Effect of a Magnetic Field on the Growth of Spinach

Ross Koning koning at ECSUC.CTSTATEU.EDU
Wed Feb 26 09:23:41 EST 1997

At 2:38 AM -0000 2/26/97, Steve Segal wrote:
>	I'm a tenth grader whose just recently won first place for the science
>fair project:The Effect of a Magnetic Field on the Growth of Spinach.
>My results show that the plants subjected to the northern magnetic
>field grew the shortest, the plants subjected to the southern magnetic
>field grew the tallest, and the control group was in the middle.
>Anyone have any ideas exactly why this happened?  Did the magnets
>alter the cells on a molecular level?  I am interested in learning the
>answer to this question as i'm sure it will be asked at the state
>level.  From my research, I can only hypothesize that the fields
>changed the cells on a molecular level (maybe something with the
>electrons?) as stated above... [that was only my own theory... it
>probably isn't right... but if anyone knows why this happened or what
>i could do to find out why this happened I would appreciate it
>greatly]		Thank You....  Please send me e-mail as i am not a
>visitor to this newsgroup.  Thanks Again!!


I would be interested in looking at your data and a description
of your set-up.  Before you decide that the magnetic field
has had an effect in your project, you need to assess two
important issues:

1. Was the experiment properly controlled?  Did you use the
same species, developmental ages, and so on in each of the three
locations around the magnet?  Were temperature, light, soil, water
and fertilizer conditions identical among the plants?  In other
words, was the ONLY variable in your project, the arrangement of
the magnetic field?  How sure are you of that?

2. In measuring growth, were the differences observed meaningful?
This is where statistical analysis of data becomes very important.
If you measured height of ten plants in each part of the field (say
30 plants total among the three locations), it would be good to
do some comparisons with plants that are OUTSIDE the magnetic field
but under the SAME conditions otherwise.  One of the simpler tests
to compare two average heights would be a Student t-test.  Your
teacher (biology or maybe math teacher) might be able to help you
with that.  If not, then a look at the ttest function in Microsoft
Excel documentation could help.  If you are at a loss, write to
me directly and I'll give you some simple instructions on that.
In any case, the t-test will help you decide if the differences
between the averages are meaningful or not.

My point is this: sometimes variables other than those we are
hoping to test are more important and lead to misinterpretation,
and sometimes measured differences are not statistically meaningful
leading to overinterpretation.  You want to make sure that you
are not making either mistake.

Good Luck with your project!


Ross Koning                 | koning at ecsu.ctstateu.edu
Biology Department          | http://koning.ecsu.ctstateu.edu/
Eastern CT State University | phone: 860-465-5327
Willimantic, CT 06226 USA   | fax: 860-465-4479

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