Vaso Desaparecedor (Igualación de Índice de Refracción)

Hacer invisible un objeto de vidrio sumergiéndolo en un líquido de índice de refracción coincidente

Classroom Demonstrations Beginner (Middle School) 15 min ~$8,00

Objetivo

Demostrar el concepto de índice de refracción haciendo desaparecer un objeto de vidrio en un líquido que coincide con su índice de refracción.

Antecedentes

We see transparent objects like glass because light bends (refracts) at the surface where the glass meets air. The degree of bending depends on the difference in refractive index between the two media. If a glass object is placed in a liquid with the same refractive index, light passes through without bending, and the object becomes effectively invisible. Pyrex glass (n ≈ 1.474) nearly matches vegetable oil (n ≈ 1.47), creating a stunning visual effect.

Advertencias de seguridad

  • Vegetable oil is slippery — clean up spills immediately to prevent falls
  • Glass objects can break — handle with care

EPP requerido

goggles

Materiales

  • Vegetable oil (or glycerol) (500 mL)
    Refractive index ≈ 1.47
  • Pyrex glass beaker or rod (1)
    To disappear
  • Regular glass rod (1)
    For comparison (different n)

Equipamiento

Large glass beaker (1 L) or clear container

Procedimiento

1

Fill the large beaker about 2/3 full with vegetable oil.

2 min
2

Show the Pyrex glass object to the audience. Note that it is clearly visible in air.

1 min
3

Slowly lower the Pyrex glass into the vegetable oil. As it submerges, it gradually becomes invisible.

3 min Lower gently to avoid splashing
4

For comparison, lower the regular glass rod into the same oil. It remains visible because its refractive index does not match.

3 min
5

Discuss: light refracts at boundaries between materials with different refractive indices. When n values match, no refraction occurs and the object seems to disappear.

6 min

Resultados esperados

The Pyrex glass becomes nearly invisible when submerged in vegetable oil. Only slight distortions at the edges may be visible. The regular glass rod remains clearly visible in the same oil.

Limpieza

Remove glass objects and wash with dish soap. Oil can be saved for reuse or disposed of in general waste. Wipe up any oil spills.

Detalles

Categoría
Classroom Demonstrations
Dificultad
Beginner (Middle School)
Duración
15 min
Costo estimado
$8,00
Pasos
5
Materiales
3

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Frequently Asked Questions

What is the objective of Vaso Desaparecedor (Igualación de Índice de Refracción)?
Demostrar el concepto de índice de refracción haciendo desaparecer un objeto de vidrio en un líquido que coincide con su índice de refracción.
How difficult is Vaso Desaparecedor (Igualación de Índice de Refracción)?
This experiment is rated as Beginner (Middle School). It takes approximately 15 minutes to complete.
What safety precautions are needed for Vaso Desaparecedor (Igualación de Índice de Refracción)?
Key safety precautions include: Vegetable oil is slippery — clean up spills immediately to prevent falls; Glass objects can break — handle with care.
What materials are needed for Vaso Desaparecedor (Igualación de Índice de Refracción)?
The main materials required are: Vegetable oil (or glycerol), Pyrex glass beaker or rod, Regular glass rod.
What results should I expect from Vaso Desaparecedor (Igualación de Índice de Refracción)?
The Pyrex glass becomes nearly invisible when submerged in vegetable oil. Only slight distortions at the edges may be visible. The regular glass rod remains clearly visible in the same oil.