by Q-reeus » Thu May 14, 2015 4:36 am
Wow this site has gotten sort of torpid with a capital T. So to attempt a kick-start back to sone life, maybe any quantum/particle physics buffs here would like to comment on linked to articles that comes up when one Googles (no - StartPages) "Humphrey Maris electron fission". The topic began with a bang back in 2000. First current link there:
https://news.brown.edu/articles/2014/10/electronshould get the ball rolling. Can the evidently well established findings match with any of you fellas theoretical models? Cut'n'paste from another site follows:
Here's an interesting comment below the main article at:
http://science.slashdot.org/story/14/10 ... e-functionI'll venture a summary of their experiment and hypothesis, though I didn't read the paper itself and I won't swear that it's accurate:
When a single electron enters a container of helium superfluid it repels the surrounding atoms, creating a bubble of definite size, which proceeds to slowly sink to the detector at the bottom at a determinate rate based on it's size - the larger the bubble, the slower it sinks. Before those electron-bubbles reach the detector; however, it is apparently detecting additional, unexplained charges traveling at at least 18 discrete speeds and, more rarely, charges that seem to travel on a continuous spectrum of speeds. They believe it to be unlikely that there are a sufficient range of impurities in the fluid to explain such a large number of speeds, and hence an alternate explanation should be sought.
Their hypothesis is that these additional charges are in fact smaller bubbles formed by electron wave functions being partially reflected at the liquid's surface: on impact an electron may either enter the fluid, or bounce off. Or, thanks to quantum superposition, it may do both simultaneously with varying levels of probability. In the latter case the partial wavefunction that did penetrate the fluid surface could be expected to create smaller (faster) bubbles in a variety of sizes - some of the electron probability is not within the bubble, and so the repulsion effect is lower and the bubble correspondingly smaller and faster moving.
As I understand it the implication is that simply interacting with the helium is insufficient "measurement" to collapse the wavefunction, instead it gets to maintain a partial presence until such time as it interacts with the detector, which measures it's presence with sufficient definitiveness that the electron must then be wholly present or absent. This would be a revolutionary finding as it would be the first time that a superposition of states has been detected to measurably impact the interaction of a particle with its environment - in all previous QM experiments when a wavefunction collapsed and a single particle was detected, its position and velocity were consistent with the history of a single classical particle traveling along the path that ended in detection, and superposition could only be detected in the statistical distribution of detections, such as the interference patterns of a two-slit experiment.
If correct, this could be a major step forward in determining what exactly constitutes a "measurement" for the purposes of collapsing a quantum wavefunction, a question which has thus far gone almost completely unanswered and spans the complete range from the vague "interaction with the macroscopic world" to the quasi-mystical "observed by a conscious mind"
And a link given in earlier comment, to a free technical article:
http://brown.edu/research/labs/electron ... ion_14.pdfMuch bland experimental procedure is followed by some interesting stuff beginning last bit p39 there. Seems they have been very thorough in eliminating some usual suspects, and sure looks to be outside normal QM expectations. Have come across other research claiming to observe separation between electron and it's wavefunction but can't recall where right now. It was iirc involving a solid-state regime not liquid He.
Wow this site has gotten sort of torpid with a capital T. So to attempt a kick-start back to sone life, maybe any quantum/particle physics buffs here would like to comment on linked to articles that comes up when one Googles (no - StartPages) "Humphrey Maris electron fission". The topic began with a bang back in 2000. First current link there: https://news.brown.edu/articles/2014/10/electron
should get the ball rolling. Can the evidently well established findings match with any of you fellas theoretical models? Cut'n'paste from another site follows:
Here's an interesting comment below the main article at: http://science.slashdot.org/story/14/10/29/1555229/researchers-at-brown-university-shattered-a-quantum-wave-function
[quote]I'll venture a summary of their experiment and hypothesis, though I didn't read the paper itself and I won't swear that it's accurate:
When a single electron enters a container of helium superfluid it repels the surrounding atoms, creating a bubble of definite size, which proceeds to slowly sink to the detector at the bottom at a determinate rate based on it's size - the larger the bubble, the slower it sinks. Before those electron-bubbles reach the detector; however, it is apparently detecting additional, unexplained charges traveling at at least 18 discrete speeds and, more rarely, charges that seem to travel on a continuous spectrum of speeds. They believe it to be unlikely that there are a sufficient range of impurities in the fluid to explain such a large number of speeds, and hence an alternate explanation should be sought.
Their hypothesis is that these additional charges are in fact smaller bubbles formed by electron wave functions being partially reflected at the liquid's surface: on impact an electron may either enter the fluid, or bounce off. Or, thanks to quantum superposition, it may do both simultaneously with varying levels of probability. In the latter case the partial wavefunction that did penetrate the fluid surface could be expected to create smaller (faster) bubbles in a variety of sizes - some of the electron probability is not within the bubble, and so the repulsion effect is lower and the bubble correspondingly smaller and faster moving.
As I understand it the implication is that simply interacting with the helium is insufficient "measurement" to collapse the wavefunction, instead it gets to maintain a partial presence until such time as it interacts with the detector, which measures it's presence with sufficient definitiveness that the electron must then be wholly present or absent. This would be a revolutionary finding as it would be the first time that a superposition of states has been detected to measurably impact the interaction of a particle with its environment - in all previous QM experiments when a wavefunction collapsed and a single particle was detected, its position and velocity were consistent with the history of a single classical particle traveling along the path that ended in detection, and superposition could only be detected in the statistical distribution of detections, such as the interference patterns of a two-slit experiment.
If correct, this could be a major step forward in determining what exactly constitutes a "measurement" for the purposes of collapsing a quantum wavefunction, a question which has thus far gone almost completely unanswered and spans the complete range from the vague "interaction with the macroscopic world" to the quasi-mystical "observed by a conscious mind"[/quote]
And a link given in earlier comment, to a free technical article: http://brown.edu/research/labs/electron-bubble/sites/brown.edu.research.labs.electron-bubble/files/uploads/fission_14.pdf
Much bland experimental procedure is followed by some interesting stuff beginning last bit p39 there. Seems they have been very thorough in eliminating some usual suspects, and sure looks to be outside normal QM expectations. Have come across other research claiming to observe separation between electron and it's wavefunction but can't recall where right now. It was iirc involving a solid-state regime not liquid He.
