magic hat

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An invisibility cap (from old German tarni , "secret") is a mythical object that is supposed to enable its wearer to temporarily make himself invisible (to be escaped).

Stealth caps in mythology

In the song of the Nibelungs, Siegfried wins the magic hat from a dwarf named Alberich , who guards the Nibelungs' hoard. In the Song of the Nibelungs, the invisibility cap is not a headgear, but - according to the early medieval German usage - a cloak or cloak, the cappa (see  cape ). In today's depictions or film adaptations of the Nibelung, however, the invisibility cap is almost always incorrectly portrayed as a helmet.

King Laurin uses a cloak of invisibility to take part in a May trip unseen, to which he was not invited to his great annoyance.

The Cyclops of Greek mythology made a helmet for the underworld god Hades that made its wearer invisible , so that he could assist Zeus in the fight against the titans .

Another cloak of invisibility is given to Perseus on his way to the gorgon Medusa from the nymphs or Perseus takes it from the Graien , whom he has previously outwitted.

Stealth in technology

Cloaking device simulation (inactive) .jpg
Invisibility cap off: light is reflected and makes the object visible.
Cloaking device simulation (active) .jpg
Invisibility cap on: light is scattered and makes the object appear invisible.


A real stealth technique is currently being researched and worked on. A stealth prototype has already been completed. Here are metamaterials used, a negative index of refraction own.

In addition, various methods of refraction are being developed that guide light through special nanotubes or crystals around the object to be camouflaged so that it cannot be detected in the visual area due to a lack of reflection.

In radar technology , the electromagnetic waves do not have to be directed around the object. It is sufficient that no or as little radiation as possible is reflected in the direction of the transmitter / receiver. Aircraft and ships in particular use stealth technology to prevent or make detection by radar more difficult.

See also

Web links

Wiktionary: magic hat  - explanations of meanings, word origins, synonyms, translations

Individual evidence

  1. ↑ Invisibility cap developed from nanomaterials . In: heise online , January 6, 2007. Retrieved January 15, 2011. 
  2. ↑ Frédéric Garlan: Stealth technology: who wouldn't want to be invisible? . In: Spiegel Online , June 2, 2007. Retrieved January 15, 2011. 
  3. ↑ Markus Becker: New invisibility cap: bath mat makes objects invisible . In: Spiegel Online , January 16, 2009. Retrieved January 15, 2011. 
  4. ↑ Materials research: Invisibility cap makes objects invisible to ultrasound . In: Spiegel Online , January 7, 2011. Retrieved January 15, 2011. 
  5. ↑ Texas scientist makes strands of 'invisibility cloak' . In: Yahoo! NEWS , November 10, 2011. Retrieved June 28, 2012. 
  6. ↑ X. Chen, Y. Luo, J. Zhang, K. Jiang, JB Pendry, S. Zhang: Macroscopic invisibility cloaking of visible light. In: Nature Communications . Volume 2, 2011, p. 176, doi : 10.1038 / ncomms1176 , PMID 21285954 , PMC 3105339 (free full text).