Contraction tests

I decided to test my theory considering how light could appear to contract and expand with the use of card and a pully system. Although at this stage I did not think it was necessary to introduce a pully system, as I could move the card adequately using my hands. I started the test by cutting out two cardboard L's that would form the structure that would control how much light would be allowed through.



I then used the same procedure, as with the initial tests, and blew smoke through a beam of light produced by spotlight torch. Although this is not how I intend to produce the final columns of light the technique produces an adequate enough beam to conduct tests with.

I then positioned the cardboard L's underneath the source of light (the torch) and linked them so that they formed a square in the middle that could be enlarged by moving the cards slightly apart. Although, this technique did reduce the size of the beam, it remained in a cylindrical form, and was considerable not as bright as above the card. The results are shown below.







Why did this happen?

Most of the light from the light source simple reflected off the card, as there was no method of control where the light was angled. If there had been a method to reflect the light through the hole the brightness wouldn't have been effected. This would have involved using curved mirrors, or even a completely different source. However, if the hole was made any smaller the same problem would still exist. Although the card did control how big the beam was coming out of it, it also caused a considerable amount of light to diffract around the edges of the hole, causing the light to spread.

Conclusion:

Although the tests were interesting, they have proven that this idea would be difficult to fulfill, requiring a complicated use of mirrors and pullys. I am consequently going to consider another method of achieving the effect as well as other possibilites of how the light could change following the input of the user.