What is shadow?

  • Nebojsa Romcevic Institute of Physics, University of Belgrade, Serbia


This paper has two parts. In the first part, intended for physics students as well as for engineering students whose primary interest is not physics, a new lesson related to shadow properties is given as a part of lectures on light. The effects resulting from a shadow ’motion’ observed on a screen were looked into. The relationship between the parameters that define the screen placement and the parameters related to the conditions of shadow formation is given. The possibility of information transfer in the optimal geometrical conditions is analyzed as well. The second part of the paper contains homework assignments. Assignments designed for physics students differ from those proposed for engineering students. The assignments are intended to encourage students to reason and to take a creative approach.


Aoki, K., Mitsui, T. (2008). A tabletop experiment for the direct measurement of the speed of light, American Journal of Physics 76 (9), 812-815.
Cooke, J., Martin, M., McCartney, H., Wilf B. (1968). Direct Determination of the Speed of Light as a General Physics Laboratory Experiment, American Journal of Physics 36(9), 847-850.
Gibbs, P. (1997). Is Faster-Than-Light Travel or Communication Possible?, http//math.ucr.edu/home/baez/phyics/Relativity/SpeedOfLight/FTL.html#3

Einstein, A. (2006). Relativity: The Special and the General Theory, Penguin Classics.

James, M.B., Ormond, R.B., Stasch, A.J. (1999). Speed of the light measurement for the myriad, American Journal of Phyisics 67(8), 681-714.

Liberati, S., Sonego, S., Visser, M. (2002). Faster-than-c signals, special relativity, and causality, Annals of Physic 298(1), 167-185.

Penrose, R. (2004). The road to Reality: A Complete Guide to the Laws of the Universe. Vintage Books.

Stachel, J.J. (2002). Einstein from „B“ to „Z“, Volume 9 of Einstein studies, Springer.
How to Cite
ROMCEVIC, Nebojsa. What is shadow?. European Journal of Physics Education, [S.l.], v. 9, n. 1, p. 15-22, aug. 2018. ISSN 1309-7202. Available at: <http://eu-journal.org/index.php/EJPE/article/view/167>. Date accessed: 16 oct. 2018. doi: https://doi.org/10.20308/ejpe.v9i1.167.