# ­xkcd thread **URL:** \ **Category:** Cafe Society\ **Tags:** comic-strips\ **Created:** [May 28, 2020, 12:57am UTC](https://boards.straightdope.com/t/xkcd-thread/854574 "2020-05-28T00:57:03Z")\ **Posts on this page:** 20\ **Page:** 221
**Author:** ![TroutMan](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/troutman/32/6721_2.png) [@TroutMan](https://boards.straightdope.com/u/TroutMan)\ **Post date:** [June 3, 2025, 5:01pm UTC](https://boards.straightdope.com/t/xkcd-thread/854574/4403 "2025-06-03T17:01:48Z")
This is the pertinent part of the book: [![](https://s3.r29static.com/bin/entry/f14/406x505,85/1937728/image.webp) ](https://s3.r29static.com/bin/entry/f14/406x505,85/1937728/image.webp) ---
**Author:** ![smithsb](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/smithsb/32/12107_2.png) [@smithsb](https://boards.straightdope.com/u/smithsb)\ **Post date:** [June 3, 2025, 5:47pm UTC](https://boards.straightdope.com/t/xkcd-thread/854574/4404 "2025-06-03T17:47:15Z")
A pleated bridge. Yes? ---
**Author:** ![Pardel-Lux](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/pardel-lux/32/20182_2.png) [@Pardel-Lux](https://boards.straightdope.com/u/Pardel-Lux)\ **Post date:** [June 3, 2025, 5:54pm UTC](https://boards.straightdope.com/t/xkcd-thread/854574/4405 "2025-06-03T17:54:20Z")
Reminds me of the **[old paradox](https://en.wikipedia.org/wiki/Ant_on_a_rubber_rope)**: > An ant starts to crawl along a taut rubber rope 1 km long at a speed of 1 cm per second (relative to the rubber it is crawling on). At the same time, the rope starts to stretch uniformly at a constant rate of 1 km per second, so that after 1 second it is 2 km long, after 2 seconds it is 3 km long, etc. Will the ant ever reach the end of the rope? The answer, of course, is counterintuitively yes. ---
**Author:** ![Dr.Strangelove](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/dr.strangelove/32/6613_2.png) [@Dr.Strangelove](https://boards.straightdope.com/u/Dr.Strangelove)\ **Post date:** [June 3, 2025, 8:07pm UTC](https://boards.straightdope.com/t/xkcd-thread/854574/4406 "2025-06-03T20:07:22Z")
Interesting that I had remembered the passage as referring to an “ant,” whereas the text just says “small insect”… but the picture is definitely that of an ant. On the other hand, I remembered it as being a dress, whereas both the 90-second film _and_ the 2018 film trailer use a string. The text says it’s a skirt. The picture looks like a string but presumably we’re meant to think of the cross-section. ---
**Author:** ![Chronos](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/chronos/32/134_2.png) [@Chronos](https://boards.straightdope.com/u/Chronos)\ **Post date:** [June 3, 2025, 10:06pm UTC](https://boards.straightdope.com/t/xkcd-thread/854574/4407 "2025-06-03T22:06:53Z")
Which ultimately derives from the fact, well-known to mathematics students, that the harmonic series diverges. ---
**Author:** ![Pardel-Lux](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/pardel-lux/32/20182_2.png) [@Pardel-Lux](https://boards.straightdope.com/u/Pardel-Lux)\ **Post date:** [June 3, 2025, 10:15pm UTC](https://boards.straightdope.com/t/xkcd-thread/854574/4408 "2025-06-03T22:15:03Z")
Yes, literally 😉 The details are not evident, though. It took me some concentration to follow the wikiexplanation. ---
**Author:** ![Andy\_L](https://avatars.discourse-cdn.com/v4/letter/a/c67d28/32.png) [@Andy\_L](https://boards.straightdope.com/u/Andy_L)\ **Post date:** [June 3, 2025, 11:41pm UTC](https://boards.straightdope.com/t/xkcd-thread/854574/4409 "2025-06-03T23:41:16Z")
Sorry it wasn’t helpful - I just find it very funny and couldn’t resist posting it. ---
**Author:** ![LSLGuy](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/lslguy/32/5813_2.png) [@LSLGuy](https://boards.straightdope.com/u/LSLGuy)\ **Post date:** [June 4, 2025, 12:33am UTC](https://boards.straightdope.com/t/xkcd-thread/854574/4410 "2025-06-04T00:33:06Z")
I’m sure I’ve never heard of L’Engle nor her books. But thanks for the vector. > [@Pleonast](#): > > I like to call this local one the “Finger of Doom”. Nothing says “Los Angeles” like a concrete-lined drainage canal with a few inches of water running through flat land with low mountains in the distance and an _avante-garde_ bridge in the foreground. Dayum I miss living there. ---
**Author:** ![Askance](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/askance/32/8281_2.png) [@Askance](https://boards.straightdope.com/u/Askance)\ **Post date:** [June 4, 2025, 1:35am UTC](https://boards.straightdope.com/t/xkcd-thread/854574/4411 "2025-06-04T01:35:33Z")
Somewhat disappointed there was no reference to [box girder bridges](https://www.youtube.com/watch?v=tNfGyIW7aHM), or card games! ---
**Author:** ![Dr.Strangelove](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/dr.strangelove/32/6613_2.png) [@Dr.Strangelove](https://boards.straightdope.com/u/Dr.Strangelove)\ **Post date:** [June 4, 2025, 1:39am UTC](https://boards.straightdope.com/t/xkcd-thread/854574/4412 "2025-06-04T01:39:56Z")
The only thing it’s missing is Arnold Schwarzenegger riding a Harley and firing a shotgun one-handed. ---
**Author:** ![Pleonast](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/pleonast/32/1183_2.png) [@Pleonast](https://boards.straightdope.com/u/Pleonast)\ **Post date:** [June 4, 2025, 11:50am UTC](https://boards.straightdope.com/t/xkcd-thread/854574/4413 "2025-06-04T11:50:44Z")
> [@LSLGuy](#): > > > [@Pleonast](#): > > > > I like to call this local one the “Finger of Doom”. > > Nothing says “Los Angeles” like a concrete-lined drainage canal with a few inches of water running through flat land with low mountains in the distance and an _avante-garde_ bridge in the foreground. “Drainage canal”? Good sir, that’s the mighty _Los Angeles River_! Harrumph. /faux outrage ---
**Author:** ![Chronos](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/chronos/32/134_2.png) [@Chronos](https://boards.straightdope.com/u/Chronos)\ **Post date:** [June 4, 2025, 12:12pm UTC](https://boards.straightdope.com/t/xkcd-thread/854574/4414 "2025-06-04T12:12:07Z")
The [Sundial Bridge](https://www.turtlebay.org/sundial-bridge) featured in a problem we did in my precalc class. ---
**Author:** ![gnoitall](https://avatars.discourse-cdn.com/v4/letter/g/bb73d2/32.png) [@gnoitall](https://boards.straightdope.com/u/gnoitall)\ **Post date:** [June 4, 2025, 12:17pm UTC](https://boards.straightdope.com/t/xkcd-thread/854574/4415 "2025-06-04T12:17:16Z")
I didn’t. Never read the stories. I would have recognized it if had been a Holtzman bridge, but the lack of Guild Spacers might make the bridge untenable. ---
**Author:** ![LSLGuy](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/lslguy/32/5813_2.png) [@LSLGuy](https://boards.straightdope.com/u/LSLGuy)\ **Post date:** [June 4, 2025, 12:34pm UTC](https://boards.straightdope.com/t/xkcd-thread/854574/4416 "2025-06-04T12:34:34Z")
> [@Pleonast](#): > > “Drainage canal”? Good sir, that’s the mighty _Los Angeles River_! Harrumph. > /faux outrage Many’s the time I drove over the mighty LA river on the 10 just east of downtown and passed the equally mighty Brew 102 brewery. Which Google Streetview suggests has now been submerged beneath the sands of time. ---
**Author:** ![smithsb](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/smithsb/32/12107_2.png) [@smithsb](https://boards.straightdope.com/u/smithsb)\ **Post date:** [June 4, 2025, 6:21pm UTC](https://boards.straightdope.com/t/xkcd-thread/854574/4417 "2025-06-04T18:21:29Z")
So are there paddlewheel steamer dinner cruises or Viking river excursions on the mighty Los Angeles river? Asking for a friend. ---
**Author:** ![Pleonast](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/pleonast/32/1183_2.png) [@Pleonast](https://boards.straightdope.com/u/Pleonast)\ **Post date:** [June 4, 2025, 6:31pm UTC](https://boards.straightdope.com/t/xkcd-thread/854574/4418 "2025-06-04T18:31:28Z")
You can pack a lunch while kayaking. > **[You can (and should) kayak the L.A. River. Here's how](https://www.latimes.com/travel/story/2022-07-14/kayak-los-angeles-river-elysian-valley-sepulveda-basin)** > > You might not think of the Los Angeles River as a kayaking destination, but the experience can be a remarkable respite from the city and an opportunity to learn about the importance of conservation. ---
**Author:** ![Lumpy](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/lumpy/32/446_2.png) [@Lumpy](https://boards.straightdope.com/u/Lumpy)\ **Post date:** [June 4, 2025, 6:44pm UTC](https://boards.straightdope.com/t/xkcd-thread/854574/4419 "2025-06-04T18:44:37Z")
> [@Pleonast](#): > > > [@LSLGuy](#): > > > > Nothing says “Los Angeles” like a concrete-lined drainage canal with a few inches of water running through flat land with low mountains in the distance and an _avante-garde_ bridge in the foreground. > > “Drainage canal”? Good sir, that’s the mighty _Los Angeles River_! Harrumph. > /faux outrage When I and my family first moved to Minneapolis, I was a bit miffed to discover that the “St Anthony Falls” are today basically a concrete spillway: [![](https://fmr.org/sites/default/files/usaf-stevecronin.jpg) ](https://fmr.org/sites/default/files/usaf-stevecronin.jpg) ---
**Author:** ![Lumpy](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/lumpy/32/446_2.png) [@Lumpy](https://boards.straightdope.com/u/Lumpy)\ **Post date:** [June 4, 2025, 6:47pm UTC](https://boards.straightdope.com/t/xkcd-thread/854574/4420 "2025-06-04T18:47:26Z")
> [@smithsb](#): > > So are there paddlewheel steamer dinner cruises or Viking river excursions on the mighty Los Angeles river? Asking for a friend. Possibly if they used something like this: [![](https://cdn.britannica.com/76/130776-050-B210C384/reconnaissance-craft-sailors-media-marines-shores-training-1996.jpg) ](https://cdn.britannica.com/76/130776-050-B210C384/reconnaissance-craft-sailors-media-marines-shores-training-1996.jpg) ---
**Author:** ![Dr.Strangelove](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/dr.strangelove/32/6613_2.png) [@Dr.Strangelove](https://boards.straightdope.com/u/Dr.Strangelove)\ **Post date:** [June 4, 2025, 7:16pm UTC](https://boards.straightdope.com/t/xkcd-thread/854574/4421 "2025-06-04T19:16:48Z")
> [@Lumpy](#): > > I was a bit miffed to discover that the “St Anthony Falls” are today basically a concrete spillway: That looks dangerous as hell. The hydraulic jump at the end is exactly the sort of thing that could trap a boat/kayak/etc. in recirculating currents. And it’s _wide_. ---
**Author:** ![LSLGuy](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/lslguy/32/5813_2.png) [@LSLGuy](https://boards.straightdope.com/u/LSLGuy)\ **Post date:** [June 4, 2025, 7:43pm UTC](https://boards.straightdope.com/t/xkcd-thread/854574/4422 "2025-06-04T19:43:01Z")
It appears there’s a row of floats and cable 1/4mi upstream to stop people from approaching from above. And directly below that is a rapids and small basin, then another similar smaller dam & lock facility. Well downriver (1/2 mi or more) is about where it starts to become a place safe enough for small boats. [Previous page](https://boards.straightdope.com/t/xkcd-thread/854574.md?page=220) [Next page](https://boards.straightdope.com/t/xkcd-thread/854574.md?page=222)