The "Dendera light" is the popular name for a set of carvings in the crypts of the Temple of Hathor at Dendera, Egypt, that show a snake rising out of a lotus flower inside a long, bulb-like oval, held up by a djed pillar. The hieroglyphic texts beside the scenes name the snake as Harsomtus, a child god of Dendera, and Egyptologists read the reliefs as a creation scene, while ancient-technology writers since the 1980s have argued they depict an electric lamp.
The debate matters because Dendera is one of the best-preserved temples in Egypt, and it carries three of the most discussed images in Egyptian archaeology: the cow-eared face of the goddess Hathor, the circular Dendera Zodiac now in the Louvre, and the "light bulb" reliefs. Knowing what the stones and their inscriptions actually say is the only fair way to judge the mainstream and alternative readings.
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Who was Hathor?
Hathor was one of Egypt's oldest and most widely worshipped goddesses, a deity of the sky, love, music, women and motherhood whose principal animal form was the cow. Britannica dates her cult to early dynastic times in the third millennium BCE; her name means "estate" or "house of Horus".
She was usually shown as a woman wearing cow horns cradling a sun disk, as a cow, or as a frontal face with cow's ears. She was called the daughter or "Eye" of the sun god Ra; in the myth of the Destruction of Mankind the Eye rages as the lioness Sekhmet until Ra pacifies her with beer dyed red to look like blood. Her gentler side was music, dance and celebration, and her sacred objects were the sistrum, a shaken rattle, and the menat necklace.
Hathor also had a role in the afterlife. In the Theban necropolis she was "Mistress of the West", the goddess who received the dead in the western desert. At the Sinai turquoise mines she was "Lady of Turquoise", and the Greeks identified her with Aphrodite. For how she fits among Ra, Osiris, Isis, Horus and Thoth, see the guide to Egyptian gods and goddesses.
The Temple of Hathor at Dendera: when and by whom it was built
The temple standing today is a late building on a very old sacred site: construction began under Ptolemy XII Auletes around 54 BCE, and the great front hall, or pronaos, was finished in the Roman period under the emperor Tiberius, who reigned from 14 to 37 CE. Decoration and additions continued into the reigns of later Roman emperors.
Dendera lies on the west bank of the Nile in Qena Governorate, Upper Egypt, north of Luxor and south of Abydos. The site was sacred long before the Ptolemies: Britannica links its earlier foundations to the Old Kingdom, and a gateway of the Middle Kingdom pharaoh Mentuhotep II found there is now in Cairo. The enclosure also holds a sacred lake, a small temple of Isis and birth houses (mammisi), the earliest built under Nectanebo II.
Hathor shared the temple with her consort Horus of Edfu and their child. Once a year, in the festival scholars call the Beautiful Reunion, her statue travelled by boat upriver to visit Horus at his temple in Edfu, a fourteen-day Ptolemaic festival many Egyptologists interpret as a sacred marriage.
What to see at Dendera: the Hathor columns, the Cleopatra relief and the sky ceiling
The three features most visitors come for are the Hathor-headed columns, the relief of Cleopatra VII on the back wall, and the astronomical ceiling of the pronaos.
The columns of the front hall are shaped like giant sistra, their capitals carved with Hathor's face, so the hall itself becomes a stone version of her sacred instrument.
On the outer southern wall, at the rear of the temple, a large sunk relief shows Cleopatra VII, who ruled from 51 to 30 BCE, with her son Ptolemy XV Caesarion, whose father was Julius Caesar. The University of Memphis Institute of Egyptian Art and Archaeology notes that Cleopatra is shown as a mature ruler standing ahead of her young co-regent, in fully traditional pharaonic style.
The pronaos ceiling is a map of the sky in painted relief. Panels show the sky goddess Nut, the 36 decans (star groups the Egyptians used to tell time at night) and the zodiac constellations.
The Dendera Zodiac: what it is and how it was dated
The Dendera Zodiac is a circular sandstone ceiling relief, about 2.5 metres across, that combines the Egyptian decans and constellations with the twelve signs of the Greco-Babylonian zodiac, and it is dated by scholars to around 50 BCE. It came from the ceiling of the eastern chapel of Osiris on the temple roof, not from the main halls.
French soldiers and the artist Dominique Vivant Denon recorded it in 1799 during Napoleon's Egyptian campaign; Denon's engravings, published in 1802, set off a long European argument about its age. In 1821, with the authorisation of Egypt's ruler Muhammad Ali, the antiquities dealer Sébastien Louis Saulnier had the engineer Claude Lelorrain cut it out of the roof with saws, jacks and gunpowder. It reached Paris in early 1822, was bought by King Louis XVIII, and is today in the Louvre (inventory E 13482). A copy now fills its original place in the chapel at Dendera.
The date comes from the sky it shows. Working from the positions of the planets in their constellations, and from two eclipse symbols identified on the disk (a solar eclipse of 7 March 51 BCE and a lunar eclipse of 25 September 52 BCE), Sylvie Cauville and Éric Aubourg placed its design around 50 BCE. The Louvre's catalogue dates it to June to August 50 BCE, in the reign of Cleopatra VII and Ptolemy XIII. That makes it a record of Ptolemaic astronomy, though it draws on far older star traditions.
What the "Dendera light" reliefs actually show
The reliefs show a snake emerging from a lotus flower, enclosed in an elongated oval and resting on a boat, with a djed pillar supporting the oval and other figures around it. They are carved in the temple's crypts, narrow hidden chambers built into the walls to hold cult objects. Each of the three related scenes is split between a southern crypt and another room of the temple.
In the lamp reading, the oval is the "bulb", the wavy snake is the "filament" and the djed pillar, shown with arms holding up the oval, is the "insulator". Nearby are a figure with raised arms and a sun disk on his head and, in one text, a monkey guardian with knives in his hands.
Unlike many disputed images, these come with captions. The hieroglyphic texts around the scenes, studied in detail by the German Egyptologist Wolfgang Waitkus, speak of "Harsomtus, the great god who dwells in Dendera" and of "the living ba in the lotus flower of the Mandjet barque", the morning boat of the sun. Harsomtus (Egyptian Hor-sema-tawy, "Horus who unites the Two Lands") was the child god of Dendera, son of Hathor and Horus of Edfu.
The Egyptological reading: a creation scene
In the mainstream reading, the reliefs depict the birth of Harsomtus from the lotus at dawn, an image of creation and daily renewal that was common in Egyptian religion. Waitkus set this out in "Die Geburt des Harsomtus aus der Blüte" (The birth of Harsomtus from the flower), published in Studien zur Altägyptischen Kultur in 2002.
In Egyptian cosmology the sun god first rose from a lotus floating on the primeval waters, and snakes appear among the primeval creator beings. The oval, called hn in the texts, may stand for the womb of the sky goddess Nut. The djed pillar is the familiar symbol of stability linked with Osiris, shown with arms because it is "holding up" the newborn god. The crypts were understood as a version of the Duat, the underworld, where cult images were kept as the gods' "bodies" until they were revived by contact with light. A scene of a sun god born from darkness fits that setting closely.
Where the electric-lamp claim comes from
The lamp reading was popularised by the writers Peter Krassa and Reinhard Habeck in their book Das Licht der Pharaonen (The Light of the Pharaohs), after Habeck photographed the reliefs on trips to Egypt around 1979 and 1980. Erich von Däniken took the idea to a wide audience in his 1989 book Die Augen der Sphinx (The Eyes of the Sphinx) and in television programmes, and the engineer Walter Garn built working models from the carvings.
Proponents compare the shapes to Crookes tubes, Geissler tubes and arc lamps, and add that Egyptian tombs show little of the soot oil lamps leave. The astronomer Norman Lockyer had passed on a colleague's half-joking version of that soot argument in the nineteenth century.
The archaeologist Kenneth Feder, in Frauds, Myths, and Mysteries, answers that working electric light needs generators, glass, wiring and filaments, and no trace of that industry has been found in Egypt. He notes that the Egyptians knew adding salt to torches reduced lampblack, and that mirrors could carry daylight inside. For Egyptologists the decisive point is that the carvings label themselves as gods and cult images. A model that lights up shows a lamp can take that shape, not that the Egyptians built one.
Billy Carson's reading
Billy Carson has filmed at the Temple of Hathor, and he places the Dendera reliefs within his wider case for lost ancient technology, alongside the Baghdad Battery and the so-called helicopter carvings at Abydos. His position is that objects like these point to knowledge earlier civilisations held and later lost, rather than standing as isolated curiosities.
Set side by side, the two readings start from the same stones. The Egyptological reading begins with the inscriptions and the religious setting of the crypts and concludes that the scene is the birth of a sun god. Carson's reading begins with the visual resemblance to a lamp and with the other anomalies in his ancient-technology file. His approach to anomalies such as the Abydos glyphs is to treat the mainstream explanation as one answer rather than the end of the question, and he invites viewers to look at the carvings and weigh both readings. He explores these themes, and the temple tradition behind them, in Egyptian Mystery School on 4BK TV. For the spiritual framework he draws on, including the neteru and Ma'at, see Kemetic spirituality explained.
Watch, read and go deeper
To see Billy Carson's teaching on Egyptian temples, symbols and lost knowledge, start with Egyptian Mystery School on 4BK TV. The Ancient Egypt topic hub gathers every related article. For the ancient-electricity question, read this alongside the Baghdad Battery article, since the two are usually cited as a pair. To walk the temples of Upper Egypt in person, see the 4biddenknowledge tours page for the current Sacred Egypt itinerary.
Frequently asked questions
What is the Dendera light?
The Dendera light is a nickname for reliefs in the crypts of the Temple of Hathor at Dendera that show a snake rising from a lotus flower inside a bulb-shaped oval supported by a djed pillar. The accompanying hieroglyphs name the snake as the god Harsomtus. Egyptologists read the scene as a creation image, while ancient-technology writers argue it depicts an electric lamp.
Is the Dendera Zodiac still at the temple?
No. The original circular zodiac was cut out of the roof chapel of Osiris in 1821, bought by Louis XVIII in 1822 and is now in the Louvre in Paris. A copy now sits in its original position on the chapel ceiling at Dendera.
How old is the Temple of Hathor at Dendera?
The present temple was begun under Ptolemy XII around 54 BCE and its front hall was completed under the Roman emperor Tiberius, who died in 37 CE. The site is far older; a gateway of the Middle Kingdom king Mentuhotep II was found there.
Why is Hathor shown with cow ears and horns?
Hathor's principal animal form was the cow, a symbol of motherhood, nourishment and the sky, which the Egyptians sometimes imagined as a great celestial cow. She is shown as a woman with cow horns and a sun disk, as a cow, or as a frontal face with cow's ears, the form carved on the columns at Dendera.
Who was Harsomtus?
Harsomtus, in Egyptian Hor-sema-tawy or "Horus who unites the Two Lands", was the child god of Dendera, son of Hathor and Horus of Edfu. He is the snake named in the texts beside the "Dendera light" reliefs, shown being born from a lotus flower.
Sources and further reading
- Wolfgang Waitkus, "Die Geburt des Harsomtus aus der Blüte: Zur Bedeutung und Funktion einiger Kultgegenstände des Tempels von Dendera", Studien zur Altägyptischen Kultur 30 (2002), pp. 373–394
- Éric Aubourg, "La date de conception du zodiaque du temple d'Hathor à Dendera", Bulletin de l'Institut français d'archéologie orientale 95 (1995)
- Sylvie Cauville, Le temple de Dendérah: guide archéologique (Institut français d'archéologie orientale, 1990)
- Musée du Louvre, collection record for the Dendera Zodiac, inventory E 13482
- Richard H. Wilkinson, The Complete Gods and Goddesses of Ancient Egypt (Thames & Hudson, 2003)
- Richard H. Wilkinson, The Complete Temples of Ancient Egypt (Thames & Hudson, 2000)
- Kenneth L. Feder, Frauds, Myths, and Mysteries: Science and Pseudoscience in Archaeology (McGraw-Hill)
- Peter Krassa and Reinhard Habeck, Das Licht der Pharaonen (Herbig), the main source of the electric-lamp interpretation
