CPSC 533C
ASSIGNMENT 1
(by Christian Chita)
Table of Contents:
1. Good Example of Visualization
1. a. Story Behind the Picture:
1. b. Critique:
2. Bad Example of Visualization
2. a. Story Behind the Picture:
2. b. Critique:
3. References:
1. Good Example of
Visualization:
1.a. Story Behind the
Picture:
The picture illustrates a visualization of the Cherenkov effect: when a
neutrino-electron (or neutrino-muon) enters a reaction with the quark
of a hydrogen (or oxygen) nucleus, the result is an electron and a muon
[1]. The muon is ejected at a speed far superior to
the speed of light in H2O, and it produces a cone of blue light --
analog with the "bang" of supersonic aircraft (click here for more
_visual_ info).
1.b. Critique:
The main reason for which I think this is a good example, would be
the very nature of the particle been visualized: for example, given
that neutrinos do not have electrical charge, the "bubble chamber" can
only show secondary particles resulting from the collision of a
neutrino with a proton.
Thus, the model available as input data looks like this:
From this 2D picture, the team of {physicians|software developers}
needs to infer trajectories, impact points, and 3D shapes created by
the emerging rays of light, among other things. This means that
infering the final image is the result of an exercise extending far
beyond a simple data-points mapping, and its value relies on its
ability to acurately extend to 3D a model previously available in 2D
only.
2. Bad Example of
Visualization:
2.a. Story Behind the
Picture:
"Plate tectonics" is the theory explaining the formation,
boundary interaction, and relative movement of litospheric plates [2]. The picture illustrates "the global system of
[the six] lithospheric plates", and their boundaries.
2.b. Critique:
a) Clearly, there are more than 6 plates in the
picture. The image fails to provide a visual cue as to which plates are
"great plates", which are "lesser plates", and which
are "subplates".
Furthermore, despite the text making this
distinction,
on the figure they are all called "plate" (like in X plate, or Y plate).
b) Even though the figure has four components (see
the "continues on next page" note), only one of them features the
legend required to understand the boundaries (that picture is shown
bellow).
This is especially important, since a major part of
this text
section deals with identifying and explaining the different types of
plate-borders.
c) Even with the legend, one struggles with the
following inconsistency: on the legend box, the Spreading Boundary is shown to have
longer "teeth" in the horizontal direction.
However, on the actual
figures, the vertical teeth are longer (than the horizontal ones). For
me at least, this was confusing and counter-intuitive.
d) Given the scope of this section, and the other
concepts introduced in this section, I find the addtion of the
longitude and latitude values as useless:
- first, at this scale, the
values are irrelevant (i.e. all I can see is that 0 degrees longitude
is somewhere in the African plate)
- second, I do not need this
information to analyze this picture -- it is a visual overload item
3. References:
[1] Science et Vie, No 971,
aout 1998, pages 52-59
[2] Strahler, A., and Strahler, A. Physical Geography - Sceince and
Systems of the Human Environment. 1997, John Wiley & Sons, New
York, NY, pages 285-289)