#sqpr — Public Fediverse posts

COW DISTINGUISHES SQPR FROM PENROSE’s Gravitational Localization: 

COW Experiment Potentially DISTINGUISHES SQPR

In the 1970s I told Sir Roger Penrose (among others at Stanford) about the basic idea of SQPR. Penrose published in the 1980s the Gravitationally Induced Spontaneous Localization theory which applies the time-energy uncertainty (TEU) relation to spacetime.  The two Objective Reduction theories are very different, because they have different collapse mechanisms.

In particular at cosmological scale, SQPR predicts observed facts, such as Dark Matter and Dark Energy, whereas the Penrose theory does not.

The theories also make very different predictions in the lab relative to Quantum Mechanics, and also relative to each other.  Let’s explore. 

*** 

Diósi-Penrose Objective Reduction (DPOR) model is a hypothesis proposing that quantum wavefunctions collapse spontaneously due to gravitational instabilities caused by mass superposition. It has the advantage of tying in gravity and Quantum Mechanics (QM) in the simplest manner.

Core Concepts

• Gravity and Superposition: When a massive object exists in a superposition of two different locations, the distribution of its mass creates a simultaneous superposition of two distinct spacetime geometries. (At least that’s what the formalism of Quantum Mechanics predicts!) [1, 2]
• Spacetime Conflict: General relativity requires a single, well-defined spacetime metric, creating a fundamental clash with quantum superposition. [1]
• Objective Reduction: Rather than needing an external observer or measurement to trigger a collapse, gravity forces the system to resolve itself into a single state. [1, 2]
• Timescale: The lifetime of the superposition is inversely proportional to the gravitational self-energy difference between the states. The exact expression obtained by applying the TEU. The duration until collapse is inversely proportional to the difference in gravitational energy between the two different locations (and proportional to Planck constant, of course! It’s direct TEU!) 

***

In the Colella-Overhauser-Werner (COW) experiment, realized in 1975, thermal neutrons enter a silicon crystal Mach–Zehnder interferometer. When the interferometer is tilted by an angle theta relative to the horizontal, one arm (Path A) is at a higher gravitational potential than the lower arm (Path B).

It turns out that the energy of the quantum state in the upper branch, Path A, is different in composition from that of the lower branch, Path B. This can be physically demonstrated through the apparition of shifting interference fringes. The effect has been observed.

The reasoning is fascinating: one makes a number of assumptions, simplest and most natural. Those assumptions bring us to a shifting interference pattern shifting in a peculiar way, which is observed. Therefore one is entitled to deduce that the assumptions made were correct, and this tells us many things about matter waves.and in particular how long the guiding waves are. It may also enable to demonstrate in the lab the existence of Objective Reduction theories, which extend understanding beyond Quantum Mechanics.

***

Penrose’s Model Makes Experimental Predictions:

If one plugs the usual numbers in, considering self-gravitation of the neutron, one gets millions of years for Penrose collapse to happen. 

However for a single neutron interacting with Earth’s massive gravitational field, going both down a ground branch of the interferometer (B) and the elevated one (A), the difference in gravitational energy is mgh, where g is the usual gravitational acceleration at sea level, m is the mass of the neutron, and h is how high A is above B. 

If we extend the COW experiment using large molecules (like fullerenes or 10^4 atoms macromolecular clusters) or Bose–Einstein Condensates (BECs) instead of single neutrons, mgh scales up by 10^4 to $10^6. Then the collapse time drops precipitously from millions of years to milliseconds or microseconds—falling right inside the passage duration of the experiment! 

https://quantumnano.at/research/universal-matter-waves/why-matter-waves

***

Penrose does not suggest a plausible mechanism to cause collapse.

DPOR is a particular case of Objective Reduction (OR) models, where one does away with the silliness of an observer and “measurements”. 

The other model is SQPR, which ignores gravity, but not matter abundance and the QM state (for example Quantum amplitudes) it is in…

***. 

The SQPR Shift:

• If localization is independent of the background gravitational field g and depends instead on the density of surrounding matter fields (and the probability of guiding-wave truncation/shedding), then tilting the interferometer or placing it in a deep gravitational potential well will not alter the intrinsic collapse rate.
• An extended COW experiment conducted at sea level versus one conducted in microgravity (e.g., on the ISS) or on the Moon would yield the exact same decoherence rate in SQPR.
• Under Penrose, microgravity suppresses collapse; under SQPR, space microgravity leaves the collapse rate unchanged because matter-field interactions and guiding-wave limits remain invariant.

[Camping in Sierra Nevada; Post will be improved in future and computations made explicit…]

Patrice Ayme

COW DISTINGUISHES SQPR FROM PENROSE’s Gravitational Localization: 

COW Experiment Potentially DISTINGUISHES SQPR

In the 1970s I told Sir Roger Penrose (among others at Stanford) about the basic idea of SQPR. Penrose published in the 1980s the Gravitationally Induced Spontaneous Localization theory which applies the time-energy uncertainty (TEU) relation to spacetime.  The two Objective Reduction theories are very different, because they have different collapse mechanisms.

In particular at cosmological scale, SQPR predicts observed facts, such as Dark Matter and Dark Energy, whereas the Penrose theory does not.

The theories also make very different predictions in the lab relative to Quantum Mechanics, and also relative to each other.  Let’s explore. 

*** 

Diósi-Penrose Objective Reduction (DPOR) model is a hypothesis proposing that quantum wavefunctions collapse spontaneously due to gravitational instabilities caused by mass superposition. It has the advantage of tying in gravity and Quantum Mechanics (QM) in the simplest manner.

Core Concepts

• Gravity and Superposition: When a massive object exists in a superposition of two different locations, the distribution of its mass creates a simultaneous superposition of two distinct spacetime geometries. (At least that’s what the formalism of Quantum Mechanics predicts!) [1, 2]
• Spacetime Conflict: General relativity requires a single, well-defined spacetime metric, creating a fundamental clash with quantum superposition. [1]
• Objective Reduction: Rather than needing an external observer or measurement to trigger a collapse, gravity forces the system to resolve itself into a single state. [1, 2]
• Timescale: The lifetime of the superposition is inversely proportional to the gravitational self-energy difference between the states. The exact expression obtained by applying the TEU. The duration until collapse is inversely proportional to the difference in gravitational energy between the two different locations (and proportional to Planck constant, of course! It’s direct TEU!) 

***

In the Colella-Overhauser-Werner (COW) experiment, realized in 1975, thermal neutrons enter a silicon crystal Mach–Zehnder interferometer. When the interferometer is tilted by an angle theta relative to the horizontal, one arm (Path A) is at a higher gravitational potential than the lower arm (Path B).

It turns out that the energy of the quantum state in the upper branch, Path A, is different in composition from that of the lower branch, Path B. This can be physically demonstrated through the apparition of shifting interference fringes. The effect has been observed.

The reasoning is fascinating: one makes a number of assumptions, simplest and most natural. Those assumptions bring us to a shifting interference pattern shifting in a peculiar way, which is observed. Therefore one is entitled to deduce that the assumptions made were correct, and this tells us many things about matter waves.and in particular how long the guiding waves are. It may also enable to demonstrate in the lab the existence of Objective Reduction theories, which extend understanding beyond Quantum Mechanics.

***

Penrose’s Model Makes Experimental Predictions:

If one plugs the usual numbers in, considering self-gravitation of the neutron, one gets millions of years for Penrose collapse to happen. 

However for a single neutron interacting with Earth’s massive gravitational field, going both down a ground branch of the interferometer (B) and the elevated one (A), the difference in gravitational energy is mgh, where g is the usual gravitational acceleration at sea level, m is the mass of the neutron, and h is how high A is above B. 

If we extend the COW experiment using large molecules (like fullerenes or 10^4 atoms macromolecular clusters) or Bose–Einstein Condensates (BECs) instead of single neutrons, mgh scales up by 10^4 to $10^6. Then the collapse time drops precipitously from millions of years to milliseconds or microseconds—falling right inside the passage duration of the experiment! 

https://quantumnano.at/research/universal-matter-waves/why-matter-waves

***

Penrose does not suggest a plausible mechanism to cause collapse.

DPOR is a particular case of Objective Reduction (OR) models, where one does away with the silliness of an observer and “measurements”. 

The other model is SQPR, which ignores gravity, but not matter abundance and the QM state (for example Quantum amplitudes) it is in…

***. 

The SQPR Shift:

• If localization is independent of the background gravitational field g and depends instead on the density of surrounding matter fields (and the probability of guiding-wave truncation/shedding), then tilting the interferometer or placing it in a deep gravitational potential well will not alter the intrinsic collapse rate.
• An extended COW experiment conducted at sea level versus one conducted in microgravity (e.g., on the ISS) or on the Moon would yield the exact same decoherence rate in SQPR.
• Under Penrose, microgravity suppresses collapse; under SQPR, space microgravity leaves the collapse rate unchanged because matter-field interactions and guiding-wave limits remain invariant.

[Camping in Sierra Nevada; Post will be improved in future and computations made explicit…]

Patrice Ayme