Scientific review

CODATA 2022: 1.616255e-35 m. Proton charge diameter / Planck length is about 1.04e20, consistent with the rounded hundred-billion-billion comparison.

The numerical length is verified. A literal universal pixel size or minimum length is unproven. The scientific review distinguishes this metaphor from an established physical limit; no experimentally resolved structures populate the gap.

• physics.nist.gov
• doi.org

CMS April 2026 report explicitly states a 1e-20 m substructure probe with no evidence for constituents.

This is model-dependent experimental sensitivity, not a measured quark size.

• home.cern

No finite known rest-mass Compton wavelength is assigned to this entry.

The stored 1e-19 m is a navigation placeholder only. Neutrino flavour states mix mass eigenstates; photon/gluon are massless in the Standard Model. Must remain excluded from physical size comparison and continuous journey.

• pdg.lbl.gov

No finite known rest-mass Compton wavelength is assigned to this entry.

The stored 1e-19 m is a navigation placeholder only. Neutrino flavour states mix mass eigenstates; photon/gluon are massless in the Standard Model. Must remain excluded from physical size comparison and continuous journey.

• pdg.lbl.gov

No finite known rest-mass Compton wavelength is assigned to this entry.

The stored 1e-19 m is a navigation placeholder only. Neutrino flavour states mix mass eigenstates; photon/gluon are massless in the Standard Model. Must remain excluded from physical size comparison and continuous journey.

• pdg.lbl.gov

No finite known rest-mass Compton wavelength is assigned to this entry.

The stored 1e-19 m is a navigation placeholder only. Neutrino flavour states mix mass eigenstates; photon/gluon are massless in the Standard Model. Must remain excluded from physical size comparison and continuous journey.

• pdg.lbl.gov

No finite known rest-mass Compton wavelength is assigned to this entry.

The stored 1e-19 m is a navigation placeholder only. Neutrino flavour states mix mass eigenstates; photon/gluon are massless in the Standard Model. Must remain excluded from physical size comparison and continuous journey.

• pdg.lbl.gov

No finite known rest-mass Compton wavelength is assigned to this entry.

The stored 1e-19 m is a navigation placeholder only. Neutrino flavour states mix mass eigenstates; photon/gluon are massless in the Standard Model. Must remain excluded from physical size comparison and continuous journey.

• pdg.lbl.gov

No finite known rest-mass Compton wavelength is assigned to this entry.

The stored 1e-19 m is a navigation placeholder only. Neutrino flavour states mix mass eigenstates; photon/gluon are massless in the Standard Model. Must remain excluded from physical size comparison and continuous journey.

• pdg.lbl.gov

No finite known rest-mass Compton wavelength is assigned to this entry.

The stored 1e-19 m is a navigation placeholder only. Neutrino flavour states mix mass eigenstates; photon/gluon are massless in the Standard Model. Must remain excluded from physical size comparison and continuous journey.

• pdg.lbl.gov

Recomputed reduced Compton wavelength hbar*c/(m*c^2) using PDG 2025 mass 172.56 GeV: 1.14352678e-18 m.

Quantum length, not particle diameter. Quark masses are renormalization-scheme dependent; no free isolated light quark radius follows from this number. Renderer correctly uses a physical-length bracket and a symbolic locator.

• pdg.lbl.gov
• physics.nist.gov

Recomputed reduced Compton wavelength hbar*c/(m*c^2) using PDG 2025 mass 125.2 GeV: 1.57609409e-18 m.

Quantum length, not particle diameter. Quark masses are renormalization-scheme dependent; no free isolated light quark radius follows from this number. Renderer correctly uses a physical-length bracket and a symbolic locator.

• pdg.lbl.gov
• physics.nist.gov

Recomputed reduced Compton wavelength hbar*c/(m*c^2) using PDG 2025 mass 91.188 GeV: 2.16395776e-18 m.

Quantum length, not particle diameter. Quark masses are renormalization-scheme dependent; no free isolated light quark radius follows from this number. Renderer correctly uses a physical-length bracket and a symbolic locator.

• pdg.lbl.gov
• physics.nist.gov

Recomputed reduced Compton wavelength hbar*c/(m*c^2) using PDG 2025 mass 80.3692 GeV: 2.45525625e-18 m.

Quantum length, not particle diameter. Quark masses are renormalization-scheme dependent; no free isolated light quark radius follows from this number. Renderer correctly uses a physical-length bracket and a symbolic locator.

• pdg.lbl.gov
• physics.nist.gov

Recomputed reduced Compton wavelength hbar*c/(m*c^2) using PDG 2025 mass 4.183 GeV: 4.7173555e-17 m.

Quantum length, not particle diameter. Quark masses are renormalization-scheme dependent; no free isolated light quark radius follows from this number. Renderer correctly uses a physical-length bracket and a symbolic locator.

• pdg.lbl.gov
• physics.nist.gov

Recomputed reduced Compton wavelength hbar*c/(m*c^2) using PDG 2025 mass 1.77693 GeV: 1.11049383e-16 m.

Quantum length, not particle diameter. Quark masses are renormalization-scheme dependent; no free isolated light quark radius follows from this number. Renderer correctly uses a physical-length bracket and a symbolic locator.

• pdg.lbl.gov
• physics.nist.gov

Recomputed reduced Compton wavelength hbar*c/(m*c^2) using PDG 2025 mass 1.77693 GeV: 1.11049383e-16 m.

Quantum length, not particle diameter. Quark masses are renormalization-scheme dependent; no free isolated light quark radius follows from this number. Renderer correctly uses a physical-length bracket and a symbolic locator.

• pdg.lbl.gov
• physics.nist.gov

Recomputed reduced Compton wavelength hbar*c/(m*c^2) using PDG 2025 mass 1.273 GeV: 1.55009411e-16 m.

Quantum length, not particle diameter. Quark masses are renormalization-scheme dependent; no free isolated light quark radius follows from this number. Renderer correctly uses a physical-length bracket and a symbolic locator.

• pdg.lbl.gov
• physics.nist.gov

Twice CODATA 2022 proton RMS charge radius 0.84075 fm gives 1.6815 fm, rounding to the existing 1.7 fm.

Standardized metadata to the same RMS-charge convention as the other nuclei. Surface and constituent illustration remain schematic.

• physics.nist.gov

Recomputed reduced Compton wavelength hbar*c/(m*c^2) using PDG 2025 mass 0.1056583755 GeV: 1.86759431e-15 m.

Quantum length, not particle diameter. Quark masses are renormalization-scheme dependent; no free isolated light quark radius follows from this number. Renderer correctly uses a physical-length bracket and a symbolic locator.

• pdg.lbl.gov
• physics.nist.gov

Recomputed reduced Compton wavelength hbar*c/(m*c^2) using PDG 2025 mass 0.1056583755 GeV: 1.86759431e-15 m.

Quantum length, not particle diameter. Quark masses are renormalization-scheme dependent; no free isolated light quark radius follows from this number. Renderer correctly uses a physical-length bracket and a symbolic locator.

• pdg.lbl.gov
• physics.nist.gov

Recomputed reduced Compton wavelength hbar*c/(m*c^2) using PDG 2025 mass 0.0935 GeV: 2.11044899e-15 m.

Quantum length, not particle diameter. Quark masses are renormalization-scheme dependent; no free isolated light quark radius follows from this number. Renderer correctly uses a physical-length bracket and a symbolic locator.

• pdg.lbl.gov
• physics.nist.gov

Updated to twice CODATA 2022 RMS charge radius 1.6785 fm: 3.357 fm.

Previously used the explicitly dated 2013 IAEA compilation. This update is minor and does not imply a hard surface.

• physics.nist.gov

Updated to twice CODATA 2022 RMS charge radius 2.12778 fm: 4.25556 fm.

Previous 2013 IAEA radius 2.1421 fm was dated rather than fabricated; updated for consistency with current CODATA.

• physics.nist.gov

IAEA Angeli/Marinova 2013 compilation gives RMS charge radius 2.4702 fm, doubled to 4.9404 fm.

Fetched CSV and checked isotope row directly. Historical compiled estimate and explicit RMS convention retained; nucleon placements are schematic.

• www-nds.iaea.org

IAEA Angeli/Marinova 2013 compilation gives RMS charge radius 3.7377 fm, doubled to 7.4754 fm.

Fetched CSV and checked isotope row directly. RMS radius is not a sharp outer edge.

• www-nds.iaea.org

Standardized to uranium-238: twice IAEA RMS charge radius 5.8571 fm = 11.7142 fm.

The previous ~15 fm geometric nuclear diameter mixed conventions with the other nuclei. Isotope and convention now explicit; image remains schematic.

• www-nds.iaea.org

Recomputed reduced Compton wavelength hbar*c/(m*c^2) using PDG 2025 mass 0.0047 GeV: 4.19844639e-14 m.

Quantum length, not particle diameter. Quark masses are renormalization-scheme dependent; no free isolated light quark radius follows from this number. Renderer correctly uses a physical-length bracket and a symbolic locator.

• pdg.lbl.gov
• physics.nist.gov

Recomputed reduced Compton wavelength hbar*c/(m*c^2) using PDG 2025 mass 0.00216 GeV: 9.13550835e-14 m.

Quantum length, not particle diameter. Quark masses are renormalization-scheme dependent; no free isolated light quark radius follows from this number. Renderer correctly uses a physical-length bracket and a symbolic locator.

• pdg.lbl.gov
• physics.nist.gov

Recomputed reduced Compton wavelength hbar*c/(m*c^2) using PDG 2025 mass 0.00051099895 GeV: 3.86159268e-13 m.

Quantum length, not particle diameter. Quark masses are renormalization-scheme dependent; no free isolated light quark radius follows from this number. Renderer correctly uses a physical-length bracket and a symbolic locator.

• pdg.lbl.gov
• physics.nist.gov

Recomputed reduced Compton wavelength hbar*c/(m*c^2) using PDG 2025 mass 0.00051099895 GeV: 3.86159268e-13 m.

Quantum length, not particle diameter. Quark masses are renormalization-scheme dependent; no free isolated light quark radius follows from this number. Renderer correctly uses a physical-length bracket and a symbolic locator.

• pdg.lbl.gov
• physics.nist.gov

1 pm is a valid example in the gamma-ray range.

A wavelength, not a photon diameter; gamma/X-ray definitions overlap and can also depend on production mechanism.

• lambda.gsfc.nasa.gov

The pico SI prefix is exactly 1e-12.

Reference dot only; not a physical particle.

• www.bipm.org

10 pm is a valid short-wavelength X-ray example.

No universal X-ray wavelength or sharply defined boundary with gamma rays.

• imagine.gsfc.nasa.gov

Twice the CODATA Bohr radius is 1.058354421088e-10 m, rounding to 1.06e-10 m.

Renderer uses a 1s exponential density slice and extends faint shading to 4 Bohr radii. This is a characteristic length, not an outer diameter. Nuclear positions are not represented at nuclear scale.

• physics.nist.gov

NIST CCCBDB equilibrium O-H bond length 0.958 angstrom and H-O-H angle 104.5 degrees are represented in the renderer.

The 0.275 nm outer span is only an illustrative electron-cloud envelope, not a uniquely measured molecular diameter. Made this explicit; source added.

• cccbdb.nist.gov

RSC covalent radius 1.45 angstrom doubled gives 0.290 nm.

A covalent-radius convention; atom shading is a qualitative envelope, not computed multi-electron density.

• periodic-table.rsc.org

RSC covalent radius 2.00 angstrom doubled gives 0.400 nm.

A covalent-radius convention, not a sharp atom diameter.

• periodic-table.rsc.org

RSC covalent radius 2.38 angstrom doubled gives 0.476 nm.

Corrected source URL spelling to the live RSC caesium page. Numerical value retained.

• periodic-table.rsc.org

The nano SI prefix is exactly 1e-9.

Reference length, not an object.

• www.bipm.org

PDB 1BNA is an experimentally determined B-DNA dodecamer, X-ray diffraction at 1.9 angstrom resolution. Nominal B-DNA duplex width ~2 nm.

App uses measured heavy-atom coordinates and conventional space-filling atom radii. Drawn surface extends beyond nominal helix width. Approximate fragment length depends on terminal atoms and rendering radii; it is not claimed as an exact measurement.

• www.rcsb.org

25 nm is a supported representative ribosome diameter.

Species and conformation vary. Existing illustrative image is not asserted to be a measured atomic model of a named species.

• journals.iucr.org
• pdb101.rcsb.org

100 nm lies in the commonly observed ~80-120 nm range for spherical influenza virions.

Influenza can also form micron-long filaments. The existing entry correctly says representative spherical particle.

• www.nature.com
• www.nature.com

Research found viable ultrasmall bacterial cells passing a 0.2 micrometre filter; volume ~0.009 cubic micrometres.

A filter size is not a universal cell diameter. Existing caveat no sharp boundary is essential; a rigorous lower size limit for life is unknown.

• www.nature.com
• newscenter.lbl.gov

Mature HSV-1 outer diameter approximately 225 nm including glycoprotein spikes; published mean envelope diameter of 186 nm excludes the spikes.

Representative reference near 200 nm replacing the supercoiled DNA silhouette. Virions are pleomorphic. The generated intact-envelope rendering is illustrative, not microscopy or a measured atomic reconstruction; colour, surface details and exact glycoprotein positions are not empirically verified.

• ictv.global
• doi.org
• journals.asm.org

400 nm lies within the often-observed 300-800 nm range reported by Rideau et al. 2022.

Representative generated cell; no single species or universal dimension claimed.

• pubmed.ncbi.nlm.nih.gov

2 micrometres is a defensible typical body length; growth state affects size.

Body length excludes flagella. Image appearance is illustrative.

• www.nature.com

Normal human red-cell disc diameter is approximately 8 micrometres.

Biconcave shape and deformability are supported. Diameter and thickness must not be confused.

• pmc.ncbi.nlm.nih.gov
• www.cellimagelibrary.org

Individual cells ~8 micrometres; total 22 micrometres is a constructed cluster arrangement.

There is no standard cluster size. Electron-microscope-style generated image is explicitly an illustration, not microscopy.

• www.cellimagelibrary.org

Guidobaldi et al. studied human sperm cells approximately 60 micrometres long.

Generated cell illustration. The app distinguishes total contour length from shorter projected span. Morphological detail is illustrative rather than a validated electron micrograph.

• arxiv.org

80 micrometres is within reported scalp-hair diameter ranges.

A representative diameter, not a universal hair thickness.

• doi.org
• bionumbers.hms.harvard.edu

~120 micrometres is a supported fully-grown human oocyte body diameter; zona pellucida increases outer size.

App measuredFraction .81 makes outer rendered span ~148 micrometres. Generated illustrative unfertilized cell, not a photograph or universally exact morphology.

• pmc.ncbi.nlm.nih.gov
• journals.physiology.org

0.5 mm falls within the sedimentary sand class ~0.0625 to 2 mm.

Size class, not one mineral or universal grain size.

• pubs.usgs.gov

A 5 mm ant is plausible; University of Maine identifies photographed Camponotus nearcticus workers of this length.

The app does not identify this illustration to species. Keep generic representative length rather than claim all ants have this size.

• extension.umaine.edu

7 mm is a normal cultured pearl diameter; GIA describes common akoya pearls in the 6-8 mm range.

Not a universal pearl diameter or an assertion that the rendered pearl has a known provenance.

• www.gia.edu

University of Florida gives adult body length 6-7 mm; app shows 9 mm illustrative span including legs/wings.

9 mm is not an independently measured biological dimension. Kept as explicitly illustrative visible span, repaired source URL and removed obsolete reference-recording interpretation from fact text.

• edis.ifas.ufl.edu

Exact decimal SI prefix: 10^-2 m.

Numerical comparison checked against the stated dimension; illustrations are not metrology or independently verified anatomy.

• www.nist.gov

15 mm is an illustrative worker body length near the upper end of the 12–15 mm extension reference. Body excludes wings, legs and antennae.

Adjusted artwork measuredFraction to0.8 after visual inspection of body versus protruding antennae/wing/leg span. Calibration is approximate because generated image is oblique.

• extension.psu.edu

European Commission specification: 16.25 mm diameter; copper-covered steel.

Numerical comparison checked against the stated dimension; illustrations are not metrology or independently verified anatomy.

• economy-finance.ec.europa.eu

67 mm is within the ITF Type 1/2 range 65.4–68.6 mm, not a unique regulation diameter.

Numerical comparison checked against the stated dimension; illustrations are not metrology or independently verified anatomy.

• www.itftennis.com

80 mm is an explicitly illustrative fish length, with no identified species or measured individual.

Illustrative selected size only. No empirical verification of the depicted specimen is claimed.

• Chosen illustrative reference; no measured specimen.

68–70 cm circumference implies 216.5–222.8 mm spherical diameter; 220 mm is a rounded example.

Numerical comparison checked against the stated dimension; illustrations are not metrology or independently verified anatomy.

• theifab.com

International foot is exactly 0.3048 m.

Numerical comparison checked against the stated dimension; illustrations are not metrology or independently verified anatomy.

• www.nist.gov

450 mm is an illustrative stage of growth. The source describes emperor penguin biology but does not measure this chick.

Illustrative selected size only. No empirical verification of the depicted specimen is claimed.

• www.antarctica.gov.au

460 mm excludes tail and is an illustrative domestic-cat body length, not a measured breed average. The general source gives total length and cannot establish this pictured individual.

Illustrative selected size only. No empirical verification of the depicted specimen is claimed.

• animaldiversity.org

800 mm is now explicitly the illustrated outer span including quills. It cannot accurately be called head-and-body length because quills occupy much of the picture. Crested porcupines can have body lengths up to about900 mm and long projecting quills.

Relabelled metric as outer span including quills, because existing silhouette width is not an anatomical body measurement.

• animals.sandiegozoo.org

Exact SI length reference.

Numerical comparison checked against the stated dimension; illustrations are not metrology or independently verified anatomy.

• www.nist.gov

1.15 m is a representative adult within the 1.1–1.3 m range.

Numerical comparison checked against the stated dimension; illustrations are not metrology or independently verified anatomy.

• www.asoc.org

1.3 m head/body falls within San Diego Zoo 1–1.4 m; tail excluded.

Numerical comparison checked against the stated dimension; illustrations are not metrology or independently verified anatomy.

• animals.sandiegozoo.org

1.75 m is a chosen adult-height reference, not a demographic average or a measurement of the generated figure.

Illustrative selected size only. No empirical verification of the depicted specimen is claimed.

• Chosen illustrative reference; no measured specimen.

2.4 m is a plausible illustrative adult; Smithsonian gives adults up to about2.74 m, with sex differences.

Numerical comparison checked against the stated dimension; illustrations are not metrology or independently verified anatomy.

• nationalzoo.si.edu

3 m is a large adult example, not average. NOAA lists maxima around13 feet (~4 m).

Numerical comparison checked against the stated dimension; illustrations are not metrology or independently verified anatomy.

• www.fisheries.noaa.gov

Representative adult male length of 3.3 m, within the published 3–3.5 m range.

Numerical comparison checked against the stated dimension; illustrations are not metrology or independently verified anatomy.

• npolar.no

4 m disc width is a representative example, not maximum; NOAA states wingspan up to26 feet (~7.9 m).

Numerical comparison checked against the stated dimension; illustrations are not metrology or independently verified anatomy.

• www.fisheries.noaa.gov

Manufacturer overall length 4.233 m, height approximately 1.55 m.

Generated side-profile illustration, not an official photo. The app calibrates the bumper span to 4.233 m and roof-to-tire span to approximately 1.55 m. Individual styling details are illustrative.

• www.volvocars.com

Approximately 5.3 m horizontal silhouette in the illustrated pose; approximately 3.3 m shoulder height retained.

Horizontal posed span replaces shoulder height as the comparison dimension. It includes visible tusks and tail; the curved trunk is not extended. This is an assigned illustrative span constrained by realistic shoulder height, not a measured specimen or the 6–7.5 m anatomical length including an extended trunk. Clean isolated artwork removes the adjacent whale fin.

• ielc.libguides.com

5.5 m matches San Diego Zoo upper male height, rather than an average giraffe.

Numerical comparison checked against the stated dimension; illustrations are not metrology or independently verified anatomy.

• animals.sandiegozoo.org

10 m illustrative specimen height

Reduced from the previous illustrative 20 m height. The species and actual height of the photographed specimen are unknown; this is an assigned comparison scale, not a field measurement.

• commons.wikimedia.org

12 m is the NHM representative adult total length; very large specimens approach13 m. Reconstruction and posture add uncertainty.

Numerical comparison checked against the stated dimension; illustrations are not metrology or independently verified anatomy.

• www.nhm.ac.uk

25 m is a representative adult length; NOAA confirms largest living animal and examples reaching30 m or more.

Numerical comparison checked against the stated dimension; illustrations are not metrology or independently verified anatomy.

• www.fisheries.noaa.gov

85 m is a large mature-tree example. NPS measured General Sherman at83.8 m; this generated tree is not General Sherman. NPS records sequoia ages up to3,400 years.

Numerical comparison checked against the stated dimension; illustrations are not metrology or independently verified anatomy.

• www.nps.gov

SpaceX manufacturer page specifies 124 m overall,52 m upper stage,72 m booster and9 m body diameter for its October 2026 design configuration.

User-supplied reference with edited background removal, retaining natural image proportions. Overall displayed height uses the manufacturer 124 m configuration. The exact version depicted in the reference and its original source are unknown; the image is not a certified engineering drawing.

• www.spacex.com

330 m including 2022 antenna is verified by the tower operator.

Existing measuredFraction and baseline crop calibrate visible architectural height separately from transparent pixel padding. Generated image details are illustrative.

• www.toureiffel.paris

828 m architectural height verified by its architect SOM.

Existing measuredFraction and baseline crop calibrate visible architectural height separately from transparent pixel padding. Generated image details are illustrative.

• www.som.com

The retained1.2 km main-building length is a rough estimate from earlier secondary reporting. Tesla verifies the facility and floor area but does not give this length on its official page; authoritative surveyed linear dimension remains unverified.

Numerical comparison checked against the stated dimension; illustrations are not metrology or independently verified anatomy.

• www.tesla.com

International mile is exactly 1,609.344 m.

Numerical comparison checked against the stated dimension; illustrations are not metrology or independently verified anatomy.

• www.nist.gov

3,776 m rounded summit elevation confirmed by Japan GSI, including after the2024 survey. It is not relief from the photographic base.

Important visual limitation: the cutout is scaled to an elevation reference; its visible foot is not sea level and its width/relief are not a surveyed terrain model. This is stated in the size label and fact.

• www.gsi.go.jp

4.3 km longest principal-axis nucleus dimension supported by the Rosetta morphology review; projected silhouette depends on orientation.

Numerical comparison checked against the stated dimension; illustrations are not metrology or independently verified anatomy.

• link.springer.com

8,849 m is rounded from8,848.86 m snow-summit elevation above sea level, in Nepal government mountaineering figures.

Important visual limitation: the cutout is scaled to an elevation reference; its visible foot is not sea level and its width/relief are not a surveyed terrain model. This is stated in the size label and fact.

• giwmscdnone.gov.np

10,935 m Challenger Deep estimate matches NOAA; survey uncertainty and differing estimates remain.

Numerical comparison checked against the stated dimension; illustrations are not metrology or independently verified anatomy.

• oceanservice.noaa.gov

12,262 m total borehole depth stated by the 1999 research paper. Some institutional listings say12,261 m. Keep source precision and do not equate bore length with exact vertical penetration.

Numerical comparison checked against the stated dimension; illustrations are not metrology or independently verified anatomy.

• doi.org

25.4 km is the2019 NICER/Riley-team J0030 model diameter, not a universal neutron-star diameter; second model gave26 km.

Numerical comparison checked against the stated dimension; illustrations are not metrology or independently verified anatomy.

• svs.gsfc.nasa.gov

42,195 m official race distance verified by World Athletics.

Numerical comparison checked against the stated dimension; illustrations are not metrology or independently verified anatomy.

• worldathletics.org

Exact decimal SI reference: 100,000 m.

Numerical comparison checked against the stated dimension; illustrations are not metrology or independently verified anatomy.

• www.nist.gov

525 km mean diameter matches NASA Vesta Trek. Irregular shape prevents one diameter describing every silhouette span.

Numerical comparison checked against the stated dimension; illustrations are not metrology or independently verified anatomy.

• trek.nasa.gov

2×469.7 km mean radius from NASA/JPL gives939.4 km mean diameter. Ceres is oblate; its photographed polar extent differs from this spherical-equivalent comparison.

Image fit=height and548/600 visible-disc fraction remove blank image margins. Its mean diameter is used as a characteristic size, not an exact angularly calibrated polar axis.

• ssd.jpl.nasa.gov

Mean diameter: 2376.6 km; JPL radius 1188.3 km.

Mean diameter is volume-equivalent; equatorial diameter is explicitly distinguished. Photographic disc boundaries and generated illustrations are approximate visual references, not independent shape measurements.

• ssd.jpl.nasa.gov

Approximately 2,700 km north–south extent of the generalized contiguous-US outline.

Schematic 1:110m outline with equirectangular longitude scaled at 37°N. Projection changes east–west distances with latitude; Alaska/Hawaii omitted. Not a survey-accurate map or a national longest-distance measurement.

• www.naturalearthdata.com

NASA radius 1,560.8 km gives 3,121.6 km diameter.

Galileo image is partially illuminated. Subsurface ocean is inferred from multiple lines of evidence, not directly photographed.

• nssdc.gsfc.nasa.gov
• science.nasa.gov

Volumetric mean radius 1,737.4 km gives 3,474.8 km diameter.

Physical globe diameter; its position on the orbital reference is schematic.

• nssdc.gsfc.nasa.gov

Mean diameter: 4878.8 km; JPL radius 2439.4 km.

Mean diameter is volume-equivalent; equatorial diameter is explicitly distinguished. Photographic disc boundaries and generated illustrations are approximate visual references, not independent shape measurements.

• ssd.jpl.nasa.gov

Solid-body diameter 5,149.4 km is consistent with NASA’s rounded 2,575 km radius.

550-pixel visual disc calibration excludes dark frame; the haze is diffuse, so its visible edge cannot supply an exact solid-body measurement. The fixed 660/766 baseline is a visual alignment.

• nssdc.gsfc.nasa.gov
• science.nasa.gov

Equatorial diameter: 6792.38 km; JPL radius 3396.19 km.

Mean diameter is volume-equivalent; equatorial diameter is explicitly distinguished. Photographic disc boundaries and generated illustrations are approximate visual references, not independent shape measurements.

• ssd.jpl.nasa.gov

Bond et al. 2017 radius 0.008098 R☉ corresponds to about 11,270 km diameter.

The retained size matches Bond2017; the previous link was Joyce2018, which reported a slightly smaller, statistically consistent radius. Artist rendering is not a surface photograph.

• arxiv.org

Equatorial diameter: 12103.6 km; JPL radius 6051.8 km.

Mean diameter is volume-equivalent; equatorial diameter is explicitly distinguished. Photographic disc boundaries and generated illustrations are approximate visual references, not independent shape measurements.

• ssd.jpl.nasa.gov

Mean diameter: 12742 km; JPL radius 6371.01 km.

Mean diameter is volume-equivalent; equatorial diameter is explicitly distinguished. Photographic disc boundaries and generated illustrations are approximate visual references, not independent shape measurements.

• ssd.jpl.nasa.gov

Mean diameter: 49244 km; JPL radius 24622 km.

Mean diameter is volume-equivalent; equatorial diameter is explicitly distinguished. Photographic disc boundaries and generated illustrations are approximate visual references, not independent shape measurements.

• ssd.jpl.nasa.gov

Equatorial diameter excluding rings: 51118 km; JPL radius 25559 km.

Mean diameter is volume-equivalent; equatorial diameter is explicitly distinguished. Photographic disc boundaries and generated illustrations are approximate visual references, not independent shape measurements.

• ssd.jpl.nasa.gov

Equatorial globe diameter: 120536 km; JPL radius 60268 km.

Mean diameter is volume-equivalent; equatorial diameter is explicitly distinguished. Photographic disc boundaries and generated illustrations are approximate visual references, not independent shape measurements.

• ssd.jpl.nasa.gov

Mean diameter: 139822 km; JPL radius 69911 km.

Mean diameter is volume-equivalent; equatorial diameter is explicitly distinguished. Photographic disc boundaries and generated illustrations are approximate visual references, not independent shape measurements.

• ssd.jpl.nasa.gov

Mamajek T5: radius 0.101 R☉; temperature 1160 K. Diameter = radius ratio × 1,391,400 km.

A class example, not a uniquely measured star. Stellar radii vary with age/composition. Artwork is illustrative; spectral class does not determine a detailed surface map.

• www.pas.rochester.edu
• www.iau.org

Mamajek M5V: radius 0.196 R☉; temperature 3060 K. Diameter = radius ratio × 1,391,400 km.

A class example, not a uniquely measured star. Stellar radii vary with age/composition. Artwork is illustrative; spectral class does not determine a detailed surface map.

• www.pas.rochester.edu
• www.iau.org

Twice the 384,400 km semimajor axis gives a 768,800 km reference diameter.

Circular Earth-centred reference, not the real eccentric orbit or an ephemeris for a date.

• nssdc.gsfc.nasa.gov

Mamajek K5V: radius 0.701 R☉; temperature 4440 K. Diameter = radius ratio × 1,391,400 km.

A class example, not a uniquely measured star. Stellar radii vary with age/composition. Artwork is illustrative; spectral class does not determine a detailed surface map.

• www.pas.rochester.edu
• www.iau.org

Nominal solar radius 695,700 km gives a consistent 1,391,400 km comparison diameter.

Uses the same IAU conversion as all stellar examples. Nominal radius is a defined conversion near the observed photospheric radius. The retained 304 Å image shows solar plasma in assigned orange colour, not natural visible light.

• www.iau.org
• sdo.gsfc.nasa.gov

Interferometric radius 1.713 ± 0.009 solar radii; current diameter 2,383,468 km.

2010 measured estimate. Art is a spectral-class illustration, not resolved surface imagery.

• arxiv.org
• www.iau.org

Mamajek F0V: radius 1.728 R☉; temperature 7220 K. Diameter = radius ratio × 1,391,400 km.

A class example, not a uniquely measured star. Stellar radii vary with age/composition. Artwork is illustrative; spectral class does not determine a detailed surface map.

• www.pas.rochester.edu
• www.iau.org

Mamajek A0V: radius 2.193 R☉; temperature 9700 K. Diameter = radius ratio × 1,391,400 km.

A class example, not a uniquely measured star. Stellar radii vary with age/composition. Artwork is illustrative; spectral class does not determine a detailed surface map.

• www.pas.rochester.edu
• www.iau.org

Illustrative chosen radius 5 R☉; not a measured or population-average class radius.

The source supports stellar evolution/class interpretation, not this arbitrary exact example radius. Real members span broad ranges. Wolf–Rayet wind/photosphere conventions are model dependent.

• science.nasa.gov
• www.iau.org

Mamajek B0V: radius 7.16 R☉; temperature 31400 K. Diameter = radius ratio × 1,391,400 km.

A class example, not a uniquely measured star. Stellar radii vary with age/composition. Artwork is illustrative; spectral class does not determine a detailed surface map.

• www.pas.rochester.edu
• www.iau.org

Mamajek O5V: radius 11.45 R☉; temperature 41400 K. Diameter = radius ratio × 1,391,400 km.

A class example, not a uniquely measured star. Stellar radii vary with age/composition. Artwork is illustrative; spectral class does not determine a detailed surface map.

• www.pas.rochester.edu
• www.iau.org

Schwarzschild diameter for 4 million solar masses ≈23.626 million km. EHT field: 140 μas at 8,150 pc.

Clarified 2017 observations released2022. Radio ring (~51.8 μas) is lensing/accretion emission, not the event horizon. Asset fraction0.1384 maps horizon scale to whole field. Spin and emission structure are not resolved by the Schwarzschild size convention.

• www.eso.org
• doi.org

Illustrative chosen radius 25 R☉; not a measured or population-average class radius.

The source supports class interpretation, not this chosen exact example radius. Real members span broad radii. Artwork remains an illustration.

• science.nasa.gov
• www.iau.org

Illustrative chosen radius 80 R☉; not a measured or population-average class radius.

The source supports class interpretation, not this chosen exact example radius. Real members span broad radii. Artwork remains an illustration.

• science.nasa.gov
• www.iau.org

1 au = 149,597,870,700 m exactly.

The defined astronomical unit is close to Earth’s mean Sun distance; the actual instantaneous distance varies.

• www.iau.org

Diameter = 2 × 764 nominal solar radii; Joyce et al.2020 gives R=764(+116/-62) R_sun. Model and distance dependent.

Adopted historical estimate is defensible; texture is an illustration, not a resolved surface photograph.

• arxiv.org

299792458 m/s ×3600 s =1079252848800 m.

Ring diameter represents distance; not radius.

• physics.nist.gov

2013 photospheric radius1708±192 R_sun, diameter2376511200000m.

This is one published estimate, not a settled current ranking or largest-star record; distance and atmosphere matter.

• arxiv.org
• www.uv.es

Approximately twice orbital semimajor axis; NASA J2000 mean a=9.53707032 AU. Current rounded2.864e12m differs by less than0.4%.

Circular schematic replaces eccentric orbit; retain rounded comparison.

• nssdc.gsfc.nasa.gov

No unique established maximum diameter; catalogue already marks placementOnly and symbolic.

3e12m is a chapter location, not a measured or theoretical bound. Should not be narrated as a physical-size record.

• arxiv.org

NASA/JPL Horizons dated heliocentric ephemeris stored with raw response; final172.16084201066573 AU at2026-10-26.

Dated prediction/ephemeris, not live telemetry; straight distance reference is not spacecraft trajectory.

• ssd.jpl.nasa.gov

36e12m diameter corresponds to120.3AU radius, near observed Voyager heliopause distances120–122AU.

The full shape is neither spherical nor directly measured by these two crossings; illustrative only.

• science.nasa.gov

Schwarzschild diameter4GM/c² using10billion solar masses =approximately59.1billion km. NASA2025 uses roughly10billion solar masses.

Do not use widely circulated100billion-solar-mass figure as settled. Disk simulation is illustrative. Nonrotating shadow diameter/horizon diameter=3sqrt(3)/2.

• science.nasa.gov

Schwarzschild diameter4GM/c² using40.7billion solar masses =approximately240.4billion km. Aggarwal2025 cites Ge et al.2019 for4.07e10M_sun.

Virial-mass estimates have large systematic uncertainty; no direct horizon image. Nonrotating model retained.

• doi.org

299792458 ×30×86400=777062051136000m.

30days explicitly defined; calendar months are not constant.

• physics.nist.gov

c × Julian year365.25days =9.4607304725808e15m, rounded in app to9.4607e15m.

Rounding error0.00032%, negligible compared with object uncertainty.

• iauarchive.eso.org
• physics.nist.gov

NASA image metadata states2.4arcmin/1.4light-years for NIRCam field.

Correct field width, not the visible shell diameter.

• science.nasa.gov

ESA/Hubble quotes nearly3ly ring diameter at650ly distance.

MeasuredFraction0.596 separates approximate bright ring from surrounding image; diffuse boundary is not precise.

• esahubble.org

NASA estimates outer radius up to100000AU, hence adopt200000AU outer diameter ≈3.16ly.

Previously2ly diameter was an underspecified illustrative scale. Extent remains uncertain; not a measured hard shell.

• science.nasa.gov

Rounded4.24ly distance; official sources quote about4.2–4.25ly.

Distance from Solar neighbourhood, not diameter; AU-scale baseline difference is negligible here.

• science.nasa.gov

Spitzer Science Center astrometrics:58.1arcmin square at430ly yields7.27ly field.

43ly was not calibrated to this photograph and resembles a tidal radius, not diameter. Correct to field width; broader cluster and Greater Pleiades Complex extend far beyond image.

• www.spitzer.caltech.edu
• www.spitzer.caltech.edu

Approximately 8 light-years, full Webb image-field width

The complete NIRCam observation is displayed immediately. The label describes the familiar subject; the measured span is the entire image field, not one pillar. A later registered transition shows the wider Eagle Nebula.

• science.nasa.gov

ESA field30.03arcmin at1400ly gives12.23ly width.

Correct image width, not total nebula diameter; source caption and metadata differ on distance, so rounded field retained.

• esahubble.org

NASA NIRCam metadata gives7.3arcmin corresponding16ly.

Image field only; wavelengths are mapped to visible colours.

• science.nasa.gov

ESO field32.08arcmin; at adopted6500ly distance,60.66ly before rotation. Rotated padded square63.59ly.

App uses one distance for registration, rather than inconsistent older7000ly ESO caption. Square frame not nebula boundary.

• www.eso.org
• science.nasa.gov

PIA14415/2012 Chandra composite has13arcmin/~600ly field.

1000ly described broad nebula but overstated this cropped field. Chandra page alt-text repeats older1100ly; its explicit Fast Facts13arcmin converts to605ly at160000ly, supporting600ly.

• chandra.si.edu
• science.nasa.gov

CfA/STScI study describes roughly1000ly cavity.

Irregular cavity; rendering is explanatory, no hard spherical boundary or literal visible colours.

• www.cfa.harvard.edu

ESO quotes stellar galaxy span50000–60000ly; app adopts60000ly.

Image is a telescope photo but no sharp isophotal edge exists; screen footprint is an approximate depiction of this adopted disc diameter, not precision image-field astrometry.

• www.eso.org

NASA quotes roughly100000ly stellar-disc diameter; observer26,000ly fromcentre in Orion Spur.

Artist concept and arm placement approximate; disc edge convention excludes much larger halo.

• www.nasa.gov
• science.nasa.gov

NASA quotes152000ly across for stellar disc.

Adopted galaxy diameter, not full halo. GALEX field background and wavelength-dependent disc edges mean visual outline is approximate.

• science.nasa.gov
• science.nasa.gov

2026 ultradeep imaging locates main-body semi-major edge radius260kpc, giving520kpc diameter.

Recent study estimate, not universal definition; intracluster light extends farther. Asset is illustrative, not this measured deep image.

• arxiv.org

NASA gives roughly10millionly diameter.

Survey projection is a neighbourhood map, dots and glows are not individual galaxy diameters.

• imagine.gsfc.nasa.gov

Conventional approximate extent110millionly, as documented by NASA-funded OpenSpace science visualization.

Different from Virgo Cluster; larger flow-defined Laniakea includes this region. Map draws projected galaxy positions, not a definitive membership boundary.

• docs.openspaceproject.com

Tully et al.2014 flow-based supercluster approximately160Mpc across,~522millionly.

Cosmicflows-3 distances used for map, whereas original boundary used peculiar-velocity reconstruction. Not a bound object or exact spherical edge.

• www.nature.com
• doi.org

Diemer L0125 density field125Mpc/h width,12.5Mpc/h depth; WMAP7 H0=70 so h=.7.

Simulation, not photographed local structure. Credit Mansfield&Diemer, tetrahedron method following Kaehler et al.

• www.benediktdiemer.com

Giga prefix10^9 times astronomical light-year.

Distance line only; same roundedLY constant as rest of app.

• www.nist.gov
• iauarchive.eso.org

Diemer L2000 density field2000Mpc/h width,160Mpc/h depth with h=.7.

Periodic simulated field is repeated to cover display, not actual observed universe map; description already states this.

• www.benediktdiemer.com

NASA2025 uses approximately92billionly present-day observable diameter.

Conventional cosmology-dependent rounded size; boundary is observational horizon, not physical edge of all space. Repeated simulation image is illustrative and not a light-cone.

• www.nasa.gov
• www.benediktdiemer.com