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I wonder what's in the newspaper
today...
One sunday morning...
hmm?
I know Dr. Wedge! He's really smart! but
alcohol and coffee glowing? That's preposterous!
This looks like a job
for...
Arf!
AMAZING DISCOVERY!Scientist Dr. Wedge has discovered that coffee and isopropyl alcohol GLOW when mixed together!
Dr. Luke Fusion,
and his trusty dog, Quark!
steph Hoechst
moments later... Hey, Dr. Fusion! What brings you to my lab?
Oh, skeptical, are you? Well, I'll tell you
exactly how I made this
groundbreaking discovery!
I was carrying my coffee into the lab the other day...
Well, Dr. Wedge, I read about
your discovery in the
newspaper, and I was rather
skeptical. How did you draw
the conclusion that coffee and alcohol
glow?
Isopropyl Alcohol
There was also a vat of alcohol in the room that my lab assistants had been using to sterilize equipment.
Isopropyl Alcohol
OOPS!
Then I dropped my coffee in the alcohol!
I turned around to get a paper towel so I could clean up, and the mixture was glowing when I looked back!
!Isopropyl
Alcohol
I then drew the
conclusion that coffee and alcohol
glow when mixed together!
Say, Dr. Wedge,
have you ever heard of
experimental design?
I think I see the
problem here...
No...
Now I'm famous for
my discovery!
Well, you
overlooked several
aspects in drawing your conclusion. If you had followed
good experimental design, your conclusion
might not be so absurd!
A chance observation isn't enough to draw a conclusion! You
need to design an experiment to
test your theory that alcohol and
coffee glow. that way, you'll
be able to draw a logical
conclusion.
First, you need a hypothesis. This is your
starting point for further investigation. It tells
what you're testing for. A hypothesis is an if/then
statement. In this case, your hypothesis would
have been, "if i mix coffee and alcohol together, then it will generate
light."
If you designed an experiment based on this
hypothesis, then you would also need a prediction. a prediction
connects your hypothesis to what might happen in the
experiment. In your case, your prediction would have been, "If
i pour a cup of coffee into a gallon of isopropyl alcohol,
then the mixture should generate some kind of visible
light."
Normally, in an experiment, you would need gradations. We
don't really need gradations, or different levels of measurement,
because our experiment is a yes/no question.
However, if we do find that our mixture glows, then we can make a new
experiment about its different levels of light
that it emits.
A control is an experiment that doesn't receive the independent
variable. YOu need one of these to make sure that the coffee and alcohol
are behaving normally and not messing up your
experiment. valid controls would be
Testing the coffee and alcohol by themselves.
Every experiment has an
Independent and a Dependent
variable. These are the factors that you
are changing and observing in the experiment. The
independent variable is what you are purposefully
changing; in this case, the coffee that's being added. the
dependent variable is what is expected to
change when you change the
independent variable. In this
experiment, it would be whether the mixture glows.
Sample size is pretty self-
explanatory. It's the number of different
samples you draw your data from. For example, we would need to use
several different kinds of coffee and alcohol
to determine that there's no one type of coffee or alcohol that causes the mixture to
emit light.
Replication is repeating the
experiment several times to
get the most accurate results.
That way, you won't run into any
freak coincidences or
outliers impacting your data.
Constants are really important as well. also known as
controlled variables, these are the parts of your experiment
that must not be out-of-the-ordinary! That makes sure that you
can effectively measure the effects of the independent and dependent variables. for us, it would be the heat of the room, the material of the bucket that the alcohol goes into, basically anything that could
affect the results of the experiment.
...
That's a lot of info to consume...
If you tested this again, the coffee and
Alcohol probably wouldn't glow. Then you
could draw a more logical conclusion based on a
thoughtful experiment.
Now that I think about it, alcohol
and coffee glowing seems pretty improbable. STill, I wonder what made that vat
glow in the first place...
Woof! Isopropyl Alcohol
Arf!
I think Quark has found an
explanation!
Isopropyl Alcohol
I think something's fishy about this vat...
Let's put on some gloves for
extra protection...
Isopropyl Alcohol
And check out what's in
here!
Did you find
anything?
Yeah, I feel something.
A Glowstick? My lab assistants must have put that in there as a
joke!
If I had used experimental design, then I would have drawn the conclusion that coffee and alcohol Don't glow, and I wouldn't have
embarrassed myself in front of the scientific community!
And that, Dr. Wedge, Is the
power of Experimental
Design!