3238: Soniferous Aether

Soniferous Aether

|< < Prev #3238 (April 27, 2026)

Title text: Imagine you could ride alongside a sound wave. It would probably be pretty cool, right? We're putting in a departmental budget request to buy a really fast plane so we can check it out.

|< < Prev Random Explanation

Explanation

This is one of 67 incomplete explanations: This page was created recently by a BOT THAT BREATHES SONIFEROUS AETHER. Don't remove this notice too soon. If you can fix this issue, edit the page!

Beginning in the late 1690s, scientists posited a luminiferous aether to explain properties of light (especially its ability to travel in a vacuum) which should not be possible for a wave. This theory was disproven by the 1887 Michelson–Morley experiment, which demonstrated that the speed of light was constant, regardless of relative movement through the supposed aether.

In this comic, Cueball and Ponytail have noticed that the speed of sound is not constant, and therefore have concluded, following a similar line of reasoning, that sound does travel through a medium. They then coin the term 'soniferous aether', following the same naming scheme, as the name for this 'newly-discovered' medium. Although their conclusion is, strictly speaking, entirely correct, it overlooks the fact that this medium has already been discovered and named. Sound is widely known to travel through physical media, such as air or water, and cannot exist in a vacuum. Since these substances are already known to modern science^{[citation needed]}, it is clearly unnecessary for new scientists to discover or name them.

The comic's caption states that the physicists are specifically reinventing air from first principles. Although sound can be carried by any form of matter, a human would likely identify air as the primary form of soniferous aether, since humans generally experience sounds that travel through air, rather than other mediums like water or metal. As air is light, colorless, and very familiar to humans, its presence is often overlooked in many situations, and this comic takes that to the humorous extreme of physicists forgetting it exists even while creating a new theory to explain its effects.

By analogy with the theory of luminiferous aether, soniferous aether would logically be an otherwise unobtrusive medium which is primarily observable through its interactions with sound waves. This is a somewhat reasonable description of air, hence why the physicists are stated to have 'reinvented air' (although air does have many other effects that humans generally take for granted, such as the presence of oxygen and the ability for scents to diffuse through 'empty' space).

The title text references Albert Einstein's thought experiment where he imagined riding alongside a light particle/wave (which was referenced in 2959: Beam of Light), but with a sound wave instead. Travelling at the speed of sound can be accomplished with a fast airplane. Usually these would be military aircraft, though the Tu-144, Concorde, and (briefly) a DC-8 were commercial aircraft that did achieve supersonic flight, and the Boom Overture is in the process of being tested as of the comic's publication.

Reinventing things from first principles has previously been discussed multiple times on xkcd.

Transcript

[Ponytail is addressing an unseen audience in front of her while she holds her hand out towards them. She is standing on a podium with Cueball behind her. Cueball holds an arm out behind him indicating a screen behind him showing a graph with three sine waves with different wavelengths. The top has two cycles, the middle four cycles and the bottom one cycle.]

Ponytail: We all know the speed of light is constant for all observers.

Ponytail: But our experiments show that the speed of sound changes based on the observer's motion.

Ponytail: Thus, we posit the existence of the soniferous aether, a medium that fills the space between us and carries sound waves.

[Caption below the panel:]

Sometimes physicists forget that air exists and rediscover it from first principles.

  Add comment        Create topic (use sparingly)       Refresh 

Discussion

Dunno how, but I managed to get to an XKCD comic within the first like 5 minutes of it's upload. Went ahead and added a really bare bones explanation. People funnier and smarter than me can take it from there. RG (talk) 04:24, 28 April 2026 (UTC)

managed to get to the xkcd comic before this page was even made somehow so yeah. --Utdtutyabthsc (talk) 04:49, 28 April 2026 (UTC)

ah, i have a script which polls for the new comic pages on comic days and sends a webhook to alert me as well as sending a request to another program of mine to index the new page, so i fairly often find that the wiki page has been made by the bot but is completely empty when i get to it--or on rare occasions the webhook triggers before the xkcd.com/<number> url can embed, apparently; i guess the comic metadata JSON gets filled in before the image is, or something like that? (the webhook triggers sending a message to discord with the link, which embeds 99% of the time) - Vaedez (talk) 05:03, 28 April 2026 (UTC)

You can also just subscribe to the xkcd.com RSS feed, which is what I do. Barmar (talk) 14:36, 28 April 2026 (UTC)

Reinventing RSS feeds from first-principles. 94.108.4.77 15:00, 28 April 2026 (UTC)

"...however the Tu-144 and Concordé..." - why the rogue accent? Was the author's reasoning that, as a French word, it is de rigueur (see what I did there) for it to include accents? As errors go, it's acute one... 50.45.232.78 05:21, 28 April 2026 (UTC)

The rogue accent has been removed with the speed of sound. But what about that supersonic DC-8. --Coconut Galaxy (talk) 05:26, 28 April 2026 (UTC)

I could imagine a far more gȑàvè error... 81.179.199.253 20:47, 28 April 2026 (UTC)

"Nowadays this property is explained by wave–particle duality, which says that light can act as both a particle and a wave. " Remove. The constancy of the speed of light has nothing to do with quantum mechanics. The observation that the speed of light is independent of the observer's motion was actually the basis on which the theory of relativity was built. Meaning that it's not "explained" by anything at all, it's just the universe we live in. 2A02:1810:84A6:3000:F877:7D1:CD53:FE41 10:45, 28 April 2026 (UTC)

I think that's somewhat my fault - I expanded the sentence in the middle of that paragraph to try to make the link to the comic content clearer, but in doing so made the last sentence more confusing. I think it was referring to light travelling through a vacuum (see first sentence), rather than to the speed of light. Have attempted to fix. 82.13.184.33 11:08, 28 April 2026 (UTC)

OK - someone else has now changed the rest of the sentence so that it doesn't make any sense again. Going to just take it out, as that seems easier, and it's tangential to the explanation anyway. 82.13.184.33 15:23, 28 April 2026 (UTC)

should someone make a category for reinventing things from first principles? I've seen that theme a lot, so it would make sense, right? --GSLikesCats307 (talk) 13:16, 28 April 2026 (UTC)

The funniest bit is that physics problems often ignore air resistance, so physicists may have forgotten that it exists and therefore need to 'discover' it from other phenomenon such as sound propogation... 73.229.34.32 13:04, 28 April 2026 (UTC)

Wouldn't riding along side a sound wave mean moving at the speed of sound? Which is where the pressure is highest from overlapping sound waves (aka. the sound barrier), where moving just a slight bit faster would outrun the sound waves and relieve most of that pressure, although it would do nothing to stop the increased air resistance at higher speeds. 69.174.184.72 (talk) 14:48, 28 April 2026 (UTC) (please sign your comments with ~~~~)

What do you think? Would it be possible to surf on top of sound waves? How about a new comic book character, Sound Wave Surfer? Not to be confused with Silver Surfer. Rtanenbaum (talk) 14:35, 28 April 2026 (UTC)

There's a relatively obscure Marvel character, associated with the X-Men (briefly a member), named Banshee that can do something like that. RegularSizedGuy (talk) 18:51, 28 April 2026 (UTC)

Soniferous aether is the first of five elemetary principles in Hindu mysticism. Will there be follow up panels dedicated to the other four principles- tangiferous, luminiferous, gustiferous and odoriferous? Borqhue del Sol (talk) 13:20, 28 April 2026 (UTC)

There's also the medium of speech transmission - vociferous aether. 82.13.184.33 15:51, 28 April 2026 (UTC)

And the medium through which things are constantly trying to travel but never quite managing to arrive - sisyphous aether. 82.13.184.33 15:54, 28 April 2026 (UTC)

The medium through which asolutely no iron can pass: nonferrous aether... 81.179.199.253 00:48, 29 April 2026 (UTC)
        Add comment