…with binoculars you can see planets, you can see Saturn and Jupiter, you can see Mars with a telescope, the sun and the moon, everything else you see in the solar system is a sphere. It’s a useful video for older learners and adults who want to understand the shape of our Blue Marble home, or need to explain it to others. It was straight overhead in Syene in Alexandria it was a little bit less than overhead, and he rationed that that change in angle from one city to another was probably indicative of us being on a. Aristarchus‘ observations of Earth’s shadow on the moon during lunar eclipses.

Eratosthenes‘ measurements of sunlight down wells in two different cities.Looking at ships or boats on the horizon with binoculars.

Listen as Thaller describes three observable ways that humans have come to know that we live on a sphere, or specifically, an irregularly-shaped ellipsoid: The ancient Greeks actually had a number of really elegant, wonderful proofs that the Earth was a sphere.

…people have known of this for way more than 2,000 years. In the most popular flat-Earth maps, the North Pole sits roughly at the center of the planetary disc, while Antarctica forms a giant ice wall along the planet's circumference. So how do we know the Earth is round? Watch this 2018 Big Think explainer: Three proofs that debunk the flat-Earth theory. Michelle Thaller, astronomer and science communicator with the NASA Goddard Space Flight Center. This is not a viable argument,” explains Dr. “It’s not okay to think that the Earth is flat.

Biggest holes in flat earth theory