The composition of the here presented data provides a very strong case of an unexplored scientific phenomenon due to the image characteristics under frame-to-frame analysis and the diverse sources (see Chapter on data reliability). The topic of white fast movers was—to my knowledge—never discussed in academic circles. However, it was heavily discussed in the context of UFO sightings, including laymen's discussions in public online forums such as the YouTube comment section. These discussions do not necessarily have to lead to good explanations, but they also do not have to generally lead to wrong conclusions. However, most suggestions for explanations I came across can be excluded right away (I marked them as extremely unlikely in my analysis below), whereas a few others cannot. In the following, I list these explanations and provide my rough estimate of their likelihood. I, of course, elaborate on my reasons for these estimates.
(i) Hoaxesimpossible
In the chapter about data reliability I defend in length that the phenomenon of WFM footage cannot be exlained by them being hoaxes. There are too many cases, the sources are socially very diverse, most of the originators show too little social and psychological traits to justify this conclusion, a case of WFM footage is not very sensational in isolation with other cases, there is no gain for an originator in hoaxing this footage, many originators do not seem technically capable of producing such hoaxed footage, some cases of possible WFM footage are only pointed out much after an upload by a viewer, and frame-by-frame analyses is in almost all cases completely consistent with real footage.
(ii) Known insect flying close to camera lens very unlikely
The smear effect that we usually find in WFM footage implies that the captured object has to fly very quickly through the frame in relation to its distance to the lens. Therefore, such an effect can be the result of a very fast moving object many meters away from the lens or a not so fast moving object very close to the lens. Thus, one might suggest that WFMs are in fact just insects that fly very close to the lens. Figure 2 shows such a case.
This explanation for the here presented WFM footage seems very unlikely for several reasons that can be directly investigated in many cases of the footage. (1) Many cases of the WFM footage are consistent with an object flying a distance of several hundred meters over the ground with a constant altitude without change of direction. (2) Insects typically change directions rapidly and often (e.g. to confuse preditors), WFMs on the other hand, fly relatively long distances in mostly linear trajectories or high-radius curves. (3) Many insects appear in swarms, but WFMs often appear swithout any other WFM close by. (4) specific species of insects are restricted to certain climates and regions, but WFMs occur in very different climate zones and on different continents. (5) WFMs' flight path are not significantly influenced by the wind direction. (6) Despite there being purely white flying insects (see figure 2), WFMs reflect the light much more intensely (see figure 3). (7) In some instances of WFM footage a clear shape of it is visible and further corroborates that these are not shaped like flying insects (e.g. having wings, a head etc, see figure 3).
Footage of insects that fly close to the lens can be misidentified as WFM, but the here presented good cases of WFM footage (i.e. being rated 4 to 5 stars) cannot be directly explained with this approach.
Fig 2. Example of white insects flying close to the lens of a videoing drone. Note the rapid and often occurring changes of direction.
Fig 3. Close-up views on WFMs. Left: case P-iFx3VIiQ0, 256 colors, original speed (25fps). Right: case d3ajks8OHCo_WFM2.
(iii) Large and known animal (e.g. bird, bat) very unlikely
Birds, bats or other known flying animals that are larger than insects are extremely unlikely to explain WFM footage. Despite the fact that the fastest falcons can reach up to about 400 km/h while diving (see Alerstam 1987, Tucker et al. 1998, Hedenström 1998), and completely white colored birds exist (see figure 4), the reliably measured movement speed of several hundred kilometers per hour up to supersonic speed in horizontal direction are out of reach for birds or other common flying animals. Furthermore, in many good cases of WFM footage the object's shape can be roughly determined (see figure 3) and is not consistent with the shape of a known flying animal. In most cases of WFM footage, the object flies in a straight line or along a curve with a great radius directly above the tree lines. This flight pattern is not typical for a common bird that changes its direction more often. Figure 5 shows some short clips of typical video drone footage showing birds in flight.
Fig 5. Bird filmed from several distances (top), and birds attacking the drone (bottom, at about 2:44)
(iv) Hail, snow, or another common weather phenomenon impossible
Some commentators (e.g. YouTuber Paranormal News Today) suggest that WFMs are hail stones that ride on layers of air. This explanation is impossible for the good cases of WFM footage because WFMs travel greater distances without any alteration of altitude or speed. They appear to not be subject to graviational forces to the degree that a piece of ice or snow should. Furthermore, some cases occurred in warm and dry areas (e.g. 4KeZ7Pzbd9U).
Good cases of WFM footage are available from very different regions under very different weather conditions. Futhermore, in comparison to other possible approaches of explanation (in particular unknown animals and alien drones), physical mechanisms are very well researched. An unknown meteorological/physical cause of WFM footage cannot be excluded with any strong argument. Many phenomena puzzled human observers for centuries deeply, and turned out to be well explained with modern physics and astronomy.—The Polar Lights, aurora polaris, for instance, were such an unexplained phenomenon until solar winds and the earth's electromagnetic forces were understood sufficiently.
However, WFMs seem to be intentionally steered. They never crash into obstacles. They change direction (e.g. 4KeZ7Pzbd9U, WFM1 at d3ajks8OHCo) and seem to approach the videoing drone intentionally (e.g. VjW_QyXtyHA, JJpSYozvasc, 2wII24qSpDw). This behavior of intentional movement make a meteorological/physical explanation as explored by the natural sciences unlikely a valid explanation. Furthermore, WFM seem to not be affected by gravitational forces or wind/air friction. We cannot very strongly exclude the possibility of WFMs being unknown natural phenomena, but the data provides good arguments against this claim.
(vi) Unknown animal low likelihood for many cases
Biological taxonomists still discover many new species of life (animals, plants, and other forms of eukaryote) and, according to consensus, millions are still undiscovered. Mora et al. (2011) predict, making various model assumptions, that there are approximately 8.7 million species globally. Only about 14% of these are cataloged by taxonomists as of today. They calculate an average historical description rate of 6,200 species per year globally over the last 20 years. Given some uncertainties about the model assumptions (Castello, Wilson and Houlding (2012) estimate only 1.8-2 million species, Scheffers et al. (2012) provide a meta study), the door is still wide open to assume a wide variety of unknown species on earth.
Are WFMs animals? Despite our scientific experience of finding new species constantly, the hypothesis of WFMs being animals or other form of terrestrial biological life forms, is still a far leap. The reason for this is that WFMs' measured movement patterns (travel speeds of several hundred kilometers per hour up to supersonic speed horizontally) cannot be accomplished by life forms that depend on already scientifically described forms of metabolism and propulsion. To substantiate this claim I refer to a classical paper of Langmuir (1938) in which, regarding a discussion about the possible travel speed of insects, the author calculates that a fly would need to consume 1.5 times is body weight per second to attain the energy for supersonic speed of flight under realistic conditions. Disregarding possible deviations in the assumptions for such a calculation, the actually measured horizontal travel speeds of insects (see Dean 2003) and other flying animals (birds and bats up to 112 km/h, see Templin 2000, McCracken et al. 2016, Henningsson et al. 2010, Alerstam et al. 2007) imply that WFMs cannot be biologically closely related to any known animal and outperform them greatly.
Therefore, if WFMs are terrestrial life forms, then they are not only a new species or class. They rather are something new on the very root of the taxonomic classification of life, i.e. on the level of domain, or kingdom. There is no very strong argument against this, but such a hypothesis surely leads to a paradigm shift in biology regarding energy and propulsion of biological entities. Such a finding might even challenge the theory of evolution, due to the seeming superiority of metabolism and propulsion.
Furthermore, in most cases where the WFM's shape can be analysed in the frames closest to the camera, no typical animal shape can be determined ;mdash; this means the object looks rather blob/cloud like without flapping wings, a boday core and the like.
Consumer drones are available with various performance levels and shapes, including white, ball-shaped models (see figure 7 for an example). Jet-propelled RC model airplanes reach speeds up to about 750 km/h, but such models are specifically designed for the purposes of reaching high speeds and allow precise steering (as opposed to most model rockets). Figure 8 shows a high-performance jet-propelled model plane. Such RC models need to be designed very flat to reduce air friction and allow steering.
Fig 7. Retailer image of the K130 6-axis gyro quadcopter (Source: KAI DENG).
As is apparent in the good cases of WFM footage, WFMs are not shaped liked high-performance RC planes (P-iFx3VIiQ0, WFM2 at d3ajks8OHCo) and their estimated travel speed exceeds the record speed of the model shown in figure 8 (but often not greatly, e.g. lnIUh2bPxu0). Furthermore, WFMs seem to be precisely steered and never leave a trail that common rocket propulsion leaves (see figure 9). Rocket propulsion is necessary to exceed the RC jet's speed with commonly available engineering equipment.
Fig 8. Turbine jet model that broke the Guiness World Record for the fastest remote-controlled (RC) jet-powered model aircraft with 709 km/h on 13 September 2013 and 749 km/h on 23 August 2017. Note that the jet engine does not leave a visible exhaust trail. (Sources: YouTube sa-TSNeTK-A, guinnessworldrecords.com).
In summary, good cases of WFM footage are not likely to show drones built with common and available technology, because, firstly, they often travel too fast to not have to leave an exhaust trail. Secondly, they are not shaped to allow the observed steering and flight stability in accordance with our laws of aerodymanics on our common technical flight devices. They rather seem to show a way of propulsion and steering that is unknown to our areas of publicised science, including not only aerospace engineering, but also physics on a principle level. Thirdly, none of the cases of WFM footage show any indication of a reason why some human would sent a drone there (e.g. a RC airshow nearby; an interesting area to spy on; increase of other technical activity in the area).
Intelligence and military services develop and use spy technology. This includes small flying vehicles, such as CIA's Insectothopter from the 1970s exemplifies (figure 10).— There is no convincing reason to believe that there is no interest in small and capable reconnaissance or spy vehicles for lower altitudes today. Furthermore, the rich history of reconnaissance arcrafts and satellites (e.g. Lockheed SR-71 Blackbird, the ZUMA mission) and the kept secrecy about their existence and capabilities make it reasonable to assume that not much is publicly known about other today's best performing spy and reconnaissance vehicles.
An important question regarding the relation between WFMs and spy/reconnaissance technology is what kind of technology is available to the military and intelligence services today. My arguments rest on the fundamental assumption that it is not possible to develop new forms of propulsion that cannot be explained by the body of published knowledge in the natural sciences in isolation to the vast majority of scientists. The reason for this is that scientific and engineering endeavors of this kind are challenging to a degree that can only be tackled by large collaborating communities. I believe that a sealed-off laboratory cannot accomplish this. My believe accords with elaborations of Robert Lazar who claims to be a whistleblower having worked in such a facility. Note that all later revealed secret military technology projects are the mere result of engineering that rests on well-established principles of the natural sciences of its times.
Another approach to explain WFMs as secret military/intelligence vehicles is to suggest that the necessary technological knowledge was gathered by a technology transfer from an alien source. But, obviously, this is at least as likely or unlikely than the claim that WFMs are alien devices temselves. Additional propositions have to be true for this, namely that a government or secret agency received the necessary technology, and it was able to use it. Furthermore, WFMs seem to occur all over the world. If they are operated by a government agency, a local clustering in a specific area on earth seems likely, but a global use as spy or reconnaissance device can also not be strictly ruled out. A larger data set of good WFM footage, which includes the location of videoing would help to strenghten or weaken this line of argument.
(ix) Human-made light or hologram effect: very unlikely
The large amount of good cases and in particular the analysis of the smear effect (see chapter on data reliability) show that WFMs are light reflecting or light emitting objects that zoom quickly through the earth's air space. These objects could be solid machines (e.g. metal-based). On the other hand, we have no very strong reason to exclude the possibility of WFMs being light effects or holograms, which are produced by a third source that is responsible for their peculiar movement behavior we observe. This claim could explain well how WFMs do not seem affected by gravitational forces and wind.
Such a source could be highler flying aerial vehicles or space-based satellites. Since there is no apparent local clustering of WFM appearances, such a system would have to be installed on a global scale or has to be relocatable to arbitrary locations. Image 11 shows a laser-induced light spot in air by creating a plasma that is produced by exploiting a tunnel ionization effect. These experiments show that bluish-white light dots can be produced in air from a distance without the use of a further substrate. (see project Fairy Lights in Femtoseconds for further infromation) WFMs do indeed appear more like plasma clouds, than like solid objects.
Fig 11. From Ochiai et al. (2016): Laser plasma induced by focused femtosecond laser.
Fig 12. From Ochiai et al. (2016): More complex laser-plasma graphics. (click for enlarged view)
An approach to substantiate this explanation is to speculate about aims for such an installation. One effect WFMs certainly have is the same one that the original Foo Fighters (see introduction) allegedly had: WFMs can be used to confuse people, including military air plane pilots. Another idea is that WFMs could more actively interfere with light or heat based guiding systems, including human pilots' vision, i.e. blinding pilots similar to the blinding effect of laser pointers to distract professional athletes in competitions. However, I could not find any reports or discussion about such problems for pilots regarding modern WFM occurrences.
There are some good arguments against the hologram idea. Some WFMs occur in rather cloudy weather conditions, which makes it difficult to produce a hologram from any machinary located above the clouds. WFMs in cloud-free weather conditions reveal that appearantly no observer spotted such a hologram device in higher altitude; at least I am not aware of any instance of such an observation being pointed out. The flying patterns of some WFMs (e.g. directly over the tree line) make them impossible to be projected holograms from a ground stationed emitter. All WFM appear white like a water vapour cloud withour any bluish light. The here described hologram method emits bluish-white light. There seems to be no good reason for such sophisticated hologram devices. These weak light-dots cannot be used as spy devices and the only observation about them is them flying around very quickly and often approaching the hobbyists' drones. If these are human-made, highly advanced and secret technical devices, then we need to find a good strategical purposes to substantiate this hypothesis. I cannot imagine this purpose.
(x) Shot projectile: impossible
A non-self-propelled projectile (e.g. golf ball, bullet) can be excluded as an explanation, because the good cases of WFM show the objects to be self-propelled. They do not lose altitude and are not subject to the earth's gravitational forces.—I show video scenes of flying golf balls for comparison in the chapter on the analysis methodology.
Even bullets that were shot with a gun or a howitzer that use explosives are subject to gravitational forces. Furthermore, such a projectile cannot fly non-linear maneuvers (e.g. 4KeZ7Pzbd9U) or in curves with large radius (e.g. lnIUh2bPxu0) as we find them in many cases of good WFM footage.
(xi) Super-light flowing particle (particularly spider web clumps): relevant candidate for many cases
This idea was suggested to me by Mick West (mickwest.com) per email in February 2021 after I asked him about his views on white fast movers.
Only very few materials are sufficiently light to be carried by even the slightest wind. A certain form of spider webs, made by collaborating clusters of spiders, glimmers as a bright white object when illumated by the sun and viewed from a correct angle. Figure 13 shows how spider web clumps are carried by the wind. Note that the extreme specifics of spider silk make it reflect light well despite its extremely light weight.
Fig 13. Flying Spiderwebs by Rich Rodgers
Mick suggested, when we discussed a case from Crucea de Piatră, that what we see is in fact a spider web clump (or a similarly mundane object) carried by the wind alone and with not more than a few feet distance to the camera. That the object might appear further away from the camera is not justified by any optic's geometry but rather a misinterpretation by me and others.
This idea is a very relevant hypothesis.
In favor of this hypothesis:
In many cases WFMs seem to approach the drone from ahead against the flight direction of the drone, which is consistent with the drone actually flying over a slowly moving close object
Spider web clumps are sufficiently light to float by only minimal upwind
Spider webs stay intact over several years
The indistinct blob/cloud like shape of many WFMs is well explained by a clump of spider web glimmering in the wind (see video above)
So far, available WFM footage shows the objects only with one camera with very good auto-focus capabilities by modern drones. This makes it hard or impossible to reliably estimate the object's distance from the footage alone.
Against this hypothesis:
WFMs travel paths seem to be unaffected by mayor wind turbulences. Even in higher layers, when seen in many frames, more erratic movement patterns might be much more likely
In some cases, like Suchá, or Queen Valley, the WFM seem to fly over ground terrain in a distinctly obstacle-avoiding way not directly consistent with wind turbulences
In a case from Fort St. John several WFMs showing the distinct blob/cloud-like appearance and seemingly steered movement. But the different fly in different directions completely inconsistent with any drifting by wind.
WFMs occur all over Europe and North America, indicating that spider clumps (or similar natural objects) travel large distances and remain for a long time in the air without being washed down by rain or dragged down to the ground by wind turbulence.
Mundane, ultra-light objects from earthly environments cannot explain WFM-like appearances in the vicinity of the moon (moon pigeon) or ISS— see next hypothesis (xii) below
Available data does not corroborate a clear positive statistical relation between travel direction of a WFM and the general wind direction measured by a close-by weather station. However, in many cases the drone's or gimbal's movement mitigate any clarity on his point from the data, and the weather station's measurement is less reliable than the drone's meta-data, which is rarely available—more and better data could resolve these open questions
If WFMs are ultra-light natural objects carried by the wind, more footage must be available where the objects follow wind turbulences, as exemplified by figure 13 above.
If WFMs are ultra-light natural objects carried by the wind, more footage must be available where the objects occur grouped, as exemplified by figure 13 above. The reason for this is that the local circumstances to create such an object (e.g. groups of spiders collaborate to create dense nets) are better given in very specific areas than somewhat evenly distributed throughout Europe and America.
The crucial characteristics of WFMs are: they move very fast, they do not show any signs of conventional propulsion (e.g. exhaust trails, flapping wings), they do not show any signs of being subject to either gravitational forces nor air resistance, they never crash and maneuver around obstacles, they have an indistinct shape, they often aim for drones and pass them closely, they occur all over the world and under all weather conditions. Our publicly available science is not able to explain how they work and they outperform the abilities of known animals greatly.
These characteristics fit well into what the so-called Advanced Aerospace Identification Program of the United States Department of Defense investigated. Figure 14 shows a video released after disclosure of the program by the New York Times (see Glowing Auras and 'Black Money': The Pentagon's Mysterious U.F.O. Program). It shows something small and very fast flying over the sea captured with an infrared camera from a combat jet.
Fig 14. To the Stars Academy's (TTSA) video Go Fast: Official USG Footage of UAP for Public Release shows a small, fast moving object.
The so-called To The Stars Academy is an organisation in which the former head of the Advanced Aerospace Identification Program, Luis Elizondo is involved and that is devoted to manage a disclosure of the gathered data and research results. They released this video and added a comment, which includes the following:
GO FAST was selected for release, like GIMBAL and FLIR1, after review by multiple government organizations. The object in this video remains unidentified.
(...)
It is important to note:
There are no obvious wings or tails on the object. Even IR imagery of a cruise missile, would have visible wings at this range.
This description and the actual video footage fits very well to what we know about WFMs. More information about this capture, in particular a reliable indication regarding the object's size, would be very helpful to strengthen or weaken the possible connection to WFMs. Where is the connection to something that could be called alien drones? The New York Times article mentions Mr. Elizondo's summarizing claim that many accounts from the Navy and other services of unusual aerial systems interfering with military weapon platforms and displaying beyond-next-generation capabilities occurred. Asked for an explanation of these phenomena during an interview on CNN Elizondo expressed his belief that there is very compelling evidence that we may not be alone with a clear indication of we referring to the human societies on earth. (CNN, 19 Dec 2017) In summary, WFMs fit neatly into what was disclosed as genuine UFOs by the specialized US military investigation program, and the head of the program expressed his conclusion that these are technological devices from non-human sources (whatever that means in detail).
There is an additional interesting detail in the footage shown in figure 13. The object in the film appears very cold and we can reliably conclude this, because infrared cameras are used. Human-made aerial vehicles captured with infrared cameras are usually very warm due to the chemical and physical effects they employ for propulsion. WFMs are very well tracable with infrared sensors (see chaper How to Gather Better Data) and if it turns out that WFMs are very cold, too, then this serves as a further argument that this released TTSA video might in fact show a WFM.
Some other clues hint to a possible connection of WFMs to non-human observers. Admittedly, the optical signal of WFMs is not very distinct: a little white cloud that flies through the image. However, in the here presented WFM footage, the high travel speed and maneuvers make them hard to be explained as mundane phenomena. In other cases, so called Moon Pigeons were reported and recorded by astronauts. Some of those have been explained as light reflecting debris or ice crystals. However, for some this explanation does not hold. Figure 15 shows an original video that was recorded during NASA's Apollo 10 mission. Note that the white object travels in the opposite direction of the module and is, therefore, not debris from the module. Furthermore, it seem to increase its travel speed or altitude after having passed the module. Due to the poor image quality, we cannot strongly exclude other reasons for this visual phenomenon than an actual small, white, flying object. However, given our knowledge of WFMs' flight behavior on earth, there is a good chance that this footage shows the same phenomenon.
Other appearances of bright light objects zooming through the camer image in a scene outside of the lower earth atmosphere can be found in footage from the International Space Station. The following footage shown in figure 16 below shows two WFM-like appearances directly outside of the ISS.
Fig 16. From ISS Life Feed, March 16, 2021. Uploaded and commented on YouTube by MrBB333.
The, in my view, most compelling connection to WFMs and non-human intelligent influence are the so-called balls of light that were allegedly seen and filmed (figure 17) near crop circles. There is a vivid discussion about the causes of crop circles (see this introduction from J. Prytz for more). We do not have to fully commit to a camp, human-made hoax or alien-made message, despite the claim that it is by no means a trivially answered question, which is to an alarming degree distorted by the majority of scientists.—With this I refer to the widespread ridicule of the topic in scientific circles.
Fig 17. Collection of videos claimed to show balls of light.
As the video clip in figure 15 shows, there is a striking similarity between WFMs and these balls of light, whereas the only difference is the speed of travel, but the size, shape and color are identical as much as the footage indicates. The crucial point I want to emphasize is that these are claimed to be filmed by people who are interested in crop circles, and WFM footage is of a completely different source, namely pilots of hobbyist drones. Furthermore, I never heard of this striking similarity been pointed out before (note that I read hundreds of online comments on WFMs and chatted with many of the originators of WFM footage). It seems that this connection is newly discovered, and given the well substantiated hypothesis that both kinds of footage are not all hoaxed, we can conclude that WFMs/balls of light occur flying near crop circles and drones. Why would WFMs be interested in crop circles? It seems reasonable to entertain the idea that WFM observe the activity around crop circles, rather than hunt for food and breed as we would assume, if WFMs are part of the animal kingdom.
Speculations about non-human reconnaissance or survaillance devices are often more nourished by a vast net of observers' background assumption than by a set of sufficiently detailed and reliable data. That is why these speculations often lead to very different conclusions about the origins of these observed objects: space aliens, angels, demons, multi-dimensional beings, time travellers or others. Whitefastmovers.org is a project aimed at getting a bit closer to an answer by more focussing on the data than on the background assumptions.
(xiii) Ghost/spirit or other parapsychological causerelevant candidate
An even more puzzling topic of speculation is a third option apart from technical devices or undiscovered biological organisms. Physical causation by—for a lack of a better term—ghosts or spirits or due to parapsychological effects has noticeable empirical support in poltergeist phenomena (i.e. flying objects, slamming doors, signals in form of electromagnetic emissions or sound waves). The reviews from Laursen (2013) and Braude (2015) provide an entry point to discover the relevant literature. These phenomena imply intelligent guidance by agents about which we do not know much more. Both these characteristics, physical causation and intention, are characteristic for WFMs, too. Therefore, this option cannot be excluded to explain WFMs, too. But similar to to the space alien hypothesis, much more empirical work is necessary to corroborate any close connection between WFMs and said other phenomena.
However, similar to possible other technology of observed unidentified flying objects (UFOs), investigations into poltergeist or parapsychological phenomena is tabooed in mainstream sciene and, therefore, this field is as underdeveloped as ufology is concerning its embedment in academically funded fields. Due to, as far as I know, the lack of scientific progress, I can neither make strong arguments in favor of WFMs falling under this category, nor against it.
(xiv) A combination of mundane explanations very unlikely
Another attempt to explain WFMs is that they a misinterpretation of a combination or compilation of mundane phenomena that are well explained with common scientific knowledge. The idea behind this is that all (not only some, but all) of the cases of possible WFM footage show one of the many possible mundane phenomena (i.e. hoaxes, weather phenomena, insects, common UAVs, projectiles) and the only connection between them is that they look very similar on the footage. This is a common strategy to explain away UFO sightings, which—for whatever reason—imply that genuine UFOs come, if at all, in a wide variety of forms: silverish saucer, black triangles, white Tic-Tacs and many others.
I strongly reject this explanation for the following reason. The cases of possible WFM footage that I rate with four or five stars are simply way too good data to be convincingly explained by these mundane approaches. The WFMs are clearly visible, it's travel speeds and trajectory is very reliably determinable. None of the mundane explanations can explain these cases. WFMs are without much doubt white, small objects with tremendous speed recorded in the footage. The data is quite clear but a convincing and sufficiently detailed explanation is missing.
References
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Fig 3. Close-up views on WFMs. Left: case 
Fig 7. Retailer image of the K130 6-axis gyro quadcopter (Source: 
Fig 8. Turbine jet model that broke the Guiness World Record for the fastest remote-controlled (RC) jet-powered model aircraft with 709 km/h on 13 September 2013 and 749 km/h on 23 August 2017. Note that the jet engine does not leave a visible exhaust trail. (Sources: YouTube 
Fig 9. Rockets with jets and exhaust trails. Solid-prepellant model (left, 
Fig 10. Spy drone 
Fig 11. From Ochiai et al. (2016): Laser plasma induced by focused femtosecond laser.
