Oct 29, 2025 06:22 PM
(This post was last modified: Oct 29, 2025 08:09 PM by C C.)
https://iai.tv/articles/if-we-look-too-h..._auid=2020
INTRO: Try to measure an object’s location too precisely, and you’ll collapse into a black hole. Physicist Daniel Carney highlights this overlooked consequence of quantum mechanics and general relativity, suggesting that it reveals many basic physical quantities to be fundamentally approximate. The path to a theory of quantum gravity, he argues, hinges on confronting the limits of measurement and observation—and perhaps leads to the realisation that ultimate reality lies forever beyond observation...
EXCERPTS: . . . Any measurement device has mass, and thus gravitates. It must also obey the laws of quantum mechanics. Do these facts imply anything about how well a measurement can be done? Thinking about situations in which both the gravity and quantum mechanics of the observational apparatus are important may sound esoteric. Gravity is most pronounced in large systems, like planets and galaxies. Quantum mechanics, on the other hand, reveals its mysteries most visibly in tiny, isolated objects like individual atoms. Yet today we have a variety of measurement devices, used in actual laboratories, where both quantum and gravitational effects are present.
[...] Understanding the logical limits of such measurement systems is an under-explored direction in physics, which may have profound consequences for our understanding of the quantum mechanics of gravity itself. Today, we lack a detailed, self-consistent theory which can tell us how measurements involving very massive quantum systems would work in full generality, let alone any experiments probing this issue directly...
[...] However, depending on one's philosophical leanings, the implications of this may be much more radical. It is tempting to speculate that measurements are just lossy images of some underlying reality. But a common view among physicists, going back to Schrodinger and exemplified by John Bell, is that “reality” is nothing more than the sum total of what can be measured. And from this viewpoint, what we have found is an argument that the very notion of space might be, at best, an approximate concept. If space cannot be measured to arbitrary accuracy without forming a black hole, then in a minimal interpretation of what it means for something to exist, space simply does not exist at arbitrarily small length scales.
[...] An ambitious direction would be to experimentally search for effects of these fundamental limitations on measurement. There are a handful of highly speculative ideas in this direction... (MORE - details)
INTRO: Try to measure an object’s location too precisely, and you’ll collapse into a black hole. Physicist Daniel Carney highlights this overlooked consequence of quantum mechanics and general relativity, suggesting that it reveals many basic physical quantities to be fundamentally approximate. The path to a theory of quantum gravity, he argues, hinges on confronting the limits of measurement and observation—and perhaps leads to the realisation that ultimate reality lies forever beyond observation...
EXCERPTS: . . . Any measurement device has mass, and thus gravitates. It must also obey the laws of quantum mechanics. Do these facts imply anything about how well a measurement can be done? Thinking about situations in which both the gravity and quantum mechanics of the observational apparatus are important may sound esoteric. Gravity is most pronounced in large systems, like planets and galaxies. Quantum mechanics, on the other hand, reveals its mysteries most visibly in tiny, isolated objects like individual atoms. Yet today we have a variety of measurement devices, used in actual laboratories, where both quantum and gravitational effects are present.
[...] Understanding the logical limits of such measurement systems is an under-explored direction in physics, which may have profound consequences for our understanding of the quantum mechanics of gravity itself. Today, we lack a detailed, self-consistent theory which can tell us how measurements involving very massive quantum systems would work in full generality, let alone any experiments probing this issue directly...
[...] However, depending on one's philosophical leanings, the implications of this may be much more radical. It is tempting to speculate that measurements are just lossy images of some underlying reality. But a common view among physicists, going back to Schrodinger and exemplified by John Bell, is that “reality” is nothing more than the sum total of what can be measured. And from this viewpoint, what we have found is an argument that the very notion of space might be, at best, an approximate concept. If space cannot be measured to arbitrary accuracy without forming a black hole, then in a minimal interpretation of what it means for something to exist, space simply does not exist at arbitrarily small length scales.
[...] An ambitious direction would be to experimentally search for effects of these fundamental limitations on measurement. There are a handful of highly speculative ideas in this direction... (MORE - details)
