Lifelong Learning Programme

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Title of the Experience
Bending of the light
Name of the teacher
Mária Dojčanová
Country where it took place
School typology
High Secondary School
Thematic Area
Experience typology
Teaching in class
Type of contact
Description of the Experience
The aim of the lesson was to show and prove to the students that light, seen as electromagnetic waves, is capable of bending, which produces an interference pattern.
Because the concept of mechanical bending of waves pupils already know from previous classes, I try to rehearse the bend wave conditions with the pupils, and induce to repeat the situation when light as electromagnetic waves is also capable of bending. Together we repeat that bending waves occurs at the obstacles of small size - small hole - eg. gap, thin object - eg. thin wire. Because experiments raise the interest and attention of students, I use a slit or double slit to sample the bending of light. The presented slit is made up of a razor blade (two knives side by side) in a black film lit used in the camera and the red laser beam. Enclosing the laser to the slit (or double slit) the interference pattern is reproduced on the screen, for example a wall. After the demonstration, pupils really like to try the experiment by themselves.
After this experiment, the pupils can see very good examples of bending light on the narrow slit or a small circular hole in the digital textbook of physics by PaedDr. Joseph Beňuška. I use this literature in my physics classes quite often. At the same time they write in their workbooks own notes and make drawings from the digital textbook illustrations of the phenomenon. Such educational presentations help students confirm and remember the findings. The positive side of educational presentations is that the students have the phenomenon yet again in demonstration in writing after they just made the experiment and to me as a teacher this saves the lesson time. Therefore I do not have to write and draw everything and can focus more on students and other class activities.

Comments on this Teachers Experience

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Date: 2014.11.02

Posted by Massimo Amato (Italy)

The bending and the interference of the light is so important as the difficult to explain they.
So this experience could be very positive for the students, to understand the phenomena and to show them some areas where interference is used to see or verify physics, chemistry, ... laws.
In Italy, near Pisa, there is a laboratory - VIRGO - to try to intercept gravitational waves with the interference of a laser ray (

Date: 2014.10.21

Posted by Sandro Gomboli (Italia)

The experiment is very interesting for the study of the wave nature of light.
The passage of the beam of light through a slit makes visible the phenomenon of diffraction and the lines of interference projected on the screen show that the light propagates as a wave and the transmitted energy is quantized.
The experience, though only qualitative, induces a reflection by the students on physical phenomena very complex.
The easy availability of necessary materials facilitates easy understanding.

Date: 2014.10.16

Posted by Milena Gosheva (Bulgaria)

The exercise is very good to illustrate the two main phenomena associated with light, such as diffraction and interference. The simplicity of the tests followed by examples in the electronic textbook help students to remember what they have learned. I think this is an applicable experience in physics classes in the 10th grade for Bulgaria.


Dissemination Seminar in Florence

31 October 2015 The seminar has been held in ITIS “A. Meucci” one of the schools involved within Goerudio project activities. Its main aim was to promote the results of the project toward a broad sample of stakeholders even overcrossing the number of people directly involved in the production of project outcomes. This purpose has been totally achieved especially thanks to the participation of students and teachers coming from different schools or from other classes instead of those ones directly involved within the project activities.