- 2 vertical sticks
- measuring tape
- clock
- camera or notes
Materials Needed
Setup Steps
- Pick a preset pair when possible: equinox + mid-latitude versus a partner 10–20° farther north or south.
- Place one vertical stick locally and coordinate with a partner farther north or south.
- Measure stick height and shadow length at the same UTC time.
- Log stick height, shadow length, latitude, longitude, and UTC timestamp for each site.
- Compute sun elevation from arctangent(stick height / shadow length).
Expected Calculation
elevation=arctan(stick heightshadow length)
altitudenoon=90 − |latitude − declination|
Δelevation=differs between latitudes at the same UTC
Different latitudes should produce different sun elevation angles at the same moment.
Graphic
This visual shows the core geometry the experiment is testing before the real-world observation is made.
What to Observe
- Angles differ consistently between locations.
- Differences align with globe geometry and solar declination.
Interpretation
A single nearby sun above a flat plane struggles to match these angle patterns globally.
Sources
Evidence Card
Claim
Do shadow angles differ by latitude at the same time?
Model Used
The experiment’s stated geometry or physical model with fixed inputs across comparisons.
Formula
elevation=arctan(stick heightshadow length)
altitudenoon=90 − |latitude − declination|
Δelevation=differs between latitudes at the same UTC
Last Verified
2026-06-30
Assumptions
- The protocol holds location, height, and distance inputs fixed while comparing observation to prediction.
- A single ambiguous photo is not enough; repeatable measurements matter.
- Primary-source references carry more weight than generic summaries.
External Sources
A page-specific source set has not been attached yet.
What Would Falsify This Page
A repeatable observation that matched the competing model better than this experiment’s stated prediction would count against this page.