G-d said, “Let there be light,” and there was light! (Genesis 1:3)
Light, according to the Bible, was the first physical creation. But… Let there be electrons?
No joke! Most physicists today, whether atheists or G-d fearing religionists believe that the universe started with a bang—the so-called “Big Bang.” That explosion begat light. Photons, the fundamental units of light energy, whizzed about frantically, colliding with each other. As the primeval blast expanded, it cooled. Like snow condensing in freezing clouds, energy condensed into matter. Colliding photons split into electrical charge and material particles—electrons and positrons (electrons’ positive twin). Thus light begat electrons. One might say that electrons are truly children of light. Or perhaps they are light’s alter-ego. At any rate, still too “hot” to settle, electrons and positrons collided and merged back into photons.
To create even a tiny bit of matter requires a huge amount of energy. That’s the lesson of Einstein’s famous equation, E = mc2. As the infant universe expanded, it cooled. Within a few seconds from Creation, there was no longer enough energy to sustain the rate of production of electrons from light. The reverse process continued until most of the electron/positron pairs had converted back to light. Cosmic temperature dropped further and the universe gradually settled into the form we see today. That is a quick, rough summary of Genesis according to modern physics.[1]
But even in the cold modern universe, electrons and light remain connected as deeply, as fundamentally, as body and soul. Like the body, electrons are matter, and can in principle be weighed. Like the soul, light is immaterial, and, in the ordinary sense, weightless. This analogy is a perfect introduction to Earthly Materials, this website intended to connect today’s scientific understanding of physical materials with the Torah.
However, mixing physics with Torah is a delicate job. Some of the relevant concepts are best “digested” in small, sequential portions. Therefore, I’ve divided this preface into three parts. Part 1 addresses the electron. Part 2 addresses the electrical nature of light. Part 3 explains what happens when light and electrons get together—and the whole visible world springs into view! I pray that G-d will help me to find the right words and imagery to make my explanations clear and vivid to you, the reader.
Consider the electron
An electron is the smallest bit of matter that plays a noticeable role in our everyday world. It’s so small that 7,000,000,000,000,000,000,000 (that’s 7 x 1021 or seven billion trillion) of them, gathered together, would weigh about as much as the ink in the period at the end of this sentence.[2] Electrons, moving, create the electric current that powers almost every device of modern technology. Electricity standing still causes the “static” (electrostatic force) that can make hair stand on end.
The following facts about electrons are relevant to the discussion which follows.[3] They may be familiar to anyone who has studied elementary physical science.
- Electrons are part of atoms. Atoms are the smallest bits of matter that behave like ordinary matter. Therefore, all ordinary matter contains electrons.
- Electrons carry “electric charge.” Electric charges exert force (push or pull) on other electric charges.
- Electric charge comes in two types. They are called, for historical reasons, “negative” and “positive.” The rules for the forces they exert are simple: Objects bearing the same charge repel each other. Objects bearing opposite charges attract each other.
- Electrons carry the negative type of charge. By themselves, electrons repel each other. They stay together within atoms because every atom’s center, called its nucleus, contains positively charged particles called protons.[4] Electrons and protons have exactly equal amounts of electric charge, but of opposite type.
- Electrons are almost weightless compared with atoms. An electron weighs approximately 1/1800 of a proton.[5] The simplest atom, hydrogen, consists of one electron and one proton. Its mass in atomic mass units 1. The electron contributes 0.0005 to that mass—essentially negligible.
- Electrons are magnetic. Due to a quantum-mechanical property called “spin,” electrons are individual magnets with north and south poles. This, combined with their arrangement in atoms, explains the magnetic properties of matter.
- Electrons surround the atomic nucleus. Their motions were once pictured as resembling the orbits of planets around the sun. Electron “orbits” have long been replaced by the far more abstract “orbitals” of quantum mechanics.
The Bohu Paradox
If everything in the material world is made of atoms, shouldn’t they be referred to, or at least hinted at, in the Bible’s narrative of Creation? Some scholars believe they have found the hint. They look to Genesis 1:2, …And the Earth was formless (tohu) and empty (bohu)…
This unusual word, bohu, is used only three times in the entire Hebrew Bible.[6] One usage is by Isaiah. Prophesying that a nation which tries to destroy Israel will itself be destroyed, he said [G-d] will stretch over it a line of tohu and stones of bohu.[7] But therein lies a paradox: Stones are the ultimate of solidness. How can stone also represent the ultimate emptiness?
One clue comes from Kabbalah, specifically the ancient Sefer HaBahir, the Book of Illumination. There Rabbi Berachia explains that the word “bohu” is made up of two parts: “bo” means “in it,” and “hu” means “it is.” Therefore, bohu means it is in it.[8]
But—What is in it?
Jump forward to the middle of the nineteenth century CE. The Malbim, Rabbi Meir Leibush ben Yechiel Michel, suggested that bohu refers to the fundamental elements of matter. In Malbim’s time the existence of atoms was not generally accepted among scientists, and certainly was not generally known outside of the scientific community. Therefore, the Malbim identified bohu with the classical elements water and earth. These are the two which, like a builder’s stones, have obvious tangible substance.[9]
Malbim’s idea was a major step toward a modern understanding of Genesis. However, it still did not resolve the bohu paradox: How could something be empty, yet solid as stone?
In 1911, secular science caught up with this Kabbalistic idea. In that year, physicist Ernest Rutherford reported on the results of his experiment to determine the structure of atoms.[10] His famous gold-foil experiment revealed the following:
- Positive charges (protons) and negative charges (electrons) occupy separate regions of atoms.
- The protons are gathered into the atom’s center (nucleus) and the electrons surround the nucleus some distance away.
- For a typical atom, the distance from nucleus to electrons varies from ten thousand to a hundred thousand times greater than the diameter of the nucleus. On the atomic scale, that’s a vast distance. The space between these two regions is empty.[11]
How stony are the “stones of emptiness”? According to the list of electron properties above, an electron weighs only 1/1800 of a proton. Another way of saying this is that one proton weighs as much as 1800 electrons. All that mass concentrated into the tiny, tiny space of the atomic nucleus makes for one hard “stone.” And yet these stones are the building blocks of all matter in our world.
The basic understanding of electrical charge provides the background to understanding the electrical nature of light, Part 2 of Let there be…
[1] Wikipedia offers several heavily-documented articles on the physical theories of creation. Data presented here was taken from en.wikipedia.org/wiki/Electron#Formation. The section is referenced to Silk, J. The Big Bang: The Creation and Evolution of the Universe (3rd ed). Macmillan, pp. 110-112 and 134-137.
[2] Strauss, Stephen, The Sizesaurus, New York: Kodansha America, Inc. 1995, calculation by S. Fishman based on data on p. 169.
[3] For more detail, refer to any physical science text grade 6 onward, through high school or introductory college texts of chemistry or physics. For simple online discussions, that avoid the complexities of quantum mechanics, see, for example, http://www.chem4kids.com/files/atom_structure.html, or a video such as https://www.youtube.com/watch?v=h6LPAwAmnCQ.
[4] Magnetic effects due to electron’s property of “spin” also play a role in keeping electrons together, as does the quantum mechanical nature of electron “orbitals.”
[5] Raymond Chang, Chemistry, 5th edition, New York: McGraw-Hill, 1994, p.40.
[6] Genesis 1:2, Jeremiah 4:23, Isaiah 34:11.
[7] Isaiah 34:11. The nation referred to is Edom, understood in Jewish tradition to be Rome and its cultural descendants.
[8] Sefer Ha-Bahir, “The Book of Illumination,” attributed to Rabbi Nehunia bar haKana, translated by Rabbi Aryeh Kaplan, York Beach ME: 1979, p.3, accessed online 10/16/2019, through archive.org/details/JudaismSeferHaBahirBahirEnglishTranslationPdfKabbalahTorahIsrael/page/n1.
[9] Malbim: Commentary on the Torah, translated by Zvi Faier with notes and scientific explanations. Book One, Beginning and Upheaval. Jerusalem, Israel: Hillel Press, 1978, p.46.
[10] Rutherford’s gold foil experiment is described in virtually every introductory chemistry text. For an online description, try https://www.youtube.com/watch?v=5pZj0u_XMbc
[11] According to modern ideas of physics, there is no such thing as empty space. Energy fields of many sorts fill what appears to be empty, occasionally producing short-lived “virtual particles.” To begin to understand modern physics, one must be prepared to ask what “is” means.