Re: [Phys-L] Edu Videos

[Paul Lulai <plulai@stanthony.k12.mn.us>]

I think we all have our pet topics.  Topics that we will check right off the bat to see if a particular text or source approaches them in a way we like.  If they don't it is easy to discard the source.  With the utmost respect, John, I don't think a large percentage of people would approach relativity or entropy in a way that would fully satisfy you.  Not because you are wrong.  And it doesn't mean you your objections aren't valued.  However, I don't think one's objections to a single video mean the series isn't valuable.  I know you didn't state many comment on the series, but a strong opposition to one video can seem like an oppostion to the series.
The creator of the video has done some research on how effective videos are in getting people to learn content.  He found explicit statements had very little effect.  He found that when he asked people content, elicited responses, and then addressed them, there were positive changes in student understanding. I find this to be a video version of the Physics By Inquiry approach that also has some research and data behind it.
The creator of the videos is becoming more aware that it looks like he is picking on people and that some see it as trying to make people look stupid.  It seems to me that he is choosing a few more children for predictions (I could be wrong, I haven't tallied them) and that he occasionally discusses how a topic took him a while to understand in enough depth to create a solution video, or that he chose a topic because he remembered being tricked or caught by the topic multiple times in the past.
Students do tend to like videos like these.  They are like candy.  Or maybe like a loss-leader in the sales industry.  Kids like to watch them, then we can have some really nice discussions on the topic.  If one uses only these videos, trouble probably follows.  However, the fact that kids will watch these and then search out more and come to class with questions and want to talk about physics is a win in my book.
Some videos that I have had, or plan to have my students watch:

Minute Physics:
How Big is the Universe:  http://m.youtube.com/watch?v=5NU2t5zlxQQ


Veritasium:
World's Roundest Object (a video on the evolution of the deifinition of a kilogram)
Kahn Academy & Effectiveness of Sci Videos http://m.youtube.com/#/watch?v=eVtCO84MDj8
Mass &Weight: http://m.youtube.com/#/watch?v=_Z0X0yE8Ioc
Young's Double Slit / What is light:  http://m.youtube.com/#/watch?v=Iuv6hY6zsd0


Bob & Alice in Wonderland:
Why doesn't the moon fall to the earth
http://m.youtube.com/#/watch?v=BXnhEDMUJt8&desktop_uri=%2Fwatch%3Fv%3DBXnhEDMUJt8
Where does my energy come from:
http://m.youtube.com/#/watch?v=ev_A1Kv1l4s&desktop_uri=%2Fwatch%3Fv%3Dev_A1Kv1l4s

While one may find issues in these videos, the videos are (at the very least) a good spark for a discussion.

* I am on my tablet, so the links might be odd for non-tablet users.

Have a good one.
Paul Lulai
plulai@stanthony.k12.mn.us

...::. Sent from a touch screen. .::...



-------- Original message --------
From: John Denker <jsd@av8n.com>
Date: 03/27/2013 11:59 PM (GMT-06:00)
To: Phys-L@Phys-L.org
Subject: Re: [Phys-L] Edu Videos


On 03/27/2013 04:12 PM, Paul Lulai wrote:
> I really like the veritasium videos. I show these, some minute
> physics, and the brief chalkboard character videos from the Perimeter
> Institute to students in grades 9-12. I watch others myself for fun
> and inspiration for teaching ideas.


I just looked at the veritasium video:
  Can We Go the Speed of Light? (The Principle of Relativity)
  http://www.youtube.com/watch?v=vVKFBaaL4uM

The only 'inspiration" I got was the urge to tear my hair out.
It looked to me like 4 minutes of grossly bad judgment as to
the physics, and worse judgment as to the pedagogy.

First of all, there are multiple reasons why the "Jaywalking" segments
cannot possibly serve any constructive purpose:
  1) [general public] -- Calling attention to misconceptions in this
   way is a disservice to the viewing public.  It is more likely to
   reinforce misconceptions than to dispel them.
  2) [interviewees] -- It's just plain mean to the interviewees.
   For one thing it embarrasses them, and furthermore it is very
   likely to consolidate their misconceptions.  It requires them
   to make a decision, whereupon they are motivated to defend
   their decision.
  3) In another video, the author claims that he doesn't do it
   just to make himself feel good, to build himself up by tearing
   other people down ... but I have to wonder.
  4) [teachers] -- Anybody who knows the first thing about teaching
   knows that students arrive with more misconceptions than anybody
   can imagine.  We get it.  We don't need to be told yet again.
  5) Even *IF* you hypothesize that somewhere there is a teacher
   or an administrator or a funding agency or a voter or a politician
   who doesn't realize how many widespread misconceptions there are,
   it is pedagogical malpractice to *begin* with the Jaywalking
   segments.  It would be better in every way to explain the right
   answer -- thoroughly -- *before* giving any airtime to misconceptions.

I put this sort of thing fairly high on the list of cheap, unprofessional
stunts for getting attention.  Maybe not as unprofessional as taking off
your clothes, but on the same list.

==========

As for the physics, it shows bad judgment to talk about Einstein's
1905 theory of relativity.  As a minor point, the principle of
relativity was set forth by Galileo, almost 300 years before
Einstein came on the scene.

Somewhat more importantly, the ideas of length contraction and
time dilation are *not* due to Einstein.  There's a reason why
it's called the FizGerald-Lorentz contraction, not the Einstein
contraction.

Thirdly, those two ideas are not sufficient to explain special
relativity or to resolve the so-called "paradoxes" posed by the
video.  You also need the breakdown of simultaneity at a distance,
and even that was known in the literature years earlier (e.g.
Poincaré, 1898).

Fourthly, FWIW, despite what the title of the video suggests,
the principle of relativity and the speed-of-light speed limit
are not the same thing.

Fifthly, it is pedagogical malpractice to teach relativity (or
anything else) in a way that revolves around "paradoxes".  The
correctly-stated laws of physics do not contain any paradoxes
that I know of.  The only way to present a paradox is to
mis-state the laws of physics, which is a terrible idea,
especially when speaking to non-expert audiences.

  If relativity seems weird and paradoxical,
  you're doing it wrong.

Sixthly and vastly more importantly, it has been known for
105 of the last 108 years that the wise approach is to define
time, distance, and mass in such a way that they do *NOT*
depend on velocity.  (Minkowski, 1908).  It is pedagogical
malpractice to talk about contraction and dilation, because
those ideas will have to be unlearned before there can be any
real understanding of special relativity, not to mention any
progress toward further developments such as general relativity.

Please, folks, let's stop pretending that the development of
special relativity _began_ and _ended_ in 1905.  Neither of
those things is true, not by a long shot.

Virtually everybody has heard of the "four dimensional space-
time continuum".  They have heard that time is the fourth
dimension.  Even Buffy the Vampire Slayer uses the idea and
doesn't feel obliged to explain it.  I mention this to make
the point that the cognitive workload of introducing this
idea is zero.  People don't necessarily take the idea as
seriously as they should, but that's a fixable problem.
If you're going to make a four-minute video, make a video
showing what's really going on in spacetime.  It's just
not that tricky.

It is straightforward to explain special relativity without
ever mentioning contraction, dilation, or velocity-dependent
mass.
  http://www.av8n.com/physics/spacetime-welcome.htm
Let's be clear:  I am not suggesting a better way of explaining
why clocks can't be trusted and rulers can't be trusted.  No
indeed.  Instead I recommend in the strongest terms defining
length, time, and mass in such a way that they *can* be trusted
... and are velocity-independent.  I recommend not mentioning
contraction and dilation at all, period.  Such things are
inconsistent with any modern (post-1908) understanding of the
subject.

When are we going to stop teaching physics that is more than
100 years out of date?
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