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Explain xkcd: It's 'cause you're dumb.
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You know when you can't hear your speakers, and you keep turning various volume controls up higher and higher in confusion, and then someone hits the mute button and there's a deafening blast of sound? That's basically what happened at Chernobyl.
Title text: You know when you can't hear your speakers, and you keep turning various volume controls up higher and higher in confusion, and then someone hits the mute button and there's a deafening blast of sound? That's basically what happened at Chernobyl.


Ambox notice.png This explanation may be incomplete or incorrect: Created by a NUCLEAR REACTOR. The title text needs an explanation. Do NOT delete this tag too soon.

Ponytail and White Hat discuss the HBO miniseries Chernobyl which depicts the 1986 Chernobyl nuclear plant disaster. White Hat asks Ponytail for an explanation of how the meltdown occurred, but his understanding of science is so limited that he finds even the first part of the first sentence of Ponytail's explanation too complicated to understand.

Ponytail starts explaining the role of the graphite in the reactor's core as the neutron moderator, but White Hat immediately interrupts her, as if he doesn't understand the word graphite. Ponytails tries starting the explanation from another angle, stating that the nuclear reactor was inadvertently put in an unstable state moments before the disaster, but White Hat interrupts again. Realizing that White Hat does not understand scientific terms of graphite and reactor, Ponytails resolves to use plain words every person should know, and to employ a metaphor.

She compares the purpose of a nuclear reactor as a heat-generating device to primitive humans' way of heating by starting a fire. She goes on describing how a fire can be started by banging rocks (pieces of flint) to create sparks, which in turn would light a fire. Seeing that White Hat understands this simple activity, she compares starting a runaway nuclear fission reaction to banging rocks too hard, presumably splitting or crushing them and injuring the wielder.

Nuclear reactions are often simplistically described and illustratively pictured as forcibly colliding colored balls representing various nuclear particles or nuclei, resulting in creating other balls, joining some into bigger ones, or splitting some into smaller ones. Fission reaction, in particular, involves a neutron causing a heavy nucleus to split into smaller parts, including more neutrons. To facilitate nuclear reactions, particles need to carry great amounts of energy as compared to their tiny sizes and masses. This may evoke a mental image of hitting rocks too hard so they split.

The title text explains the cause of the accident using an analogy with the volume of an audio system. To sustain a controlled nuclear fission chain reaction, various mechanisms are involved in controlling the level of neutrons produced and consumed by the nuclear fuel. Due to various design flaws and operation errors leading up to the Chernobyl disaster, the reactor core was producing less heat than desired by the reactor operators, who were preparing to conduct a simulated power outage experiment. To increase heat production, the operators pulled out almost all available control rods, akin to turning the volume knob to maximum on a muted sound system. Then the commencement of the experiment, which reduced the coolant water supply, further enhanced the positive feedback loop of the neutron production. Seeing a rapid rise in the power output, the operators began an emergency shutdown. A critical design flaw of the reactor caused the neutron production to increase temporarily in the reactor once the emergency shutdown started in this condition, which resulted in a runaway reaction caused by the multiple positive feedback loops taking place, ending up with the melting of the reactor core. The heat caused a water splitting, and the accumulated hydrogen finally caused a (chemical) explosion that destroyed the reactor. Per the title text, this is analogous to unmuting a sound system that has the volume turned all the way up, creating a "deafening blast of sound."


[Ponytail and White Hat facing each other.]
Ponytail: Did you like Chernobyl?
White Hat: Yeah!
White Hat: But I still don't understand the meltdown. Can you explain it...simpler?
[Zoom in to closeup of Ponytail holding one hand out with palm up, with White Hat off-panel to the right]
Ponytail: Well, the graphite--
White Hat (off-panel): Already too complicated.
Ponytail: Uh...they put the reactor in an unstable--
White Hat (off-panel): Nope, sorry.
[Zoom back out to full view of Ponytail and White Hat, with Ponytail holding hand to her chin]
Ponytail: Hmm, ok.
Ponytail: Long ago, humans banged rocks together to make fire.
White Hat: Ok...
[Full view of Ponytail and White Hat, who has both hands held straight out to both sides]
Ponytail: 30 years ago, we banged some rocks together too hard.
White Hat: Oh no!
Ponytail: Yeah, we messed up real bad.

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