I mean, what more can we say? Otherwise, let's just start looking at things as a life of truth or dare.
Here's the Dare to prove the truth, right?
Observable ones too.
Here's our shortlist.
Do enjoy reality, however you 'see' it.
1. Observing Ships Disappearing:
Process: Stand on a beach or pier and watch a ship sail away. As the ship goes further, it doesn't shrink proportionally but its hull disappears first, then the masts, eventually dipping "hull first" over the horizon. This wouldn't happen if the Earth were flat.
2. Observing Constellations Change:
Process: Travel north-south and compare the visible constellations. Different constellations become visible as you move, demonstrating the curvature of the Earth.
3. Lunar Eclipse:
Process: Observe a lunar eclipse. The Earth casts a round shadow on the moon, which wouldn't be possible if the Earth were flat.
Remember, numerous historical and modern scientific observations conclusively demonstrate the Earth's sphericity. These experiments offer a glimpse into how we understand its shape, but the scientific consensus is well-established based on far more rigorous evidence.