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| Semaphore |
 Title text: The speed of light in air is 50% faster than in fiber, but it's a challenge to get the arms to move fast enough to realize the latency advantage. |
Explanation
This comic is similar to 2651: Air Gap. An air gap may be usable for security if information cannot move through it (for example, keeping an AI in a "box"), but in this case the purpose is undermined, because the system is designed to transmit information across the gap.
Semaphore is a maritime signaling system involving the representation of messages through the use of patterned flags held at specific angles. In the comic, the connection between two components is a system based on the flag-signaling system instead of a typical electrical cable. In order to send information, the sending component repeatedly moves the flags such that the flags spell out the information in semaphore, then the receiving component recognizes the semaphore with a camera (and presumably translates the semaphore into electrical signals).
Semaphore towers have historically been used for long-distance communication, with optical telegraph chaining towers capable of displaying semaphore-style signals. Before electric communication technologies were available, a message relayed between towers allowed cross-country communication faster than it was possible to travel.
The title text notes that the speed of light is faster in air than in an optical fibre. This is correct: in air, light travels at close to the same speed as in a vacuum (about 300,000,000 m/s), but optical fibres are made of glass that is optically dense, and refraction causes the effective speed of light in glass to be much slower. This is known as the latency of the connection. In principle, therefore, it is quicker to transmit a signal by light through air than by light through a fibre. However, the transmission of the signal is limited by how fast the flags can move between positions in a manner that can be understood by the other station, and this can only add to the point-to-point transmission time.
Wireless communications using radio waves (like wi-fi, bluetooth, 5G, etc.) do travel at the speed of light in air, making them technically faster than fibre optics. This advantage is used, for example, in high-frequency trading between Frankfurt and London, where microwave links can provide a small but lucrative latency advantage over fibre-optic connections.
Transcript
- [Two identical machines sit facing each other. Each one consists of a box with a wire connecting it offscreen, a webcam, and a machine with 2 flags. Each webcam is pointing at the other machine's 2 flags. Motion lines indicate that the machines are able to move the 2 flags independently.]
- [Caption below the panel:]
- Networking tip: Separate sensitive components with a semaphore gap.
This Week's Explanation for Improvement
As part of the Explanation Improvement Project, each week the community selects one older, neglected, or otherwise stagnant explanation to expand and polish together. This week's pick is comic 331: Photoshops; help us by editing its explanation!
To get involved with the project, you can also nominate an explanation that you think should be improved, or vote on current nominations!
| Photoshops |
 Title text: When I look into your eyes, I see JPEG artifacts. I can tell by the pixels that we're wrong for each other. |
Explanation
|
Welcome to This Week's Explanation for Improvement! Anyone is encouraged to help explain comic 331: Photoshops; click here to get started! If you are new to wiki editing, you can read our editing FAQ for guidance. Here are some suggestions for improving this explanation: .svg){kind=icon} The explanation only does a surface graze of the topic of photoshopping images.
.svg){kind=icon} Add parallels to today's AI image editing.
.svg){kind=icon} Better explain the meme this comic is based on and the context behind it.
.svg){kind=icon} Better explain what JPEG artifacts are.
.svg){kind=icon} Title text section needs to explain seeing in someone's eyes that they're wrong for you. |
This is another comic in the My Hobby series. It plays on the then-popular internet meme "This Looks Shopped". Adobe Photoshop is a popular image editing application that was first launched in 1990, and it reached its peak in popularity around the 2000s as the industry standard for editing graphics. The verb "photoshop" (as in "to photoshop") is a verbalization/denominalization (informally known as verbing) of the noun "Photoshop", referring to the act of using editing software to digitally alter an image, often to make the image look more appealing, dramatic, or to trick people online. Its derived adjective "photoshopped" and its shortened version "shopped" are applied to an image that has been manipulated in this way. One particular popular usage of Photoshop is image compositing: combining two or more images together into a single, seamless picture. This allows the digital artist to create humorous and/or falsified scenarios, like making someone who does not hold a rapier hold one. Adobe Photoshop is still considered a prominent image editing service, but has since lost its monopoly in the market.
Cueball insists that real-life items can be digitally manipulated, even though it is generally not possible to do this to actual physical objects outside of a computer[citation needed]. Megan claims that the sabre she found is a 19th-century heirloom, but Cueball is insisting for fun that the sabre is in fact photoshopped, presumably for fun or to rile Megan up. He then goes on to cite the wrongness of the shadows as why the sabre is photoshopped. This is an especially bizarre claim to make, because real world objects generally cannot cast wrong shadows, unlike a photoshopped image might[citation needed].
Alternatively, calling the artifact "photoshopped" could be Cueball's unique and strange way of suggesting it's a fake. The joke could also refer to the paranoia some internet users have when trying to discern whether images online are real or edited, suggesting that this behaviour might extend into real-life situations, mistaking actual physical objects as "photoshopped" because of how petty such people can be.
This comic also unintentionally (probably) foreshadowed the rising and unavoidable presence of AI image creation and editing on the internet, several years after its publication. However, manipulating images on social media to create misleading content has been and still is very commonplace. Today, people would often accuse content creators or websites of using images generated by AI, as creating visual aids and content this way is considered lazy and minimizes the purpose of human artists. There are a lot more layers to the debate with AI creating digital media, which are thoroughly explored in this article.
Identifying both photoshopped and AI images both follow the same base principle of examining minute details for inconsistency. With photoshopped images, it can include inaccurate shadows (as mentioned by Cueball) and differences in quality in sections of the image[actual citation needed]; with AI, the best tell is inconsistencies with reality.
The title text contains the second part of the internet meme, the complete text of which is: "THIS LOOKS SHOPPED / I CAN TELL FROM SOME OF THE PIXELS AND FROM SEEING QUITE A FEW SHOPS IN MY TIME." Most people have seen this from the popular image file format JPEG, which uses an image compression algorithm that works by converting an image's color data, breaking it into small blocks, changing those blocks into frequency patterns, rounding off details human eyes cannot see easily, and packing the final data tightly. This works remarkably well, but can sometimes leave artifacts (noticeable distortions or errors in the image) that are visible when zooming in far enough. Cueball is treating Megan's eyes as literal digital images on a screen, claiming that he can tell that he and Megan are "wrong for each other" based on the supposed JPEG artifacts and pixels her eyes are made of.
Transcript
- [Megan holds a sword, handle outward, to Cueball. A dark blotch is on the center of the blade, and hangs off it slightly.]
- My hobby: Insisting that real-life objects are photoshopped.
- Megan: This sabre is a 19th-century family heirloom.
- Cueball: It looks photoshopped.
- Megan: Huh?
- Cueball: Yeah, the reflections are all wrong. Definitely photoshopped.
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