3257: Beam Pipe

Beam Pipe

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Title text: 'If you keep trying to spray your collaborators with the beam when they're not looking, I'm turning off the ion source and NO one will get to play with the beam!' --Physics's mom

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Explanation

This is one of 46 incomplete explanations: This page was found with a Physics Nobel Prize. Don't remove this notice too soon. If you can fix this issue, edit the page!

With pipes such as hosepipes, water can come out in a more rapid and more concentrated stream by covering up part of the exit nozzle with an object, such as a finger. This forces the water to come out of a smaller space, increasing the effective pressure. As the LHC can be considered a sort of "pipe" (a beam pipe, as pointed out in the comic title), this comic makes the ridiculous assumption that the same logic applies there, and its beam can be concentrated and redirected by partially covering the end of the beam. This wouldn't work in real life: water molecules are moving at low speed and thus do not have sufficient energy to overcome the electrostatic repulsion between their electrons and those of the thumb, forcing them to change path. In contrast the kinetic energy of the particles in the LHC (14 TeV) is far far larger than the repulsion of the thumb. Most particles will pass through unaffected, while those hitting a thumb nuclei directly will produce a cascade of new particle similar to those the LHC is intended to produce.

While there is no recorded case of a human getting struck by the particle beam at LHC, Anatoli Petrovich Bugorski did accidently hold his head into the proton beam of a 76 GeV (about 180 times less than the energies at the LHC) particle accelerator while trying to repair a faulty part. This had severe but not lethal consequences: during the acute radiation sickness the affected parts of his face swell and the skin was flacking off, and the affected nerves never recovered, leaving his left face paralysed and his left year deaf. The damage to his brain resulted in several epileptic seizures, but did not affect him otherwise allowing him to continue his work as a physicist and at time of publication he was still alive at the age of 82.

Thus while pointless, holding the thumb into the LHC beam is unlikely to significantly harm the anyone trying it.

The title text expands the joke, once more treating the LHC as if it were a hosepipe. Applying the effect above to a hosepipe is a common thing for children to do — often to spray family and friends with the pressurized water. This applies the same logic to the LHC, imagining the mother of "physics" (the science, as opposed to a person) telling off their presumably adult child for "spraying their colleagues with the beam" — something very incomprehensible in real life.

Transcript

This is one of 28 incomplete transcripts: Don't remove this notice too soon. If you can fix this issue, edit the page!

[A picture shows a (partly obscured by the panel) particle accelerator (namely this one being the Large Hadron Collider at CERN). Megan is shown on a stepladder, covering the beam pipe with her thumb. Cueball is shown standing behind the ladder, watching.]

[Caption below the panel:]

This year's physics Nobel will go to the scientists who figured out that you could make the Large Hadron Collider more powerful by covering part of the beam pipe with your thumb.

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Discussion

Ok why did this take so long to be created? GSLikesCats307 (talk) 12:58, 11 June 2026 (UTC)

I think it was because explainxkcd was down when this comic was published (agian :/) --Clarkexckd8 (talk) 13:01, 11 June 2026 (UTC)

It was like that with the last comic as well. What's causing these outages? GSLikesCats307 (talk) 13:03, 11 June 2026 (UTC)

Maybe it's something with the servers. I have no clue why it took until 12:00 (UTC) to upload though.--Clarkexckd8 (talk) 13:15, 11 June 2026 (UTC)

I'm going to theorise that some third party, out there, is running something that hammers our servers. From the little information the change-logs gives, they're starting it around 22:00 (server time) and it only ends (or people, including the comic-update-BOT, only realise it has ended) at around 12:00 (server time, again).

While this inconsiderate thing is happening, everyone else (and probably themselves, if they're running their hammering massivelg in parallel) is finding it almost impossible to connect, as the back-end is too busy serving the site-database results to the hammerer. (Some edits were made ~05:00ish, the other day. Might have been lucky/persistent to do that. Or hit a rare pause by the bad-actor's efforts.)

Probably not a deliberate DDOS, as these other periods of sanity wouldn't be in such a plan by someone. I suggest it's either someone/something doing (or trying to do) a lot of webscraping, without any though to throttling it down to a less disruptive level, or even an intended auto-spammer (getting thwarted by the initial hurdles that protect this site, but their spamming algorithm just keeps trying).

And the inconvenience to us mere mortals is as applicable to the comic-upload-BOT. The only difference being that it can (in a way programmed specifically not to self-defeatingly DDOS the site) just try again, perhaps every half an hour or so, so is more likely to be the first contributor to the site (when there's a new comic still to post, in its backlog) once the data-pummelling has stopped for the day.

What can we do about it? Not much. Curse the person who (intentionally or otherwise) did this? But it seems to not involve any traces of activity that aren't purely server-log level, or maybe on the prody servers that we also don't control. With any luck, they'll realise their (unintended) mistake and rethink it. Or just have no more reason to do so. Not very comforting, but the best outcome I can imagine happening easily. 82.132.236.149 12:53, 12 June 2026 (UTC)

This is probably nitpicking, but covering the opening of a hose doesn't increase the pressure of the stream, it increases flow rate instead, and with it the nozzle velocity. The pressure at the end of a hose is equal to ambient pressure, and the flow rate adjusts itself to achieve this. (At least in sub-sonic conditions that you would normally encounter, though this may not apply to the LHC...) 2A02:590:1404:9301:2CAC:E347:73BF:C11 14:30, 11 June 2026 (UTC)

Yeah, I noticed that... decreasing the diameter should actually decrease the pressure by bernoulli's law, right? 12.159.97.176 14:31, 11 June 2026 (UTC)

Yeah I was about to mention that too GreaterDog6065 (talk) 14:55, 11 June 2026 (UTC)GreaterDog6065 09:54, 11 June 2026 (CDT)

What if you put your hand in a particle accelerator: https://www.youtube.com/watch?v=8UgKki1tCKI

Also, LHC actually has two adjacent parallel beamlines (or beam pipes) each containing a beam, which travel in opposite directions. Cf. https://en.wikipedia.org/wiki/Large_Hadron_Collider#Design --134.102.219.31 12:40, 12 June 2026 (UTC)
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