe
@8:18 Arriving at the final result
@9:02 A table of the horizon dip for different heights on a globe
@11:00 Don't forget to double it!
@12:16 Comparing the math with what Critical Think saw
@12:45 Critical Think measures the angle (spoiler alert... he nailed it)
@13:08 A much simpler method suggested by Walter Bislin
source material:
Antonio Subirats "Flat-Earther Lesson For Globlings." youtube.com/watch?v=6OtahJUCIJQ
Bobby Shafto "Horizon Tube Challenge" youtube.com/watch?v=Ev_3gfQ80CY
Critical Think "Globling teaches Antonio Subirats a lesson in horizon drop" youtube.com/watch?v=54FiuS9ZplM
Critical Think "Antonio Subirats' Superluminous Stupidity" youtube.com/watch?v=YHGdT_V-vtA
Walter Bislin's page: http://walter.bislins.ch/bloge/index.asp?
Does the horizon really rise to eye level?
What does the math say for a globe?
tl;dr: They tried the test. Yep. It's a globe.
I had an error in the previous version, so here is the correction. Thanks to Walter Bislin for pointing that out.
jump ahead:
@0:10 Antonio Subirats suggests a test for flat-Earth vs Globe
@0:55 Bobby Shafto performs the test (spoiler alert... he got the globe result)
@1:00 Critical Think performs the test (spoiler alert... he got the globe result too)
@1:38 Deriving the equations for the horizon dip on a globe
@8:18 Arriving at the final result
@9:02 A table of the horizon dip for different heights on a globe
@11:00 Don't forget to double it!
@12:16 Comparing the math with what Critical Think saw
@12:45 Critical Think measures the angle (spoiler alert... he nailed it)
@13:08 A much simpler method suggested by Walter Bislin
source material:
Antonio Subirats "Flat-Earther Lesson For Globlings." youtube.com/watch?v=6OtahJUCIJQ
Bobby Shafto "Horizon Tube Challenge" youtube.com/watch?v=Ev_3gfQ80CY
Critical Think "Globling teaches Antonio Subirats a lesson in horizon drop" youtube.com/watch?v=54FiuS9ZplM
Critical Think "Antonio Subirats' Superluminous Stupidity" youtube.com/watch?v=YHGdT_V-vtA
Walter Bislin's page: http://walter.bislins.ch/bloge/index.asp?
