Editing 1621: Fixion

This comic was released on {{w|Christmas}} day as a present from [[Randall]] to all {{w|physicists}}. It introduces a new particle, the ''Fixion'', which explains everything. The word "Fixion" can be read as a pun: Either it can mean something like "fix-i-on," with "[https://en.wiktionary.org/wiki/-on#Suffix -on]" being a suffix for many particles, and this particle being able to "fix" things. Coincidentally it's also very similar to the word "fiction" aptly describing its wish fulfilment nature.

In physics, there are still many {{w|List of unsolved problems in physics|big questions and mysteries}}. There are many phenomena which don't seem to fit, and we don't know how to explain yet. The "Fixion" is satirically presented as a particle which acts as a {{w|Deus ex machina}}, (see also {{tvtropes|DeusExMachina|tvtropes}}), which solves all of these mysteries without any serious fundamental reasons.

The style of the chart suggests a {{w|Feynman diagram}} - an easy way of drawing particle interactions. Every time there is an interaction, the main central Fixion-line changes direction. Typically, {{w|fermions}} (the "solid" particles like {{w|electrons}} and {{w|quarks}}) are shown with solid lines, {{w|photons}} (and generally the weak-force-carrying {{w|bosons}}) are shown with wavy lines, {{w|gluons}} with spiraling lines and other mediating particles (such as {{w|pions}} in the {{w|nuclear force}}, or the {{w|Higgs boson}}) with a dotted line. Randall obeys these rules only very loosely, which makes sense - many of the things involved in this Feynman diagram are either so theoretical that they have no widely used standard representation, or would never appear in a sensible diagram (spacecraft, for instance). All mentioned types of lines - and even more types - are presented in the diagram. All that the Fixion does is described in the [[#Table of Phenomena|table below]].

|| Our best measurements of the universe predict that visible matter is only about one-twentieth of the matter in the universe; the remaining matter is "{{w|dark matter}}" that cannot be seen. The leading candidates for dark matter are {{w|weakly interacting massive particles}} (WIMPs). These would be new, undiscovered forms of matter which barely interact except through gravity and thus give off little or no light. Some of the dark matter is likely made up of {{w|Massive compact halo objects}} (MACHOs); effectively dead stars too dim to see. MACHOs are probably only a minority of the dark matter, however. Studies of two colliding galaxy clusters suggest that dark matter can pass through other matter without slowing down, unlike ordinary matter. Moreover, calculations of the elements produced during the {{w|big bang}} - which match the observed distribution of elements in the universe very precisely - don't leave room for enough additional {{w|protons}} and {{w|neutrons}} to form the dark matter.

|| {{w|Quark confinement}} means that we never see particles with {{w|color charge}} (i.e. {{w|quark}}s and {{w|gluon}}s) on their own. They only exist in groups that cancel out the color charge. Try to separate the groups, and the energy you add will instead cause new particles to pop into existence. Quarks are also referenced in  [[474: Turn-On]], [[1418: Horse]] and in [[1731: Wrong]].

|| {{w|Magnetic monopoles}} (e.g., a north charge without a south charge) should exist according to many {{w|Grand Unified Theory|grand unified theories}} (GUTs) and {{w|String theory|string theories}}, but none have ever been seen.

|| The universe today is made almost entirely of matter. {{w|Antimatter}} and matter are identical, except that the charges are opposite. Antimatter and matter "{{w|Annihilation|annihilate}}" when they come into contact. So why is the universe made of matter? Why didn't the universe have equal amounts of both, and if it did, why didn't it annihilate itself immediately? This is a big question in physics today. The Fixion would explain this by its ability to suppress the formation of antimatter in the early universe. Antimatter is also referenced in [[683: Science Montage]], [[826: Guest Week: Zach Weiner (SMBC)]],  and [[1731: Wrong]] as well as being the subject of the ''[[what if? (blog)|what if?]]'' article ''{{what if|114|Antimatter}}''. It was also mentioned in another ''what if?'': ''{{what if|79|Lake Tea}}''.  

|| Two arrows points to two dotted lines going out left and downwards below the first solid line. It is thus two mediating particles that go out from the Fixion.

|| Many GUTs predict that {{w|proton decay|protons will decay}}, but experiments have shown the proton to have a half-life of at least 10³³ years - very much longer than the {{w|age of the universe}} (1.38x10¹⁰ years).

|| Two arrows point to four wavy lines. The waves of the lines have different wavelength. The one line coming out left is of the same wavelength as the top of the three coming out right. The two below each decrease in wavelength compared to the one before them. Maybe this is not meant to represent photon-like particles, but are just different frequencies of microwaves from the microwave oven – thus relating to the subject.

|| {{w|Fast radio burst}}s (FRBs) are unexplained bursts of radio-frequency energy from space, that could even be extragalactic signals, with speculations that they might be signs of {{w|extraterrestrial intelligence}}. {{w|Peryton (astronomy)|Perytons}} are things that ''look like'' FRBs, but come from Earth (specifically, from the {{w|microwave oven}} at {{w|Parkes Observatory}} [https://arxiv.org/abs/1504.02165]). Randall's Fixion makes some perytons change frequency distribution so they appear to come from space; thus meaning all FRBs come from microwave ovens.

|| A {{w|naked singularity}} is like a black hole without an {{w|event horizon}}. So far no naked singularity has been observed (except, arguably, the big bang) and the {{w|cosmic censorship hypothesis}} suggests they can't exist, although some people have suggested ways of making them. Randall has mentioned these in the ''[[what if? (blog)|what if?]]'' article ''[https://what-if.xkcd.com/140/ Proton Earth, Electron Moon]''.

|| This refers to the {{w|flyby anomaly}} which is sometimes (but not always, one in three {{w|Flyby_anomaly#Observations|according to Wikipedia}}) seen when spacecraft fly close to Earth, where they pick up more speed than expected. It's not always seen – for instance the {{w|Rosetta (spacecraft)|Rosetta}} space probe which had an anomaly when passing Earth the first time had no flyby anomaly the next two times it passed Earth like this. Two other probes have shown similar anomalies, but the probe depicted (the same on both sides of the Fixion) looks like Rosetta, the other two don't look like this. Also  Randall has depicted Rosetta before in [[1446: Landing]]. (Previously another anomaly for space probes, a deceleration this time known as the {{w|Pioneer Anomaly}}, has been mentioned in the title text of [[502: Dark Flow]]).

|| Recently (2014), several {{w|sinkholes}} opened up in {{w|Yamal_Peninsula#Yamal_craters |remote parts}} of Siberia. The explanation is currently unknown.

|| Refers to the {{w|faster-than-light neutrino anomaly}}, where it seemed that a neutrino beam from {{w|CERN}} on the France/Switzerland border to the {{w|OPERA experiment}} in Italy traveled faster than light. Scientists were not able to reproduce the result. This Neutrino experiment was also mentioned in [[955: Neutrinos]].

|| Sigma (σ) refers to the {{w|standard deviation}} - a mathematical measure of how much an observed value differs from the expected value. For a formal scientific discovery in particle physics, the standard is 5 sigma which means that there is about a 1 in 3.5 million chance that the results were caused by random errors (of course, they could be caused by ''systematic'' errors, such as measurement problems). Some tantalizing experiments have found interesting results at 3 or 4 sigma but either can't reach 5 sigma or {{w|Oops-Leon|are subsequently dis-proven}}. The question is, does the way the Fixion works here in this comic push the sigma value one way or the other? Does it suppress the value so it goes below or above the level of significance? Is it artificially pushed in the direction so a result seems like it is significant when it is not (see for instance [[882: Significant]]), or is it the other way around so that some experiments, which could have found what the experimenters wanted to find, did not because the sigma has been artificially lowered below the proof threshold? Either way it is a very annoying fact of the Fixion, but it would explain a lot, and probably also make it very hard to find the Fixion because of this intrinsic behavior.|| N/A

|| This is a continuation of the joke already mentioned above regarding fast radio bursts (FRBs) and perytons. GUTs normally predict that all the forces we see are the different low-energy versions of a single force which can only be seen at extremely high energies (much higher than any Earth-based collider could produce). A high-energy FRB would be a {{w|gamma ray burst}} and if it came from a close enough object, would obliterate all life on the hemisphere of Earth facing the burst. It would also wreck the sensitive electronics at Parkes Observatory. This "high energy unification" is stated in a way reminiscent of the unification of electromagnetic and weak forces at high energies; but unlike the latter, it involves two things only "appearing" (or, in this case, not appearing) to be the same, not actually becoming the same.