Atistarn Arunaramwong 55010028
Have you ever heard of an evil machine that can easily pollute your food? Or decrease your lifespan with cancer? That is a rumor of something we called “Microwave oven”. If you don’t have a clue about this, take a look at these pictures.
Have you ever heard of an evil machine that can easily pollute your food? Or decrease your lifespan with cancer? That is a rumor of something we called “Microwave oven”. If you don’t have a clue about this, take a look at these pictures.
Above is a science project, done
by a high school student that had been forwarded through email. As you can see,
after days of watering plant with microwaved and purified water, the microwaved
one died out while the purified one still lived. It claimed that microwaved
water can kill plant, according to the pictures. Furthermore, it suggested that
eating microwaved food can cause cancer or brain damage. To prove this, we, the student of DSS, conducted the experiment of our own.
The experiment
There are some differences in our
experiment. We used rice for the plant and grew them in 3 different pots. Each
pot differed with the types of water that resulted in the growth of plant. The
first pot was watered with tap water, second with kettle-boiled water and third
with microwaved water. All of the water was cooled before used on plant. The
growth was measured by the height every week, for 5 weeks. And here is the
result.
Time (week)
|
Average height (cm)
|
||
Tap
|
Kettle-boiled
|
Microwaved
|
|
0
|
20.25
|
20.25
|
20.25
|
1
|
25
|
23.375
|
26.75
|
2
|
29.75
|
28.25
|
34.875
|
3
|
31.5
|
32
|
39.25
|
4
|
32.375
|
40.75
|
39.75
|
5
|
46.5
|
47
|
58.5
|
Having trouble with numbers? We can make it more
understandable with a graph.
And here is a picture to prove it.
As you can see, the third pot is
the highest one while first and second are approximately the same. Moreover,
rice in the third pot produces grains while others couldn't.
From
this experiment, it turns out that microwaved water didn’t kill or damage the
plants, but instead increase their growth. What really happen? What kind of
property does the microwaved water really has?
First, we have to know what “microwave” is. Microwave is an
electromagnetic wave that has frequency within 0.3 – 300 GHz. It can easily
reflect with the metal surface and transmit through non-metal one. But if the
substance has water within, microwave will be absorbed. That is how food can
heat in the microwave oven.
So when we boil water with the microwave oven, the oven will
radiate microwave with frequency of 2.45 GHz. The wave will go through water
molecules that make the water hotter. This method is called a dielectric
heating.
Aside
from heating up, microwave didn’t cause any other effects to water. All the microwave do is spin the molecules
around and cause them to bump into each other, but nothing else. So, the
microwaved water didn’t kill the plant by all means.
But don’t
trust us so easily like you trust the forward-email. There are also other
experiments about microwaved water effect on plant that has reliable results.
See https://www.youtube.com/watch?v=x9Us_jMV8hA
, an experiment conduct by MythBusters. Or you can try this at home to see it
with your own eyes!
References:
1.
Banik, S., S. Bandyyopadhya and S. Ganguly. 2003. Bioeffects of
microwave – a briefreview. Bioresource Technology 87 : 155 – 159.
2. Pozar, David M. (1993). Microwave
Engineering Addison-Wesley Publishing Company. ISBN 0-201-50418-9.
