high convictionactive · updated 2026-05-30T00:00:00.000Z
Earth-sized interferometry → image of a black hole's event-horizon shadow
To "see" a black hole you need a telescope the size of Earth; you fake one by catching the same wavefront of light in ~8 observatories worldwide at once and combining them.
The chain
1
Resolving the event horizon of a black hole requires an aperture effectively as large as the Earth.
michelle-thaller in 2026-05-28-youtube-powerfuljre-joe-rogan-experience-2506-michelle-thaller: "They managed to make a telescope that's actually as big as the Earth, and they were able to take a picture of the dark parts of a black hole."
2
No single dish is that big, so ~8 observatories spread across the planet are combined — interferometry synthesizes an aperture the size of their separation.
michelle-thaller in 2026-05-28-youtube-powerfuljre-joe-rogan-experience-2506-michelle-thaller: "They had these eight observatories all around the planet... you wanted the telescopes to be as far apart on the Earth as possible, because then you could basically make a giant telescope the size of the separation of these telescopes." (sites incl. South Pole and Chile)
3
To combine them, each must catch the **same wavefront / same photon** simultaneously, correcting for Earth's curvature, rotation, and each site's altitude — being off by ~one millionth of a meter ruins the image.
michelle-thaller in 2026-05-28-youtube-powerfuljre-joe-rogan-experience-2506-michelle-thaller: "If it was one wavefront later, one millionth of a meter later, traveling at the speed of light, they wouldn't have gotten the image... the same photon, the same wave of light had to be caught in all of those telescopes at once." (data too big for the South Pole link — shipped on hard drives, replayed together)
4
Combining the synchronized data yields a real image of the event-horizon shadow.
michelle-thaller in 2026-05-28-youtube-powerfuljre-joe-rogan-experience-2506-michelle-thaller: "Now we can take a picture of an area right in front of your eyes where space and time doesn't exist." (the imaged "shadow" is slightly larger than the event horizon because spacetime bends light around it)
What would falsify this
- Step 3: failure to maintain wavefront synchronization across sites would prevent any image (it didn't — the result has been reproduced).
Contradictions / tensions
- The many-worlds *interpretation* of interferometry is contested; many interferometrists reject it. The measurement itself is not in dispute.
Implications
- Turns black-holes from purely theoretical into directly imaged objects; via the event-horizon-telescope. The same interferometry principle ("the same photon measured in eight places at once") is what makes some physicists invoke many-worlds interpretations — explicitly flagged as interpretation, not fact (see quantum-entanglement).
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Open questions
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