Filippo Biondi Pyramid Scan: A Complete Investigation

Why the Filippo Biondi pyramid scan still deserves a careful look

The pictures ask an irresistible question. Beneath the familiar outline of an Egyptian pyramid, long vertical forms descend through the rock. Some appear wrapped in spirals. Farther down sit immense chamber-like volumes. Taken literally, the reconstruction would transform our understanding of the Giza plateau. It would also require an explanation for an engineering project on a scale quite different from the monuments visible above ground.

That visual power explains much of the attention surrounding the Filippo Biondi pyramid scan. Viewers encounter a finished underground model before they encounter the chain of measurements, assumptions and calculations that produced it. The scene looks like a destination someone could enter. In the public evidence reviewed for this article, however, no independent field investigation has established that the deep structures shown in those reconstructions exist.

There is still a substantial story to tell. Biondi and his collaborators proposed an indirect imaging method, published their approach, offered interpretations of the results and took their argument to a large public audience. Their work sits beside a real revolution in non-invasive archaeology: scientists are finding concealed spaces in Egyptian monuments using particles, radar, ultrasound and electrical measurements. Understanding which discovery belongs to which technique makes the whole subject more interesting.

The publication status and the physical question

The latest development requires attention without turning the article into a verdict on the researchers. On 10 August 2026, Remote Sensing retracted Biondi and Corrado Malanga’s 2022 paper about Khufu’s Great Pyramid. The journal says an investigation identified methodological and statistical problems serious enough to undermine its conclusions. Its short retraction notice also records that the authors disagreed. It does not publish the detailed technical assessment behind that decision.

A reader can reasonably want to examine that assessment. Journals can make mistakes, as can authors, reviewers and critics. The notice changes the publication’s standing; it does not supply an item-by-item demonstration that every proposed cavity is absent. Equally, disagreement with a journal cannot establish an underground structure. The decisive questions remain physical and testable: what was measured, what can be reconstructed from it, and what separate observations support the result?

This investigation follows those questions from the satellite to the limestone. It gives the team’s explanation room to be understood, compares it with documented ScanPyramids findings, and describes practical tests that could strengthen or weaken the deep-structure interpretation. Readers interested in a particular part can use the contents above. Readers following the whole story will find that the uncertainty becomes more specific as the evidence comes into focus.

Who are Biondi, Malanga and the Khafre project?

Filippo Biondi works in radar and signal processing. His research record includes studies of micro-motion and structural monitoring, subjects with legitimate applications in engineering. In his January 2026 interview with Joe Rogan, he describes a background in telecommunications engineering and explains how an interest in extracting subtle motion information from satellite observations developed into work on the pyramids.

Corrado Malanga is Biondi’s co-author on the 2022 pyramid paper. The publication lists affiliations in electronic and electrical engineering at the University of Strathclyde for Biondi and chemistry at the University of Pisa for Malanga. Those are affiliations printed on a particular publication. They should not be read as a present-day declaration that either institution endorses the later Khafre claims.

Armando Mei appears with Biondi and Malanga on the project’s 2025 press-conference abstract. Their public presentation moves beyond the Great Pyramid to Khafre and the wider plateau. The distinction between the two stages matters throughout this article: the journal paper concerns Khufu, while the spectacular deep shafts that drove much of the later coverage belong to the expanded Khafre project.

Expertise and independent checks

Professional expertise is relevant because it helps identify what a researcher is trying to do. It cannot remove the need for a test. A specialist can develop a useful method in one setting and overestimate what it reveals in another. Critics can understand archaeological context while misunderstanding signal processing. A productive assessment therefore involves people who can examine the instrument, the mathematics, the rock and the archaeology together.

The team’s own HarmonicSAR website presents an ambitious programme of observing structures inside matter and below the surface. That page is a primary statement of the proponent’s position. Its importance is attribution: it tells us what is being claimed. A statement by a developer and a performance assessment by an independent investigator serve different purposes, even when both are worth reading.

It is also useful to distinguish the project from the many channels discussing it. A video essay, a podcast reaction and a rendered animation can repeat the same original claim. Their agreement does not necessarily add a new measurement. When a new story appears, the first useful question is whether it introduces a document, a dataset, a survey or a physical observation that was unavailable before.

What would move the discussion forward

That approach leaves room for the researchers to answer criticism. It also gives readers a way to recognise a real development. A complete technical response, a blinded recovery of known targets or a successful field prediction would each move the discussion forward in a different way. The reputation of any participant cannot substitute for those results, and an unpopular idea can earn confidence by producing them.

Three pyramids, several names and one frequent source of confusion

Giza’s three principal pyramids belong to Khufu, Khafre and Menkaure. Older European names appear constantly in the literature: Cheops for Khufu, Chephren or Khefren for Khafre, and Mycerinus for Menkaure. Biondi and Malanga also use the name Khnum-Khufu. Recognising those alternatives prevents a surprisingly common mistake: treating results from different monuments as observations of the same hidden feature.

Khufu’s Great Pyramid contains the King’s Chamber, Queen’s Chamber and Grand Gallery, together with descending and ascending passages and a subterranean chamber. The Great Pyramid is the monument associated with the ScanPyramids Big Void announced in 2017 and the North Face Corridor characterised in 2023. Those two spaces are themselves separate discoveries.

Khafre’s pyramid is the second major pyramid at Giza, recognisable in many views by the remaining pale casing near its summit. Its known internal arrangement is less elaborate than Khufu’s. The large deep-shaft reconstructions that became widely discussed in 2025 are associated principally with the area beneath this monument. That is a different location and a different scale from a corridor behind Khufu’s north-face masonry.

The plateau around the monuments

Menkaure’s pyramid is the smallest of the three principal monuments. A 2025 investigation reported two air-filled anomalies behind part of its eastern facade. These were shallow features investigated with several non-destructive techniques. Their detection does not establish a plateau-wide network, though it provides an excellent example of how a careful investigation can add something new to a very old site.

The plateau also contains temples, causeways, cemeteries, quarries, tomb shafts and geological features. An underground opening at Giza is therefore plausible in a general sense. What needs establishing is its particular location, extent, origin and relationship to surrounding structures. A known tomb shaft cannot automatically be assigned to a much deeper system merely because a line on an illustration seems to connect them.

Whenever a headline says that “the pyramid” has been scanned, ask which pyramid it means. Whenever it says a void has been confirmed, ask which void and by which instrument. These small geographical distinctions do more to clarify the controversy than a long argument over whether modern technology can discover anything new in Egypt.

The chronology: how two research stories became entangled

Long before the recent satellite controversy, particle physicists investigated Khafre’s pyramid. Luis Alvarez and an Egyptian–American collaboration installed cosmic-ray detectors in its Belzoni Chamber during the 1960s. Their 1970 Science paper describes the experiment and its search for concealed chambers in the pyramid’s stonework. The detector’s position and field of view defined the region it could examine.

That early experiment is sometimes invoked as though it surveyed every possible space below Giza. It did not. Muons arriving from the sky probe material above a detector along particular directions. A result about an observed part of a pyramid cannot be extended automatically to hypothetical structures hundreds of metres below the instrument. The historical experiment belongs in the discussion because it demonstrates a method and its geometrical limits.

In 2017, the ScanPyramids collaboration reported a large low-density space above Khufu’s Grand Gallery. A separate north-face anomaly had already been reported in 2016. Later measurements and complementary investigations refined the north-face feature, leading to its 2023 characterisation and endoscopic inspection. This sequence is important when assessing later suggestions that an independently publicised cavity was predicted before its discovery.

From Khufu to the Khafre project

Biondi and Malanga published their Khufu SAR paper on 19 October 2022. It proposed a three-dimensional interpretation of internal and subsurface features. Their subsequent Khafre work was presented publicly in 2025. Those reconstructions widened the debate from a pyramid’s internal architecture to much larger proposed structures deep beneath the plateau.

On 23 January 2026, Biondi appeared in episode 2443 of The Joe Rogan Experience. The programme gave him time to explain the claimed vibration mechanism, discuss apparent benchmark targets and describe the deep forms. It also introduced a much larger audience to interpretations involving ancient technology and the purpose of the pyramids.

The 10 August 2026 retraction concerns the 2022 Remote Sensing paper. It comes after that interview and after the Khafre presentations. Readers watching the interview today need this chronology because a reference to a peer-reviewed paper during the recording describes its status at the time. This article’s review date is 31 October 2026; the dated events should remain distinct as later developments emerge.

What the 2022 paper actually proposed

The title of Biondi and Malanga’s paper promises a detailed reconstruction of previously undiscovered structures inside the Great Pyramid. Its first important qualification appears in the abstract: conventional SAR electromagnetic waves have limited penetration into a large solid object. The authors therefore propose analysing micro-movements associated with background seismic vibrations rather than treating radar as a beam that simply passes through all the stone.

In their account, internal geometry influences mechanical motion. A satellite records information related to motion at observable surfaces, and processing attempts to infer a hidden spatial arrangement. The distinction is fundamental. A criticism that assumes the authors merely forgot that ordinary radar has limited penetration fails to engage with the mechanism they actually describe.

The proposal nevertheless contains a substantial inference. A measurement of surface response must be connected to a model of the interior. That connection depends on how waves propagate, which surfaces contribute to the echo, what the background excitation is and how much independent information the observations contain. A complete assessment needs to address that chain rather than settle for a slogan about penetration.

From a processed image to an archaeological claim

The paper uses COSMO-SkyMed observations and discusses known features alongside additional proposed passages, rooms and ramps. It also presents a much broader interpretation involving water circulation and acoustic behaviour. Those are separate layers of the argument: producing a processed volume, identifying a shape in it and assigning an ancient function to that shape each require their own support.

The authors explicitly acknowledge in their conclusion that field confirmation is needed to validate the hypothesis. That caveat deserves to be carried into summaries of the work. Readers should also know that the paper makes confident statements elsewhere about the visibility of reconstructed geometry. A balanced account preserves both the proposed achievement and the authors’ stated need for physical follow-up.

Another revealing detail is its treatment of the ScanPyramids Big Void. The paper says the authors did not detect a corresponding structure with their SAR analysis. That disagreement provides a concrete place to investigate the methods. The measurements could be sensitive to different properties; the reconstruction could be incomplete; or one interpretation could be mistaken. Resolving those possibilities requires an explicit comparison of positions, sizes, sensitivities and uncertainty.

Reading the paper in its current form

The paper remains readable as a record of the proposal, with its retracted status clearly displayed by the publisher. It should be cited in that form. Removing it from discussion would make the controversy harder to understand. Treating it as an unchanged certificate of validation would also mislead. The useful task is to examine what was proposed and identify the observations that can test it.

The Khafre shafts, spirals and large chamber-like forms

The project’s March 2025 press-conference abstract describes eight cylindrical structures arranged in two rows, descending to a claimed depth of 648 metres and joining two approximately cube-shaped volumes with sides of about 80 metres. These are dimensions reported by the team, derived from its interpretation. They are not distances established by an excavation or an independently verified underground survey.

The same public material discusses a much wider subsurface interpretation extending beneath the plateau. Viral accounts often combine the individual shaft depth, the dimensions of lower volumes and larger-scale claims into a single sentence. That makes the proposed architecture sound more settled than the available evidence allows. Keeping the original quantities attached to the particular feature they describe is essential.

In the Rogan interview, Biondi describes spiral forms, vertical structures and large volumes at depth. He says the group initially considered whether its results might be noise or processing artefacts, and that it subsequently used observations from more than one satellite system. Those are relevant statements about the team’s reasoning. They still need a documented test that an unrelated group can examine.

Why precise predictions matter

A model with eight repeated shafts is more specific than a claim that “something unusual” lies underground. Specificity can make a hypothesis easier to test. It permits predictions about relative positions, depth ranges and dimensions. The benefit is lost if a failed prediction can always be moved to another part of a large, adjustable reconstruction.

The term “city” adds an archaeological interpretation that the rendered forms alone cannot provide. A city implies human occupation, organisation and activities, usually supported by connected material evidence. A putative void, even a very large one, cannot tell us whether people lived there. Before discussing an underground city, investigators would need to establish structures, their artificial character and their relationship to actual human use.

There is no need to minimise how extraordinary the proposed geometry would be if confirmed. The responsible way to preserve that sense of possibility is to retain the conditions attached to it. The claim could become a major discovery through independent observations. At present, the images are best understood as an ambitious interpretation that generates testable questions.

What synthetic aperture radar measures

A radar satellite sends microwave signals towards Earth and records returning echoes. Each return carries information about how strongly a target reflects the signal and about the timing or phase of the wave. The resulting image can reveal patterns that a normal camera misses. It can also look unfamiliar because brightness represents radar scattering rather than the colour of the ground.

The word “synthetic” describes how the instrument uses its motion. A spacecraft receives echoes from a target as it travels along part of its orbit. Processing combines those observations as though they came from a much longer antenna. This greatly improves the ability to separate nearby targets along the flight direction. The technique is established and used for many purposes unrelated to pyramids.

The Italian Space Agency’s COSMO-SkyMed description identifies the system’s high-resolution X-band radar instruments and several observation modes. These instruments can collect sharp surface imagery. A separate question is whether a proposed transformation of those observations can recover detailed geometry hundreds of metres below the surface.

The satellite image and the derived product

A useful way to read any satellite claim is to separate the instrument’s specification from the derived product. A supplier may guarantee the characteristics of a radar acquisition without endorsing an archaeological interpretation made later by a customer. Access to high-quality data is valuable, but the quality of the input does not establish the validity of every calculation performed on it.

Radar also has a particular viewing geometry. It normally observes the terrain from the side rather than looking straight down like a diagram in a textbook. Surfaces at different heights can overlap in the recorded range coordinates. Slopes can appear compressed. Some areas fall into radar shadow. Tall, steep pyramids are therefore an interesting and demanding target for interpretation.

These effects are described in Capella Space’s SAR introduction. They are ordinary features of the measurement process, not proof that a particular reconstruction is wrong. An analysis must show how it handles them. The same requirement applies to weak signals: noise, geometry and the instrument’s own processing should be quantified before a visual pattern is assigned an underground address.

Where the depth information comes from

For a reader, the key question is where the information supporting a given depth actually enters the calculation. The spacecraft’s orbit, radar wavelength, image pixel size and surface precision are all relevant quantities. None alone answers that question. A reliable depth estimate needs an identified physical relationship between the hidden target and the measured signal.

Tiny motion is measurable; hidden architecture is a further inference

The idea that satellite radar can detect very small motion is firmly established. Interferometric SAR compares the phase of radar observations to measure changes in the distance between the sensor and a reflecting surface. It is widely used to investigate subsidence, earthquakes and other ground deformation. The European Space Agency’s explanation of interferometry describes why even a small displacement can change phase measurably.

That sensitivity can sound paradoxical. How can a system whose image pixels cover a visible patch of ground detect movement much smaller than a pixel? Because locating two separate objects and measuring a change in the wave phase from a reflecting target are different tasks. The second can reveal a small displacement without producing a photographic image at that scale.

Consider a distant building with an identifiable reflector. Its motion towards or away from the radar can change the measured phase even though the instrument cannot draw every crack in the wall. That does not mean the measurement is imaginary. It means precision in one quantity should not be confused with resolution in another.

Motion sensitivity and image resolution

This distinction becomes especially important in discussion of the Biondi pyramid scan. Measuring a minute surface displacement would be an achievement at the first stage of the proposed chain. Inferring an unknown chamber’s depth, dimensions and shape from that displacement is a further task. Both stages need validation, and success at one cannot be assumed to settle the other.

Standard interferometry also requires attention to orbit geometry, atmospheric effects and changes in the scattering surface. Biondi’s proposed processing involves its own treatment of the radar data and motion information. It should be assessed on the details of that implementation. Explaining conventional InSAR provides context; it does not establish that every method using the words “phase” or “micro-motion” works in the same way.

A clear technical demonstration would connect these levels explicitly. It would show the measured motion, its uncertainty, the model translating motion into a buried structure and the limits within which that translation is reliable. The more links a chain contains, the more useful it becomes to test them separately. A problem at one stage can then be corrected without reducing the whole discussion to competing impressions.

Can vibrations carry information from inside stone?

Yes, mechanical response can contain information about a structure’s interior. Engineers use vibration measurements to study buildings, bridges and machinery. A change in stiffness, mass or boundary conditions can alter the way an object responds to a disturbance. Seismologists likewise infer hidden properties from waves travelling through the ground.

That general principle gives Biondi’s proposal a recognisable scientific starting point. A cavity can affect the response of the surrounding material. It is reasonable to ask whether a remote sensor can measure enough of that response to infer something useful. The difficulty lies in identifying what information survives to the surface and how uniquely it constrains the hidden geometry.

A musical analogy helps, provided its limits are kept in view. Tapping a hollow object can reveal that it differs from a solid one. Recovering a complete map of every internal passage from a few sounds is a much harder problem. The outcome depends on where the object is struck, where the response is measured, which frequencies are available and what is already known about its material.

The challenge of an uncontrolled setting

The Giza plateau adds complications. It contains masonry, bedrock, fractures, joints and variations in material properties. Background excitation is not a laboratory hammer applied at a fully controlled point. Wind, ambient seismic motion and human activity can have different spatial and temporal patterns. A model needs to account for that complexity well enough to distinguish the proposed target from alternatives.

The word “phonon” also appears in discussion of the method. It belongs to the physics of vibrations in matter. Using the term does not by itself demonstrate that a satellite has recorded a depth-resolved signal. What matters is a quantitative account of the measured quantity, the wave behaviour and the reconstruction. Readers should be able to follow the argument without accepting technical vocabulary as a substitute for a test.

An indirect approach may genuinely extract information that a direct electromagnetic image cannot provide. Its strength would come from demonstrating the relationship under controlled conditions and then showing that it remains valid at the new site. Such a result would be valuable far beyond Egypt. It could improve infrastructure monitoring, geological investigation and the protection of archaeological sites.

How much information survives?

The fair question is therefore how much interior information the particular observations contain. A broad indication of an unusual mechanical response, an approximate depth estimate and a detailed spiral staircase are very different levels of inference. They should be reported with correspondingly different claims about accuracy.

The inverse problem: why several underground models may fit

In a forward calculation, a researcher begins with a model of a structure and predicts the signals it should produce. An inverse calculation works in the other direction: it starts with observations and tries to recover the structure. That reversal is common in science. It is also where ambiguity can enter.

Imagine two underground arrangements that produce nearly the same surface response within the instrument’s uncertainty. If the observations cannot distinguish them, the reconstruction cannot honestly select one with unlimited confidence. Additional assumptions may make a particular model easier to calculate, but those assumptions should remain visible in the interpretation.

This is why inverse methods often use regularisation. A mathematical procedure may favour smoother structures, fewer features or another constrained class of solutions. Such choices can be useful and necessary. They can also influence the appearance of the final image. A crisp boundary can reflect the model’s rules as well as information supplied directly by the data.

A three-dimensional rendering adds another layer. Researchers select thresholds, convert a volume into surfaces, decide which features to connect and choose a visual perspective. Those steps can make a result easier to understand. They can also make uncertain relationships look like finished architecture. A responsible display should explain which boundaries are well constrained and which depend strongly on processing choices.

How processing choices shape a model

Suppose a weak band becomes a continuous shaft only after smoothing. That does not immediately invalidate the interpretation. It creates a useful sensitivity test: show the result with less smoothing, with a reasonable alternative parameter choice and with comparable data from a control area. A feature that survives those changes is more persuasive than one that depends on a narrow setting.

The same reasoning applies to repeated or symmetrical forms. Repetition might reflect deliberate construction. It might also arise from the instrument’s sampling, repeated masonry, a filter or a reconstruction operator. The way to distinguish those explanations is to test examples whose answer is known, then examine whether the same pipeline creates similar patterns where no comparable target should be present.

These are general questions about imaging, not accusations about the Khafre team. They are also useful standards for a critic’s work. Someone claiming that an algorithm inevitably generates false shafts should demonstrate that behaviour under conditions relevant to the original analysis. A reconstruction and a criticism of it both become stronger when another person can repeat the calculation.

Depth, precision and resolution: three quantities worth keeping apart

The scale of the proposed Khafre system makes resolution a central issue. A reader sees a depth value and a clean geometric form, then naturally assumes that the shape was measured with the precision of the drawing. Scientific images often require a more careful reading. The spacing of displayed samples can be much smaller than the smallest feature the data can independently resolve.

Depth is the estimated position of a feature below a chosen reference surface. Precision describes how tightly a result is determined under a stated procedure. Resolution describes the ability to distinguish separate features. Accuracy asks whether the result is close to the true value. An estimate can be precise within a flawed model, and a finely sampled picture can still have poor physical resolution.

A practical example is a blurred photograph enlarged on a screen. The software can create many additional pixels, but that does not recover details the camera never measured. An inverse method can be more sophisticated than simple enlargement and may use useful prior information. It still needs a demonstration that its claimed detail comes from observations that constrain the target.

Each method needs its own performance limits

For a vibration-based reconstruction, the relevant limits involve mechanical wave behaviour, observation duration, sampling, signal strength, geometry and the assumptions used in the inversion. For conventional ground radar, electromagnetic properties and frequency are central. For muography, detector geometry, exposure, particle statistics and the density of the traversed material matter. A single depth slogan cannot describe all three methods.

That is why a shallow radar result inside a pyramid cannot supply a universal maximum depth for every possible indirect approach. It is also why an indirect approach cannot simply inherit the depth capability of seismic methods without showing that it measures sufficient wave information. Each instrument has to establish its own relationship between signal and target.

Readers should look for uncertainty bounds around the reported structures. How far could a shaft move while still fitting the observations? Could two nearby features be separated? How much do dimensions change with different plausible material properties? If such questions are unanswered, the appropriate response is to treat the model as less constrained than its visual sharpness suggests.

Turning depth into a testable prediction

The proposed 648-metre depth is consequently a prediction to evaluate. It should be tied to coordinates, a reference level and an uncertainty range. Those details would turn a dramatic number into something an independent investigation could use. They would also make a disagreement more informative: different teams could compare the same location rather than argue about different pictures.

What repeated scans and benchmark targets can establish

Biondi’s interview describes an important instinct: checking an unexpected result with additional observations. If a feature appears in several acquisitions, a one-off disturbance becomes a less satisfactory explanation. If observations come from separate satellite systems, some instrument-specific problems may also become easier to identify. These checks deserve attention.

However, the strength of repetition depends on what is independent. Two images may still share similar viewing geometry. Two datasets may be processed with the same assumptions. Several reconstructions may therefore reproduce a systematic effect. Repetition is evidence of stability; deciding what that stability represents requires controls.

A useful benchmark is a structure whose location and geometry are already known. In the interview, the Great Pyramid’s familiar rooms and the underground facilities at Gran Sasso are offered as examples of the method’s capability. These should be treated as claimed validations until their inputs, predictions and comparison criteria can be independently assessed.

Gran Sasso provides a good opportunity to define the target precisely. The INFN description identifies large underground experimental halls beside a road tunnel, with substantial rock overburden. A test could specify which halls are to be recovered, their expected coordinates and the amount of error allowed. A visual resemblance to a published plan would be less informative than a prediction scored before that plan was revealed to the analyst.

Benchmarking without knowing the answer

Blinding helps separate discovery from recognition. An analyst who already knows where the King’s Chamber sits may unconsciously select the processing variant that makes a nearby feature look meaningful. That is a human risk in many fields. Hiding target coordinates, locking the method in advance and reporting every attempted target makes the test more convincing.

Negative controls matter too. A method that produces chamber-like shapes in a pyramid and similar shapes in an ordinary comparison area may be responding to something other than buried rooms. Good controls should match relevant conditions as closely as possible. A smooth desert patch and a steep stone monument differ in ways that need to be considered before interpreting a contrast.

The best benchmark report would therefore include successes, failures, uncertainty and the rules used to decide which was which. It would distinguish a fully implemented original method from an approximation reconstructed by someone else. That standard protects an innovative developer from a poor imitation while protecting readers from a demonstration that only shows the most attractive results.

The 2026 retraction: what the notice says and what it leaves open

A retraction is a significant change in the scientific record. It tells readers that a journal no longer stands behind a publication in its original form. For the Biondi–Malanga paper, the stated reason concerns the reliability of the methods and statistics. That is directly relevant to a story whose central question is whether a processing technique can recover hidden geometry.

The public notice is also brief. It says concerns were raised by a reader, an editorial investigation followed, and the journal decided the conclusions were undermined. The document records approval by the editor-in-chief and disagreement from the authors. It does not identify individual equations, reproduce a failed calculation or publish a detailed response from the researchers.

That limited explanation constrains what a magazine can responsibly infer. We cannot reconstruct the complete technical case from the notice alone. We also cannot conclude that the assessment was mistaken simply because its supporting detail is absent from that short document. The transparent position is to report the decision, its stated basis, the disagreement and the information needed to evaluate the dispute more fully.

What a fuller technical exchange could show

It would be valuable to see a detailed account of the identified problems and a point-by-point author response. If a calculation contains a correctable error, readers should be able to understand what changes after correction. A fundamental difficulty in the link between surface motion and deep geometry needs a clear demonstration. If the authors believe the investigation misunderstood the method, their strongest reply would identify the misunderstanding and show the appropriate test.

Scientific publishing includes judgement, and judgement can fail. Initial peer review can miss a weakness; a later assessment can also be incomplete or mistaken. These possibilities are reasons to ask for evidence, rather than grounds for assuming either institution or individual must be right. The same openness that allows an unconventional proposal should allow its calculations to be challenged.

The decision concerns the 2022 Khufu paper. It is not a separately published technical analysis of every later Khafre presentation. Because the later claims depend on a related proposed method, the retraction is relevant to their evidential context. Relevance should not be stretched into an assertion that the journal physically surveyed the proposed deep shafts and proved them absent.

A paper’s status and a physical hypothesis

Nothing in the notice reviewed here establishes deliberate fabrication or a motive to deceive. This article makes no such allegation. A method can be disputed without turning its authors into villains. Likewise, a journal’s assessment can be questioned without inventing a campaign to suppress a discovery. Both positions are better served by publishing enough technical detail for the disagreement to be examined.

For now, the citation should state that the paper is retracted. The physical hypothesis remains capable of being tested. If new, independently checkable evidence emerges, it should be assessed on its merits. The useful outcome is a clearer understanding of the measurement, whether that understanding ultimately supports the proposed structures, narrows them or points elsewhere.

How muography looks through a pyramid

High-energy particles arriving from space interact with Earth’s atmosphere and produce showers of secondary particles, including muons. Many muons reach the ground. Some have enough energy to pass through substantial thicknesses of rock. Their survival depends on the material they encounter and the path they take.

A detector records the directions from which muons arrive. If more particles come through a particular direction than a solid-stone model predicts, the path may contain less material than expected. A cavity is one possible explanation. The result is a measurement of integrated density along a line of sight, from which researchers can constrain the position of a low-density region.

Several viewpoints help narrow that position. Think of seeing a distant light along one direction: it could lie at several distances on that line. A second observation from another position provides another constraint. Muography has more complex statistics and physics than that analogy, but the importance of geometrical coverage is similar.

The technique does not produce a conventional photograph. A density anomaly cannot tell us the colour of the walls, whether an inscription is present or what a chamber was used for. Those questions require other observations. A scientifically strong detection can therefore leave a historically fascinating purpose unresolved.

What the particles cannot tell us

Muography’s practical constraints include detector placement, exposure time and the number of particles that traverse the relevant paths. More rock generally means fewer surviving particles. A proposed deep target below a plateau may require access to an appropriately positioned tunnel or borehole, and the geometry may be impractical. It is misleading to suggest that a portable detector placed anywhere will immediately map every underground space.

These limitations do not diminish the method’s achievements. They explain how those achievements should be read. A well-defined detection supported by multiple instruments can establish a low-density feature with confidence while preserving uncertainty about its exact architecture. That combination of a strong finding and a bounded interpretation is particularly useful in archaeology.

The Big Void: a measured discovery with an unresolved purpose

The 2017 Nature paper reports a space at least 30 metres long above the Grand Gallery in Khufu’s pyramid. Its signal was observed with nuclear emulsion films, scintillator hodoscopes and gas detectors, with three independent analyses. Different detector technologies converged on the finding.

That is why the Big Void has a different evidential status from a dramatic architectural rendering. The published result does not depend on a single type of detector or one attractive view. At the same time, the paper does not identify the space’s intended purpose. “Void” describes the density finding without assigning it a royal burial, treasure store or machine function.

The distinction is important when looking at reconstructions. Illustrators may draw a neat rectangular room to help audiences understand the approximate location. Such a drawing can accidentally imply a surveyed floor, ceiling and entrance. The observations need to determine how confidently those details can be assigned. A visual explanation should not quietly turn an unresolved geometry into an explored chamber.

A structural role is one possible line of investigation. Construction requirements offer another possibility. Any hypothesis about function needs to account for its position within the pyramid, the way loads are transferred and its relationship to known passages. An appealing story about what might lie inside does not add a measurement.

Function remains a separate question

The Big Void also offers a specific comparison for the satellite method. Since Biondi and Malanga’s 2022 paper discusses an absence of a corresponding SAR feature, a careful study could ask what the proposed technique should detect there. Does the model predict a measurable response? What size or material contrast would be required? Could the relevant signal be hidden by other structures?

A disagreement between instruments can teach us about both. It should not be resolved by assuming that the newer, more visually detailed image automatically wins. Nor should the existence of a strong muon result prohibit another technique from being investigated. The task is to calculate each method’s expected sensitivity and compare actual observations within those limits.

The North Face Corridor and the value of a camera check

The North Face Corridor is separate from the Big Void. It lies behind the chevron masonry above the Great Pyramid’s original entrance. The 2023 Nature Communications study describes a corridor about nine metres long, with a cross-section around two by two metres. It refines an anomaly first reported by the ScanPyramids team in 2016.

The discovery illustrates a useful progression. A non-invasive signal suggested an unexpected space. More targeted measurements narrowed its location and dimensions. Radar and ultrasound contributed further information near the north face. Investigators then used a small opening between stones to guide an endoscopic camera into the space, providing a direct view.

The Technical University of Munich’s announcement explains that sequence. It also makes clear that the work involved Cairo University and Egyptian authorities. This was a coordinated investigation in a sensitive monument, rather than a discovery that instantly authorised unrestricted access to the surrounding masonry.

The camera check is especially valuable because it connects a remote inference with a physical scene. The investigators could compare the predicted space with what the lens actually showed. That comparison helps evaluate the instruments and guides subsequent questions. It does not settle every issue about the corridor’s original function or what may lie beyond a wall.

What the camera added

There is a chronology lesson here too. A 2022 reconstruction that resembles a north-face cavity may be interesting, but the anomaly had already been reported before that publication. To establish a genuinely independent prediction, one must compare the dates, coordinates and details available at each stage. The date of the camera footage is not automatically the date when scientists first had evidence of the space.

This is not an argument against acknowledging a useful match. It defines what the match would demonstrate. Recovering a previously reported feature can be a validation exercise. Predicting a new location before any relevant observations are public is a stronger discovery claim. Both can contribute, but they should not be presented as the same achievement.

What the 2025 follow-up studies show about imperfect images

The North Face Corridor did not stop being scientifically interesting once a camera entered it. Later work compared measurements based on different physical properties. A 2025 multimodal image-fusion study brought together ground-penetrating radar, ultrasound and electrical resistivity tomography. Combining complementary measurements helped constrain the same feature.

A separate 2025 resistivity investigation is particularly useful for understanding uncertainty. Its discussion describes differences between reconstructed dimensions and the corridor’s geometry, including effects associated with joints, air gaps and resolution. The paper acknowledges limitations rather than treating every contour in its model as an exact wall.

This is what methodological transparency looks like in practice. Researchers can have a real target and still obtain a blurred or shifted representation of it. A correct detection does not guarantee perfect dimensions. A model that includes simplified stone properties may fit the broad anomaly while missing the complications created by individual blocks and joints.

That example is relevant to the wider debate because it replaces an unrealistic expectation of perfect imaging with a measurable standard. An effective technique should explain its errors. If a known two-metre-scale corridor is reconstructed slightly too wide, the discrepancy can be examined. If a proposed technique reports a much deeper object, the same questions about bias and resolution become even more important.

A real target can still produce an imperfect image

Multiple methods help because their mistakes need not be identical. Radar responds to electromagnetic contrasts, ultrasound to acoustic behaviour and resistivity to electrical properties. Agreement at the same coordinates is more informative when each instrument has been independently calibrated. Combining several highly processed images without addressing their shared assumptions would be a weaker exercise.

Readers can use this case as a reference point. Look for a clearly identified target, a stated observation geometry, an explanation of the inversion, comparisons with other evidence and discussion of error. These features will not make a paper infallible. They make it possible to learn from it and to identify which conclusion might need revision.

Menkaure: a real anomaly is still different from a complete entrance

In November 2025, researchers from Cairo University and TUM reported two air-filled anomalies behind the eastern facade of Menkaure’s pyramid. The investigation used radar, ultrasound and electrical resistivity. The university’s account connects the work to an existing hypothesis about an additional entrance in an unusually finished area of granite masonry.

Here the measured voids and the proposed explanation have different levels of support. The findings support further investigation of a possible entrance. They do not, by themselves, map a continuous passage all the way into a burial chamber or a network beneath the plateau. That restraint makes the finding easier to evaluate rather than less exciting.

It is also a useful reminder that conventional archaeology keeps changing. A site can have been examined for generations and still contain unknown features. New instruments, improved access and a better question can reveal something that earlier surveys did not resolve. Acknowledging that possibility should make us interested in a new scan without requiring immediate acceptance of its largest interpretation.

The Menkaure work should therefore appear beside the Khafre controversy as a separate case with its own location and supporting measurements. A headline that combines them into a single confirmation creates a false connection. The existence of genuine discoveries nearby makes accurate attribution more important, since readers may otherwise assume that all the images belong to one validated project.

Why separate discoveries should stay separate

For the same reason, an illustrated cutaway in this article is labelled conceptual. It helps explain differences in scale and inference. It does not reproduce a measured plan of the unknown interior. The beauty of a diagram should make the evidence easier to understand, without increasing its apparent certainty.

The Western Cemetery and the difference between an anomaly and archaeology

A 2024 Archaeological Prospection study investigated the Western Cemetery at Giza using ground-penetrating radar and electrical resistivity. It is another distinct location in a plateau full of archaeological remains. Its relevance here is methodological: researchers combine surveys to investigate a bounded subsurface question rather than infer an entire civilisation from one image.

An anomaly is a measured departure from the expected response. Its explanation remains a separate task. The departure could relate to an archaeological structure, disturbed ground, a geological boundary or a combination of materials. Survey context helps narrow the possibilities, and excavation may eventually provide evidence that a remote measurement cannot.

This separation is especially important for dates. A geophysical instrument does not normally read an age directly from the outline of a cavity. Investigators need stratigraphy, associated objects, construction relationships, inscriptions or appropriately contextualised samples. Even a clearly artificial underground structure could have been made, modified or reused at several different times.

Consequently, a future confirmation of an unexpected Giza chamber would begin an archaeological investigation. It would not finish one. Questions about builders and purpose would require their own evidence. The prospect is exciting precisely because a new physical context can provide new information, not because an attractive geometric form already contains a complete historical explanation.

Why the limestone beneath Giza belongs in the investigation

The plateau is a geological structure as well as an archaeological site. Its limestone was formed long before the pyramids were built. Different beds, joints, weathering patterns and excavated areas affect how the ground behaves. A model that treats the whole area as a uniform block risks assigning too much meaning to variations that arise naturally.

Ancient Egypt Research Associates has documented relationships between the Sphinx quarry and blocks used in associated temples. Its account of Khafre’s monuments as a unit describes how geological layers can help connect quarrying and construction. That work illustrates the kind of physical context against which a remote reconstruction should be tested.

A low-density region could be a natural opening. An abrupt contrast could follow a material boundary. An elongated feature could relate to a fracture or a human excavation. These are possibilities to compare, rather than ready-made explanations for every new signal. The geological alternative also needs evidence at the relevant location and scale.

The proposed deep Khafre volumes create a particularly important modelling challenge. Their interpretation should be checked against the properties of rock at depth, possible groundwater conditions and the mechanical effect of large voids. Those questions cannot be answered solely by looking at the monument’s exterior. A geologist and a structural specialist would add information that an architectural rendering cannot supply.

Testing natural and artificial explanations

There is also a distinction between recognising a regular shape and proving that it was built. A repeated rectangular pattern may make an artificial explanation attractive, but a processing pipeline can impose regularity. Conversely, a real human structure may have become distorted by collapse or later disturbance. Shape is evidence to evaluate in context, not a universal signature.

A sensible field programme would begin by mapping what is already known in the target area. Existing tombs, shafts, quarry boundaries and conservation interventions should be recorded in the same coordinate system as the predicted anomalies. That comparison could identify promising tests while preventing an old feature from being announced as new under a different name.

What a scan can tell us about age, builders and purpose

The leap from an underground form to a lost civilisation is much larger than it first appears. First the feature must be shown to exist. Then investigators need to determine whether it is natural or artificial. Only after that can they examine when it was made, by whom and for what activities. Each stage introduces a different evidential question.

A hypothetical chamber does not acquire an Ice Age date because the visible pyramids are difficult to explain. A modern survey measures present physical properties. It does not automatically identify the period in which a cavity formed. Dating would require relevant material or a relationship to a sequence of construction, use and deposition.

Context is especially important for samples. A fragment found in a passage could belong to its construction, a later visit, an animal intrusion or recent contamination. An isolated date needs to be connected to the feature being dated. A good excavation record preserves those relationships so that another researcher can understand what the sample actually establishes.

Dating requires physical context

The archaeological case for Old Kingdom activity at Giza includes much more than a conventional timeline repeated in textbooks. The published translation of Merer’s logbook records movements involving Tura and Akhet-Khufu. Work on the papyri connects them to limestone transport during Khufu’s reign. They are direct evidence of an organised building landscape, though they do not describe every engineering step used to construct the pyramid.

The distinction works both ways. A logbook about stone transport cannot prove that every possible underground cavity belongs to the same construction phase. A newly proposed cavity cannot erase the logbook or the archaeological context around it. An expanded history would need to explain the existing evidence as well as the new observation.

Our guide to Graham Hancock’s lost-civilisation arguments explores related questions about the distance between a suggestive pattern and a dated archaeological case. For the Biondi pyramid scan, the useful next step remains more immediate: establish what is physically present at a specified location. Historical interpretation becomes stronger when it grows from that foundation.

The power-plant and acoustic-resonator interpretations

The 2022 paper goes beyond proposing hidden passages. It offers a possible water-filled acoustic system, connecting the geometry of rooms and shafts to resonance and fluid circulation. In public discussion, those ideas are often mixed with claims that the pyramids functioned as power plants or were designed to manipulate natural energy.

These are hypotheses about function. They require a different kind of evidence from a scan. A model could recover the shape of a real room correctly while its account of the room’s purpose remains wrong. An acoustic effect in a stone chamber would establish a physical behaviour, not necessarily the intention of the builders.

Many enclosed spaces resonate. Many structures interact mechanically with wind or ground motion. To argue that an ancient building was deliberately designed around a particular effect, researchers need to show why that function explains the architecture better than alternatives. They should also identify the material traces that would be expected from its operation.

For a proposed water system, useful questions concern supply, sealing, pressure, drainage, deposits and wear. Do the predicted connections exist? Could water move through them as described? Are the necessary barriers and outlets present? A functioning hydraulic model would need to respect the actual levels and materials rather than a simplified arrangement chosen for a demonstration.

Testing water and energy proposals

For an energy-generation proposal, the investigation would need an identified source, conversion process, output and use. A spiral-shaped interpretation does not by itself establish an electrical coil. The physical composition and connections matter. Stone geometry can resemble a modern component without sharing its operating mechanism.

These questions can be asked without dismissing ancient ingenuity. Egyptian builders organised enormous works and manipulated materials with considerable skill. Their achievements deserve study in their own context. Giving them speculative technology without the supporting archaeological evidence can obscure the techniques they demonstrably developed.

The same caution applies to the traditional funerary interpretation. It should be explained through the wider complex of pyramids, temples, burials, texts and architectural relationships, rather than through an assertion that every empty room has one obvious purpose. There is room to investigate construction roles, ritual activities and later reuse within that broader context.

An interesting acoustic experiment could contribute to this discussion if it separated measurable effects from claims about ancient intention. A credible underground survey could contribute a new piece of architecture. Neither has to carry an entire alternative history at once. Progress is often more convincing when individual questions are answered in a sequence.

Watch Filippo Biondi explain the method to Joe Rogan

The official PowerfulJRE upload of The Joe Rogan Experience, episode 2443, is embedded below. It was published on 23 January 2026. Biondi explains the proposed relationship between surface vibration and hidden structures, describes the move from Khufu to the wider plateau and discusses the forms he believes the processing reveals. The interview predates the August retraction.

Official video: PowerfulJRE, 23 January 2026. Starts near the explanation of the proposed method. An interview records the researcher’s account; it does not independently validate the reconstructed structures. The site may ask for YouTube consent before playback.

Useful starting points are approximately 3:30 for the method, 9:36 for initial doubts and additional satellite observations, 18:00 for the displayed reconstructions and 44:30 for proposed exploration. Timestamps are approximate and can shift if a publisher changes an upload.

One of the most useful moments is the discussion of an image as a reconstruction. A model assembled to make an interpretation understandable should be examined alongside the measurements from which it was built. That is a fair request for any scientific visualisation, including the conceptual graphics in this article.

The interview also helps readers distinguish the researcher’s confidence from an independent finding. Biondi describes checks he considers persuasive. Those checks are worth documenting and testing. A host’s agreement with a guest is not an additional dataset, just as a dismissive reaction from another commentator is not a field survey.

How to watch the interview critically

Long-form conversation provides context that a short viral clip can lose. It also permits speculation to move quickly between technology, archaeology and ancient history. Viewers can enjoy the conversation while pausing at each transition to ask what evidence supports the next step. That habit preserves curiosity and prevents an interesting possibility from becoming an assumed fact through repetition.

How to evaluate criticism without treating it as a verdict

There is a temptation to organise a controversy around personalities: the innovator, the gatekeeper, the enthusiast and the debunker. Those roles make a simple story, but they do little to identify whether an imaging method works. A technical criticism is useful when it points to a check that can be performed and explains what the outcome would mean.

A critic might challenge whether the observed displacement is real, whether it comes from the target, whether the inversion can localise it or whether the proposed geometry is uniquely supported. These are different objections. A reply addressing only radar penetration would not settle all of them. A reply addressing one incorrect objection would not automatically validate the complete reconstruction.

Public reproduction attempts can be valuable when their code, inputs and corrections are available. They also need careful attribution. An independent implementation may approximate an unpublished step or choose a parameter differently. Its failure may expose an important limitation, or it may reveal that the method has not been specified clearly enough to reproduce. Those possibilities should be distinguished.

The most informative exchange would let both sides run agreed tests. The developers could identify a faithful implementation. Critics could specify controls and scoring rules. An independent group could hold back target information until the predictions were locked. This would replace arguments about selected pictures with comparable outcomes.

Making the disagreement reproducible

Public scrutiny can make mistakes too. If a critical calculation is corrected, the correction should be reflected in later coverage. If a developer revises a method, the new version should be identified separately from the old one. Scientific disagreement becomes much easier to follow when claims are attached to dated versions rather than treated as fixed positions held by teams.

This article therefore does not use the retraction, the interview or the existence of a critical website as a substitute for the missing independent field evidence. Each is a relevant part of the record. Their meaning depends on what they establish. The physical question remains open to a well-designed investigation, with confidence proportionate to its results.

A practical test programme for the Biondi pyramid scan

A useful programme would start before anyone drills a hole. The first task is to define a small set of predictions that can be scored. A target described as “a large system somewhere under the plateau” leaves too much room for interpretation. A target described by coordinates, depth range, orientation and dimensions gives another team a practical question.

The method should then be frozen for that test. Researchers would record the software version, parameter settings, input acquisitions and processing steps. Any later adjustment could be documented as a new analysis. This prevents a search through many variants from being presented as a single prediction made in advance.

Known targets should be included alongside genuinely unknown ones. Some target coordinates could be hidden from the analysts. Comparison areas should have similar surface and geological characteristics where possible. A mixture of expected positives and negatives provides more information than a demonstration built entirely around impressive successes.

The scoring rules need to define a match. How close must the location be? What error in depth is acceptable? How accurately must size and orientation be recovered? If a wide diffuse anomaly counts as a success for a small room, the test may be too permissive. Rules chosen before the answer is revealed are easier for everyone to trust.

Agree the scoring rules before the result

Separate teams should investigate the same targets with methods appropriate to the physical setting. That might involve seismic work, resistivity, gravity measurements or muography where a suitable detector position exists. There is no universal instrument for every depth and geometry. An independent survey must establish what it could detect before a null result is interpreted.

A result should be compared quantitatively. Do predicted and observed locations overlap within their stated uncertainty? Does an instrument respond to the proposed void size, or only to a broader geological change? If two methods agree, are they responding to the same physical feature? These questions prevent a vague similarity from being announced as confirmation.

Only then would a targeted physical inspection become a carefully defined possibility. Egyptian authorities and conservation specialists would need to assess access, structural risk and the value of the proposed intervention. A small camera opening might answer a shallow question. A very deep target presents different engineering challenges and cannot be treated as a routine extension of a north-face inspection.

The project would benefit from publishing every outcome, including unsuccessful targets. A partial success could be valuable: perhaps a method detects broad material changes but cannot recover detailed architecture. An unsuccessful test could identify a limitation that leads to a better technique. A strong success at a genuinely unknown target would give the discussion a much firmer foundation.

Could the ScIDEP Khafre project help?

The 2025 ScIDEP paper describes the development of new muon telescopes intended to investigate Khafre’s internal structure. It reports detector construction, commissioning work and simulations. Those are preparations for measurements, rather than a published confirmation of the deep structures shown in the Khafre SAR reconstructions.

The distinction between a planned survey and its results matters because announcements can circulate for years. A detector being developed for a pyramid does not mean it has already produced a complete scan. Any later claim of confirmation should be tied to a dated measurement report with detector positions, exposure, analysis and uncertainty.

Even a successful new survey would have a defined field of view. Detectors placed within or near Khafre can constrain particular paths through the monument. They cannot automatically inspect every point far below the plateau. A project could therefore answer valuable questions about the pyramid while remaining unable to test the deepest SAR claims.

That outcome would still be worthwhile. Mapping unknown parts of Khafre’s internal structure could improve archaeology and conservation. The science does not need to resolve the largest internet claim to have value. It should be judged by the questions its instruments were designed to answer.

Questions readers ask about the pyramid scans

Has an underground city beneath Giza been confirmed?

No independent field confirmation of the specific deep city-like system was established in the primary and project sources reviewed for this edition. The project’s visualisations describe a proposed interpretation. Giza certainly contains real underground archaeological and geological features, but that general fact does not verify the particular large network shown in the viral reconstructions.

Can satellite radar see through hundreds of metres of limestone?

Conventional satellite SAR should not be described as a direct camera through such a thickness of rock. Biondi proposes an indirect route based on surface micro-motion and its relationship to hidden structure. The central issue is whether that relationship provides enough reliable information to recover the claimed geometry. It needs to be tested as an indirect method.

Does the retraction prove that nothing is there?

No. The retraction changes the status of a particular paper and records the journal’s assessment of its reliability. It is not a physical survey of every proposed underground target. The notice also records the authors’ disagreement. A separate, appropriately sensitive investigation would be needed to establish or exclude a specific structure.

Could the journal’s assessment itself contain mistakes?

Yes, a journal assessment can be mistaken, just as a paper or a criticism can be mistaken. That possibility needs to be investigated through specific evidence. The brief public notice does not provide a detailed technical case to inspect, so this article reports its limits without assuming that the decision is either infallible or invalid.

Are the Big Void and the North Face Corridor the same thing?

No. Both are associated with Khufu’s Great Pyramid, but they occupy different locations and have different discovery histories. The Big Void is above the Grand Gallery. The North Face Corridor is behind the chevron masonry near the original entrance. Neither is the proposed set of deep shafts beneath Khafre.

Did Biondi predict the corridor before ScanPyramids found it?

The timeline needs care. ScanPyramids reported the north-face anomaly in 2016, before the 2022 Biondi–Malanga paper. The more precise characterisation and camera inspection came later. A claim of an independent prediction should compare what was published, where it placed the feature and when that information became available. A later camera date alone cannot establish priority.

Are the pictures in this article actual radar scans?

The four new illustrations are original AI-assisted editorial graphics. They include conceptual scenery and clearly labelled schematics. They are not raw satellite observations, documentary views of underground structures or precise surveyed plans. Primary sources are linked so readers can examine the original figures and descriptions in their proper context.

What evidence would change the current assessment?

A preregistered, independently successful recovery of unknown targets would strengthen the proposed method. Convergence with another suitable instrument at the same coordinates would add further support. A properly authorised physical inspection could establish what a feature actually is. Each result should be reported with limits and uncertainty, allowing the assessment to change as evidence improves.

The most interesting next discovery would be a test that works

The lasting value of the Filippo Biondi pyramid scan controversy will depend on what investigators can make testable. Its proposed method raises a legitimate question about extracting structural information from motion. The deep Khafre reconstructions make unusually specific claims that deserve an equally specific examination.

The 2026 retraction belongs in that examination, together with the authors’ disagreement and the limits of the published notice. It should neither disappear from coverage nor become a shortcut around the technical discussion. More transparent calculations and independently checked predictions would help readers evaluate both the original proposal and the criticisms of it.

Giza already rewards patient investigation. Muon detectors have revealed a major low-density space. A combination of instruments and a camera has established a hidden corridor. Other surveys continue to add bounded findings and new questions. That record gives us a reason to keep looking, while being precise about what each discovery shows.

If a carefully designed test confirms one of the proposed deep structures, the story will become more compelling. If it identifies a processing limitation, that will also be useful knowledge. The aim is to reach a physical answer that remains persuasive after the image has stopped being surprising.