explain xkcd - User contributions [en]

Talk:3097: Bridge Types

2025-06-03T02:44:53Z

162.158.174.63: fixup my previous edit

For budget overrun, see olympic stadium of Montreal, Quebec, Canada.

[[Special:Contributions/162.158.126.202|162.158.126.202]] 01:23, 3 June 2025 (UTC)

Very disappointed there's no bridge card game reference, but I guess that's not one of Randall's types of nerdiness :( [[Special:Contributions/172.71.254.203|172.71.254.203]] 01:45, 3 June 2025 (UTC)

I would like to note that cable stayed bridges, budget overrun here, are much cheaper than equivalent suspension bridges. It because they use less materials and can be built faster meaning less labor. [[Special:Contributions/172.69.58.51|172.69.58.51]] 01:50, 3 June 2025‎

The [[wikipedia:St. Louis Arch|St. Louis Arch]] is a repurposed-elevator-suspended-arch-but-without-the-base-and-wires bridge if you squint hard enough. The elevator is also fun. [[Special:Contributions/172.69.67.214|172.69.67.214]] 01:57, 3 June 2025 (UTC)

Nothing about a a [[wikipedia:Bridge circuit|bridge circuit]] or these [[Wikipedia:Bridges (disambiguation)|many]] [[wikipedia:other|other]] bridges either. Sigh. [[Special:Contributions/172.69.67.214|172.69.67.214]] 01:57, 3 June 2025 (UTC)

The L'Engle is a take off on a Wrinkle in time? But this one is in space? -- [[User:162.158.91.124|162.158.91.124]] ([[User talk:162.158.91.124|talk]]) 02:26, 3 June 2025‎ ''(please sign your comments with <nowiki>~~</nowiki>~~)''
:There's some space-warping in L'Engle's books. [[Special:Contributions/162.158.174.63|162.158.174.63]] 02:44, 3 June 2025 (UTC)

Talk:3097: Bridge Types

2025-06-03T02:44:15Z

162.158.174.63: L'Engle bends space too

For budget overrun, see olympic stadium of Montreal, Quebec, Canada.

[[Special:Contributions/162.158.126.202|162.158.126.202]] 01:23, 3 June 2025 (UTC)

Very disappointed there's no bridge card game reference, but I guess that's not one of Randall's types of nerdiness :( [[Special:Contributions/172.71.254.203|172.71.254.203]] 01:45, 3 June 2025 (UTC)

I would like to note that cable stayed bridges, budget overrun here, are much cheaper than equivalent suspension bridges. It because they use less materials and can be built faster meaning less labor. [[Special:Contributions/172.69.58.51|172.69.58.51]] 01:50, 3 June 2025‎

The [[wikipedia:St. Louis Arch|St. Louis Arch]] is a repurposed-elevator-suspended-arch-but-without-the-base-and-wires bridge if you squint hard enough. The elevator is also fun. [[Special:Contributions/172.69.67.214|172.69.67.214]] 01:57, 3 June 2025 (UTC)

Nothing about a a [[wikipedia:Bridge circuit|bridge circuit]] or these [[Wikipedia:Bridges (disambiguation)|many]] [[wikipedia:other]] bridges either. Sigh. [[Special:Contributions/172.69.67.214|172.69.67.214]] 01:57, 3 June 2025 (UTC)

The L'Engle is a take off on a Wrinkle in time? But this one is in space? -- [[User:162.158.91.124|162.158.91.124]] ([[User talk:162.158.91.124|talk]]) 02:26, 3 June 2025‎ ''(please sign your comments with <nowiki>~~</nowiki>~~)''
:There's some space-warping in L'Engle's books. [[Special:Contributions/162.158.174.63|162.158.174.63]] 02:44, 3 June 2025 (UTC)

3090: Sail Physics

2025-05-16T20:55:56Z

162.158.174.63: /* Explanation */ created by ...

{{comic
| number = 3090
| date = May 16, 2025
| title = Sail Physics
| image = sail_physics_2x.png
| imagesize = 699x263px
| noexpand = true
| titletext = Turning in other directions can be accomplished by using a magnetized centerboard and ocean currents, since a current flowing through a magnetic field induces a Laplace force.
}}

==Explanation==
{{incomplete|This page was created by a wind-blown electron. Don't remove this notice too soon.}}

==Transcript==
{{incomplete transcript|Don't remove this notice too soon.}}

{{comic discussion}}<noinclude>

2829: Iceberg Efficiency

2023-09-18T21:53:02Z

162.158.174.63: /* Explanation */

{{comic
| number = 2829
| date = September 15, 2023
| title = Iceberg Efficiency
| image = iceberg_efficiency_2x.png
| imagesize = 649x251px
| noexpand = true
| titletext = Our experimental aerogel iceberg with helium pockets manages true 100% efficiency, barely touching the water, and it can even lift off of the surface and fly to more efficiently pursue fleeing hubristic liners.
}}

==Explanation==
{{incomplete|Created by A 90% EFFICIENT ICEBERG. Do NOT delete this tag too soon.}}

This comic humorously plays with the idea of efficiency in a typically absurd and satirical "Black Hat" fashion. Black Hat starts by critiquing traditional {{w|iceberg}}s, which are mostly hidden underwater, as inefficient. Efficiency is typically measured in relation to a desired outcome or purpose; Black Hat seems to imply that the obvious purpose for icebergs is to be seen above the water. He then presents his solution - a foam-filled iceberg that floats almost entirely above the water, claiming it to be highly efficient.

Black Hat's idea is absurd. Icebergs are naturally formed structures, with no particular purpose in existing. It is possible to imagine edge cases where a "more efficient" iceberg would be desirable, such as if the goal were to increase the overall {{w|albedo}} of the planet (perhaps to mitigate climate change), but on the whole his proposal to create a "foam-filled iceberg" is not only impractical but also comically exaggerated.

Black Hat then absurdly suggests that his lightweight iceberg can still pose a threat to ocean liners (as if that's the "purpose" of icebergs – in the 20th century, at least six ships sank directly as a result of iceberg collisions, famously the ''Titanic'') through the use of torpedoes. In addition, given that Black Hat is promoting the idea that icebergs ''should'' be able to damage ships, it's not really so inefficient to have much of the iceberg underwater, since ocean liners also have a significant portion of their hulls underwater, which can be damaged by an iceberg. The second panel shows that the foam-filled iceberg has a small attachment underneath it, which is apparently a turret for launching torpedoes.

The unnamed individuals in the last panel are clearly baffled and concerned.

The title text introduces the concept of an "experimental aerogel iceberg with helium pockets." {{w|Aerogel|Aerogels}} are a class of solid, porous materials known for their extremely low density (making them among the lightest solid materials yet synthesized). Their low density should make them float well in liquids, though their low mass and their porous and brittle material properties make them unsuitable as a ramming implement. They are very strong for their mass, but would not be able to support iceberg-sized amounts without collapsing without internal supports which would vastly outweigh the aerogel. Most aerogels cannot float in water without some kind of surrounding coating or container, since the water would soak into the aerogel as it does a sponge. Worse, most aerogels are very hygroscopic, and [http://www.aerogel.org/?p=1433#:~:text=It%20is%20possible%20to%20make,superinsulating%20abilities%20without%20supercritical%20drying. contact with liquid water can destroy them] because attraction to the water collapses the structure. (This can be prevented by treating the aerogel with a hydrophobic material that coats the aerogel particles.) The structure of an aerogel surrounds pockets of air, leaving spaces that could be infused with a specific gas such as Helium. {{w|Helium|Helium}} is lighter than air, and is often used to make gas-filled objects such as balloons float. An aerogel iceberg infused with helium gas could theoretically hover or fly like a balloon as suggested in the comic. This idea of producing a man-made flying iceberg for the sole purpose of endangering cruise liners, would likely be seen as preposterous, as more practical or direct methods of attacking such vessels exist{{citation needed}}, thereby adding an extra layer of exaggerative humor to the comic.

The mention of this high-tech iceberg being able to "more efficiently pursue fleeing hubristic liners" is a playful nod to the comic's theme of optimizing icebergs for efficiency. It implies that not only can this special iceberg float efficiently, but it's also equipped to chase after and "efficiently pursue" arrogant or prideful ocean liners, turning the concept of iceberg efficiency into a surreal scenario. The "hubris" alludes to the (possibly apocryphal) quote "God himself couldn't sink this ship," and similar sentiments expressed in reference to the ocean liner {{w|Titanic}}, which struck an iceberg and sank with many casualties.

==Transcript==
{{incomplete transcript|Do NOT delete this tag too soon.}}
:[Black Hat is holding a stick and standing next to an image of an iceberg halfway submerged in water, presenting to an unseen audience.]
:Black Hat: A standard iceberg is only 10% efficient.
:Black Hat: 90% of the ice is hidden underwater, totally wasted.

:[Black Hat is now standing next to an image of the same iceberg, with another "iceberg" almost entirely above the surface of the water to the right of it.]
:Black Hat: Our next-generation foam-filled iceberg achieves near-100% efficiency, floating almost entirely above the ocean surface.

:[Black Hat is still holding a stick, but is standing next to nothing. There are no other people directly shown, but three distinct 'off-frame' voices are indicated.]
:Black Hat: "But wait," you might be thinking. "How will such a lightweight iceberg pose a threat to hubristic ocean liners?"
:Black Hat: That's where the torpedoes come in.
:Off-panel voice 1: I'm sorry, what project are you part of, again?
:Off-panel voice 2: I assumed he was with you.
:Off-panel voice 3: Security?

{{comic discussion}}

[[Category:Comics featuring Black Hat]]
[[Category:Physics]]