UAP sightings have outpaced explanations for decades. Across thousands of cases, five traits keep appearing: positive-lift (apparent anti-gravity), instantaneous acceleration, hypersonic speeds without signatures, low observability, and trans-medium travel. We use these Five Observables to translate pilot reports and multi-sensor tracks into engineering constraints—the boundary conditions any viable theory must satisfy.

Dr. Kevin Knuth’s talk, “UAP Flight Characteristics — The Five Observables,” doesn’t try to solve the UAP puzzle in one dramatic leap. Instead, it takes a slower, more scientific approach: narrow the field, define what’s worth studying, and quantify behaviors we can measure. The result is a clearer map of a messy landscape—one where most sightings are mundane or mistaken, but a small, stubborn subset exhibits flight characteristics that don’t sit comfortably inside today’s aerodynamics and propulsion playbooks.

Knuth approaches the topic with the perspective of a working physicist and data analyst. He collaborates with UAPx—a group of former Navy personnel, scientists, and engineers actively collecting instrumented data—and he recently briefed the aeronautics community at an American Institute of Aeronautics and Astronautics (AIAA) session. That audience matters: it signals an attempt to translate extraordinary claims into a language practitioners can interrogate. Equally important, he stresses triage. Most reports, he notes, are misidentifications of atmospheric or astronomical phenomena or conventional aircraft, and many others are hoaxes. Only a few percent are “of interest,” and his focus is on the still smaller fraction that appear to involve structured craft with anomalous behavior.

“Only about three percent of all UAP reports are of genuine scientific interest — but in that sliver lives a set of flight characteristics so extreme that they effectively define the problem.” — Dr. Kevin Knuth

Before diving into the “observables,” Knuth makes a simple but powerful point: identification isn’t binary. As with birdwatching—a craft he knows well—you can identify something at the level of “a bird,” or you can classify species, sex, and seasonal plumage. In UAP work, he’s concerned with the cases where witnesses and sensors converge on “structured craft,” even when the type or origin remains unknown. That framing—partial but meaningful identification—sets the tone for the rest of the analysis.

Observable 1: Positive Lift without Conventional Signatures

One of Knuth’s anchor examples is the 2013 Homeland Security infrared footage from Aguadilla, Puerto Rico. The object hovers and maneuvers without visible wings, rotors, or control surfaces—and crucially, without the heat plumes we expect from jet or rocket exhaust. He folds in case reports of long-duration hovers, sometimes to the point where intercepting jets run low on fuel and have to break off—an operational contrast that underlines the energetic oddity on display. Claims from program leads of “minutes, hours, days” of hovering further lean into the paradox: substantial lift with neither obvious fuel consumption nor waste heat. Even at the level of first principles, that is hard to reconcile with familiar machinery.

The absence of thermal signatures recurs across examples. In long-wave infrared (LWIR), engines and exhaust usually advertise themselves; here, they don’t. That doesn’t prove exotic propulsion, but it constrains hypotheses: whatever is producing lift and control isn’t coupling energy into the surrounding air the way hot exhaust plumes do. It’s an empirical fact pattern, not a theory, but it nudges the conversation from “Is something there?” to “How is it interacting with its environment?”

Observable 2: Extreme (Often “Immeasurable”) Acceleration

Knuth is careful about words like “instantaneous”—as a physicist, he prefers measured rates and bounds. In the 2004 Nimitz incident, radar operator Senior Chief Kevin Day reported “Tic Tac” objects cruising near 28,000 feet, then descending to near sea level in a reported 0.78 seconds. If you treat that as a symmetric accelerate-then-decelerate profile and incorporate uncertainties in altitude and time, you can compute a minimum acceleration necessary to make the maneuver. The point isn’t to proclaim a single sensational number; it’s to show that even conservative bounds land far outside what human-rated airframes can tolerate without structural failure or pilot injury—and far beyond what hot-gas propulsion could achieve without violent signatures. Knuth and colleagues have published analyses along these lines, making the methodology transparent.

Two aspects matter here. First, the kinematics don’t rely on exotic speculation—just the familiar equations of motion coupled to sensor-reported time and altitude changes. Second, the accelerations implied by those times and distances would normally dump huge amounts of energy as heat, pressure waves, and ionized trails. When those signatures aren’t observed, you’re left with a mismatch between motion and expected byproducts. That mismatch is where new physics hypotheses try to sneak in, but the honest conclusion is simpler: the data stress our current models.

Observable 3: Hypersonic Velocity without Shock/Heat Signatures

Knuth clusters this with acceleration because the diagnostic problem is similar: high speeds in air should create shock waves, boundary-layer heating, and luminous effects. Many sensor tracks and videos, however, lack those telltale footprints. In LWIR, you don’t see the thermal glow you’d predict; visually, you don’t see the bright plasma sheath that often accompanies re-entry-class heating. Again, absence of evidence is not proof—sensor geometry, range, and atmospheric conditions matter—but across enough cases, consistent non-detections of expected signatures become their own constraint. In engineering terms: if the medium isn’t being violently pushed out of the way, perhaps the craft is altering the interaction with the medium itself. Knuth doesn’t insist on any one mechanism; he keeps it at the level of observed lack of coupling.

“The mystery isn’t just that some UAP accelerate violently—it’s that they do so without the heat, shock, or acoustic signatures our models demand. Energy bookkeeping becomes the real story, and right now the books don’t balance.”— Dr. Kevin Knuth

Observable 4: Trans-Medium Travel

Here Knuth brings the discussion back to Aguadilla, but focuses on a small object that drops into the water. Using the Scientific Coalition for UAP Studies (SCU) analysis, he notes that the target enters the water at roughly 110 mph, slows only modestly to around 80 mph, and averages ~85 mph while submerged—then exits and continues flight. For a football-sized object, maintaining that kind of speed underwater without obvious cavitation or a loud acoustic signature is, at minimum, unusual. The object “doesn’t seem to be impeded”; it doesn’t interact with water the way we expect.

That raises a second, thornier question. Some UAP are reportedly tracked on sonar; sonar works by reflecting pressure waves from an object. If a craft can traverse water with minimal coupling—no big pressure fronts, no frothing cavitation—what, exactly, is the sonar reflecting from? Knuth doesn’t pretend to reconcile this. He flags the possibility of multiple technologies, multiple craft types, and even multiple operating modes for a single craft (think hybrid cars switching between gasoline and electric, or science-fiction standbys toggling “impulse” and “warp”). The meta-point is methodological humility: don’t overgeneralize from one case to all cases.

Observable 5: Low Observability (and Why Video Still Matters)

“Low observability” can mean radar stealth, optical camouflage, or simply sensor peculiarities. In UAPx fieldwork, Knuth’s team captured a passenger jet and a second object on infrared. The jet is hot—exactly as expected in LWIR—while the unknown object appears very cold, near −60°F. It showed up on two cameras while the jet appeared on one, which argues against an artifact. More intriguingly, that cold target didn’t appear in visible light or in short-wave IR night-vision devices at the time. This pattern—present in LWIR, absent in visible/SWIR—repeats in other recordings and matches pilot testimony from the USS Roosevelt encounters, where radar-detected targets weren’t visually acquired until they were nearly on top of aircraft. All of that rolls up into a working definition of “low observability” across bands.

Knuth also pushes back on a common critique: that the released military videos are too ambiguous to be “impressive.” Their value, he argues, is often corroborative—tying pilot reports to instrument data streams. We shouldn’t expect Hollywood-grade clarity from forward-looking infrared pods designed for tracking, not for making nature documentaries. That doesn’t make them worthless; it just defines their evidentiary role.

A Physicist’s Caution: Don’t Force One Theory to Fit Everything

Tempting as it is to jump from anomalies to a single grand theory, Knuth keeps multiple hypotheses on the table. He notes that one recently published warp-metric concept (Bobrick–Martire) yields a field geometry whose silhouette resembles shapes seen in the “Gimbal” video and in footage recorded by researcher Ray Stanford. Is that a coincidence, a pattern-matching illusion, or a clue? Unknown. He also highlights reports of strong electromagnetic fields associated with some UAP, including effects on nearby aircraft electronics. Those hints point in very different directions—relativistic metrics versus high-field electrodynamics—which is precisely why premature unification is risky.

There’s another tension he surfaces. If a craft were levitating by generating a gravitational gradient—“gravity up top, anti-gravity below”—you might expect blue-shifted thermal radiation on the underside (hotter appearance) and red-shifted above. Yet UAPx has logged very cold objects in LWIR, which cuts against that simple picture. On the other hand, strong relativistic effects can, in principle, shift radiation enough to explain some reported biological impacts (e.g., radiation burns), though connecting those dots requires caution and more data. The take-home isn’t that “warp is real” or “anti-gravity is false”; it’s that any candidate mechanism must reconcile with a counterintuitive thermal profile—cold where some models predict “hot.”

Method Before Mystery: How Knuth Frames the Work

Two habits stand out in Knuth’s presentation. First, he bounds claims with instrumentation and kinematics. The Nimitz descent is a good example: start with reported altitude and time; compute a minimum acceleration for a symmetric speed profile; compare that to known airframes; ask what signatures should appear if the motion were driven by conventional thrust. This keeps the conversation tethered to numbers while still allowing the data to be “weird.” Second, he insists on case-by-case analysis. The Aguadilla footage might support claims about trans-medium travel for small objects; that doesn’t license sweeping statements about all UAP. Some may be plasma-like, some rigid; some might generate fields that spoof radar or alter refractive indices, others might exploit exotic flow control to reduce drag and heat. The plural of “anecdote” is not “data”—but dozens of multi-sensor cases, treated carefully, can become a dataset.

Knuth is also explicit about the role of multi-band sensing. Long-wave IR has been especially fruitful for his team: it allows temperature estimation (assuming approximate black-body behavior), and it has surfaced targets that weren’t visible in other bands at the time of capture. That’s both a lesson and a warning for all-sky survey projects aiming primarily at optical telescopes: if a subset of targets is low-observable in visible/SWIR bands, you’ll miss them unless you diversify sensors.

Where This Leaves the “Five Observables”

Taken together—positive lift without exhaust, extreme accelerations, hypersonic speeds without shock/heat signatures, trans-medium behavior, and low observability—these observables do not form a complete theory. They do form a consistent set of empirical constraints that any successful theory must satisfy. If your candidate mechanism can’t hover large craft for prolonged periods without radiating heat or expelling reaction mass, it’s out. If it can’t explain rapid altitude changes without sonic booms or thermal footprints, it’s out. If it can’t traverse water without hydrodynamic penalties—or explain how sonar sometimes still sees such targets—it’s incomplete. And if it can’t account for objects that look colder than their backgrounds in LWIR while remaining invisible in visible/SWIR, it’s not ready. That’s what makes the observables useful: they winnow.

Knuth’s measured speculation about warp-like geometries, EM field effects, and multi-mode operation is an attempt to keep multiple explanatory doors open while the data accumulate. The working hypothesis may ultimately be plural: different classes of phenomena, perhaps even different origins, expressed through overlapping signatures. In such a regime, forcing all cases into a single template would be a mistake.

The Humility Clause (and the Path Forward)

The talk ends where good science often begins: with limits and logistics. It is difficult to knit together disparate reports, sensors, geometries, and contexts into “concrete conclusions.” Yet some subset of UAP appears to be physical—structured craft interacting with their environments—and those craft exhibit consistent, measurable effects. The right response is disciplined curiosity: collect more multi-sensor data, focus on events with cross-validation (radar, LWIR, visual, EM effects), and publish methods and bounds rather than grand pronouncements. That’s the UAPx mindset Knuth describes, along with the practical note that such work benefits from public support.

There’s also a cultural point embedded in his defense of those much-debated military clips. They aren’t meant to be definitive; they anchor testimony and encourage better data collection. In court, a blurry photo paired with consistent witness statements and physical traces can still be probative. In aerospace, a marginal FLIR clip that matches radar tracks and pilot reports can motivate a focused campaign to instrument a hotspot with LWIR, SWIR, optical, and RF sensors. That, more than any viral frame grab, is how mysteries shrink.

Bottom line: Knuth’s reframing of the “five observables” doesn’t claim a unifying explanation. It does something more useful right now: it specifies what is odd in a way engineers and physicists can test, replicate, and try to break. Whether the answers ultimately invoke new physics, clever field control, or more prosaic but still-surprising phenomena, any successful account will have to thread the same needle: lift without exhaust, acceleration without shock, speed without heat, boundary-crossing without drag, and a knack for hiding in plain sight—except, often, in long-wave infrared. That is a tall order. But it is an order we can now write down, instrument against, and slowly, methodically, try to fill.

This article draws on in-depth interviews with Kevin Knuth (“UAP Flight Characteristics: The Five Observables”) and (“How UAP Achieve “Impossible” Speeds & Acceleration”), along with his presentation materials from APEC Conference Events.