Candle Under Water | Te Mura Raro Wai
Introduction
Abstract
A ghostly candle appears to burn under water using a thinly-silvered mirror.
Principles Illustrated
Formation of virtual images by a mirror, reversibility of light rays, “one-way” mirrors that are not “one-way” at all.
Content
Video
English version
Te Reo Māori Version
English version
Te Reo Māori Version
Instructions
Set up beaker inside box and candle outside. Fill the cylinder, asking students if the candle will go out when the water level rises too high. They say that it will not go out. As the water level rises to the flame height, blow out the candle. This will surprise the students. Then relight the candle and show the flame under water. See movies below. Students enjoy this one!
If time permits, have students look through the “one-way” mirror from each side. From one sees the cylinder through the mirror and from the other direction one sees the candle through the mirror. It passes light in both directions. So how does it work? How does it give the one-way effect? See one-way mirrors and strange reflections.
Other Information
Safety
Watch flames and matches! The candle never goes inside the box.
Individual teachers are responsible for safety in their own classes. Even familiar demonstrations should be practised and safety-checked by individual teachers before they are used in a classroom.
Related Resources
He Kōwhai Rūkahu? (Is it Really Yellow?), Kitenga Tae (Seeing Colours), Te Kokinga o te āhea o Ngā Whatu (Eye Resolution).
See also one-way mirrors and strange reflections
Notes, Applications, and Further Reading
This demonstration is related to PIRA 6A10.60.
Credits
This teaching resource was developed by the Te Reo Māori Physics Project with support from
- Te Puni Kōkiri
- The MacDiarmid Institute
- Faculty of Science, Victoria University of Wellington
- School of Chemical and Physical Sciences, Victoria University of Wellington
- The New Zealand map shown on the poster frame above is used with permission from www.nz.com.
- This demonstration was filmed in cooperation with Te Kura Maori o Porirua in Porirua , Wellington, New Zealand.