Editing 2776: Crystal Ball

{{comic
| number    = 2776
| date      = May 15, 2023
| title     = Crystal Ball
| image     = crystal_ball_2x.png
| imagesize = 257x336px
| noexpand  = true
| titletext = They often use ball lenses to collect light at the ends of optical fibers, so when you look stuff up on the internet you're actually scrying through a crystal ball.
}}

==Explanation==
In optics, {{w|spherical aberration }} is an image imperfection that occurs due to the increased refraction of light rays that occurs when rays strike a spherical lens near its edge, in comparison with those that strike nearer the center. The origin lies within the fact, that reflection/ refraction on a spherical surface is not perfectly focused on a single point, in contrast to paraboloid reflective surfaces, that have a single focus point. From the perspective of a viewer, this causes the image to appear blurry. 

The comic makes the joke that, since a {{w|crystal ball}} is a sphere, anyone trying to use one for {{w|scrying}} or seeing the future would have to deal with this issue as well; the wizard is telling Cueball that he can only make out the parts of his future which are near the center, as the rest are distorted. Spherical aberration is specifically a property of refracted light, and since the crystal ball is presumably not showing an image originating from the other side of the ball (unless it is a {{w|3-sphere|hypersphere}} additionally extending itself though a time-like dimension), the image should not be distorted by both entering and leaving the sphere, perhaps only in the manner of a hemispherical lens (for which the internally formed holographic image-source perhaps could be properly anamorphically adjusted to exit in all directions a coherent manner). However, traditional scrying may have actually relied on spherical aberration, to allow unexpected shapes to emerge from subtleties such as surrounding flickering candles, that the seer may have used to amplify intuition and visions.
The comic also incorrectly implies that spherical aberration only affects the edges of the image, possibly confusing it with field curvature. In reality, spherical aberration affects the full field of view.

The comic is also making use of the vague meaning of something being "hard to see". One would expect that this would mean that Cueball's future is vague or mysterious, as is often the case in many fantasy novels. But in this case, the wizard is telling Cueball that his future is ''literally'' hard to see due to the spherical aberration.

The title text observes a real-world action that could [[1475: Technically|technically]] be described as "scrying through a crystal ball", that being the usage of the internet. Information over the internet is often transmitted via light sent through {{w|fiber-optic cables}}, which is sometimes collected using ball lenses.[https://www.edmundoptics.com/knowledge-center/application-notes/optics/understanding-ball-lenses/] Due to the similarity between ball lenses and crystal balls, Randall argues that this is technically scrying through a crystal ball because you're receiving information from elsewhere (searching for something) and receiving it by way of a crystal ball (through the ball lenses).  This is flawed as any lenses at the end of a fiber optic cable are to assist a detector in decoding potentially billions of light flashes per second into computer signals as opposed to actually allowing a human to view the contents of the internet with their eyes.

==Transcript==
{{incomplete transcript|Do NOT delete this tag too soon.}}

:[A bearded wizard with a pointed hat is sitting at a table and investigating a crystal ball. Cueball is sitting at the opposite side.]
:Wizard: Your future is hard to see.
:Wizard: I can make out some hazy details in the center, but the off-axis components are particularly unclear.

:[Caption below the panel:]
:Wizards never did figure out how to fix spherical aberration.

{{comic discussion}}

[[Category:Characters with hats]]
[[Category:Comics featuring Cueball]]
[[Category:Physics]]