Re: Parallel Universe

[John Clement <clement@HAL-PC.ORG>]

As far as explaining it, they have to pick up the idea of interference which
may take a while.  However you can very readily show that the phenomenon has
regular properties and can be modeled.  For example they can observer that
bigger holes produce different patterns.  If you have different color lasers
they can also observe how the pattern changes.  You could also then do
double slit interference and show that there is a similarity.

Once these sorts of connections are made double slit interference can be
readily explained.  Some good movies/simulations can be used.  I also favor
drawing the waves on 2 lengths of adding machine tape, and then attaching
one end ef each to a drawing of the slits.  Students can then observe that
at various angles the wave line up, but at others they antialign or
interfere.

And of course this is a good way to segue into waves.  The big issue for
building understanding is not calculus but whether the students are formal
operational, concrete or in between.  The formal op. students tend to be
able to pick up the ideas much more readily and they benefit a bit more from
lectures.  Both benefit from concrete experiences and experiments.

Showing that the phenomenon is regular and that it can be well described my
actually be convincing that it is natural and explainable in our universe
and not produced by a mysterious parallel universe.

One does not need a parallel universe to explain the results, so for
simplicity, we do not invoke such a thing.  However this theory of parallel
universes has to do with explaining that fact that these experiments also
give the same results with single photons, which is an impossible experiment
for you to do.  In addition the theory appears to be a reinterpretation of
standard quantum theory to make it deterministic.  These types of theories
have been around for quite a while, but have never become popular in the
physics community.  This type of theory is far outside anything that can be
easily explained to a HS class.  The only thing you can say is that if
legitimate it is a maverick model which is not accepted because the current
standard model does an excellent job without appealing to a mysterious
parallel universe.

Since this article also mentions photons, this article could also provide an
opportunity to segue into some modern physics.

John M. Clement
Houston, TX

> Hello,
> I hope someone can help me.  A student sent me this web site
> <http://www.allsci.com/parallel.html>
> and suggested that we do the activity in class (it is very simple and
> involves poking holes in a card and shining a laser beam at the holes,
> then observing
> the interference pattern).  However, the web site claims that the observed
> pattern is evidence for parallel universes.  I would like to be able to
> explain
> convincingly to my students that it is no such thing.  Some of my students
> have had calculus and some have not, and all are high school seniors with
> extreme
> senioritis (only 2 more weeks of class for them).  Any takers?
> Thanks,
> Fran Poodry
> West Chester East High School
> West Chester, PA