# ­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:** 274
**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:** [January 22, 2026, 5:26pm UTC](https://boards.straightdope.com/t/xkcd-thread/854574/5463 "2026-01-22T17:26:11Z")
Okay, you’re going to have to explain that one to me. ---
**Author:** ![Q.Q.Switcheroo](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/q.q.switcheroo/32/5713_2.png) [@Q.Q.Switcheroo](https://boards.straightdope.com/u/Q.Q.Switcheroo)\ **Post date:** [January 22, 2026, 5:30pm UTC](https://boards.straightdope.com/t/xkcd-thread/854574/5464 "2026-01-22T17:30:20Z")
_Five Easy Pieces_: Bobby wants toast with his breakfast at a diner with a “no substitutions” policy, so he orders a chicken salad sandwich on toast…hold the lettuce, hold the mayo…… ---
**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:** [January 22, 2026, 11:37pm UTC](https://boards.straightdope.com/t/xkcd-thread/854574/5465 "2026-01-22T23:37:20Z")
> [@Frodo](#): > > Northern Hemisphere people also get most meteor showers and (lately) total eclipses, it’s not fair man. Hey, you get the three brightest stars, two extra naked-eye galaxies, and the only naked-eye supernova in the past few centuries. Let us have this. ---
**Author:** ![Mollie\_Magill](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/mollie_magill/32/20882_2.png) [@Mollie\_Magill](https://boards.straightdope.com/u/Mollie_Magill)\ **Post date:** [January 23, 2026, 1:56pm UTC](https://boards.straightdope.com/t/xkcd-thread/854574/5466 "2026-01-23T13:56:38Z")
I’ll always remember looking up in awe during the Penguin Parade at the Magellanic Clouds and Orion standing on his head instead of the literal march of penguins in front of me. ---
**Author:** ![dtilque](https://avatars.discourse-cdn.com/v4/letter/d/d6d6ee/32.png) [@dtilque](https://boards.straightdope.com/u/dtilque)\ **Post date:** [January 25, 2026, 3:11am UTC](https://boards.straightdope.com/t/xkcd-thread/854574/5467 "2026-01-25T03:11:13Z")
> **[Double-Pronged Extension Cord](https://xkcd.com/3198/)** [![](https://imgs.xkcd.com/comics/double_pronged_extension_cord.png) ](https://imgs.xkcd.com/comics/double_pronged_extension_cord.png) “‘Oh, and can I borrow 50 sacks of loose flour, a pile of lithium-ion batteries, a bucket of bleach, and a bucket of vinega–’ ‘NO!!!’” ---
**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:** [January 25, 2026, 3:19am UTC](https://boards.straightdope.com/t/xkcd-thread/854574/5468 "2026-01-25T03:19:59Z")
Now if he’d mentioned a tank of chlorine trifluoride then she should have been worried. ---
**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:** [January 25, 2026, 12:24pm UTC](https://boards.straightdope.com/t/xkcd-thread/854574/5469 "2026-01-25T12:24:46Z")
I’ll take “high energy chemistry trivia” for $200, Alex. ---
**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:** [January 25, 2026, 6:24pm UTC](https://boards.straightdope.com/t/xkcd-thread/854574/5470 "2026-01-25T18:24:03Z")
I don’t know anything about chlorine trifluoride, but just the name scares me. ---
**Author:** ![markn\_1](https://avatars.discourse-cdn.com/v4/letter/m/f9ae1b/32.png) [@markn\_1](https://boards.straightdope.com/u/markn_1)\ **Post date:** [January 25, 2026, 8:41pm UTC](https://boards.straightdope.com/t/xkcd-thread/854574/5471 "2026-01-25T20:41:41Z")
You don’t need a cord. A simple screwdriver will work fine. ---
**Author:** ![Little\_Nemo](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/little_nemo/32/3120_2.png) [@Little\_Nemo](https://boards.straightdope.com/u/Little_Nemo)\ **Post date:** [January 25, 2026, 8:46pm UTC](https://boards.straightdope.com/t/xkcd-thread/854574/5472 "2026-01-25T20:46:02Z")
> [@Chronos](#): > > I don’t know anything about chlorine trifluoride, but just the name scares me. It’s that dihydrogen monoxide you’ve got to watch out for. A single spill of that stuff back in 1889 killed over two thousand people in Pennsylvania. ---
**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:** [January 25, 2026, 8:57pm UTC](https://boards.straightdope.com/t/xkcd-thread/854574/5473 "2026-01-25T20:57:31Z")
The name doesn’t scare me because it sounds chemical-y and I don’t understand what it means. It scares me because I do understand what it means. ---
**Author:** ![Peter\_Morris](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/peter_morris/32/359_2.png) [@Peter\_Morris](https://boards.straightdope.com/u/Peter_Morris)\ **Post date:** [January 25, 2026, 9:01pm UTC](https://boards.straightdope.com/t/xkcd-thread/854574/5474 "2026-01-25T21:01:39Z")
> [@Chronos](#): > > I do understand what it means Well I don’t. Please explain. ---
**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:** [January 25, 2026, 9:07pm UTC](https://boards.straightdope.com/t/xkcd-thread/854574/5475 "2026-01-25T21:07:40Z")
If you know anything about gaseous (molecular) fluorine, then here’s a factoid: Chlorine Trifluoride has been described as a more powerful oxidizer than molecular fluorine. ---
**Author:** ![puzzlegal](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/puzzlegal/32/3827_2.png) [@puzzlegal](https://boards.straightdope.com/u/puzzlegal)\ **Post date:** [January 25, 2026, 9:09pm UTC](https://boards.straightdope.com/t/xkcd-thread/854574/5476 "2026-01-25T21:09:32Z")
Yikes! ---
**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:** [January 25, 2026, 9:10pm UTC](https://boards.straightdope.com/t/xkcd-thread/854574/5477 "2026-01-25T21:10:22Z")
There is a **[wikiarticle](https://en.wikipedia.org/wiki/Chlorine_trifluoride)** about chlorine trifluoride, a compound that mixes two halogens, highly reactive (oxydising) compounds. From that article, a nice quote: > It is, of course, extremely toxic, but that’s the least of the problem. It is hypergolic with every known fuel, and so rapidly hypergolic that no ignition delay has ever been measured. It is also hypergolic with such things as cloth, wood, and test engineers, not to mention asbestos, sand, and water—with which it reacts explosively. It can be kept in some of the ordinary structural metals—steel, copper, aluminum, etc.—because of the formation of a thin film of insoluble metal fluoride that protects the bulk of the metal, just as the invisible coat of oxide on aluminium keeps it from burning up in the atmosphere. If, however, this coat is melted or scrubbed off, and has no chance to reform, the operator is confronted with the problem of coping with a metal-fluorine fire. For dealing with this situation, I have always recommended a good pair of running shoes. ---
**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:** [January 25, 2026, 9:22pm UTC](https://boards.straightdope.com/t/xkcd-thread/854574/5478 "2026-01-25T21:22:20Z")
Nazi Germany had a pilot plant to produce it but it was considered “too dangerous” to use, unlike 85% concentration hydrogen peroxide, or fuel mixtures containing hydrazine. ---
**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:** [January 25, 2026, 9:27pm UTC](https://boards.straightdope.com/t/xkcd-thread/854574/5479 "2026-01-25T21:27:47Z")
To put it in simplest terms: It’s a molecule of one atom of chlorine and three atoms of fluorine. All four of those atoms would very much prefer to be in molecules with pretty much anything else. ---
**Author:** ![Al128](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/al128/32/16541_2.png) [@Al128](https://boards.straightdope.com/u/Al128)\ **Post date:** [January 25, 2026, 10:26pm UTC](https://boards.straightdope.com/t/xkcd-thread/854574/5480 "2026-01-25T22:26:14Z")
> [@LSLGuy](#): > > As @Chronos said. The aurora are happening 50 miles above the surface, not the 6 or 7 miles an airliner cruises at. You can’t see aurora looking down. as a southerner, who is also fighting ignorance, I’d like to show you my appreciacion for not calling an aurora … ahem … northern lights … b/c we have them too … just in the south ---
**Author:** ![Al128](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/al128/32/16541_2.png) [@Al128](https://boards.straightdope.com/u/Al128)\ **Post date:** [January 25, 2026, 10:36pm UTC](https://boards.straightdope.com/t/xkcd-thread/854574/5481 "2026-01-25T22:36:00Z")
> [@Pardel-Lux](#): > > There is a **[wikiarticle](https://en.wikipedia.org/wiki/Chlorine_trifluoride)** about chlorine trifluoride, a compound that mixes two halogens, highly reactive (oxydising) compounds. From that article, a nice quote: > > > It is, of course, extremely toxic, but that’s the least of the problem. It is hypergolic with every known fuel, and so rapidly hypergolic that no ignition delay has ever been measured. It is also hypergolic with such things as cloth, wood, and test engineers, not to mention asbestos, sand, and water—with which it reacts explosively. It can be kept in some of the ordinary structural metals—steel, copper, aluminum, etc.—because of the formation of a thin film of insoluble metal fluoride that protects the bulk of the metal, just as the invisible coat of oxide on aluminium keeps it from burning up in the atmosphere. If, however, this coat is melted or scrubbed off, and has no chance to reform, the operator is confronted with the problem of coping with a metal-fluorine fire. For dealing with this situation, I have always recommended a good pair of running shoes. sounds like something, Derek Lowe would write … [https://www.science.org/blogs/pipeline](https://www.science.org/blogs/pipeline) ---
**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:** [January 25, 2026, 10:47pm UTC](https://boards.straightdope.com/t/xkcd-thread/854574/5482 "2026-01-25T22:47:18Z")
It was **[John D. Clark](https://en.wikipedia.org/wiki/John_Drury_Clark)**. There are similarities, but he is no longer among us. He was an American [rocket fuel](https://en.wikipedia.org/wiki/Rocket_fuel) developer (thus the quote), [chemist](https://en.wikipedia.org/wiki/Chemist), and [science fiction writer](https://en.wikipedia.org/wiki/Science_fiction_writer). He was instrumental in the revival of interest in [Robert E. Howard’s](https://en.wikipedia.org/wiki/Robert_E._Howard) _[Conan](https://en.wikipedia.org/wiki/Conan_the_Barbarian)_ stories and influenced the writing careers of [L. Sprague de Camp](https://en.wikipedia.org/wiki/L._Sprague_de_Camp), [Fletcher Pratt](https://en.wikipedia.org/wiki/Fletcher_Pratt), and other authors. He had an interesting life. [Previous page](https://boards.straightdope.com/t/xkcd-thread/854574.md?page=273) [Next page](https://boards.straightdope.com/t/xkcd-thread/854574.md?page=275)