The Size, Age, and Origin of the Universe: Modern Scientific and Jewish Mystical Views

The Size, Age, and Origin of the Universe: Modern Scientific and Jewish Mystical Views

For many years I led a hands-on educator’s workshop at NASA’s Jet Propulsion Laboratory that had an activity demonstrating the size and scale of the Solar System, our Sun and the planets. If the Sun were a grapefruit, the Earth would be a mustard seed about 37 feet away from the grapefruit-sun. Jupiter – the size of a grape – would be about 185 feet away, and tiny distant Pluto (it was still a planet back then)  would be a speck of dust at about 1300 feet. The nearest star (another grapefruit) would be at St. Louis, Missouri (thousands of miles from the JPL, which is in California). Space is vast and almost entirely empty. 

But our Sun is only one of about 200 billion stars that comprise the Milky Way Galaxy, a whirlpool of stars that is about 100,000 light years across. What is a light-year? It’s the distance light travels in one year. Light can travel from the Sun to the Earth, 93 million miles, in about 8 minutes, so a light year is a big distance, almost six trillion miles.  

And the Milky Way is only one of about 200 billion galaxies in the Universe that we can see, spread out over nearly a hundred billion light-years.  

In an earlier blog post on October 20, 2022, Rabbi Mitelman pointed out that Genesis isn’t a scientific textbook, but there are some interesting connections and parallels between biblical and rabbinic sources and modern science. 

The awesome size of our Universe and our utter smallness within it was contemplated by Jewish mystics centuries ago, before modern science knew about galaxies. The Kabbalah, the expansive set of Jewish teachings and ideas on mysticism, speaks of the size, age, and origin of the Universe.

Rabbi Moses Cordovero (the Ramak) brings in the image of the mustard seed (Hebrew: gardir hardal) in the contemplation of our smallness. Dr. Daniel Matt’s book The Essential Kabbalah translates the Ramak’s teaching as follows: “I am a mustard seed in the middle of the sphere of the moon, which itself is a mustard seed within the next sphere. So it is with that sphere and all it contains in relation to the next sphere. So it is with all the spheres – one inside the other – and all of them are a mustard seed within the further expanses. And all of these are a mustard seed within further expanses.”

Perhaps even more engaging is the Jewish mystic’s view of the age of the Universe. The Hebrew calendar dates from the creation of the world at 5783 years ago. The 19th century scientific analysis by the British physicist William Thompson (Lord Kelvin), which centered on the cooling of the Earth, put its age at 20-400 million years. Later 20th century work on the measurement of the known rate of radioactive decay in elements such as uranium accurately puts the Earth’s age, and thus our entire Solar System, at 4.5 billion years.

But our present Universe of 200 billion galaxies is even older than the Earth and the Solar System. The argument that the Universe even had a beginning was a theme of Kabbalah, as outlined in its core text, the Zohar. The first chapter describes the appearance of the light of Creation as a botsina d’cartenuta – a kernel of light from which the Universe emanated. Modern cosmology has only recently settled on the idea that the Universe had a beginning – the Big Bang.

Until the 1960’s, there was a competing model of a “steady-state universe” in which matter was continuously being created without a beginning. The key evidence for the moment of Creation was the expansion of the Universe – all those galaxies are moving away from each other – and the detection of the remnant thermal radiation from the original point of light in which all matter was created. 

The Kabbalah even mentions an inflationary Universe that cosmologists believe occurred shortly after the Big Bang. To quote The Essential Kabbalah again: “With the appearance of the light, the universe expanded (nitrachev).”

In the first three seconds after the Big Bang, simple elements formed. The earlier stages of the Universe – before galaxies and stars came into existence – were dominated by radiation (light, x-rays, infrared, and radio waves) that became the remnant thermal radiation we see today.  The Kabbalah speaks of the Or Ganuz (hidden light) that permeated the Universe at its beginning. This light disappeared – as it nearly has in the view of modern cosmology – but it will be there for the righteous in the World-to-Come.    

Based on the rate of the expansion of those 200 billion (or so) galaxies, the universe is about 13.7 billion years old. Again, it’s a mind-boggling number, but Rabbi Isaac ben Shmuel of Acco (Acre, in northern Israel), a kabbalist active in the 13th-14th century, was able to contemplate it. According to one interpretation of his writings by modern kabbalist and physicist Rabbi Aryeh Kaplan (1934-1983), there were 42,000 years before Adam was created. Each day was a thousand years, as in Psalm 90: “A thousand years in Your sight are but as yesterday”. Multiply 42,000 by 365 by 1000, and you get 15.3 billion years.

Faith and science both exist in the world of wonder, seeking enlightenment and knowledge, and opening up questions of our place in the Universe. The great questions of origin and scope, and the awe at our smallness coupled with our ability to contemplate that smallness, are hallmarks of both fields. But only faith can contemplate purpose. 


(This post is part of Sinai and Synapses’ project Scientists in Synagogues, a grass-roots program to offer Jews opportunities to explore the most interesting and pressing questions surrounding Judaism and science. Bonnie J. Buratti, a longtime member of Pasadena Jewish Temple and Center, is a planetary astronomer who has been involved with numerous NASA flight missions. She is a Fellow of the American Geophysical Union and received the Carl Sagan Medal for Excellence in Public Communication and the Gerard P. Kuiper Prize in Planetary Sciences).


Daniel Matt: The Essential Kabbalah (HarperOne, 2009)

Daniel Matt: God and the Big Bang (Jewish Lights, 2016)

Steven Weinberg: The first three minutes (Basic Books, 1993)


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