Re: Talking vs Doing

[P3D Larry Berlin <lberlin@xxxxxxxxx>]

>Date: Fri, 10 Oct 1997
>From: P3D Brian Reynolds writes:
>
>>>Larry Berlin wrote:
>>.............................
>> ******  This includes (some) NASA staff astronomers who have the 
>>mistaken
>> attitude that existing space images, especially a few stereo moon
>> images, ........................... The stereo images in question show the
>> distant horizon warping forwards and being closer to the observer
>> than obviously nearer objects and crater edges................
>>.............................. the distortions are grossly out of
>> proportion to the rest of the image.
>..........................
>
>I think you are missing an unstated assumption.  In scientific work it
>is a requirement that if you give a third party your original data and
>a description of the techniques used to analyze (or manipulate) it
>that third party must be able to come up with the same results. 

*****  This was NOT a 3rd party situation, or involving original data directly. 

The third party scenario could only be played out by someone else visiting
the same spot on the moon and taking another stereo photo of the identical
spot. If it turns out looking different in physical reconstruction than the
existing one, and I guarantee it will, one of them has to be flawed. I know
many could prove mathematically and lots of other ways which version was
more accurate. That third party effort isn't needed since the data they
would be able to retrieve is already known. It just hasn't been applied to
the image. The image is not the original data, just a representation of
data. It currently misrepresents the data with reference to the data's true
condition and the physical paramaters of the source, which are both known.
Is this argument scientific enough to convey the point?

This isn't science, it's a poorly presented physics lab report. The lab
itself could represent the condition of true science.

> ..................  If instead I fed all my data into Photoshop (for
>example) and then started to tweak this part of the frame for a bit
>better contrast, or smoothing that other part to get rid of a camera
>problem (perhaps some vignetting) I would not be able to give you the
>raw data and expect that you could reproduce my results.  You might be
>able to come up with something similar, but you would not get my
>results.

*****  This reminds me of a TV special that described the governments
research into Psi power. In one experiment the participants were expected to
draw something representing what their clairvoyent powers revealed to them.
They came up with sketches of various skill levels depicting such places as
military bases and other places.

For the purpose of science, was their correspondence of data dependent on
the quality of their drawing? NO. They were looking for content correlation
to a real place that existed at specific coordinates. That correlation was a
scientific quest. Your example takes the scenario out of scientific
intention. The image has been tweaked for contrast, grayscale, and a host of
other steps. There was obviously one set of steps, somewhere in their
process  with some other intention, that forced existing data to be
incorrectly located in the final image. It would be incorrect to repeat that
mistake should you reprocess the image from original data. You have two
choices. Repeat the entire process and correct the steps that are in error,
or correct the existing image distortions with known solid data. Your
purpose would determine which method you use. If it's to improve your
website, I submit that correcting the image itself is easier and more
practical than repeating the entire process over again. It wouldn't affect
the data or it's other interpretations at all.


>.................. However NASA (and other
>scientific organizations that produce work for public consumption)
>must walk a tight rope.  It's OK for Sky Publishing (or some other
>commercial enterprise) to produce manipulated pretty pictures to hang
>on the wall, but NASA is expected to be held to a higher standard.

*****  The higher standard is sloppy lab work? I don't believe it. A higher
standard is a higher standard, not a standard to do your work poorly by
intention.

>.............. but they have to be very clear about explaining what
>manipulations were done and whether or not they have any scientific
>basis.

*****  How about basic planetary geometry as a scientific basis.

Larry Berlin

Email: lberlin@xxxxxxxxx
http://www.sonic.net/~lberlin/
http://3dzine.simplenet.com/


------------------------------

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