Editing 1621: Fixion

{{comic
| number    = 1621
| date      = December 25, 2015
| title     = Fixion
| image     = fixion.png
| titletext = My theory predicts that, at high enough energies, FRBs and perytons become indistinguishable because the detector burns out.
}}

==Explanation==
The second [[:Category:Christmas|Christmas comic]] in a row, the first being [[1620: Christmas Settings]].

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; or it means "fiction".

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 [http://tvtropes.org/pmwiki/pmwiki.php/Main/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 (spacecrafts, 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]].

The title text is a continuation of one of the jokes already mentioned in the main comic (fourth phrase from the top to the left) about {{w|Fast radio burst}}s (FRBs) and {{w|Peryton (astronomy)|perytons}}. See explanation in the last entry in the [[#Table of Phenomena|table below]].

===Table of Phenomena===
*Below, all the phenomena mentioned in the comic (and in the title text) have been listed and described.
*The order is the top left phenomenon first, and then alternating between right and left down to the bottom and then the title text at the end.
{| border =1 width=100% cellpadding=5 class="wikitable"
|'''Phenomenon''' || '''In the comic''' || '''Description''' || '''Solved?'''
|-
| Main component of dark matter
|| An arrow points to the very first part of the main line.
|| Our best measurements of the universe predict that visible matter is only about one-sixth 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.
|| No. Proving the nature of dark matter will most likely win someone a {{w|Nobel Prize}}.
|-
| Confines quarks and gluons
|| An arrow points to the very first part of the main line.
|| {{w|Quark confinement}} means that we never see particles with {{w|colour charge|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]].
|| The basic facts of confinement are well understood, but some of the details are too complicated to tease out.
|-
| Neutralizes monopoles
|| An arrow points to the first solid line into the main line, from left and upwards. This is thus a solid particle merging with the Fixion.
|| {{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.
|| No! Despite claims that pop up in the news every year, creating a monopole-like state in the magnetic spins of a crystal is not the same as creating a real monopole.
|-
| Suppresses antimatter in early universe
|| No arrow.
|| 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?]] ''{{what if|114|Antimatter}}''. It was also mentioned in another ''what if?'': ''{{what if|79|Lake Tea}}''. 
|| Lots of theories, no conclusive evidence for any yet. The most notable theories revolve around the {{w|weak interaction}}, which has been shown to treat matter and antimatter asymmetrically. Now that the {{w|Higgs boson}} has been found, the biggest project for the {{w|Large Hadron Collider}} experiments is to try to crack this.
|-
| Spontaneously emits dark energy
|| 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 Fixon.
|| Prior to the 1990s, most {{w|cosmologists}} expected that the universe's expansion after the Big Bang would either slow down or stay constant. In 1998, cosmologists discovered that the expansion of the Universe is accelerating. Under {{w|Einstein|Einstein's}} theory of {{w|general relativity}}, the observed acceleration predicts that ordinary matter and dark matter make up about 30% of the universe's total energy, with the rest coming in the form of "{{w|dark energy}}." The nature of dark energy is not certain. However, the leading candidate is that space itself has intrinsic energy (either constant or variable), and so as space expands, the energy of the universe increases.
|| Again, Nobel Prize territory.
|-
| Mediates proton decay, but then hides it.
|| An arrow points to three lines going to and from the main line. The outer line does not connect with the main line. The three lines probably represent the 3 quarks a proton is made of, and how a proton is usually drawn in Feynman diagrams (see for example [https://en.wikipedia.org/wiki/Beta_decay#/media/File:Beta_Negative_Decay.svg Beta Negative Decay]). The diagram represents a proton decaying, mediated by the Fixion, however then recombining. Presumably the hypothetical Fixion causes protons to decay all the time, however according to the diagram the quarks recombine again which makes the process impossible to detect.
|| Many GUTs predict that {{w|proton decay|protons will decay}}, but experiments have shown the proton to have a half-life of at least 10<sup>33</sup> years - very much longer than the {{w|age of the universe}} (1.38x10<sup>10</sup> years).
|| It's not ''necessarily'' a problem. All theories predict that proton decay is a very slow process (10<sup>32+</sup> years), which is consistent with the current data.
|-
| Introduces dispersion in perytons from kitchen microwaves, explaining fast radio bursts
|| 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 at 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, they 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}}). Randall's Fixion makes some perytons change frequency distribution so they appear to come from space; thus meaning all FRBs come from microwave ovens.
|| No, but it's probably something very big - a star collapsing to a {{w|black hole}} or (as now looks likely) a {{w|magnetar}} (magnetic neutron star)
|-
| Broken symmetry causes ϴ=0, explaining unobserved neutron dipole moment
|| An arrow points to the part of the main line just before the first wavy line.
|| The {{w|neutron electric dipole moment}} is a measure of how balanced electric charge is inside the neutron. ϴ (theta) is a number in {{w|quantum chromodynamics}} (QCD) which quantifies the breaking of a type of symmetry called {{w|CP violation|CP symmetry}}. If ϴ is not 0, one result of this should be a neutron dipole moment. {{w|Symmetry breaking}} is a common explanation of effects in some areas of theoretical physics (for instance, it's an important part of {{w|Peter Higgs|Higgs'}} theory about why particles have mass), but normally it explains why a value is ''not'' zero. Presumably the Fixion would break CP symmetry independently of QCD, which would mean that ϴ can be 0 while preserving observed CP-breaking effects.
|| Again, it's not (yet) a problem - the predicted dipole moment is tiny, and we're only just reaching the point when we can measure it that accurately.
|-
| Causes alpha effect
|| No arrow.
|| The {{w|alpha effect}} is a weird effect from chemistry, where putting an "alpha" atom with a {{w|lone pair}} of electrons close to a molecule makes the molecule more likely to give up its electrons. 
|| Lots of competing explanations.
|-
| Covers naked singularities 
|| No arrow – but the text is situated next to the middle of the three wavy lines going right.
|| 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?]] article [http://what-if.xkcd.com/140/ Proton Earth, Electron Moon].
|| Not necessarily something that needs explaining - none have been seen, and most theories say they don't exist. If support grows for {{w|loop quantum gravity}}, then we might have to start really searching.
|-
| Intercepts certain gravitational waves before they're observed.
|| An arrow points to a spiraling line going upwards to the left, so this is drawn like a gluon.
|| If {{w|gravity}} behaves like {{w|Fundamental interaction|the other forces}}, it must be conveyed by waves. At the time of the comic's publication, our best detector, {{w|LIGO}} had yet to detect any {{w|gravitational waves}}, though this is probably just due to the low probability of events that would be detectable. Only extreme events like {{w|binary black hole}} mergers are detectable with the current setup. The proposed {{w|LISA Pathfinder}} spacecraft will be able to see things like orbiting black holes and {{w|neutron stars}}. 
|| In February 2016, researchers at LIGO [http://www.nytimes.com/2016/02/12/science/ligo-gravitational-waves-black-holes-einstein.html reported the detection of gravitational waves].
|-
| Causes coronal heating
|| No arrow – but the text is situated next to the middle of the three wavy lines going right.
|| For some reason the outer layer of the {{w|sun}} (the {{w|corona}}) is hotter than most reasonable theories predict. This is for instance mentioned in Randall’s new book ''[[Thing Explainer]]'' in the entry about the sun. This can also be seen on the [[Thing Explainer#Preview Pages|back cover of the book]]. 
|| It's a mystery, but it possibly has something to do with waves in the corona (for example, the {{w|High Resolution Coronal Imager}} has seen "braids" in the corona that whip around and unravel themselves).
|-
| Higgs-ish
|| As this is just a property of the Fixion there is no arrow.
|| The {{w|Higgs boson}} is a manifestation of the Higgs field... but many supersymmetry and string theories predict multiple Higgs-like particles. It's almost a prerequisite of any new theory that it has a Higgs-ish element. So the Fixion blends in with this.
|| N/A
|-
| Superluminally smooths anisotropies in early universe (but adds faint polarization for BICEP3 to find)
|| An arrow points to the point of the main line just below the bottom space probe.
|| The {{w|Cosmic Microwave Background}} (CMB) is incredibly uniform. In fact it is so uniform that the conclusion is that these areas must have been in contact at some time in the early universe. But with the universe being infinite, and the speed of light being finite, most parts of the universe will never be able to interact (any more at least). The explanation usually given for the uniformity is that the universe expanded really fast in the beginning during what is called the {{w|Inflationary epoch}}. {{w|BICEP_and_Keck_Array#BICEP2|BICEP2}} is a {{w|radio telescope}} at the South Pole whose operators claim to have seen polarization in the CMB indicative of inflation. (See [[1365: Inflation]] that references BICEP2's results). The Fixion would fix the problem since it would allow {{w|Faster-than-light|superluminal}} smoothing of the early anisotropies to explain the smoothness observed today, but also add just enough signal that the new {{w|BICEP_and_Keck_Array#BICEP3|BICEP3}} telescope would be able to find it.
|| As stated, {{w|Inflation (cosmology)|inflation}} is the standard explanation and it holds up fairly well. Other studies haven't seen the polarization that BICEP2 has - the {{w|Planck (spacecraft)|Planck space telescope}} also suggests that the BICEP2 team were looking at an unusually dusty bit of space, which could cause polarization. Hopefully this will improve with the BICEP3 data that should be published in 2016.
|-
| Accelerates certain spacecraft during flybys
|| Two arrows point to two solid lines going away from the main line (left and right). At the end of each line there is a space craft with satellite dish and solar panels, representing the items that the Fixion interacts with.
|| 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]]).
|| It could be an unpredicted quirk of gravity and relativity... or it could be experimental error.
|-
| Triggers Siberian sinkholes
|| No arrow, but it is right next to the solid line with an arrow going into the main line just before the first hole where the main line disappears and becomes dotted. Thus it could be a reference also to these holes.
|| Recently (2014), several {{w|sinkholes}} opened up in {{w|Yamal_Peninsula#Yamal_craters |remote parts}} of Siberia. The explanation is currently unknown.
|| While there are lots of weird theories, there's a good chance they were caused by {{w|Arctic methane release}} due to melting {{w|permafrost}} which is probably caused by {{w|global warming}}. See ([http://www.independent.co.uk/news/science/mystery-of-the-siberian-holes-at-the-end-of-the-world-solved-scientists-offer-explanation-9642988.html Mystery of the Siberian holes… solved]).
|-
| Melts ice in "Snowball Earth" scenario
|| No arrow.
|| {{w|Snowball Earth}} is the theory that the whole planet was covered in ice at some point. To melt all that ice by the {{w|greenhouse effect}} would require far more carbon dioxide in the atmosphere than seems plausible. However, if volcanoes were to deposit black soot on the surface of the ice, it would start absorbing heat more efficiently (in scientific terms, the Earth's {{w|albedo}} would decrease) and that would also make the planet heat up.
|| There are {{w|Snowball_Earth#Scientific_dispute|scientific dispute}} regarding the theory for a Snowball Earth. There is no conclusive evidence that it ever occurred, but those in favor have presented lots of {{w|Snowball_Earth#Evidence|evidence}}…
|-
| Transports neutrinos faster than light, but only on certain days through one area of France
|| An arrow points to the part of the main line that becomes dotted between the two “{{w|wormholes}}”. This is where the neutrinos move faster than light…
|| 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]].
|| In the end, there was no mystery, just a [http://www.redorbit.com/news/science/1112551696/cern-confirms-neutrinos-not-faster-than-light/  defective cable causing a measurement error].
|-
| Suppresses sigma in experiments
|| No arrow but the last solid line, with an arrow pointing left, that is going away from the main line, point almost directly at it.
|| 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
|-
| My theory predicts that, at high enough energies, FRBs and perytons become indistinguishable because the detector burns out.
|| From the title text.
|| 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 Earth. 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.
|| N/A
|}

==Transcript==
:[Caption above the panel:]
:A Christmas gift for physicists:
:The '''Fixion'''
:A new particle that explains everything

:[A chart resembling a Feynman diagram is shown. It begins with a solid line coming down at the top, going a little to the left. The line continues downwards all the time, but changes direction 16 times before exiting at the bottom almost straight under the starting point. At every point where it changes direction, there is some kind of “interaction” with something outside this line. There are 19 phrases, 10 on the left and 9 on the right. 11 of these are distinct labels for points on the line as 14 gray curved arrows points between these 11 phrases to specific points on the line. Three of the phrases on the left has two arrows pointing to two different, but close, parts of the line. The main central line is solid all the way, except at the very bottom, where it “disappears” inside a hole only to “reappear” later from a similar hole. Between these two holes the line is dotted. The lines going away (or to) the main line can be straight and solid, straight and dotted, wavy lines (with different waviness), even looking like a spiral. Two straight solid lines ends up at two space probes, and finally the last two straight solid lines coming in (and out) on either side of the “hole” in the line has arrow pointing in and out. Below the phrases will be listed in reading order, taking one on each side alternatingly. Above each is described if there are any arrow and, if there are, what they points at.]

:[Left: Arrow pointing to the very first part of the main line:]
::Main component of dark matter

:[Right: Arrow pointing to the very first part of the main line, but below the previous arrow:]
::Confines quarks and gluons

:[Left: Arrow points to the first solid line going left and upwards:]
::Neutralizes monopoles

:[Right: No arrow:]
::Suppresses antimatter in early universe

:[Left: Two arrows points to two dotted lines going out left and downwards below the first solid line:]
::Spontaneously emits dark energy

:[Right: Arrow pointing to several lines going almost parallel with the main line. The first line closest to the arrow is not connected with the main line. It bends closer to the other lines in the middle. The next line is connected to the main line, and is thus actually two lines going in to the main line. The same goes for the inner line, where there is some distance between the entry and exit, as the middle of these three lines connect to the main line in between. In principle there are four lines going in/out and one not connected, but it looks like three lines:]
::Mediates proton decay but then hides it

:[Left: One arrow points to the first wavy line (7 peaks) coming out and up towards the dotted lines above. A second arrow points further down the main line where there are three more wavy lines coming out, but to the right, they are all of the same length and go almost straight right, only a little down. The first has as short a wave length as the line above to the left, but as it is shorter it only has 6 peaks. Then the wavelength decreases to a very long one for the last, 5 peaks and then 3 peaks. The arrow points almost where the middle wavy line exits the main line:]
::Introduces dispersion in perytons from kitchen microwaves, explaining fast radio bursts

:[Right: An arrow point to the part of the main line between the three parallel lines and the first wavy line:]
::Broken symmetry causes ϴ=0, explaining unobserved neutron dipole moment

:[Left: No arrow:]
::Causes alpha effect

:[Right: No arrow, but right next to the middle of the three wavy line:]
::Covers naked singularities

:[Left: An arrow points to a spiraling line going upwards to the left:]
::Intercepts certain gravitational waves before they're observed.

:[Right: No arrow, but right next to the bottom of the three wavy line:]
::Causes coronal heating

:[Left: No arrow:]
::Higgs-ish

:[Right: A long arrow point to the point of the main line just below the line pointing to the bottom (and left) of the space probes:]
::Superluminally smooths anisotropies in early universe (but adds faint polarization for BICEP3 to find)

:[Left: One arrows point towards the point on the main lines where a solid line goes to the right and up and another arrow points on another solid line going away from the main line towards left and down. At the end of both lines are drawn spacecrafts with satellite dish and solar panels:]
::Accelerates certain spacecraft during flybys

:[Right: No arrow, but right next to the solid line with an arrow going into the main line just before the first hole where the main line disappears and becomes dotted:]
::Triggers Siberian sinkholes

:[Left: No arrow:]
::Melts ice in "Snowball Earth" scenario

:[Right: Arrow points to the dotted part of the main line between the two holes:]
::Transports neutrinos faster than light, but only on certain days through one area of France

:[Left: No arrow but the last solid line, with an arrow pointing left, that is going away from the main line, point almost directly at it:]
::Suppresses sigma in experiments

{{comic discussion}}

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