3085: About 20 Pounds - Revision history

81.179.199.253: /* How black holes actually work */ Black holes isn't (necessarily) the dark matter. Though note that as we don't know that much at all about how dark matter works (even assuming it does, and it's not something else), I think there's better ways to say it

2026-05-20T21:18:47Z

‎How black holes actually work: Black holes isn't (necessarily) the dark matter. Though note that as we don't know that much at all about how dark matter works (even assuming it does, and it's not something else), I think there's better ways to say it

GSLikesCats307 at 16:12, 20 May 2026

2026-05-20T16:12:23Z

GSLikesCats307 at 16:01, 20 May 2026

2026-05-20T16:01:50Z

Jkshapiro: /* Explanation */ Removing irrelevant material about LLMs

2026-04-16T03:12:45Z

‎Explanation: Removing irrelevant material about LLMs

TheErgster: trimmed explination by deleting a few unecesary paragraphs

2025-11-13T14:55:14Z

trimmed explination by deleting a few unecesary paragraphs

FaviFake: /* Explanation */ it realy should

2025-09-24T15:56:01Z

‎Explanation: it realy should

2.50.0.22: /* Explanation */

2025-09-24T05:25:24Z

‎Explanation

149.71.230.64: /* Explanation */ Added wikipedia link for unsolved problems in Physics.

2025-09-15T11:53:00Z

‎Explanation: Added wikipedia link for unsolved problems in Physics.

47.153.194.249: Changed pentacle to pentagram. A pentacle is a pentagram inside a circle. There is no such circle in this comic.

2025-09-13T15:59:31Z

Changed pentacle to pentagram. A pentacle is a pentagram inside a circle. There is no such circle in this comic.

82.132.238.27: Undo revision 386260 by BobcatInABox (talk) The removed caveat still applies, and "roughly 9" implies far more unit-precision than might be inherited from the "about twenty" range.

2025-09-09T14:00:25Z

Undo revision 386260 by BobcatInABox (talk) The removed caveat still applies, and "roughly 9" implies far more unit-precision than might be inherited from the "about twenty" range.

@@ Line 22: / Line 22: @@
 In [[2035: Dark Matter Candidates]] these 20 lb dark matter particles fit between magic 8 balls and space cows.  The squirrels that make up [[2186: Dark Matter]] near the earth must be pretty chunky. Talking to a floating sphere is becoming [[:Category:Time traveling Sphere|a returning subject in xkcd]].
-==How black holes actually work==
+==How dark matter actually works==
 In general, not all forces interact with all particles; indeed, {{w|gravity}} is believed to be the only force that interacts with everything we have observed. If a force doesn't interact with a particle, then the particle's existence cannot be directly observed via disturbances in that force. In particular, something that doesn't interact with electromagnetism cannot be 'seen', as photons will pass through it relatively unaffected, and likewise cannot be felt, because collision is a side effect of the {{w|Pauli exclusion principle}}.

@@ Line 10: / Line 10: @@
 ==Explanation==
-{{incomplete|
+{{incomplete|the comic has been divided. However, the Dark Matter explanation section is somewhat chunky}}
-*'''The article might be off-topic'''. We should focus on explaining the comic. If this is solved, remove this notice.
+The nature of {{w|dark matter}} is a significant {{w|List of unsolved problems in physics|unsolved problem in physics}}. We observe that galaxies spin faster than we expect based on the nearby observable matter.  Also, Galaxies seemed more clumped than are supposed to be only observing the normal matter, and this has led to physicists to believe there is non-visible mass that is clumping the galaxies together.  Dark matter is the name we give to this mass.  In the comic, [[Cueball]] and [[Ponytail]] consult an {{w|oracle}}-envisioned as a small black ball- to learn about dark matter, & solve these problems.  The oracle responds by saying that Dark Matter is a particle, weighing about 20 pounds - So not any way near as grand as expected.
-*It should be divided into one or more sections.}}
+So, mission solved, the scientists ask the oracle what they are to do, given how they now know what it is, and cannot proceed further. The oracle then suggests they get {{w|burritos}}, taking the [[1269|Beret Guy view on things]]-if all goes wrong, at least there's still burritos.
 The pentagram and candles suggest that the oracle is supernatural, summoned by an occult ritual; something which would present its own challenges to our understanding of the physical world.  There may be a pun here, in that they may be using 'dark magic' to communicate with something from the 'dark realm' on the assumption that it will know about dark matter. However, the word 'dark' in dark matter simply means that we do not know how to observe it; we have no evidence that dark matter is evil or satanic, though [[Randall]] may consider it [[:Category:Comics with cursed items|cursed]].
 In general, not all forces interact with all particles; indeed, {{w|gravity}} is believed to be the only force that interacts with everything we have observed. If a force doesn't interact with a particle, then the particle's existence cannot be directly observed via disturbances in that force. In particular, something that doesn't interact with electromagnetism cannot be 'seen', as photons will pass through it relatively unaffected, and likewise cannot be felt, because collision is a side effect of the {{w|Pauli exclusion principle}}.
@@ Line 30: / Line 36: @@
 Despite all this, twenty pounds is also much too ''small'' to be detectable via gravitational interaction; its {{w|Perturbation (astronomy)|influence on the orbits of planets}}, say, or the strength of its {{w|gravitational lensing}} effect, would be entirely negligible. In the scenario posed by the comic, then, there is no plausible way to observe more about dark matter while on Earth. Even if we did find some such particles naturally occurring, and had instruments that could measure such small gravitational forces, since it would interact only via gravity, the only properties it could have other than mass would be its decay rates from other particles. Which, again, would all be essentially nil, due to its mass<!-- except that because 10kg is roughly a billion Planck masses, the particle must decay by collapsing into a black hole and then exploding in a burst of 10²²K Hawking radiation-->.
 ==Transcript==

@@ Line 14: / Line 14: @@
 *It should be divided into one or more sections.}}
-The nature of {{w|dark matter}} is a significant {{w|List of unsolved problems in physics|unsolved problem in physics}}. We observe that galaxies spin faster than we expect based on the nearby observable matter.  Also, Galaxies seemed more clumped than are supposed to be only observing the normal matter, and this has led to physicists to believe there is non-visible mass that is clumping the galaxies together.  Dark matter is the name we give to this mass.  In the comic, [[Cueball]] and [[Ponytail]] consult an {{w|oracle}} to learn about dark matter.
+The nature of {{w|dark matter}} is a significant {{w|List of unsolved problems in physics|unsolved problem in physics}}. We observe that galaxies spin faster than we expect based on the nearby observable matter.  Also, Galaxies seemed more clumped than are supposed to be only observing the normal matter, and this has led to physicists to believe there is non-visible mass that is clumping the galaxies together.  Dark matter is the name we give to this mass.  In the comic, [[Cueball]] and [[Ponytail]] consult an {{w|oracle}}-envisioned as a small black ball- to learn about dark matter, & solve these problems.
 The pentagram and candles suggest that the oracle is supernatural, summoned by an occult ritual; something which would present its own challenges to our understanding of the physical world.  There may be a pun here, in that they may be using 'dark magic' to communicate with something from the 'dark realm' on the assumption that it will know about dark matter. However, the word 'dark' in dark matter simply means that we do not know how to observe it; we have no evidence that dark matter is evil or satanic, though [[Randall]] may consider it [[:Category:Comics with cursed items|cursed]].

@@ Line 16: / Line 16: @@
 The nature of {{w|dark matter}} is a significant {{w|List of unsolved problems in physics|unsolved problem in physics}}. We observe that galaxies spin faster than we expect based on the nearby observable matter.  Also, Galaxies seemed more clumped than are supposed to be only observing the normal matter, and this has led to physicists to believe there is non-visible mass that is clumping the galaxies together.  Dark matter is the name we give to this mass.  In the comic, [[Cueball]] and [[Ponytail]] consult an {{w|oracle}} to learn about dark matter.
-The pentagram and candles suggest that the oracle is supernatural, summoned by an occult ritual; something which would present its own challenges to our understanding of the physical world.  There may be a pun here, in that they may be using 'dark magic' to communicate with something from the 'dark realm' on the assumption that it will know about dark matter. However, the word 'dark' in dark matter simply means that we do not know how to observe it; we have no evidence that dark matter is evil or satanic, though [[Randall]] may consider it [[:Category:Comics with cursed items|cursed]]. The oracle is used very similarly to how people have been using and customizing {{w|large language model|large language models}}.
+The pentagram and candles suggest that the oracle is supernatural, summoned by an occult ritual; something which would present its own challenges to our understanding of the physical world.  There may be a pun here, in that they may be using 'dark magic' to communicate with something from the 'dark realm' on the assumption that it will know about dark matter. However, the word 'dark' in dark matter simply means that we do not know how to observe it; we have no evidence that dark matter is evil or satanic, though [[Randall]] may consider it [[:Category:Comics with cursed items|cursed]].
 In general, not all forces interact with all particles; indeed, {{w|gravity}} is believed to be the only force that interacts with everything we have observed. If a force doesn't interact with a particle, then the particle's existence cannot be directly observed via disturbances in that force. In particular, something that doesn't interact with electromagnetism cannot be 'seen', as photons will pass through it relatively unaffected, and likewise cannot be felt, because collision is a side effect of the {{w|Pauli exclusion principle}}.

← Older revision		Revision as of 14:55, 13 November 2025
Line 22:		Line 22:
	Even {{w\|neutrino}}s, famous for {{what if\|73\|interacting with ''almost'' nothing}}, still interact via the {{w\|weak force}}, allowing them to be detected with sufficiently large tanks of dense material. This is the main reason neutrinos cannot be dark matter: they interact far too much to be a viable option. A particle that interacts with ''nothing'' except gravity could only be detected by a {{w\|LIGO\|gravitational telescope}}.		Even {{w\|neutrino}}s, famous for {{what if\|73\|interacting with ''almost'' nothing}}, still interact via the {{w\|weak force}}, allowing them to be detected with sufficiently large tanks of dense material. This is the main reason neutrinos cannot be dark matter: they interact far too much to be a viable option. A particle that interacts with ''nothing'' except gravity could only be detected by a {{w\|LIGO\|gravitational telescope}}.

−	We can theorise the presence of dark matter thanks to how ''something'' interacts with the matter we can see, i.e. the nature of the rotation of far away galaxies implies significant additional mass that does not emit, absorb, reflect ''or'' diffuse light. While there are also other theories which try to account for what we do see, a number of the suggestions are that it is one or other form of unseeable but gravitationally-interactive substance, given the soubriquet of "dark matter".
−
−	In trying to determine what form this actually exists in, and on the assumption that if it exists at all then it is also drifting past (and through) our own neighbourhood, experiments here on Earth are trying to detect it using any other means. For example, a popular dark matter candidate is a {{w\|weakly interacting massive particle}}, which interacts via the {{w\|weak nuclear force}}. Dark matter experiments build large tanks of liquid xenon with a gaseous top, keep them extremely dark, and look for some way in which passing particles might interact and produce electroluminescent scintillations. There are good theoretical reasons to expect some interaction, which would mean the oracle in the comic is lying, but there are no sufficiently conclusive results as of now.

	There is one dark matter candidate where the only interaction is overwhelmingly gravitational: black holes formed through collapse in the early Universe. These {{w\|primordial black holes}} may not be detectable through any terrestrial experiment. However, even these objects can be found through their lensing effects if they are sufficiently large and common to account for the 'missing mass' we are looking for. Black holes of around 10 kg would also likely quickly evaporate through Hawking radiation, so are not a good dark matter candidate. Black holes of around asteroid mass would be extremely hard to detect and are a good dark matter candidate given current information.		There is one dark matter candidate where the only interaction is overwhelmingly gravitational: black holes formed through collapse in the early Universe. These {{w\|primordial black holes}} may not be detectable through any terrestrial experiment. However, even these objects can be found through their lensing effects if they are sufficiently large and common to account for the 'missing mass' we are looking for. Black holes of around 10 kg would also likely quickly evaporate through Hawking radiation, so are not a good dark matter candidate. Black holes of around asteroid mass would be extremely hard to detect and are a good dark matter candidate given current information.

@@ Line 18: / Line 18: @@
 The nature of {{w|dark matter}} is a significant unsolved problem in physics. We observe that galaxies spin faster than we expect based on the nearby observable matter.  Also, Galaxies seemed more clumped than are supposed to be only observing the normal matter, and this has led to physicists to believe there is non-visible mass that is clumping the galaxies together.  Dark matter is the name we give to this mass.  In the comic, [[Cueball]] and [[Ponytail]] consult an {{w|oracle}} to learn about dark matter.
-The pentacle and candles suggest that the oracle is supernatural, summoned by an occult ritual; something which would present its own challenges to our understanding of the physical world.  There may be a pun here, in that they may be using 'dark magic' to communicate with something from the 'dark realm' on the assumption that it will know about dark matter. However, the word 'dark' in dark matter simply means that we do not know how to observe it; we have no evidence that dark matter is evil or satanic, though [[Randall]] may consider it [[:Category:Comics with cursed items|cursed]]. The oracle is used very similarly to how people have been using and customizing {{w|large language model|large language models}}.
+The pentagram and candles suggest that the oracle is supernatural, summoned by an occult ritual; something which would present its own challenges to our understanding of the physical world.  There may be a pun here, in that they may be using 'dark magic' to communicate with something from the 'dark realm' on the assumption that it will know about dark matter. However, the word 'dark' in dark matter simply means that we do not know how to observe it; we have no evidence that dark matter is evil or satanic, though [[Randall]] may consider it [[:Category:Comics with cursed items|cursed]]. The oracle is used very similarly to how people have been using and customizing {{w|large language model|large language models}}.
 In general, not all forces interact with all particles; indeed, {{w|gravity}} is believed to be the only force that interacts with everything we have observed. If a force doesn't interact with a particle, then the particle's existence cannot be directly observed via disturbances in that force. In particular, something that doesn't interact with electromagnetism cannot be 'seen', as photons will pass through it relatively unaffected, and likewise cannot be felt, because collision is a side effect of the {{w|Pauli exclusion principle}}.

@@ Line 30: / Line 30: @@
 There is one dark matter candidate where the only interaction is overwhelmingly gravitational: black holes formed through collapse in the early Universe. These {{w|primordial black holes}} may not be detectable through any terrestrial experiment. However, even these objects can be found through their lensing effects if they are sufficiently large and common to account for the 'missing mass' we are looking for. Black holes of around 10 kg would also likely quickly evaporate through Hawking radiation, so are not a good dark matter candidate. Black holes of around asteroid mass would be extremely hard to detect and are a good dark matter candidate given current information.
-The particle's mass is described vaguely as ''about twenty pounds'', roughly nine kilograms, in line with how all-knowing oracles legendarily use ambiguous statements. This is a ludicrous amount of energy for particle physics. Any interaction would have to involve an equally ludicrous amount of other particle mass being in exactly the right place and time, a coincidence that might be so rare that one would not expect it to occur ever in the history of the universe. By comparison, the {{w|top quark|heaviest single particle}} we have observed, with a mass over a hundred times that of the proton, is around a tenth of a trillionth<!-- short scale "trillion", right? ...as if that matters much here --> of a trillionth of a pound.
+The particle's mass is described vaguely as ''about twenty pounds'', roughly 10 kilograms<!-- anywhere near 22 is feasibly "about 20", so editors needn't try to add false precision to either side of this comparison -->, in line with how all-knowing oracles legendarily use ambiguous statements. This is a ludicrous amount of energy for particle physics. Any interaction would have to involve an equally ludicrous amount of other particle mass being in exactly the right place and time, a coincidence that might be so rare that one would not expect it to occur ever in the history of the universe. By comparison, the {{w|top quark|heaviest single particle}} we have observed, with a mass over a hundred times that of the proton, is around a tenth of a trillionth<!-- short scale "trillion", right? ...as if that matters much here --> of a trillionth of a pound.
 Under more normal circumstances, we might still hope to observe the properties of the particle via creating it ourselves under controlled laboratory conditions. But again, there is no reasonable way to focus the energy required into a single particle interaction. The {{w|Large Hadron Collider|most powerful particle accelerator in the world}}, for example, peaks at about ten thousand times the mass of the proton (a solid billion times less energy than required) so it's out too. 20 pounds is about 2.6e36 eV which is way over any accelerator could achieve in the foreseeable future.