Previously we discussed about the importance of precautions in scientific process. Now, we look at the factors that deny us from obtaining the most accurate result possible.
Like a game of chess, mere knowledge of the openings are not enough. A friend of mine once told me that he never thought endgame knowledge was necessary because he never got to one. I think that the reason he never got to one was because he didn't know anything about the endgame.
Similarly, in an experiment, identifying the sources of error is of paramount importance as it allows you to learn from your mistakes.
(Note: Systematic errors are too easy to identify and therefore will not be covered.)
Now, amongst the common sources of errors we have:
-Uneven heating. This might be caused by a flickering flame, or failing to ensure that all sides get heated evenly. This can be averted by using a water bath, or removing the factors that cause the flame to flicker. (i.e. air movement)
-Overheating. To a minor degree, after the flame is switched off, the temperature of the reactants might get heated further due to the heated apparatuses.
-Limiting factor of labeled mass/weights. This is when a weight's actual mass differs from what that is stated. I'm afraid this factor lies out of our hands. Therefore it is important to get the highest quality weights for maximum accurancy.
-Resonance. In every oscillating system, students tend to overlook resonance. Engineers themselves learned their lesson the hard way when resonance resulted in the 1940 collapse of "Galloping Gertie," the original Tacoma Narrows Bridge. (This example is not 100% accurate, please view the source for more info.)
-Electromagnetic interactions between equipment.
-Calibration. Instruments must be checked against a known, precise, standard and adjusted to be as accurate as possible.
Sources: http://en.wikipedia.org/wiki/Resonance#Failure_of_the_original_Tacoma_Narrows_Bridge
April 7, 2011
April 6, 2011
Expermental Precautions.
Today we're going to take a look at the fundamentals of any scientific experiments - precautions.
Precautions are necessary to obtain the most consistent and accurate result in whatever scientific experiment you're doing, and therefore it would be handy to prepare a list of them before you even begin the experiment.
That said, the precautions below are fundamentals and must be observed at all time. By that I mean that they are general enough to be used in any experiments. It's a rough list, but I suppose it's passable.
Precautions:
1. Close all windows to simulate a closed environment.
2. Switch off all fans to reduce air movement
3. All instruments are checked for parallax errors before the experiment
4. Care is taken not to disturb the instruments while the experiment is ongoing
5. All readings are taken at eye level to avoid parallax errors
6. Multiple readings are taken and the mean is used to obtain a more accurate value.
That said, precautions vary according to the type of experiment. Exercise logic combined with a little scientific knowledge and you'll do fine.
The more precautions you have, the more likely your result will be accurate.
Precautions are necessary to obtain the most consistent and accurate result in whatever scientific experiment you're doing, and therefore it would be handy to prepare a list of them before you even begin the experiment.
That said, the precautions below are fundamentals and must be observed at all time. By that I mean that they are general enough to be used in any experiments. It's a rough list, but I suppose it's passable.
Precautions:
1. Close all windows to simulate a closed environment.
2. Switch off all fans to reduce air movement
3. All instruments are checked for parallax errors before the experiment
4. Care is taken not to disturb the instruments while the experiment is ongoing
5. All readings are taken at eye level to avoid parallax errors
6. Multiple readings are taken and the mean is used to obtain a more accurate value.
That said, precautions vary according to the type of experiment. Exercise logic combined with a little scientific knowledge and you'll do fine.
The more precautions you have, the more likely your result will be accurate.
April 3, 2011
A rainbow.
While I was strolling down the exhibits of the Ikeda Photography Exhibition, something caught my eye.
We weren't allowed to bring cameras, so no, no pictures to show here.
It was a picture of a rainbow. A photograph of a rainbow.
The tour guide explained to us that the purpose of the photograph was to celebrate the magnificence of the rainbow. The rainbow is a reflection of human life force. Forever Vibrant.
My words will do the rainbow no justice. I lack the skills to share with you the grandeur of the rainbow. Perhaps this excerpt here will... light the way.
Faust, Part II, Act II
But see how, rising from the turbulence,
the rainbow forms its changing-unchanged arch
of Human striving it's a perfect symbol
ponder this well to understand more clearly
that what we have as life is a many-hued reflection.
I had my breath taken away.
We weren't allowed to bring cameras, so no, no pictures to show here.
It was a picture of a rainbow. A photograph of a rainbow.
The tour guide explained to us that the purpose of the photograph was to celebrate the magnificence of the rainbow. The rainbow is a reflection of human life force. Forever Vibrant.
My words will do the rainbow no justice. I lack the skills to share with you the grandeur of the rainbow. Perhaps this excerpt here will... light the way.
Faust, Part II, Act II
But see how, rising from the turbulence,
the rainbow forms its changing-unchanged arch
of Human striving it's a perfect symbol
ponder this well to understand more clearly
that what we have as life is a many-hued reflection.
I had my breath taken away.
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