Science in the Bible – Round Earth

(3 Minute Read)

What did Christopher Columbus, Pythagoras, and Aristotle have in common with the Hebrew prophet Isaiah?

They all knew earth is a sphere!

Which one knew it first?

The Hebrew prophet Isaiah knew it in 700 B.C., long before the other three. He wrote,
“Do you not know? Have you not heard?
Has it not been told you from the beginning? Have you not understood since the earth was founded?
It is He who sits above the circle of the earth, and its inhabitants are like grasshoppers. He stretches out the heavens like a curtain and spreads them out like a tent to dwell in.” (Isaiah 40:21-22)

The Hebrew word for circle is חוּג (Strong’s H2329), transliterated chuwg or khoog. It is usually translated circle, circuit, or compass. It only appears two other times in the Bible (Job 22:14; Proverbs 8:27), so there’s not a lot of context available to determine a precise meaning. The essence of the word is round.

It is certainly the case that Isaiah made an accurate statement about the shape of the earth – when viewed from a distance it’s circular (He sits above the circle of the earth). Only a sphere projects a circular image in every direction.

Earth’s Shape

Isaiah even seems to say that people should know the earth is a globe! For he introduces his claim that the earth is round with the words,
“Do you not know? Have you not heard?
Has it not been told you from the beginning? Have you not understood since the earth was founded?” (Isaiah 40:21)

Earth’s shape is not a hard thing to figure out. The masts of ships gradually appearing over the horizon followed by the ships imply it’s a globe.

During a lunar eclipse, the moon moves through the earth’s shadow from the sun. The edge of the shadow is always circular, as many, including myself, have personally witnessed during lunar eclipses of the full moon. The always-circular shadow shows that the earth must be spherical.

Today many high-flying pilots have seen the curvature of the earth. We even have NASA pictures from space that show earth is a globe, such as the one above.

Historical Knowledge of Earth’s Shape

Pythagoras, of Pythagorean Theorem fame (a² + b² = c² for a right triangle), was a Greek mathematician and philosopher of the 6th century B.C. He’s the earliest we know of who thought the earth was round, rotated on an axis, and orbited a central point.

The Greek mathematician Aristotle (384–322 B.C.) thought Earth was a sphere, because as one moved south from Greece into Egypt, different constellations became visible. This indicated the surface of the earth was curved. He also cited the earth’s curved shadow on the moon during eclipses.

Eratosthenes (276-194 B.C.) was a Greek mathematician, geographer, and astronomer from Cyrene, North Africa (now Libya). He was the director of Alexandria’s great library. He is called the Father of Geography (literally, earth writing), because he was the first to coin the word with his book Geography.

Eratosthenes knew the earth was a globe, and he was the first to calculate the circumference of the earth around 240 B.C. Using geometry and trigonometry and some observations of solar shadows, he calculated the circumference to be 25,000 miles. The actual value is 24,901 miles — less than half a percent error!

One hundred and fifty years after Eratosthenes, the Greek astronomer Posidonius (135-51 B.C.) erroneously calculated the earth’s circumference to be 18,000 miles. Nevertheless, Eratosthenes’ value for the circumference was commonly accepted during the Middle Ages.

Contrary to what is commonly taught in government schools, Christopher Columbus and many mariners of his time knew the earth was a globe in the 1400s A.D. In fact, Columbus used Posidonius’ smaller value for earth’s circumference in order to persuade his investors that he could sail west from Europe to Asia in 1492.

Ferdinand Magellan‘s circumnavigation of the earth (1519−1522) demonstrated the earth is a globe.

Science Catches Up to the Bible

The Bible’s hint in Isaiah about the earth’s shape is the earliest information man has on the subject. Although the Bible is not primarily a science textbook, it does contain many scientific truths like this and like those mentioned in this Science in the Bible series, truths that long pre-date their discovery by today’s scientists. This is strong evidence of divine authorship of the Bible.

Questions to Ponder

1. Critics like to satirize Biblical Christians as the “Flat Earth Society.” Have you ever met anyone who actually believed the earth is flat?
2. What have you seen with your own eyes that confirms the earth is round?

Share your thoughts on these questions in the comments below. It could encourage or help another reader.

Soli Deo Gloria.

This is the sixth in the Science in the Bible series of blog posts. While there is much science connected with Creation and Noah’s Flood, this series will focus on lesser known scientific truths that were alluded to in the Bible long before they were known to scientists.
Read the prequels:
1. Science in the Bible – Blood
2. Science in the Bible – Ocean Currents
3. Science in the Bible – Undersea Mountains
4. Science in the Bible – Ocean Reservoirs
5. Science in the Bible – Good Medicine

Read the sequel:
7. Science in the Bible – Don’t Marry Kin

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©William T. Pelletier, Ph.D.
“contending earnestly for the faith”
“destroying speculations against the knowledge of God”
“for the defense of the gospel”
(Jude 1:3; 2 Cor 10:5; Phil 1:16)
Wednesday March 8, 2017 A.D.

Thy word is a lamp to my feet and a light to my path. (Psalm 119:105)