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		<updated>2026-04-18T18:38:18Z</updated>
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	<entry>
		<id>https://www.explainxkcd.com/wiki/index.php?title=1531:_The_BDLPSWDKS_Effect&amp;diff=94549</id>
		<title>1531: The BDLPSWDKS Effect</title>
		<link rel="alternate" type="text/html" href="https://www.explainxkcd.com/wiki/index.php?title=1531:_The_BDLPSWDKS_Effect&amp;diff=94549"/>
				<updated>2015-05-30T00:22:19Z</updated>
		
		<summary type="html">&lt;p&gt;BBCXI: /* Explanation */ Update Peltzmen per suggestion in talk. Less circuitous explanation for Sapir-Whorf; if he meant &amp;quot;firetruck&amp;quot; he could have said that.&lt;/p&gt;
&lt;hr /&gt;
&lt;div&gt;{{comic&lt;br /&gt;
| number    = 1531&lt;br /&gt;
| date      = May 29, 2015&lt;br /&gt;
| title     = The BDLPSWDKS Effect&lt;br /&gt;
| image     = the bdlpswdks effect.png&lt;br /&gt;
| titletext = This well-known effect has of course been replicated in countless experiments.&lt;br /&gt;
}}&lt;br /&gt;
&lt;br /&gt;
==Explanation==&lt;br /&gt;
&lt;br /&gt;
The BDLPSWDKS Effect in the title is an {{w|acronym}} for Bernoulli-Doppler-Leidenfrost-Peltzman-Sapir-Whorf-Dunning-Kruger-Stroop Effect, as explained by [[Ponytail]] in the comic. She stands in front of a slide that shows [[Cueball]] being subjected to this effect.&lt;br /&gt;
&lt;br /&gt;
The effect mentioned appears to be a mashup of seven scientific principles (with nine scientists names included) from different scientific fields, with elements from each principle appearing in the resulting description of the effect:&lt;br /&gt;
&lt;br /&gt;
{{w|Bernoulli's principle}} in fluid dynamics (also mentioned in [[803: Airfoil]]) states that an increase in the speed of a fluid with certain properties occurs simultaneously with a decrease in pressure or a decrease in the fluid's potential energy. This is referenced by the lifted firetruck hurtling rather than just speeding.&amp;lt;!-- lift is already provided by the Leidenfrost effect, the Bernoulli effect would lead to the truck going higher and higher, eventually flying over your head --&amp;gt;&lt;br /&gt;
&lt;br /&gt;
The {{w|Doppler effect}} in physics refers to the change in a wave's frequency for an observer moving relative to its source. Sound from the oncoming firetruck increases in pitch. In tonal languages, changes in pitch change the meaning, making it harder for Cueball to understand the word screamed by the driver.&lt;br /&gt;
&lt;br /&gt;
The {{w|Leidenfrost effect}} refers to how liquid will produce an insulating vapor layer when in near contact with an extremely hot surface, causing it to hover over said surface. This is referenced by the firetruck lifting off on a layer of superheated gas.&lt;br /&gt;
&lt;br /&gt;
The {{w|Peltzman effect}} refers to how regulations intended to increase safety are ineffective or counterproductive because people, feeling safer, will engage in riskier behaviours. The firetruck, a vehicle associated with safety, is speeding, and subsequently creates a significant hazard.&lt;br /&gt;
&lt;br /&gt;
The {{w|Sapir–Whorf hypothesis}} states that a person's world view and cognitive processes are affected by the structure of the language the person speaks. If Cueball speaks (or is currently thinking in) a language without a word for &amp;quot;firefighter&amp;quot;, he might be slower to recognize the role and authority of the driver warning him, and thus slower to react to the danger.&lt;br /&gt;
&lt;br /&gt;
The {{w|Dunning–Kruger effect}} refers to unskilled people mistakenly perceiving themselves as more skilled than they really are, while skilled people underestimate their own abilities. Obviously, if Cueball isn't fluent in the language, s/he'd take more time to process &amp;quot;green&amp;quot;, as opposed to &amp;quot;red&amp;quot; in a well-understood language.&lt;br /&gt;
&lt;br /&gt;
The {{w|Stroop effect}} refers to the phenomenon in which it is easier to name the color of the ink in which a word is written when the word refers to the same color as the ink than when the word refers to a different color. Firetrucks are red, this suggests that the driver shouting '''&amp;lt;span style=&amp;quot;color:red&amp;quot;&amp;gt;RED&amp;lt;/span&amp;gt;''' would get a faster response than the driver shouting '''&amp;lt;span style=&amp;quot;color:red&amp;quot;&amp;gt;GREEN&amp;lt;/span&amp;gt;'''.&lt;br /&gt;
&lt;br /&gt;
Usually, for an effect to be considered real, the scientific method requires the effect to be replicated by different experimenters in different times and places. It is hard to imagine several scientists in different parts of the world creating the setup to replicate this effect; however the title text mentions (maybe  {{w|Sarcasm|sarcastically}}{{Citation needed}}) it has been done countless times.&lt;br /&gt;
&lt;br /&gt;
Furthermore, the opportunity of publishing this comic strip may (or may not) be related to the recently issued sequels of franchises such as `Mad Max` and `Carmageddon`, where it's not unusual to find heavy wheeled vehicles trampling pedestrians for fun, or simply because the drivers do not care.&lt;br /&gt;
&lt;br /&gt;
==Transcript==&lt;br /&gt;
&lt;br /&gt;
:[Ponytail stands next to a screen displaying a firetruck hurtling toward Cueball on what appears to be a layer of gas.]&lt;br /&gt;
&lt;br /&gt;
:Ponytail: The Bernoulli-Doppler-Leidenfrost-Peltzman-Sapir-Whorf-Dunning-Kruger-Stroop Effect states that if a speeding fire truck lifts off and hurtles towards you on a layer of superheated gas, you'll dive out of the way faster if the driver screams '''''&amp;quot;red!&amp;quot;''''' in a '''''non'''''-tonal language that '''''has''''' a word for &amp;quot;firefighter&amp;quot; than if they scream '''''&amp;quot;green!&amp;quot;''''' in a '''''tonal''''' language with '''''no''''' word for &amp;quot;firefighter&amp;quot; which you '''''think''''' you're fluent in but '''''aren't'''''.&lt;br /&gt;
&lt;br /&gt;
{{comic discussion}}&lt;br /&gt;
&lt;br /&gt;
[[Category:Comics featuring Ponytail]]&lt;br /&gt;
[[Category:Comics featuring Cueball]]&lt;br /&gt;
[[Category:Science]]&lt;/div&gt;</summary>
		<author><name>BBCXI</name></author>	</entry>

	<entry>
		<id>https://www.explainxkcd.com/wiki/index.php?title=User:BBCXI&amp;diff=94548</id>
		<title>User:BBCXI</title>
		<link rel="alternate" type="text/html" href="https://www.explainxkcd.com/wiki/index.php?title=User:BBCXI&amp;diff=94548"/>
				<updated>2015-05-30T00:07:50Z</updated>
		
		<summary type="html">&lt;p&gt;BBCXI: Created page with &amp;quot;Hello.&amp;quot;&lt;/p&gt;
&lt;hr /&gt;
&lt;div&gt;Hello.&lt;/div&gt;</summary>
		<author><name>BBCXI</name></author>	</entry>

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