3047: Rotary Tool

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Pole Vault Pole

|< < Prev #3183 (December 19, 2025)

Title text: My goal in life is to be personally responsible for at least one sports rule change.

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Explanation

This is one of 58 incomplete explanations: This page was created by a BOT OF UNLIMITED LENGTH. Don't remove this notice too soon. If you can fix this issue, edit the page!

The comic shows three hypothetical ways to cheat at pole vault, taking advantage of the fact that the rules don't limit the physical size of the pole. World Athletics' competition rules, rule 28.11, states, "The pole may be of any material or combination of materials and of any length or diameter, but the basic surface must be smooth."

The first way uses a pole that's short but with a very large diameter. It's then turned 90 degrees horizontally, so it can actually be used as a large wheel. The vaulter balances on top, then uses their feet to make it roll towards a crossbar at about the same height as the pole's diameter. When it reaches the bar, they simply jump a short amount to clear the bar.

The second method uses a pole whose length is more than twice the height of the crossbar. It's stretched over the bar and somehow attached to the ground at each end. Then the vaulter simply climbs up and over the bar.

The third method ties the ends of a very long and wide pole together, forming a large hoop that can be rolled towards the crossbar. The vaulter grabs onto the hoop, and when they reach the top they let go, and their momentum tosses them over the bar.

There are several flaws with these designs:

• Chiefly, the reason that the IAAF has not yet specified a standard measurement for poles is because there have not been any attempts to use a bizarre or potentially-advantageous design like these in sanctioned competitions. Were someone to try to do so, the authorities would take notice (though as we will see in the title text, Randall would count this as a win).

• All three designs may violate rule 28.2.2, which states that no part of the pole may touch the ground beyond the box until after the athlete has cleared the bar (there is an exception for the pole touching the landing mats after being properly planted in the box, but none of these designs would be properly planted, and all three would likely touch the ground beyond the landing mats). The first and third design may avoid this with careful timing, but it would be a deal breaker for the second. In addition:

• The first design is hampered by its size; any material sturdy enough to take a human's weight would cause a wheel that big to be considerably massive, difficult for a human to start in motion from a dead stop, dangerous if the user falls off while rolling it down the track, and capable of continuing on after the vaulter makes their jump, dislodging the bar from the vaulting frame and thereby disqualifying the attempt.

• The second design violates rule 28.2.3, which effectively prohibits climbing the pole by banning moving the upper hand or swapping which hand is the upper hand after leaving the ground which was introduced after someone actually did it. In addition, the time it takes for the pole to be sturdily embedded in the take-off & landing pits, plus the time to traverse the arch, may exceed the time limit allowed for the vault.

• The third design combines the first design's risks of the vaulter falling off and dislodging the bar with an additional violation of rule 28.1.1 that states that the use of tape may not result in the creation of any "ring" on the pole.

The title text says that Randall wants to be responsible for a sports rule change. Based on the contents of the comic, the implication is that he would go about this by exploiting some loophole that the organizers would be forced to patch. Though his second design couldn't possibly do that, as something similar already happened in 1890.

How you could jump higher at certain places on Earth than others, for instance using a pole, was the subject of 852: Local g. Pole vaulting and unfair methods of gaining height are also discussed in the first chapter of How To.

Transcript

This is one of 31 incomplete transcripts: Don't remove this notice too soon. If you can fix this issue, edit the page!

[At top left: A large wheel whose diameter is more than 4 times Cueball's height. Cueball is at the top, running backwards so that the wheel will roll towards a pole-vaulting crossbar at the same height.]

[At top right: A long pole is bent into an arch going over a very high pole-vaulting crossbar. Cueball is climbing up the left part, and is about 3/4 of the way to the top.]

[Along the bottom: A long pole has been bent into a circular hoop, with the ends tied together. It's rolling left-to-right towards a very high pole-vaulting crossbar, and three positions are shown. On the left Cueball is running to catch up with it. In the middle he has jumped and caught the left part of the pole. On the right, he has let go and is thrown into the air towards the crossbar.]

[Caption below the panel:]

Fun fact: There are no limits on the length or diameter of the pole in pole vault.

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Discussion

How come it's at 0.017 RPM for a minute?? and yet 1 RPM for a second? pls fix this randall Midnightvortigaunt (talk) 18:01, 5 February 2025 (UTC)

Its 0.017 RPM for the minute hand. The minute hand revolves once per hour or at 1/60 RPM ≈ 0,017 RPM --172.71.148.59 18:14, 5 February 2025 (UTC)

Ohhh that makes sense I didn't think about it like that Midnightvortigaunt (talk) 19:27, 5 February 2025 (UTC)

Mr.Dude (talk) 17:20, 7 February 2025 (UTC) I wonder what torque is needed to launch the average backyard telescope worthy of a tracking mount at Mach 8 given standard state pressures and temperatures of perhaps average conditions found in Randall’s back yard.

How come the comment above is invisible to me? 172.68.245.229 18:03, 5 February 2025 (UTC)

Possibly because people indented with spaces rather than with colons? 162.158.79.77 19:40, 5 February 2025 (UTC)

72 RPM for a record player...? 162.158.74.25 18:08, 5 February 2025 (UTC)

I could only find 78 RPM disks in the german wikipedia. 172.70.114.56 18:41, 5 February 2025 (UTC)

I came here to make the same comment: 72 is most probably a typo. The old records (at this date, very old, since the transition to vinyl records was 1948 to 1958 (in the US)) were 78 rpm, not 72 rpm https://en.wikipedia.org/wiki/Phonograph_record Rps (talk) 19:30, 5 February 2025 (UTC)

72 is (for example) relevent to font sizes (size 1 = 1/72 of an inch, size 72 = 1 inch), which might therefore have envaigled Randall's head for numbers by a different route, and got him confused. Conceivably he has had to deal with playing old 78s, but probably not for a long time... even the retro-revival of vinyl, recently, has probably not had quite so many old old records released to fill such nostalgic needs. So an easy brain-fudge/thinko to trip over on. 162.158.74.48 00:54, 6 February 2025 (UTC)

There used to be a record label call 72RPM records. 172.69.229.146 (talk) 19:07, 5 February 2025 (UTC) (please sign your comments with ~~~~)

We need one of those tables in here. DollarStoreBa'al (talk) 18:37, 5 February 2025 (UTC)

I made a change to the explanation that all of these numbers are realistic because, I checked out the speed of dental drills and they really do rotate that fast. I haven't checked out all of the other tools, but I suspect that they are also accurate. If you find that any of them are misstated, please correct my correction. Rtanenbaum (talk) 22:38, 5 February 2025 (UTC)

TABLE REQUEST When someone uploads a table, I'd like to recommend a second column for the frequency / reciprocal of the speed. "0.000000000073 minutes" is one every 13.7 billion minutes, or ~26,000 years. Thanks! 172.70.46.107 20:20, 5 February 2025 (UTC)

Me again. Should the column header "revolution time" be "rotation time"? In every instance, the axis of motion is within the object itself; even the second/minute/hour hands go around the axis. 141.101.76.73 16:41, 6 February 2025 (UTC)

TRIVIA 16 2/3 RPM phonographs were used for some voice-recorings back in the day. 172.68.26.24 21:01, 5 February 2025 (UTC)

My parent's old record player (60's, probably) had 4 possible speeds: 16, 33, 45, 78. By the early 80's the current ones only had 33 and 45. Rps (talk) 16:59, 7 February 2025 (UTC)

Album goes back to stacks of 78s. A symphony or opera would be 2, 3, 4 or more disks. They were bound like a photo-album with a leaf for each disk. "78" wasn't "standardized" until the format was fading. 3600-rpm motor and 46-tooth gear is incomplete (one tooth gear??) Early discs were from 60 to 130 rpm. Users would adjust speed by ear (also to ease pitch-matching for karaoke). Only as LPs arrived did someone invent the number "78.26 rpm" (no recordplayer and few lathes of the period were near that accurate). --PRR (talk) 02:34, 6 February 2025 (UTC)

Indeed, my parents had a large collection of old records and at least one had a speed marking of 80rpm.--172.68.186.43 09:17, 6 February 2025 (UTC)

With wind-up players, a lot of them started off playing at one speed and ended playing at a completely different one anyway...172.68.186.50 09:43, 6 February 2025 (UTC)

I suspect there's not many consumers needing a Uranium Enrichment Centrifuge... at least outside of a few countries in the Middle East. --172.70.58.6 08:50, 6 February 2025 (UTC)

Might face some regulatory / export license issues too.172.70.86.129 11:34, 6 February 2025 (UTC)

I feel like there was a lost opportunity to have Dr. Who's Sonic Screwdriver on the list. Maybe the rpms are unknown.162.158.159.107 13:05, 6 February 2025 (UTC)

The table says that 0.00070 "seems off; a sidereal day is 23.93 hours". That's just because (like all of the other settings) 0.00070 is quoted with only 2 significant digits. Every period between 23.64 and 23.98 hours would round to 0.00070 RPM. 162.158.134.199 13:58, 6 February 2025 (UTC)

The question I have is: why are dental drill speeds so high? 172.70.247.92 17:21, 6 February 2025 (UTC)

"why are dental drill speeds so high?" It hurts less. (Are you old enough to remember routine use of belt-driven dental drills?) You can cut a given amount of material (wood, steel, tooth) quickly with heavy force or high speed. Neither is really fun, but hi-speed is generally preferred. --PRR (talk) 19:08, 6 February 2025 (UTC)

Although some materials behave badly to heat (either work-hardening, for some alloys, or melting/burning, like plastics) and that's why variable-speed hand-drills/etc usefully have low speeds (for essentially the same force, when that's done via reostat rather than an actual gearbox). On the few occasions I've had my teeth drilled, I'm pretty sure I've detected the pungent smell of fried tooth-fragments, but it was nothing like as strong as smelling my own nose-flesh being burnt one of the times I had it cauterised to try (and fail) to prevent excessive nosebleeds. 172.69.79.139 21:15, 6 February 2025 (UTC)

The latest NMR CPMAS probes send their rotors to go at 9.6 Mrpm, M=mega. [1] --172.69.109.172 21:56, 7 February 2025 (UTC)

Should we list the rotor diameters to achieve the mach 8 speed mentioned in the title text in the table? I don't think that we should. guess who (if you desire conversing | what i have done) 06:01, 24 February 2025 (UTC)

I (obviously since I worked it all out) think it is in the spirit of the ridiculous idea of the comic and XKCD generally to do these calculations. That said, I'm getting different numbers than your update to make it Mach 8. Denver87 (talk) 16:21, 24 February 2025 (UTC)

I get the following: 4,799au, 74,866km, 37,733km, 3,144km, 52.4km, 1,588m, 1,165m, 728m, 175m, 34.9m, 21.0m, 149.7cm, 87.3cm, 174.7mm. Denver87 (talk) 16:21, 24 February 2025 (UTC)

Happy to share calculation notes, but here's the example for the dental drill: 300,000rpm = 5,000 rps; diameter of: 174.7mm --> circumference of: pi * 174.7mm = 548.8mm; 548.8mm * 5000rps = 2,744,000mm/sec = 2744m/sec; Mach 8 = 8 * 343m/sec = 2744m/sec. Denver87 (talk) 16:21, 24 February 2025 (UTC)

If you agree with the calculations, one of us can at least update it. Denver87 (talk) 16:21, 24 February 2025 (UTC)
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