www.explainxkcd.com Open in urlscan Pro
2606:4700:3037::ac43:9d38  Public Scan

Form analysis
1 forms found in the DOM

/wiki/index.php

<form action="/wiki/index.php" id="searchform">
  <div id="simpleSearch">
    <input type="search" name="search" placeholder="Search explain xkcd" title="Search explain xkcd [alt-shift-f]" accesskey="f" id="searchInput" tabindex="1" autocomplete="off"><input type="hidden" value="Special:Search" name="title"><input
      type="submit" name="go" value="Go" title="Go to a page with this exact name if it exists" id="searchButton" class="searchButton">
  </div>
</form>

Text Content

We still need to complete some explanations like this one: 1547: Solar System
Questions. All incomplete explanations are here.




MAIN PAGE

Explain xkcd: It's 'cause you're dumb.

Jump to: navigation, search

Welcome to the explain xkcd wiki!
We have an explanation for all 2929 xkcd comics, and only 4 (0%) are incomplete.
Help us finish them!


LATEST COMIC

Go to this comic explanation


 * |<
 * < Prev
 * Comic #2929 (May 6, 2024)

Good and Bad Ideas
Title text: While it seemed like a fun prank at the time, I realize my prank
fire extinguishers full of leaded gasoline were a mistake.


EXPLANATION

This explanation may be incomplete or incorrect: Created by a BLOOD FOR THE
BLOOD GOD- Please change this comment when editing this page. Do NOT delete this
tag too soon.


This is a scatter plot comparing how good an idea sounds to how good the idea
is. For example, leaded gasoline sounded like a good idea due to its
anti-knocking effects, but is a bad idea due to lead toxicity. Fake prank fire
extinguishers both sound bad and are bad, as they can make a dangerous situation
worse. Putting mold on infections sounds like a bad idea, but some molds, like
ones containing penicillin, have helpful antibiotic effects.

The title text combines leaded gasoline and a fake prank fire extinguisher into
something worse than either. The fire extinguisher is fake and releases
flammable material onto the fire, and there is additional lead toxicity.


TABLE OF THE ENTRIES

Idea What it means How good it sounds How good it actually is Explanation Leaded
gasoline Adding tetraethyl lead as an antiknocking agent to allow for increased
performance ++ --- Leaded gasoline was introduced in the early 1920s to allow
higher pressures and temperatures in an engine without causing detonation
(knocking), allowing for increased fuel efficiency and engine performance; it
also works to prevent engine valve wear. In essence, it artificially raises the
octane rating of the fuel, reducing the need for fuel refinement, thus reducing
waste and/or expense. Lead, however, is both toxic and bioaccumulative, meaning
that lead released into the air over decades built up to harmful levels in
people (as well as other animals) and almost certainly contributed to a host of
health issues. Some scientists even suppose that crime levels are influenced by
lead exposure. (It should be noted that this only "[sounded] like a good idea"
due to deliberate campaigns to obscure the known dangers). Bloodletting
Releasing "bad blood" from the veins --- --- You need (most of) your blood.
Losing more than 15% of a person's total blood volume results in adverse
effects. Bloodletting has been performed as a medical procedure for at least
2000 years until the 19th century. The idea was to withdraw blood to balance the
body's "humors". Despite this long history, the notion that bleeding someone is
bad seems like basic common sense, and it's now well-understood that
blood-letting (outside of certain rare and specific cases) does no good, causes
significant harm and quite certainly causes many deaths when it is used.
Asbestos Mineral which does not burn, tolerates extremely high temperatures and
forms small fibers. These qualities make it excellent for insulation and fire
protection +++ --- Asbestos was used extensively in ships and buildings
throughout most of the 20th century. Unfortunately, the microscopic fibers that
make up asbestos greatly increase the risk of lung disease and cancer when
inhaled, causing its use to be banned in most countries. Extension cords with
prongs on both ends allows easy connection between 2 female connectors 0
(neutral) --- Prongs on both ends would make it easier to plug the extension
cord in on either side. But once plugged into an outlet, the other end becomes a
serious shock hazard, as seen in this Backyard Scientist video. Stair kayaking
Riding down a flight of stairs in a kayak -- --- Stair kayaking is a stunt where
a person positions a kayak at the top of a flight of stairs and then, using
their paddle to push off, rides the kayak down the stairs. This poses
significant easily foreseeable risks of injury or death, as well as being very
bad for the kayak, which is designed to ride on water, not stairs.[citation
needed] Fake prank fire extinguishers Intentionally placing empty or otherwise
non-functional fire extinguishers as a practical joke. --- --- The idea of
placing fake fire extinguishers as a prank, presumably so that a person who
thinks they are grabbing a real fire extinguisher will instead find a decoy,
sounds very dangerous and potentially life-threatening for many people, and it
would be highly dangerous. In the United States, (and presumably most
countries), this would also be a felony in most, if not all, jurisdictions. An
example of a similar situation, although not intended as a prank, can be found
here.

The title text expands this idea by having the prank fire extinguishers filled
with (leaded) gasoline. This is literally adding fuel to the fire.

Always saying what you think ...regardless of the feelings of others or other
considerations ++ -- Openness and honesty are seen as positive character traits
in people. However, taking it to the extreme of always telling people what you
think about them, can lead to awkward or unpleasant situations. It may harm your
relationship with the other person if they don't like what you think, or they
may reply without concern for your feelings or other considerations. Keeping
negative thoughts to yourself or telling "white lies" can be considered a better
alternative in some situations. Replying to spammers Clicking on the "Reply"
button from spam emails and writing (and sending) a reply (or worse, clicking on
the links in these emails) -- -- At best, you confirm your email address and
identify yourself as someone likely to respond to such unsolicited messages and
so encourage the spammers to deluge you with even more messages. At worst, the
spammer may use your correspondence to extract sensitive information about you
or make you a victim of a scam. Solar cars Having solar panels on the car's
surface (mostly hood and roof) for power generation +++ - Powering electric
vehicles with solar panels seems like an excellent idea: it would provide free
power with no increased land use, and theoretically could allow a vehicle to
operate indefinitely without being fueled or charged. However, such vehicles
couldn't operate without batteries (due to power requirements, weather
conditions, shade from roadside features and nighttime driving), so they'd have
increased complexity compared to plug-in or hybrid cars. Adding solar panels
would add cost, weight, manufacturing complexity and maintenance requirements.
Solar panels on moving cars are less efficient than in stationary installations
and subject to damage from both collisions and road debris. Solar cars do exist
(the World Solar Challenge is a competition for such cars), but as a practical
form of transportation, the negatives likely outweigh the positives. Heelies
Heelys are shoes with an inline skate wheel embedded in the sole, at the heel. +
- Heelys allow the wearer (usually children) to shift between normal walking and
rolling like being on skates. This sounds like fun but has been suggested to be
a potentially significant injury risk. Prequels A work of fiction (mostly movie)
telling the "story before the story" of another work of fiction. +++ - More of a
good story sounds great on the surface, and audiences who are invested in a set
of characters and/or a setting often love the idea of finding out what led up to
certain events. But there are several pitfalls. Any spin-off of a popular
property risks becoming a low-quality cash grab. Prequels, specifically, are
constrained by the fact that they have to lead to the story that's already been
released, which can lead to contrived storytelling. There's less room for
suspense since the future of the storyline has already been established. There's
a tendency to invent or fill in detailed backstories, which can undermine
character arcs, and/or destroy the mystery and nuance of certain characters.
And, since they tend only to be made where the original is already
well-received, regression to the mean tends to mean they are more likely than
not to fail to live up to expectations. Prequels can be good, of course, but
there are a lot of ways they can go wrong. Transitions® lenses A brand name for
photochromic lenses in glasses, which get darker (like sunglasses) in bright
light. + - Photochromic lenses are clear lenses that darken when exposed to UV
light, then turn clear again when the exposure is removed. The advantage is that
wearers of glasses don't need to buy separate (prescription) sunglasses.
However, the process is relatively slow (about a minute) so not so useful when
there is a quick succession of shade and bright light, perhaps in a forest or
when driving. If used in a car, the windscreen filters out UV light to some
degree, which prevents the glasses from darkening as required. Finally, the
process is temperature dependent, so in hot weather the glasses don't become as
dark, and in cold weather they might stay dark for too long.

Additionally, the following should be considered. UV-conscious people protect
their face against UV light, so the skin doesn't form wrinkles and ages slower.
Sunscreen is difficult to apply around eyes without getting the substance on
eyeballs (cosmetic substances should not get there). One of the reasons behind
wearing sunglasses may be to protect skin around eyes from forming so called
crow's feet. Under UV-filtering sunglasses, UV-activated transitions contact
lenses will not darken defeating their purpose. At the same time transitions
contacts are typically at least twice as expensive as the regular ones.

Cutting pizza in squares Cutting (a presumably round) pizza in squares - - Most
people cut pizza into wedges and hold it by the crust. Cutting it into squares
could allow for more pieces to be shared, if the resulting wedges would be too
thin to be practical. However, pieces near the center will have no crust to hold
it by, getting cheese and sauce all over your fingers. Cuts around the edge will
probably leave smaller leftover scraps which are mostly crust. While hardly a
disaster like the other items in its quadrant, square pizza pieces are just not
very useful and rather inefficient. Cutting a rectangular pizza into squares
might not suffer from the problems above, but, unless the pizza itself is square
and cut only into four squares, some people will end up with a higher
crust-to-topping ratio than others. Cutting a round pizza into squares is
popular in Chicago and is sometimes called tavern-style or party-cut and
some[who?] consider it the real Chicago style pizza rather than deep dish
pizza.[dubious] Project Orion Study by the U.S. government looking into nuclear
pulse propulsion for spacecraft. --- - Using repeated nuclear explosions to
generate motion sounds bad for both the spacecraft and everything else,
especially with a ground launch, but there are ways to address a lot of the
concerns, so it isn't as bad as it sounds. Project Orion's theorized specific
impulse and thrust would also be far higher than anything chemical rockets can
accomplish. The efficiency of Project Orion is extremely low, however, and the
ablation issues are extremely difficult to overcome.

See also 2423: Project Orion.

Soup Soup 0 (neutral) 0 (neutral) Soup is probably one of the oldest foods
created by prehistoric cooks. Many people enjoy it, though some consider many
soups somewhat lacking as a meal on their own, or boring. Combo washer dryers A
device that combines washing machine and laundry dryer into one device +++ +
Better at space efficiency, but worse at each task than separate devices, and
unable to do both tasks in parallel (useful when you have more than one batch of
laundry). Cutting sandwiches diagonally Cutting sandwiches diagonally + +
Generally regarded as the superior way to slice a sandwich, providing more
aesthetically pleasing display of the contents, better support in the hand and
fewer all-crust bites. Required in the assembly of a club sandwich,[actual
citation needed] where the diagonal components are stacked again. Diverging
diamond interchanges Road junction where the two (sets of) lanes cross over to
switch sides (so if you normally drive on the right, now you drive on the left),
then switch back to normal after the junction - + Highway engineers believe the
shape improves safety and traffic flow through the interchange because switching
to the other side facilitates merging to and from the other road in the
junction. However, the shape appears to be insanity to an unfamiliar driver.
Toasting sandwiches Making a sandwich first and then cooking it, as in a
dedicated sandwich toaster, a toaster oven, frying pan or under a grill. ++ ++
The grilled cheese sandwich is a familiar form to most people, and many other
sandwiches are improved by toasting as a final step. Others, such as the Western
or club are prepared using toast. The Elvis is a specific case of a sandwich
that normally wouldn't be toasted, but is improved by it - peanut butter, bacon,
banana, and jelly, with the assembly lightly fried. Crumple zones Designated
areas of a car that crumple in case of a crash. -- ++ Most people's intuition
would be that stronger cars are safer, and intending parts of a vehicle to
collapse by design might seem crazy. But engineered crumple zones are designed
to absorb the kinetic energy in a vehicle collision, and do so in such a way as
to protect the integrity of passenger cabin. The result is that the occupants
experience less intense deceleration and ideally without the damage
significantly compressing the shell around them. This significantly reduces the
danger of injury or death from crashes. Sliced bread Bread, sliced by the baker
before packaging for sale +++ ++ It's far more convenient for making sandwiches
or toast, but unfortunately pre-sliced bread will go stale faster and some
applications may be better off thicker or thinner than the slices provided.
Sliced bread is often used as a comparator for how good something is, using the
phrase 'the best thing since sliced bread'. Pizza Pizza ++ ++ Pizza is a widely
popular dish throughout much of the world, uncontroversial except certain
toppings. Eating citrus fruit while at sea Having a supply of citrus fruit on
long sea journeys, especially during the Age of Sail 0 (neutral) +++ For a long
time, scurvy was a danger to sailors, who generally subsisted on a monotonous
diet of shelf-stable foods with low vitamin content while on long voyages. Most
citrus fruits are rich in vitamin C, which prevents scurvy. Eating orange or
lemons doesn't seem like a significant activity one way or the other, but it's
an easy way to prevent a disease that causes serious ill-health and possibly a
painful death. Putting mold on infections Seemingly a reference to the ancient
practice of pressing moldy bread against infected wounds --- ++ While this
sounds like a good way to get a fungal infection, with the correct mold this is
a primitive way to obtain an antibiotic. Certain fungi naturally produce
antibiotic substances, and this is where humans discovered penicillin. Wheels on
luggage Some luggage bags have small wheels inset on their frame and a carrying
handle. +++ +++ A relatively simple fitting for rigid or semi-rigid luggage that
substantially eases its transport over long distances on flat surfaces such as
travel terminals. Heat pumps A technology that moves heat energy from a cold
area to a warm area, most familiar as the technology that keeps a refrigerator
cold. It can be used to heat a home interior in winter or cool it in summer. ++
+++ Unlike traditional furnaces, heat pumps do not generate heat (beyond a small
overhead). Instead, they move existing thermal energy from a coolable
environment across to a warmable one. This allows a space to be heated with
significantly less energy use than a furnace or resistance heater that just
generates heat 'from scratch'. Because these units are operated by electricity,
they can provide heating with renewable energy (potentially using thermal energy
storage for load-shifting), reduce or eliminate the need for natural gas
connections, and prevent several risks that come with traditional furnaces (such
a carbon monoxide leaks and fires). In addition, heat pumps can operate in the
reverse direction as air conditioners, so a single unit can be designed to both
heat and cool a building. It sounds like a good idea and works out pretty well
in real life.

See also 2790: Heat Pump.

Laser eye surgery Surgical techniques using lasers for precision cutting in the
eyeball. - +++ In the popular imagination, lasers are often thought of as
something used for destroying their target. Firing them into people's eyes,
then, does not sound like a great idea. However. this technology has
substantially improved the eyesight of millions of people worldwide by allowing
the treatment of eye problems otherwise only corrected by lenses or entirely
untreatable. Randall has previously commented on laser eye surgery, amongst
other ideas both good and bad, in 1681: Laser Products. Fecal transplants
Transfer of the gut microbiome of a healthy person to the sterilized gut of an
ill person. --- +++ The gut microbiome is a collection of bacteria that lives in
our guts. It can influence our health. It is responsible for the last stages of
digesting our food. It can also produce neurotransmitters that are carried by
blood to our brain influencing our behavior. A healthy microbiome can be
destroyed by bad eating habits, unhealthy lifestyles, acquired infections or the
use of antibiotics. The important part is the composition of different species
of bacteria that compromise the biome. Sometimes it may be necessary to
completely sterilize the gut and then take a sample of a healthy biome from
another person. A sample is enough as the bacteria will multiply. As long as the
patient eats correctly, the microbiome after transplant should develop
correctly.

It sounds bad because we tend to think of our feces as something gross, to be
discarded, and other people's bacteria as infectious. It is called fecal
transplant as our feces contain about 50% of gut bacteria, but nowadays the
sample usually takes the form of a coated pill that is applied rectally.


TRANSCRIPT

[Two axes with double arrows cross each other in the middle. At the end of each
arrow, there are labels. Scattered over the chart are 28 entries. Below these
entries are given for each of the four quadrants, plus three that are on the
Y-axis. For each quadrant the entries are listed in reading order, top to bottom
left to right.] [X axis from left to right:] Sounds like a good idea Sounds like
a bad idea [Y axis from top to bottom:] Actually a bad idea Actually a good idea
[Top left quadrant (sounds like a good idea, actually a bad idea):] Leaded
gasoline Asbestos Always saying what you think Solar cars Heelies Prequels
Transitions® lenses [Top middle (actually a bad idea):] Extension cords with
prongs on both ends [Top right quadrant (sounds like a bad idea, actually a bad
idea):] Bloodletting Fake prank fire extinguishers Stair kayaking Replying to
spammers Cutting pizza in squares Project Orion [Center (neutral):] Soup [Bottom
left quadrant (sounds like a good idea, actually a good idea):] Combo washer
dryers Cutting sandwiches diagonally Toasting sandwiches Sliced bread Pizza
Wheels on luggage Heat pumps [Bottom middle (actually a good idea):] Eating
citrus fruit while at sea [Bottom right quadrant (sounds like a bad idea,
actually a good idea):] Diverging diamond interchanges Crumple zones Putting
mold on infections Laser eye surgery Fecal transplants


TRIVIA

 * A much leaner version of this comic appeared in the first "What If?" book,
   chapter "Weird (and Worrying) Questions from the What If? Inbox, #9".




Is this out of date? Clicking here will fix that.


NEW HERE?

LAST 7 DAYS (TOP 10)

RankScorePagesChangesUsername 1 46 40 48 Psychoticpotato 2 30 27 29 TheusafBOT 3
25 12 54 Unknown so shut up 4 25 15 38 Asdf 5 19 15 19 Apollo11 6 15 5 30
Elektrizikekswerk 7 10 3 14 Paintadot 8 7 7 7 B for brain 9 7 1 9 Mtcv 10 4 4 4
Certified nqh

Lots of people contribute to make this wiki a success. Many of the recent
contributors, listed above, have just joined. You can do it too! Create your
account here.

You can read a brief introduction about this wiki at explain xkcd. Feel free to
sign up for an account and contribute to the wiki! We need explanations for
comics, characters, themes and everything in between. If it is referenced in an
xkcd web comic, it should be here.

 * If you're new to wiki editing, see the explain xkcd:Editor FAQ for a specific
   guidance to this Wiki and the more general help on how to edit wiki pages.
   There's also a handy wikicode cheatsheet.

 * Discussion about the wiki itself happens at the Community portal.

 * You can browse the comics from List of all comics or by navigating the
   category tree at Category:Comics.

 * There are incomplete explanations listed here. Feel free to help out by
   expanding them!


RULES

Don't be a jerk!

There are a lot of comics that don't have set-in-stone explanations; feel free
to put multiple interpretations in the wiki page for each comic.

If you want to talk about a specific comic, use its discussion page.

Please only submit material directly related to (and helping everyone better
understand) xkcd... and of course only submit material that can legally be
posted (and freely edited). Off-topic or other inappropriate content is subject
to removal or modification at admin discretion, and users who repeatedly post
such content will be blocked.

If you need assistance from an admin, post a message to the Admin requests
board.

Retrieved from
"https://www.explainxkcd.com/wiki/index.php?title=Main_Page&oldid=339844"
Categories:
 * Pages with ignored display titles
 * Links to xkcd.com
 * Pages using the "citation needed" template
 * Charts
 * Scatter plots
 * Rankings
 * Food
 * Root category




NAVIGATION MENU


PERSONAL TOOLS

 * Not logged in
 * Talk
 * Contributions
 * Create account
 * Log in


NAMESPACES

 * Main page
 * Discussion


VARIANTS




VIEWS

 * Read
 * View source
 * View history


MORE




SEARCH




NAVIGATION

 * Main page
 * Latest comic
 * Community portal
 * xkcd.com
 * Recent changes
 * Random page
 * All comics
 * Browse comics
 * RSS feed
 * Help


TOOLS

 * What links here
 * Related changes
 * Special pages
 * Printable version
 * Permanent link
 * Page information




ADS


 * This page was last edited on 17 April 2024, at 07:50.

 * Privacy policy
 * About explain xkcd
 * Disclaimers

 *