Chronology Current Month Current Thread Current Date
[Year List] [Month List (current year)] [Date Index] [Thread Index] [Thread Prev] [Thread Next] [Date Prev] [Date Next]

Re: [Phys-L] electricity in the atmosphere



David,

You say: "scientists investigate a phenomena through observation and experiment"

Yes, absolutely.

"... makes it seem like a single person does all of the things"

If presented that way, I completely agree that the description would be incorrect and misleading.

Moral: if you use "the scientific method" as a (sketchy) description of how science works, of the various diverse elements that need to be part of the process, then please _don't_ claim that each scientist does all these things. (Also, don't use strawman arguments.)

"there are experimentalists and there are theorists"

Indeed. A point that I invariably make when describing to students how science as a whole functions. Many researchers just collect data (cue the Rutherford quote on "stamp collecting": http://www.aps.org/publications/apsnews/201412/backpage.cfm), others just change a parameter and repeat the experiment, without spending much time in selecting which parameter to vary. So to my mind, communication between the theorists and experimentalists is helpful, giving ideas of what might be interesting to try next.

"Guessing the outcome can introduce bias."

Yet you say that a good scientist knows which outcomes are more likely, before performing the experiments. This "knowing" is due to his/her education and experience, it is an educated guess -- until tested by the actual experiment. It would be extremely naïve to imagine that a scientist performs an experiment or investigates a phenomenon without any idea of what to expect, so do we conclude that all experiments are biased? I don't think we can accept this argument as a deathknell to the simplified scientific method as often presented. An expectation of what might be observed is normal, but it is still essential to be on the lookout for the unexpected, the serendipitous discovery.

Actually, I find myself in agreement with 95% of what you wrote, and only disagree with the complete denial of any value of the presentation of the scientific method. In my experience, it surprises the student with little or no background in the field to learn that science requires testing possible explanations. The value of the "scientific method" explanation lies not in its completeness -- it certainly is not -- but in pointing out that science doesn't provide proof, but it does allow us to eliminate models that make incorrect predictions. In such cases, much more experimentation is needed, and our models may need to be modified or (rarely) replaced.

Well, this is probably not the time or place to rehash much of the philosophy of science. There is a wealth of material published on the topic, and yes, many experts decry mention of "the scientific method" (as if there were only one right way), while others point out that there is a core of truth in the (over-) simplification.

Back to grading.... (and no, that's not part of science, except in facilitating the emergence of the next generation of scientists)

KC

P.S. You mention the importance of explaining "how scientific data is evaluated, understanding statistics, etc." I will say that we now do a much better job of this than what I learned as an undergrad. Although maybe it was "taught, but not learned".

-----Original Message-----
From: Phys-l [mailto:phys-l-bounces@mail.phys-l.org] On Behalf Of David Marx via Phys-l
Sent: Saturday, 10 February, 2018 19:01
To: Phys-L@Phys-L.org
Cc: David Marx <marx@phy.ilstu.edu>
Subject: Re: [Phys-L] electricity in the atmosphere


Ken,

Real scientists do not form a single hypothesis at all. It is often presented as a guess. Instead, scientists investigate a phenomena through observation and experiment. There is no need to guess the outcome of an experiment, since you just do it and see what happens. Guessing the outcome can introduce bias.

A hypothesis is best described as a possible outcome and a good scientist knows which ones are more likely than others. But picking one in advance has no benefit, unless there is some safety issue that as to be accounted for in the experimental design.

The phony scientific method, as you point out, makes it seem like a single person does all of the things: observation, hypothesis, testing, refinement of experiment, theory/law. In reality, the scientific enterprise is most often carried out by a large number of people over a long period of time.

Also, there are experimentalists and there are theorists.

It's important for students to understand that theorists create models that are testable against the universe. The models compete to determine which is correct. The model that survives is the theory. It's important for students to understand that a theory is as close to truth as we get and that with new methods and information that we may need to alter it or replace it.

We much better serve our students, particularly at the high school and university level by fully explaining how science works. Including, how scientific data is evaluated, understanding statistics, etc.

David


On Sat, February 10, 2018 2:45 pm, Ken Caviness wrote:
Great stuff!


Yes, real life is never as simple as our explanations: actual history
is far more complicated than the textbook presentations, the real
universe is a lot more complicated than our scientific theories, and
especially the way science is done in the real world has dimensions
not even hinted at in the stereotypical presentation of the scientific method.

But! -- I would not call the streamlined, simplified explanation of
the scientific method "phony". It's extremely simplified, but still
helpful to emphasize fundamental features involved in the scientific
enterprise. I routinely point out to my students that I personally
can't be involved (by lack of aptitude, experience, and/or interest)
in all aspects of the enterprise, but somewhere these factors are involved.

KC


Ken Caviness
Physics
Southern Adventist University


Sent from my HTC


----- Reply message -----
From: "David Marx via Phys-l" <phys-l@mail.phys-l.org>
To: "Phys-L@Phys-L.org" <Phys-L@Phys-L.org>
Cc: "David Marx" <marx@phy.ilstu.edu>
Subject: [Phys-L] electricity in the atmosphere
Date: Sat, Feb 10, 2018 2:51 PM



Thanks, John, for highlighting the NOVA episode, At the Edge of Space.
To me it is one of their best in showing how scientists actually do
science. None of this phony "scientific method" stuff. I have used
the full episode when I taught our lowest level general education
physics class. I have students watch it outside of class and write a
short analysis (not a summary) and answer a set of questions about it.

My daughter is taking an intro geology course and they require the
students to know the phony scientific method: hypothesis-theory-law.
I can't believe this stuff is still taught at the university level.




On Sat, February 10, 2018 9:35 am, John Denker via Phys-l wrote:

On 02/09/2018 06:47 PM, Derek McKenzie wrote:



I particularly appreciate the number estimates, as well as the idea
of modeling the phenomenon as a spherical capacitor.

For those who want to know more about the model.....



*) Magnificent reference:
"Electricity in the Atmosphere"
http://www.feynmanlectures.caltech.edu/II_09.html



If you haven't recently read the Feynman lectures cover-to-cover, I
strongly recommend it.



*) Decent introduction at the qualitative level (no equations):
http://www.lightningsafety.noaa.gov/science/scienceintro.shtml



*) The books by Uman are useful but even the latest "revised"
edition is 50 years out of date. I haven't seen the 700-page tome by
Rakov and Uman but I gather it is more up-to-date.



*) Sprites in the upper atmosphere were predicted in 1921 by C.T.R.
Wilson but not observed until 1989, and are still a hot topic of
research:
https://www.youtube.com/watch?v=vSCwiQWzMa0



Longer version:
https://www.youtube.com/watch?v=Tfryt3TILx0



That NOVA episode gives a realistic portrayal of scientists doing
their job. In particular, ask your students how they would feel if
they spent years putting together a team and building equipment, then
when the conditions are right staying up all night and spending an
additional
$100,000.00 to carry
out the mission, and coming back with ... nothing! If you don't know
what that feels like, you don't know what it's like to be a scientist.

Most remarkably, NOVA did not leave out the painful part of the
story.

A few nights later, good conditions come around again, so they carry
out the mission again, and come back with ... data. Gorgeous, highly
informative data.

Additional points to tell students:
-- Not all physics was done in the 1600s. There are still
interesting unanswered questions. -- Physics is mostly a team sport;
you don't have to be a lone genius like Galileo or Newton or Einstein
to make a contribution. -- A lot of it requires building fancy
instruments and exploiting modern technology. -- OTOH it usually
doesn't require CERN-sized teams or CERN-sized instruments.
Sometimes a Gulfstream-V full of fancy cameras will do nicely. --
There is joy at the end of the rainbow, but you have to tolerate a
lot of risk and pain before you get there. This requires strength of
character. Technical skill is not enough. -- It must be emphasized
that exploring blind alleys is part of the cost of obtaining
information. A mission that comes back with no data of the desired
kind is not a mistake and not a waste. Scientists take calculated
risks, carefully balancing risk versus reward. Don't take any more
risk than necessary, or any less.
https://www.av8n.com/physics/research-maze.htm



_______________________________________________
Forum for Physics Educators
Phys-l@mail.phys-l.org
http://www.phys-l.org/mailman/listinfo/phys-l





_______________________________________________
Forum for Physics Educators
Phys-l@mail.phys-l.org
http://www.phys-l.org/mailman/listinfo/phys-l
_______________________________________________
Forum for Physics Educators
Phys-l@mail.phys-l.org
http://www.phys-l.org/mailman/listinfo/phys-l




_______________________________________________
Forum for Physics Educators
Phys-l@mail.phys-l.org
http://www.phys-l.org/mailman/listinfo/phys-l