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The Physics of Chanukah: On the Nature of Light

by Rabbi Simon Jacobson


Library » Philosophy » Torah vs. Science | Subscribe | What is RSS?


We need to listen to the story that the Chanukah lichtelech (flames) tell us
 – The Rebbe Yosef Yitzchak Schneersohn

A little light dispels a lot of darkness
- The Sages

Light is the core of physics. Light – energy – defines the very parameters of existence.

In modern physics it is now commonly accepted that light, or in more general terms, electromagnetic radiation (microwaves, radio waves, light rays, x rays, gamma rays) has a dual nature: it behaves both like a wave and a particle. The same has been proven regarding the behavior of subatomic matter: it appears as both a particle and a wave.

And this is no small matter: A particle and a wave are opposites. A particle is an entity confined to a very small volume, while a wave is spread out over a large region of space.1 How light can be both a wave (a field of energy) and a particle (a discrete entity) remains one of the biggest mysteries in science, yet it has been proven time and again despite its inherent paradox.

A fascinating fact: Long before science discovered the importance of light, the Kabbalah uses light (ohr) as the ultimate metaphor to describe G-d’s ‘expression,’ i.e. the Divine transmission – the energy that brings existence into being and makes up all of existence. Light reflects, expresses and transmits the Divine energy. Existence is ‘light’ emitted from the Divine.

And like physics would later discover, Jewish mysticism (as explained at length in Chassidic thought, see for example, the discourse Vayeilech 5666 from the Rebbe Sholom DovBer) describes the dual nature of light. Light combines both substance and no substance: it has no substance of its own; it always reflects its (luminary) source. Yet, precisely because of its transparent bittul (selflessness), light purely reflects and channels the deepest ‘substance’ of the source, with no ‘personality’ of its own to get in the way.

A fascinating fact: Long before science discovered the importance of light, the Kabbalah uses light (ohr) as the ultimate metaphor to describe G-d’s ‘expression’
Light, with all its paradoxical qualities, is our best metaphor for understanding the process of creation. By contemplating the paradox of light -- that it is clearly real and yet appears to have no substance or shape -- we can approach an even greater paradox:  the unity of our physical universe with the ‘universe’ of G-d. The mysterious qualities of light illustrate the main truth of our physical universe: that an existence must not be defined only in terms of its own being, but as a means to illuminate a higher truth. Light becomes both a pure expression of the Divine and the metaphor that, through our reason and other faculties, allows us to experience the ways of G-d.

Light straddles the defining line that runs between the physical and the spiritual. Light – sans weight, sans mass, sans just about any of matter's properties – is the most ethereal of physical “things.”' Perceptibly real, yet free of the qualities we ascribe to the objects of our perceptible universe, light serves as a bridge of allegory between a mind grounded in a material environment and the metaphysical abstractions it contemplates.

Light, in other words has a dual quality of both particle and wave. It is a defined entity of its own with its own distinct ‘space,’ yet its ‘particle’ identity’ is wave-like, spread out like an energy field, carrying Divine energy into existence, like ocean waves washing up on the shore.

Chanukah is the Festival of Light. All the events of Chanukah are remembered and celebrated with light. We kindle the Chanukah flames to commemorate the victory of the ‘few over the many,’ the ‘weak over the mighty’ and the miracle of discovering the small crucible of olive oil which then burned for eight days. The Temple was subsequently rededicated (hence the name Chanukah which means ‘dedication’). All this is commemorated with light.

Chanukah – like light – is paradoxical:

The essential miracle – and message – of Chanukah is the dominance of light over dark, of spiritual radiance over material gloom. Even in dark times, even when the mighty materialistic Syrians/Greeks desecrated all things sacred, even as all sources of pure light (from pure olive oil) were gone, ultimately one crucible of purity remained, and revived the soul. The powerful quality of light – even a minimal amount – prevailed over the strongest forms of darkness.


  • 1. A wave is not just a bunch of particles moving in a wave pattern; it is a distinct form of energy, as different from traveling particles ‘as the notion of waves on a lake from that of a school of fish swimming in the same direction’ (Victor Weisskopf, Physics in the Twentieth Century – selected essays, p. 30).


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Holidays » Chanukah » About

(pl. Mitzvot). A commandment from G-d. Mitzvah also means a connection, for a Jew connects with G–d through fulfilling His commandments.
(pl: Shabbatot). Hebrew word meaning "rest." It is a Biblical commandment to sanctify and rest on Saturday, the seventh day of the week. This commemorates the fact that after creating the world in six days, G-d rested on the seventh.
Torah is G–d’s teaching to man. In general terms, we refer to the Five Books of Moses as “The Torah.” But in truth, all Jewish beliefs and laws are part of the Torah.
Usually referring to the Babylonian edition, it is a compilation of Rabbinic law, commentary and analysis compiled over a 600 year period (200 BCE - 427 CE). Talmudic verse serves as the bedrock of all classic and modern-day Torah-Jewish literature.
An eight day mid-winter holiday marking: 1) The miraculous defeat of the mighty Syrian-Greek armies by the undermanned Maccabis in the year 140 BCE. 2) Upon their victory, the oil in the Menorah, sufficient fuel for one night only, burned for eight days and nights.
(Pl.: Chassidim; Adj.: Chassidic) A follower of the teachings of Rabbi Israel Baal Shem Tov (1698-1760), the founder of "Chassidut." Chassidut emphasizes serving G-d with sincerity and joy, and the importance of connecting to a Rebbe (saintly mentor).
Jewish mysticism. The word Kaballah means "reception," for we cannot physically perceive the Divine, we merely study the mystical truths which were transmitted to us by G-d Himself through His righteous servants.
A Chassidic master. A saintly person who inspires followers to increase their spiritual awareness.
Candelabra. Usually a reference to the nine-branched candelabra kindled on the holiday of Chanukah.
1. Usually a reference to the Holy Temple which was/will be situated in Jerusalem. 1st Temple was built in 825 BCE and was destroyed in 423 BCE. The 2nd Temple was built in 350 BCE and was destroyed in 70 CE. The 3rd Temple will be built by the Messiah. 2. A synagogue.
It is forbidden to erase or deface the name of G-d. It is therefore customary to insert a dash in middle of G-d's name, allowing us to erase or discard the paper it is written on if necessary.