Re: [Phys-L] real-world physics

[John Denker <jsd@av8n.com>]

On 06/07/2012 08:33 AM, LaMontagne, Bob wrote:
> If that episode of Mythbusters showed them performing that
> calculation and then declaring that it was obviously theoretically
> impossible - followed by moving on to the next myth - how long would
> they be on the air?
>
> Even more important, If the episode consisted of them showing the
> calculation only and declaring impossibility - anyone watching the
> episode would forget about it completely (probably before the end of
> the show). By actually testing the myth, they have created an image
> that is not easily forgotten. Even a group of physics teachers has
> been talking about it for days.
>
> This might be a lesson for us as teachers to bring into our work. An
> artful derivation or proof might contain everything one would ever
> need to know about a certain topic, but it will probably be forgotten
> by students before the next class. An absurd visual image (and
> hopefully the physics related to it) will be remembered and talked
> about long after.

On 06/07/2012 09:18 AM, Paul Nord wrote:
> > All too true, Bob.

I disagree!

There's a proverb that says no matter what you are doing, you can 
always do it wrong ... but I would hasten to add that you are not 
_obliged_ to do it wrong.

Specifically:  It is always possible to discuss crash protection in 
a non-entertaining way, but you are not _obliged_ to do it that way.

Having busted a myth does *not* prevent you from having fun with it.
The show does this all the time:  they bust a myth and then investigate 
what it would take to achieve a similar result, and/or a scaled-up 
result, or whatever.

In the crash protection example:  Start by showing the bogus video.
Then do the simple calculation that establishes 100 g as a lower bound 
(for an ideal material).  Then note that bubble wrap is far from ideal,
and could easily be worse by a factor of e.

At this point, there is absolutely nothing preventing you from doing
all of the experiments that were done on the show.  Indeed you now have
multiple hypotheses to check against the experiments, including:
 -- the bogus hypothesis from the video
 -- the 100 g lower bound
 -- the 100 e g estimate

The episode showed the bogus video again and again.  In the entertainment 
business, this sort of thing is called a MacGuffin.  Generally that refers 
to something that serves as a pretext to get the story started.  It is 
permissible (and indeed common) for it to be an exceedingly _flimsy_ pretext.

After doing the calculation and the initial experiment, the original myth
should have been considered busted twice over:  analytically and experimentally.
However, my point remains:  this does not prevent doing what the show always 
does:  Investigate to see what it would take to produce a similar result and/or 
a scaled-up result and/or some tangentially-related entertaining result.

Obvious tangents include
 -- how much bubble wrap would it take?
 -- can you build effective crash protection using only duct tape?
 -- can you build effective crash protection using a combination of
  duct tape and bubble wrap?

I say again:  Being smart does *not* prevent you from being entertaining.
There is one type of humor that revolves around making fun of how clueless
people can be, e.g.
  http://www.google.com/search?q=jaywalk+all-stars
... but this is *not* the only kind of entertainment in the world.

Galileo is called the Father of Modern Science precisely because he showed
the power of uniting analysis and experiment.  This is where genuine
understanding comes from.

The guys on the show demonstrate considerable skill at doing experiments, 
but they avoid showing anything resembling skillful analysis.  This is one
of the reasons I say they pretend to do science without actually doing it.
To the extent that the audience believes what they are seeing is science,
it sets science back 400 years.

Again: Being smart does *not* prevent you from being entertaining.  In
particular, having done the analysis does *not* prevent you from doing the 
experiment.  Furthermore, as discussed in previous messages, there have been 
many situations where if they had had the first clue about physics, they 
would have been able to do a *more* entertaining experiment.

> If that episode of Mythbusters showed them performing that
> calculation and then declaring that it was obviously theoretically
> impossible - followed by moving on to the next myth - how long would
> they be on the air?

That misses the point in yet another way, insofar as it disparages calculation
as compared to experimentation.  We agree that calculation is sometimes laborious
and time-consuming and no fun to watch ... but I emphasize that the same goes for
experimentation as well.  Do you have any idea how long it takes to build a boat 
out of duct tape?   The show fast-forwards over a great deal of the construction 
process.  Sometimes they show the outline of the process, and sometimes not even 
that.

This again illustrates the point that no matter what you are doing -- experimental
or analytical -- you can always present it in a non-entertaining way ... but you are 
not obliged to present it that way.

Note the contrasting directions of money-flow:
 -- If you have plenty of money and are willing to pay to watch somebody
  entertain you, then you don't need to carry out the details or even
  watch the details.  You can fast-forward over all of that.
 -- If you want to have a job where somebody pays you, then you need to
  actually carry out the details.

In other words, there are multiple differences between doing science and watching
entertainment.  Not only is there a difference between science and entertainment,
there is a difference between doing and watching.

========

Here's where the rubber meets the road, for people on this list:

Given a resource that has good points and bad points, we can make direct use 
of the good points.  We can skip the bad points, or find ways to turn the lemons
into lemonade.  In this case, the show is a rich source of realistic or semi-
realistic scenarios that are entertaining and well-motivated.  We can then 
explain how having a clue about the physics makes things *more* interesting.