Category Archives: Words

An Online Course by Coursera

Education, Words

DSC03202 This is an introductory page for a Coursera  online course for interested people.  An email message contained direct access to several free courses online, one of which was this one entitled Metadata, taught by Jeffrey Pomeranz of the University of North Carolina at Chapel Hill.  It will begin on July 14, 2014, will last for eight weeks, and requires about six hours of work per week with readings.  I am definitely interested in participating in this course.

Metadata is aggregated data.  According to the  course introduction, we are all familiar with it.

Theoretically, anybody with access to a computer can get a free college education online, though I have not heard of it.  It may be that some personal connections are needed for it to really work well.

Cilantro Seeds Diameter Measurement

Experiments, Science, Scientific Method, Seeds, Words, , , , ,

Here are the cilantro seeds in the self-fallen off group (left), and the pulled-off group (right).   Because the seed weight experiment, done earlier,  suggested, but did not prove that the seeds in the self-fallen-off group were larger than the seeds in the pulled-off group of seeds, I pursued what I had set up to do earlier, and count the number of seeds in the same length, six inches. Problem.  Do these two groups of seeds have a different diameter, as suggested by live visual examination? Hypothesis.  The  cilantro seeds that fell off of the stems have a larger diameter than the cilantro seeds which were pulled off by hand later. DSC03186 The two groups of seeds with the self-fallen-off seeds on the left, and the pulled off seeds on the right (above). Method.  Place a six inch ruler on top of the single layers of each group, and count the number of seeds touching the line within six inches three independent times, once for each of the three placements. DSC03180 Self-fallen-off seeds in a single layer. DSC03181 Self-fallen off seeds in a single layer with a six inch ruler on top #1 DSC03183 Different alignment of ruler for a new measure of the number of seeds in six inches #2.DSC03182 Same as above, but different ruler alignment, #3. DSC03172 Pulled-off seeds in a single layer.  DSC03179 Pulled-off seeds ruler alignment #1DSC03178 Pulled-off seeds ruler alignment #2DSC03177 Pulled off seeds ruler alignment #3 Results.  As counted on the computer screen, I got the following results not nececarily in the same order posted above.  Algnmnt stands for Alignment.  SD stands for Standard Deviation, a statistical determination of data spread.  The measure is the number of seeds in six inches Algnmnt #1           Algnmnt #2          Algnmnt #3         Average        SD Self-fallen                             49                                51                               48                             49.3               1.52 Pulled-off                              52                                54                               53                              53.0              1.00 The means of these measures are different.  There were 49.3 seeds in 6 inches in the fallen-off group, and there were 53 seeds in 6 inches in the pulled-off group.  The standard deviation, a measure of data spread, was larger in the fallen-off group. These results do suggest that the groups do differ in diameter, because the number of seeds in six inches is smaller on the average in the fallen-off group than in the pulled-off group by 3.7 seeds.  The fewer seeds there are,  the larger the diameter.  The actual diameters are inversely proportional to the number of seeds. Conclusions.  This suggests that if this information stands the test of time, then:

  1. The fallen-off group of seeds has a larger diameter, and the hypothesis is supported.  Yes the fallen-off group of seeds are wider.
  2. There may be more variability in the fallen-off group diameter.
  3. The diameter of the fallen-off group of seeds is 0.123 inches and the diameter of the pulled-off group of seeds is 0.113 inches.

Further work. Confirm and refine the results of this and the weight measurement experiments.

  • Explore the diameter by measuring actual print-outs of the single seed layered photos above.
  • Weigh higher numbers of the above seed groups, such as 1000 seeds and 2000 seeds (a lot of counting).
  • Measure the volumes of the counted seed seed groups above.
  • Determine the density of the seeds in weight per seed.
  • Check to see if there is a flotation in water difference in the largest seed group.

Comments.

  • I  consider neither this experiment nor the seed weight experiment to be very important.  I am just pursuing these for demonstration purposes, and for my own entertainment.
  • It looks as if the density of the two seed groups may actually differ. (A new hypothesis.)

Cilantro Seeds Weight, Measurement

Experiments, Garden, Scientific Method, Seeds, Words, , , , ,

Harvesting these cilantro seeds (coriander)led me to this small investigation of the seed size.

My reason told me that they might be a bit different because the seeds which fell off of the cilantro may have been more ready to grow, and perhaps larger.   My eyes told me that the following two groups of cilantro seeds were of different sizes, with the seeds which fell off by themselves being a little larger.

Problem.  So I asked the question, “Are the seeds which fell off of the cilantro stems larger than the seeds which, being leftover, I pulled off of the cilantro stems?”   This is the problem.

DSC03180 These seeds had fallen off of the stems into the plastic bag.

DSC03172 These seeds were pulled off the stems after the others had fallen off.

DSC03186 The plate on the left holds the seeds which had fallen.  The plate on the right holds the seeds which had been pulled off.

I applied the scientific method, as I first learned it.  State the:

  1. Problem
  2. Hypothesis
  3. Method
  4. Results
  5. Conclusion

Hypothesis.  The hypothesis is that the seeds that fell off of the stems are larger than the ones which I pulled off of the stems.

Method.   Weigh 500 seeds  and  700 seeds in each group to the nearest gram using this kitchen scale. The assumption here is that the weight of the seeds parallels the volume of the seeds as they are visible to the eye.  In other words we are assuming that the seeds have the same average density.

DSC03197This scale measure to the nearest one twentieth of an ounce, or to the nearest gram.

Results.  The numbers in parentheses indicate that the scale had shown that number briefly before settling on the number beside it not in parentheses.

Seed Weights In Grams

500 Seeds                                              700 Seeds

Fell off                                                                                                4 (5)                                                               6

Pulled off                                                                                  (3) 4                                                                (5) 6

Conclusions.

  1. By themselves, without including trends, show no difference in the weights between the respective number of seeds for each group.
  2. The initial weights suggest that there is a difference between the seed weights in the two harvest groups, consistent with the hypothesis that the seeds which fell off earlier are a little larger.

Certainly, I did not disprove the hypothesis, but I did not prove it very well either, because as conducted here, the scale is not sensitive enough.