On Measurement
Diagnostic Exam, thank you for reminding me that I should get my notes back from high school, and that I must familiarize myself with the basic concepts that would surely assist me in this laboratory course. I know how to determine significant digits, how to compute for the mean, median, and mode (the plank, the wave, and the hat – Is that right?!), but sadly, I just can’t remember the book definition for those. Accuracy, precision—I got to read them again. I remembered putting in my math grades, since they we’re asked there. Yes, the Hades-powered grades that I got from the most unforgettable professors of Math building: Canlubo and Agapito. From the deities of math to a never-grade-conscious student, what grade would we expect? Anyway, so much for the semester blues.
With Jesica and Cathee, we form the only all-girl group in this class. Yeah! \m/ *insert danceable music here*. Hopefully, we’ll have an equal share of involvement with the group activities. Just no cat fights please. Well, I really doubt if there would be even one.
The activity focused on measurements. The discussion started with the introduction of how and why measurements are done -- popping in the basic ideas needed such as the concern of significant digits, scientific notation, and rounding off. Basic ideas, right? But smart eyes are really in for the job. And this skill of being the ‘master of sig-figs’ has to be polished. How important is it? Well, I guess, a physicist’s language is mathematics. Mathematics provides the excellent and elegant way of presenting ideas, in a sophisticated approach that anyone could grasp. And the numerical information achieved out of mathematical and scientific methods are subject to computation, and further computation; where the basic skill just mentioned is a necessity. And I’m convincing myself that I should take sig-figs so seriously. Please bear with me. :)
Just what any other normal high school student does in any class where measurement is done (not necessarily a Physics class since measurement isn’t limited to it, such as a P. E. class where height, weight, BMI, et cetera are required for anyone to know), I used to ‘manipulate’ the measured values. I know it’s a different world out there, and now I’m making an oath that I’ll never do such a thing in this lab class (and any class), now and forever. I just realized, and it’s been mentioned, that every measuring device has its own limitation; that at some point, the reading has to stop, and thus there is no such thing as an ‘absolute reading’. May limitation na nga yung device, and may natural limitation na din ang human, tapos magmamanipulate pa ‘ko intentionally.. Bad yun.
“Not 2. Not 4.” “Not 3.2. Not 3.4” “Not 3.29. Not 3.31” Being able to know what the values that those statements are referring to, is one proof that the concept behind scientific notation and significant figures to be well-understood. The exercises were a big help; plus the well-presented and well-communicated form of discussion.
Orders of approximation we’re also discussed – something not mentioned back in junior school: the zeroth order which focuses on the ‘order of magnitude’ or simply the exponent of the base 10; the first order which uses significant figures, and mentioned to be known by chemists and biologists; and the second order which has the expected value plus the range of values reported, thus giving the best estimate of the quantity, and mentioned to be applied by physicists.
Fermi questions – I find this thing interesting. Soon to be a hobby? Let’s see. J
At-this-moment status:: Drained by GE’s. Still on-the-go for more physics lab activities, though.