Counting the Stars: Ancient Insights Meet Modern Science

This article is divided into three parts. First, we explore the total number of stars in the universe, a fascinating topic highlighted in various sources, including Rabbi Zamir Cohen's book. This serves as an introduction to parts two and three, where we delve into galaxies: the number of stars within them and their spatial arrangement.

Part 1: Counting the Stars

On a clear night, a few thousand stars are visible to the naked eye. But is it possible that people 1,500 to 2,000 years ago had an estimation of all the stars in the universe?

Modern scientists in Australia estimate an astronomical number: 10²² stars. Similarly, NASA estimates about 10²¹ stars, while the European Space Agency suggests 10²² to 10²⁴ stars.

Is this hinted at in Jewish texts? Here's a 1,500-year-old excerpt from the Talmud:

"Said Hashem to the people of Israel:

I created 12 constellations in the sky.

For each constellation, I created 30 legions.

For each legion, I created 30 divisions.

For each division, I created 30 hosts.

For each host, I created 30 platoons.

For each platoon, I hung 365,000 myriads of stars, corresponding to the days of the solar year.

And all this was created for you."

(Talmud, Berachot 32b)

This suggests the universe's stars are organized into layers: 12 groups, each with 30 sub-groups, continuing until each contains 3.65 billion stars. This approximates scientific estimates of the universe's stars.

Bear in mind, the Torah's count needn't match exactly due to these reasons:

1. Scientifically, stars are constantly formed and destroyed ("supernovae"), so counts reflect visible stars now, not at creation. The Talmud's "I created" implies numbers at the creation moment.

2. Scientific numbers are rough estimations based on Earth-bound observations and mathematical models, not precise counts.

Now, let's calculate the Talmud's number. "Myriad" means 10,000. So:

12 X 30 X 30 X 30 X 30 X 30 X 365,000 X 10,000 = 10¹⁸

This totals 10¹⁸ stars. The numbers are similar! Who could fathom such a number of stars thousands of years ago?

This was explored in Rabbi Zamir Cohen's works; now, let's move to the latest findings.

Part 2: Understanding Galaxies

Modern science, with a century of observation and research, identifies galaxies as fundamental cosmic units, even earning a unique status. But how big is a galaxy?

Science offers these estimates:

The Talmud's description mirrors this: large groups with smaller subsets. The smallest contains "365,000 myriads" of stars.

"Myriad" equals 10,000, making it:

Does the Talmud's count align with these numbers?

Thus, the basic star group size in the Talmud matches the scientific galaxy size range.

a. The Talmud: 3.65 billion stars.

b. Science: about 10 billion stars.

Thousands of years ago, who could imagine so many stars, let alone estimate a galaxy's size? And yet, the Talmud is strikingly accurate. It's amazing!

But there's more. The Talmud not only considers the star count and galaxy size but also their structured grouping hierarchy—unobservable with the naked eye. Is this accurate too?

It turns out, yes.

Part 3: Galactic Clusters

All matter attracts other matter through gravity. Hence, stars cluster together, forming "galaxies," systems of stars relatively close compared to other galaxies.

Recent discoveries show galaxies also form distinct structures:

• Nearby galaxies gather into groups
• These groups form "galactic clusters"
• Clusters together form "superclusters"

And so on, galaxies structured into groups, clusters, superclusters, and beyond. This modern scientific classification remarkably aligns with our sages' ancient descriptions, as detailed in the Talmud over millennia ago.

Text adapted from "Interwoven Worlds." For the full chapter in PDF, click here.

The author holds a B.Sc in Physics with honors from the Technion.