3158: Shielding Chart - Revision history

FaviFake: From the [[explain xkcd:Editor FAQ#citation|Editor FAQ § [Citation needed]:]] "This template should only be placed when there is a deeper sense of humor and should not be overused."

2026-05-25T18:54:15Z

From the Editor FAQ § [Citation needed]: "This template should only be placed when there is a deeper sense of humor and should not be overused."

2603:6011:1F0:2A40:40CE:4E81:F3D4:9FA9: /* Explanation */

2026-05-18T01:46:55Z

‎Explanation

70.61.237.182: Capitalization

2026-05-16T16:36:29Z

Capitalization

70.61.237.182: Some of others not space

2026-05-16T16:34:28Z

Some of others not space

70.61.237.182: Various fixes

2026-05-16T16:32:43Z

Various fixes

70.61.237.182: Heat glass danger

2026-05-16T16:27:05Z

Heat glass danger

70.61.237.182: /* Table */

2026-05-16T16:24:13Z

‎Table

70.61.237.182: Air technical fix

2026-05-16T16:23:36Z

Air technical fix

70.61.237.182: /* Table */

2026-05-16T16:11:36Z

‎Table

FaviFake: /* Transcript */

2026-04-04T12:30:38Z

‎Transcript

@@ Line 90: / Line 90: @@
 | style="background:#FFF978;"|Air can be a fairly effective thermal insulator when constrained, as in {{w|aerogels}} and many types of insulation. However, freely moving air as depicted in this panel flows as it heats up, transferring heat from the campfire to Cueball's marshmallow. Additionally, air does little to block thermal radiation from the heat source.
 | style="background:#FFF978;"|Lead conducts heat, allowing Cueball to toast a marshmallow on the surface of the shield.  However, since lead is poisonous, he should not do this.
-| style="background:#FFF978;"|Heat will raise the temperature of water. If the temperature is raised high enough the water will start to boil; boiling has long been used by humanity to prepare food. Marshmallows however are not meant to be boiled.{{Citation Needed}}
+| style="background:#FFF978;"|Heat will raise the temperature of water. If the temperature is raised high enough the water will start to boil; boiling has long been used by humanity to prepare food. Marshmallows however are not meant to be boiled.
 | style="background:#FFF978;"|Cueball appears to be holding a glass bottle over an open fire, into which he has presumably placed his marshmallows. Depending on the temperature, the type of glass, and its thickness, it is possible to heat the contents of a glass container this way, but if the container is unsuitable this can be dangerous to the user, because the glass may abruptly shatter. Also, it is unclear how he proposes to consume the sticky marshmallow mess this would create.
 | style="background:#DDDCB2;"|The lack of matter in a vacuum completely blocks transmission by conduction and convection, the two main ways in which heat is spread. It still allows transmission by radiation, which is less efficient. For the specific example of the thermos shown in the image, the way they are constructed completely blocks radiation, but there are enough residual air particles for a very slow convection. The fact that the shielding is made from one single (very thin) piece, and it has lips, also allows some conduction.

@@ Line 90: / Line 90: @@
 | style="background:#FFF978;"|Air can be a fairly effective thermal insulator when constrained, as in {{w|aerogels}} and many types of insulation. However, freely moving air as depicted in this panel flows as it heats up, transferring heat from the campfire to Cueball's marshmallow. Additionally, air does little to block thermal radiation from the heat source.
 | style="background:#FFF978;"|Lead conducts heat, allowing Cueball to toast a marshmallow on the surface of the shield.  However, since lead is poisonous, he should not do this.
-| style="background:#FFF978;"|Heat will raise the temperature of water. If the temperature is raised high enough the water will start to boil; boiling has long been used by humanity to prepare food. Marshmallows however are not meant to be boiled.
+| style="background:#FFF978;"|Heat will raise the temperature of water. If the temperature is raised high enough the water will start to boil; boiling has long been used by humanity to prepare food. Marshmallows however are not meant to be boiled.{{Citation Needed}}
 | style="background:#FFF978;"|Cueball appears to be holding a glass bottle over an open fire, into which he has presumably placed his marshmallows. Depending on the temperature, the type of glass, and its thickness, it is possible to heat the contents of a glass container this way, but if the container is unsuitable this can be dangerous to the user, because the glass may abruptly shatter. Also, it is unclear how he proposes to consume the sticky marshmallow mess this would create.
 | style="background:#DDDCB2;"|The lack of matter in a vacuum completely blocks transmission by conduction and convection, the two main ways in which heat is spread. It still allows transmission by radiation, which is less efficient. For the specific example of the thermos shown in the image, the way they are constructed completely blocks radiation, but there are enough residual air particles for a very slow convection. The fact that the shielding is made from one single (very thin) piece, and it has lips, also allows some conduction.

@@ Line 143: / Line 143: @@
 | style="background:#C4C5C7;"|Glass will effectively protect you against sharks, provided that it is thick enough. In fact, sharks are commonly (and safely) shown to the public in aquariums.
 | style="background:#C4C5C7;"|In the vacuum of space, Cueball is very far from sharks' ocean habitat (though he may be at risk of [https://www.youtube.com/watch?v=y5xcvAoKojo dolphins]).
-| style="background:#FFF978;"|Although shark-shaped Oven mitts are quite common due to their similar appearance, oven mitts are not very effective at stopping sharks.{{cn}}
+| style="background:#FFF978;"|Although shark-shaped oven mitts are quite common due to their similar appearance, oven mitts are not very effective at stopping sharks.{{cn}}
 | style="background:#DDDCB2;"|Depending on the design of the armor, a shark might be able to permanently deform it enough that it causes injury, though the more flexible {{w|Chain_mail#Practical_uses|chain mail}} ''is'' successfully used to prevent actual piercing damage from bites.
 | style="background:#FFF978;"|A biohazard suit is weak enough that a shark can rip through it.

@@ Line 134: / Line 134: @@
 | style="background:#FFF978;"|Biohazard suits do not block radio waves, and someone wearing such a suit can send and receive radio transmissions without issue.
 | style="background:#C4C5C7;"|A {{w|Faraday cage}} is specifically designed to block electromagnetic fields such as radio waves. In fact, this is the ''only'' thing listed that it blocks.
-| style="background:#FFF978;"|The openings in a shark cage are too wide for the cage to experience the properties of a Faraday cage. Cueball again questions why a space mission requires this particular protective equipment.
+| style="background:#FFF978;"|The openings in a shark cage are too wide for the cage to experience the properties of a Faraday cage. Cueball again questions why his mission requires this particular protective equipment.
 |-

@@ Line 128: / Line 128: @@
 | style="background:#C4C5C7;"|Although lead is a relatively poor conductor and therefore attenuates radio waves less than most metals, a lead enclosure can still work as a Faraday cage with a sufficiently thick layer of lead.
 | style="background:#C4C5C7;"|Radio waves from two-way radios, like the kind shown in the comic, {{w|Radio propagation#Direct modes (line-of-sight)|cannot penetrate deep water}}. There are {{w|Radio propagation#Surface modes (groundwave)|radio frequencies that ''can'' penetrate deep water}}, but these have a much lower frequency, require more powerful transmitters, and (in the case of {{w|Extremely low frequency#Difficulties of ELF communication|extremely low frequencies}}) cannot transmit audio.
-| style="background:#FFF978;"|In a similar way that glass is transparent to visual light, it is also transparent to radio waves, allowing them to pass through. It is also in this frame that cueball begins to have doubts about whether being put in a glass case is part of his mission.
+| style="background:#FFF978;"|In a similar way that glass is transparent to visual light, it is also transparent to radio waves, allowing them to pass through. It is also in this frame that Cueball begins to have doubts about whether being put in a glass case is part of his mission.
 | style="background:#FFF978;"|As there is nothing getting in the way of radio waves in a vacuum, radios work very well in space. This allows ground control to communicate with astronauts in space.
 | style="background:#FFF978;"|Oven mitts, typically being made of fabric, have no effect on radio waves.
 | style="background:#C4C5C7;"|A metal suit of armor blocks radio waves. This is because metals are very good electrical conductors, which block the radio waves.
 | style="background:#FFF978;"|Biohazard suits do not block radio waves, and someone wearing such a suit can send and receive radio transmissions without issue.
-| style="background:#C4C5C7;"|A {{w|Faraday cage}} is specifically designed to block electromagnetic fields such as radio waves. In fact, this is the ''only'' 'hazard' here that it blocks.
+| style="background:#C4C5C7;"|A {{w|Faraday cage}} is specifically designed to block electromagnetic fields such as radio waves. In fact, this is the ''only'' thing listed that it blocks.
-| style="background:#FFF978;"|The openings in a shark cage are too wide for the cage to experience the properties of a Faraday cage.
+| style="background:#FFF978;"|The openings in a shark cage are too wide for the cage to experience the properties of a Faraday cage. Cueball again questions why a space mission requires this particular protective equipment.
 |-

@@ Line 51: / Line 51: @@
 |-
 ! scope="row"| {{w|Neutrons}}
-| style="background:#FFF978;"|Neutrons are not stopped by low density materials such as air.
+| style="background:#FFF978;"|Neutrons are not stopped by low-density materials such as air.
 | style="background:#DDDCB2;"|Lead's high density means that neutrons will keep bumping into lead nuclei, losing their energy through inelastic scattering. However since lead nuclei are much heavier than neutrons, most of the energy will remain with the neutron; as a result, many collisions are needed to slow the neutrons. Some neutrons will also be absorbed by the nuclei, although the {{w|Cross section (physics)|cross section}} is rather low.
 | style="background:#C4C5C7;"|Since protons and neutrons have almost the same mass, a collision with a hydrogen atom in water will result in the neutron losing almost half of its energy, resulting in a very rapid attenuation. Moreover the cross section for the fusion of neutrons and protons is high, leading to most neutrons being captured to form deuterium.

@@ Line 100: / Line 100: @@
 |-
 ! scope="row"| {{w|Swords}}
-| style="background:#FFF978;"|Air has a negligible force against objects and is unable to stop Megan's sword's thrust.
+| style="background:#FFF978;"|Air exerts negligible force against objects of such high density at low speed, and cannot stop Megan's sword's thrust.
 | style="background:#C4C5C7;"|Lead is a heavy and dense metal, and as a result, it can stop blows from a sword.
 | style="background:#FFF978;"|While water has a greater force than air against objects, it is still not enough to stop Megan's attack.

@@ Line 71: / Line 71: @@
 | style="background:#FFF978;"|Because a lack of air does not impact the travel of light, it reaches Cueball without issue.
 | style="background:#C4C5C7;"|Cueball is able to use the opaque oven mitts to cover the light source, successfully preventing the light from reaching him.
-| style="background:#C4C5C7;"|The helmet Cueball is wearing is opaque, blocking the light from reaching him. It also makes this a fairly useless set of armor.
+| style="background:#C4C5C7;"|The helmet Cueball is wearing, except the eye slit, is opaque, blocking the light from reaching him.
 | style="background:#C4C5C7;"|As with the oven mitts, Hairy uses the helmet part of the biohazard suit to block the light source.
 |colspan=2; style="background:#FFF978;"|As both types of cages have holes in them, it is easy for the light to pass through the holes and reach Cueball.

@@ Line 151: / Line 151: @@
 ==Transcript==
-{{incomplete transcript|Don't remove this notice too soon.}}
+{{incomplete transcript|Check if it's complete.}}
 :[The whole comic is in one panel]
 :[A 10x10 matrix sits in the middle with rows labelled as follows:]