3276: Recursive Trucker's Hitch

Recursive Trucker's Hitch

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Title text: As if the americium smoke detector incident wasn't enough, now nuclear regulators have ANOTHER reason to worry about the Boy Scouts.

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Explanation

This is one of 47 incomplete explanations: This page was created WITHOUT A HITCH. Don't remove this notice too soon. If you can fix this issue, edit the page!

The comic depicts the supposed possibility of using the mechanical advantage of recursively using a trucker's hitch — which is essentially a compound block and tackle system using only the rope — to generate sufficient pressure for nuclear fusion. This would be impossible in practice, due to the rope-on-rope friction and the extreme speed at which the pulling end must move.

A trucker's hitch is a knot typically used for securing a load. It provides a theoretical 3:1 mechanical advantage, ignoring friction. The comic shows this hitch being used repeatedly for a supposed mechanical advantage that scales exponentially with the number of layers. After many layers, it is tied to and around a pair of connectors that, when pulled together, will smoosh a small circular object labeled as a "fusion capsule". The conceit of the comic is that by doing so, one could produce sufficient pressure to ignite fusion by using just a simple rope.

This would not work, for multiple reasons:

1. The rope would break under the tension long before fusion-level pressure was produced, as would the connectors attached to the wall and plunger.
2. There would be too much friction in any practical setup to produce as much tension as would be theoretically feasible if we ignore friction.
3. To produce fusion-level pressure quickly enough to achieve fusion without the pellet being hopelessly deformed, the rope would need to be pulled out at impractically rapid speeds. (Mechanical advantage works by trading greater motion for greater force.)
4. The friction produced from rapidly pulling the rope would ignite, melt, or vaporize the rope and/or other tackle, depending on the materials and setting assumed.

Some descriptions of the trucker's hitch require that the free end of the pulled knot be tied, in turn, to the exposed (non-knot) looped length, usually with two half-hitches. This allows the whole structure to remain taut, even when not being actively tended to. The structure depicted does not tie off the knot in this way.

The title text mentions the exploits of David Hahn, who attempted to build a nuclear reactor using the americium-241 material sourced from ionization-type smoke detectors. Hahn was a member of the Boy Scouts of America at the time, and the Scouts are also known for teaching how to tie many kinds of rope knots. (The organization formerly known as "Boy Scouts of America" was renamed to "Scouts BSA" in 2019.)

Transcript

This is one of 33 incomplete transcripts: Don't remove this notice too soon. If you can fix this issue, edit the transcript!

[A winch arm is shown (labelled 'Plunger'), with a small circle within it labelled 'Fusion Capsule' and a string attached to the arm and attaching to the base, which is then continually knotted in a block and tackle system until it reaches the end of the string, labelled as F_in.]

[Below is a box within the panel shows the following equation:]

$Mechanicaladvantage=\frac{F_{out}}{F_{in}}=\frac{1}{3}(2^{(2n+1)}+1)\approx \frac{2}{3}{4}^n$

[After the box, more text is shown, as follows:]

$MA(1)=3:1$

$MA(5)=683:1$

$MA(20)=733,007,751,851:1$

$MA(50)=845,100,400,152,152,934,331,135,470,251:1$

[Caption below the panel:]

The International Atomic Energy Agency regulates the recursive trucker's hitch, since the unlimited mechanical advantage it offers is powerful enough to ignite fusion.

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Discussion

The method for making the 'block-and-tackle'-like loop seems to be inconsistent and/or varying in all versions of the knot that I've seen documented. But, where intended to be a permanent ('unmanned') knot-in-place, most suggest that the single pulled end be secured to the looped-back 'end', in various ways (usually via hitches), if not around the fixture that the loop-back loops back through (it doesn't have to be as strong a direct tie-down knot, as it has both mechanical advantage and the advantage of the inherent friction in the loop-in-loop connection). And that seems missing from the recursed version A minor point, but open to mentioning (in some way or other) if you care to be pedantic. 92.23.5.92 00:31, 25 July 2026 (UTC)

I still don't get this one after the explanation, or it least how a trucker hitch works. Are there any videos of it in action? 2600:1700:3B93:1020:8B2F:1F8C:780F:A571 00:33, 25 July 2026 (UTC)

It seems like at the limit this should be the same as the capstan equation,

T_load / T_hold = e^(µ 2π N)

, which I guess is pretty close to

2/3 4^n

Constants… JohnHawkinson (talk) 03:18, 25 July 2026 (UTC)

jhawk? From Panix? Nitpicking (talk) 13:01, 26 July 2026 (UTC)

A bit last century of you, but hi. JohnHawkinson (talk) 18:00, 26 July 2026 (UTC)

Using to the given mechanical advantage number, if the pulled part of the rope travels at light speed, the fusion part moves 11 femtometers (billionth of a micrometer) per year. Fabian42 (talk) 10:10, 25 July 2026 (UTC)

I've started working on the transcript, but I don't see how to add the mathematical symbols in. How do you do that? GSLikesCats306 (talk) 13:30, 25 July 2026 (UTC)

Weird version of a trucker's hitch. I get it, but I think of the loop in a trucker's hitch as a fig 8 on a bight tied in line with the standing part, not a slipped overhand like this. Yorkshire Pudding (talk) 18:11, 25 July 2026 (UTC)

I use the alpine butterfly for the loop - it's quick and easy to tie, and reasonably easy to untie even when pulled tight. Highly recommended knot! 2601:603:200:6010:15EE:D12:D05B:5A13 01:52, 6 August 2026 (UTC)

"Whereas this compound knot seems to have no indicated intention to similarly tie off the whole structure in order to remain taut even when not being actively tended to." That's a very long sentence fragment. I'd fix it if I knew what it meant, but I don't. Nitpicking (talk) 13:01, 26 July 2026 (UTC)

It just means that instead of having the end tied off, it's dangling freely, so the whole setup will be loose if no one hangs onto it.Yorkshire Pudding (talk) 16:54, 26 July 2026 (UTC)

Something like “However, the recursive trucker’s hitch seems to have no indicated intention to hold the end of the rope in place to remain taut.” might work. Logalex8369 (talk) 16:56, 26 July 2026 (UTC)

Have attempted to improve it - hopefully I haven't lost the sense of it. 82.13.184.33 08:27, 27 July 2026 (UTC)

The formula given in the comiic does not appear to match the drawing. In the drawing, each hitch adds 2 ropes pulling on the load. Hence, with no hitches the advantage is 1, with one hitch the advantage is 3 and with two hitches, the advantage is 5.The correct formula should be MA =(1+2n). To get exponential growth one must replace every existing horizontal rope with a hitch at each stage.This is not what is drawn. 2a04:4e41:4a09:fee6::711e:4ee6 (talk) 09:19, 27 July 2026 (UTC) (please sign your comments with ~~~~)

As a long time sailor, no, Randall is right here in that there's an exponential nature here. Your formula only holds when the turning blocks are all mounted to the same end plates. That's not the case here, where each hitch is multiplying it's tension on the rope above it. Drawing a force diagram is a good way to prove it. Hanneshdc (talk) 15:36, 27 July 2026 (UTC)

FWIW, it’s no longer the “Boy Scouts”. It became “Scouts BSA” (with “BSA” having no meaning, just as “KFC” no longer officially means anything) since 2019. A young person enrolled in the Organization is a “Scout”, not a “Boy Scout”; female members are Scouts too. (The Girl Scouts of America is an entirely different organization.) -- MarcH61 (talk) 13:48, 27 July 2026 (UTC) (please sign your comments with ~~~~)

There are still restaurants with "Kentucky Fried Chicken" signs, so it still has some meaning. SDSpivey (talk) 02:34, 30 July 2026 (UTC)

Assuming they aren't actually like the "Kenya Fried Chicken" or "Kuala Lumpur Fried Chicken", with Suspiciously Similar Substitute logos, and riding on the (now vacated) original KFC branding unofficially and cheekily! 92.23.5.92 20:19, 30 July 2026 (UTC)
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