Spherical microscope

Zoom, enhance, investigate!

10 minutes


  • You will use a safe Class 1 laser in the experiment. It is perfectly safe when used as outlined in the instructions.
  • Do not aim laser beam at eyes or face.
  • Never leave lenses exposed to direct sunlight; this is a fire hazard.
  • Never eat or drink any of the substances provided. Do not use for culinary purposes.
  • Read the "Working with Batteries" section of the safety guidelines carefully before proceeding. Always disconnect the setup after finishing the experiment.

Step-by-step instructions

Be very careful in a dark room—prepare everything you’ll need in advance; clear the path from the light switch to the table or ask someone to turn the lights off.

Some lighting effects can only be seen up close, so you’ll need to make a screen.


In past experiments, the lenses had a cylindrical shape. The lens will now be a transparent sphere. See how the shape of the lens affects the light spot on the screen compared to the previous experiments.


Let's put some opaque particles on the lens.


Observe how these opaque particles change the light pattern on the screen! You’ve made a microscope!



  • Dispose of solid waste together with household garbage.
  • Dispose of used batteries in accordance with local regulations.

Scientific description

Do you want to zoom in on the laser’s point? In the first experiment, you used the transparent cylinder  to reveal the line of the light’s path. Its round sides stretched out the light spot in a line. If you want to stretch the spot in all directions, you’ll need a transparent object that is rounded on all sides—a transparent sphere .

When the light beam  passes through the sphere , its rays refract at the borders in such a way that they gather at one spot behind the ball and then diverge in all directions. This widens the beam and the light spot grows.

When you pour the oat flour suspension on the sphere , the oat flour particles  stop the rays  that hit them, casting shadows behind them. The shadows are bigger than the flour particles because the rays diverge and magnify the dark spot, the same way a small object can cast a large shadow if it is located close to the light source.