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#600 by Peter Lauwer on 10 Oct, 2018 15:02
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WRT Tajmar's Paper, I think that's killed the EM dream for me.
Well done to the Dresden group for some hard work to develop such a sensitive test stand..
Not so fast. The effect (the EMDrive) was quite improbable from the first time, of course. But the experiments by Tajmar et al and other groups are quite limited up to now. And don't we demand a peer reviewed publication now? The Kössling et al paper (the Dresden group) is probably not peer reviewed, it is a congress paper. -
#601 by Peter Lauwer on 10 Oct, 2018 15:11
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McCulloch's job advert looking for a post-doc:
https://hrservices.plymouth.ac.uk/tlive_webrecruitment/wrd/run/ETREC107GF.open?VACANCY_ID=536609C8bp&WVID=1602750fTZ&LANG=USA
Anybody here wants to apply?
Tricky. What if the researcher finds in the first months already that the theory is bollocks?
Someone versed in QM and relativity can probably make this up in the first month. Then he/she must choose between the job (well, only 14 months) or scientific integrity.
And emphasize on modelling? They probably should concentrate on whether the theory is compatible with "the classic tests" (solar system dynamics, shapiro time delay, gravitational waves). -
#602 by moreno7798 on 10 Oct, 2018 20:25
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WRT Tajmar's Paper, I think that's killed the EM dream for me.
Well done to the Dresden group for some hard work to develop such a sensitive test stand..
Not so fast. The effect (the EMDrive) was quite improbable from the first time, of course. But the experiments by Tajmar et al and other groups are quite limited up to now. And don't we demand a peer reviewed publication now? The Kössling et al paper (the Dresden group) is probably not peer reviewed, it is a congress paper.
Here's the problem.
How do you reconcile a peer reviewed paper from a NASA scientist (Dr. Sonny White) from Eagleworks Labs, with these independant papers? Why have peer review then if there is no consensus amongst peers?
These new papers must be peer reviewed or their findings are as good as good as Roger Shawyer's. -
#603 by cvbn on 11 Oct, 2018 00:27
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What if the researcher finds in the first months already that the theory is bollocks?
The dark matter hypothesis is probably bollocks and it doesn't stop anyone from researching it. ;( -
#604 by meberbs on 11 Oct, 2018 01:23
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McCulloch is obviously biased at this point. Points 6 through 8 on that page are not even valid arguments, and discredit everything else he says. Points 1 through 5 at least would sound valid if they weren't followed by nonsense, but the general counter to all of them is that dark matter does a better job fitting all of the available data than any other theory anyone has come up with (and unlike his claim in point 7, physicists have tried other theories https://xkcd.com/1758/).What if the researcher finds in the first months already that the theory is bollocks?
The dark matter hypothesis is probably bollocks and it doesn't stop anyone from researching it. ;(
There is data (more recent than the linked blog post) showing that galaxies exist that have different concentrations of dark matter than typical. This data is nearly impossible to explain without dark matter. -
#605 by Peter Lauwer on 11 Oct, 2018 09:50
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Here's the problem.
How do you reconcile a peer reviewed paper from a NASA scientist (Dr. Sonny White) from Eagleworks Labs, with these independant papers? Why have peer review then if there is no consensus amongst peers?
Peer reviewed only means that it meets up to certain scientific quality standards (which are different from journal to journal) and that it is new. The peers can point at certain weaknesses in the study, which then can be fixed (or not, of course) [1]. It does not mean that was is written necessarily has to be true. It is just one step in the scientific process and it is not meant as a presentation to the general public.
What concerns the difference in standards: the White et al. paper could not have been published in a physics journal, I think (NB, that does not mean I have great respect for their work. There were some simple tests though, which, with just a few days extra work, would have made things a lot clearer).
Added: [1] There doesn't have to be consensus between peers. It doesn't/shouldn't work that way. The referee can have a different opinion, think the new paper will proof to be not correct in the future, but judge that the author(s) use arguments and/or data of sufficient quality that they should be allowed to state otherwise (if the referee is honoust and unbiased enough). For instance in the dark matter/modified gravity debate. -
#606 by cvbn on 11 Oct, 2018 11:59
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McCulloch is obviously biased at this point. Points 6 through 8 on that page are not even valid arguments, and discredit everything else he says. Points 1 through 5 at least would sound valid if they weren't followed by nonsense, but the general counter to all of them is that dark matter does a better job fitting all of the available data than any other theory anyone has come up with (and unlike his claim in point 7, physicists have tried other theories https://xkcd.com/1758/).What if the researcher finds in the first months already that the theory is bollocks?
The dark matter hypothesis is probably bollocks and it doesn't stop anyone from researching it. ;(
There is data (more recent than the linked blog post) showing that galaxies exist that have different concentrations of dark matter than typical. This data is nearly impossible to explain without dark matter.
Dark matter hypothesis is an ad-hoc hypothesis and a fudge factor. They have to fit it for every galaxy to make it fit observations. Hence, it cannot predict anything. What's the use of a hypothesis, which cannot predict? It is a pointless exercise and waste of money, really. -
#607 by Monomorphic on 11 Oct, 2018 13:09
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And emphasize on modelling? They probably should concentrate on whether the theory is compatible with "the classic tests" (solar system dynamics, shapiro time delay, gravitational waves).
I know that dark matter is required to create simulations of the universe that closest match observations. If McCulloch can show his model can also simulate the large scale structure of the universe, in addition to rotational curves of galaxies, then that would be an accomplishment.
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#608 by dustinthewind on 11 Oct, 2018 13:15
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McCulloch is obviously biased at this point. Points 6 through 8 on that page are not even valid arguments, and discredit everything else he says. Points 1 through 5 at least would sound valid if they weren't followed by nonsense, but the general counter to all of them is that dark matter does a better job fitting all of the available data than any other theory anyone has come up with (and unlike his claim in point 7, physicists have tried other theories https://xkcd.com/1758/).What if the researcher finds in the first months already that the theory is bollocks?
The dark matter hypothesis is probably bollocks and it doesn't stop anyone from researching it. ;(
There is data (more recent than the linked blog post) showing that galaxies exist that have different concentrations of dark matter than typical. This data is nearly impossible to explain without dark matter.
I wanted to point out that the Janus cosmological model introduces dark matter in another parallel dimension of reverse time. If it comes down to the necessity for dark matter that might pass. that is if gravity penetrates the dimensional barrier. They presume it does and it looks like it should.
There is a separate thread in the new physics forms for the Janus cosmological model.
Mikes Quantized inertia may also be superimposed over it possibly? -
#609 by MikeMcCulloch on 11 Oct, 2018 14:00
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Dear monomorphic. Dark matter is an arbitrary hypothesis, so the fact that a computer can use it to produce what we already know to be there is no surprise: they just fiddled with it till it worked. QI is not arbitrary at all, but the idea of me spending two years trying to model cosmic voids and then have dark matter people say "Oh, we can do it too!" does not appeal A lab test with an immediate application is the only way to progress.
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#610 by Peter Lauwer on 11 Oct, 2018 14:33
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Dear monomorphic. Dark matter is an arbitrary hypothesis, so the fact that a computer can use it to produce what we already know to be there is no surprise: they just fiddled with it till it worked. QI is not arbitrary at all, but the idea of me spending two years trying to model cosmic voids and then have dark matter people say "Oh, we can do it too!" does not appeal
A lab test with an immediate application is the only way to progress.
QIstillcertainly has an arbitrariness: the Unruh radiation process, which still has to be proven to play a role. I advise you to focus on that. Let a specialist in quantum field theory do basic research on that.
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#611 by Star-Drive on 11 Oct, 2018 14:53
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Dear monomorphic. Dark matter is an arbitrary hypothesis, so the fact that a computer can use it to produce what we already know to be there is no surprise: they just fiddled with it till it worked. QI is not arbitrary at all, but the idea of me spending two years trying to model cosmic voids and then have dark matter people say "Oh, we can do it too!" does not appeal
A lab test with an immediate application is the only way to progress.
Mike:
You might like to read through the attached papers by Paul Stevenson, Sonny White and Eric Davis on what cosmological dark matter and dark energy may actually be and and how the quantum vacuum may play a part in this puzzle when it comes to explaining the origins of inertia, and what dark matter actually may be. Then lets think about what form the cosmological dark energy field AKA GRT spacetime takes in regards to whether it is background independent as required by Einstein's GRT and thus requiring the graviton as its fundamental force carrier, or whether it could be just photonic i.e., E&M in nature. Once we have those answers in place, your quantized inertia conjecture may make a lot more sense to the GRT / cosmological community. And only then comes the engineering stuff that this forum is fond of reviewing...
All the Best, Paul March
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#612 by meberbs on 11 Oct, 2018 17:23
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Dark matter hypothesis is an ad-hoc hypothesis and a fudge factor. They have to fit it for every galaxy to make it fit observations. Hence, it cannot predict anything. What's the use of a hypothesis, which cannot predict? It is a pointless exercise and waste of money, really.
This is simply an invalid argument. Every hypothesis is designed by definition to fit the available data. A real waste of time and money is to explore a hypothesis that from the beginning does not fit the available data. Dark matter has not been proven correct, but it is the only major theory that actually fits the data. Unless it is actually proven wrong, it would be absurd to abandon a theory that has a reasonable chance of being correct, and even more absurd when there is no viable alternative.Dear monomorphic. Dark matter is an arbitrary hypothesis, so the fact that a computer can use it to produce what we already know to be there is no surprise: they just fiddled with it till it worked. QI is not arbitrary at all, but the idea of me spending two years trying to model cosmic voids and then have dark matter people say "Oh, we can do it too!" does not appeal
One of the problems with your theory is that there is no way it can match the data. The data I linked before shows that gravity apparently varies between otherwise comparable galaxies. You fundamentally cannot explain this without having something that we cannot otherwise see affecting gravity, which is basically the definition of dark matter. A lab test with an immediate application is the only way to progress.
It seems your post is nothing more than using an invalid argument (it is a nice to have if a model has less unknowns to fiddle with, but not at the cost of it working) to tear down the best theory we have because you don't like that your theory has trouble competing with in the realm of "can it describe reality." Considering that as I said you essentially lied in the blog post that was linked above, I am not sure how you expect to be taken seriously.I wanted to point out that the Janus cosmological model introduces dark matter in another parallel dimension of reverse time.
Not to go too far into it here, but while that passes the variability test for the data I linked earlier, there are other properties of dark matter such as not significantly colliding with itself that would be harder for such a model to explain. (not impossible, but it adds more complications)
...and we have now been completely sidetracked from the actual topic of this thread, and should probably break this discussion out to somewhere relevant (there probably is an existing dark matter thread on this site.)
Edit: I couldn't find one, so I created one, please put any replies there: https://forum.nasaspaceflight.com/index.php?topic=46549.0 -
#613 by spupeng7 on 12 Oct, 2018 02:12
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Dear monomorphic. Dark matter is an arbitrary hypothesis, so the fact that a computer can use it to produce what we already know to be there is no surprise: they just fiddled with it till it worked. QI is not arbitrary at all, but the idea of me spending two years trying to model cosmic voids and then have dark matter people say "Oh, we can do it too!" does not appeal
Mike, A lab test with an immediate application is the only way to progress.
are you developing any experiments? An emdrive repeat or something else which your theory suggests. I ask because we both must find physical evidence and, well, ten heads are better than one. -
#614 by flux_capacitor on 13 Oct, 2018 16:51
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Dear monomorphic. Dark matter is an arbitrary hypothesis, so the fact that a computer can use it to produce what we already know to be there is no surprise: they just fiddled with it till it worked. QI is not arbitrary at all, but the idea of me spending two years trying to model cosmic voids and then have dark matter people say "Oh, we can do it too!" does not appeal
Mike, A lab test with an immediate application is the only way to progress.
are you developing any experiments? An emdrive repeat or something else which your theory suggests. I ask because we both must find physical evidence and, well, ten heads are better than one.
This prior post of mine will answer your question:
https://forum.nasaspaceflight.com/index.php?topic=45824.msg1859723#msg1859723
Mike will not at first develop an experiment to test quantised inertia on its own, but three groups in Spain and Germany will. Sadly the third group, which worked with Mike for more than a year, recently published a paper on viXra (29 September 2018):
• Electrostatic Accelerated Electrons Within Information Horizons Exert Bidirectional Propellant-Less Thrust
but then removed any mention of quantised inertia apparently to be able to publish (it is only a preprint!) on the arXiv, confirming the weird behavior of the mainstream and essential preprint (or is it "postprint" finally?) platform (10 October 2018):
• Electrostatic accelerated electrons within symmetric capacitors during field emission condition events exert bidirectional propellant-less thrust -
#615 by Monomorphic on 13 Oct, 2018 21:04
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Famous Experiment Dooms Alternative to Quantum Weirdness
https://www.quantamagazine.org/famous-experiment-dooms-pilot-wave-alternative-to-quantum-weirdness-20181011/
https://journals.aps.org/pre/abstract/10.1103/PhysRevE.92.013006
In a thought-provoking paper, Couder and Fort [Phys. Rev. Lett. 97, 154101 (2006)] describe a version of the famous double-slit experiment performed with droplets bouncing on a vertically vibrated fluid surface. In the experiment, an interference pattern in the single-particle statistics is found even though it is possible to determine unambiguously which slit the walking droplet passes. Here we argue, however, that the single-particle statistics in such an experiment will be fundamentally different from the single-particle statistics of quantum mechanics. Quantum mechanical interference takes place between different classical paths with precise amplitude and phase relations. In the double-slit experiment with walking droplets, these relations are lost since one of the paths is singled out by the droplet. To support our conclusions, we have carried out our own double-slit experiment, and our results, in particular the long and variable slit passage times of the droplets, cast strong doubt on the feasibility of the interference claimed by Couder and Fort. To understand theoretically the limitations of wave-driven particle systems as analogs to quantum mechanics, we introduce a Schrödinger equation with a source term originating from a localized particle that generates a wave while being simultaneously guided by it. We show that the ensuing particle-wave dynamics can capture some characteristics of quantum mechanics such as orbital quantization. However, the particle-wave dynamics can not reproduce quantum mechanics in general, and we show that the single-particle statistics for our model in a double-slit experiment with an additional splitter plate differs qualitatively from that of quantum mechanics.
http://iopscience.iop.org/article/10.1088/1742-6596/701/1/012007
We provide support for the claim that momentum is conserved for individual events in the electron double slit experiment. The natural consequence is that a physical mechanism is responsible for this momentum exchange, but that even if the fundamental mechanism is known for electron crystal diffraction and the Kapitza-Dirac effect, it is unknown for electron diffraction from nano-fabricated double slits. Work towards a proposed explanation in terms of particle trajectories affected by a vacuum field is discussed. The contentious use of trajectories is discussed within the context of oil droplet analogues of double slit diffraction.
http://math.mit.edu/~bush/wordpress/wp-content/uploads/2017/12/Pucci-Slits-2017.pdf
Couder & Fort ( Phys. Rev. Lett. , vol. 97, 2006, 154101) demonstrated that when a droplet walking on the surface of a vibrating bath passes through a single or a double slit, it is deflected due to the distortion of its guiding wave field. Moreover, they suggested the build-up of statistical diffraction and interference patterns similar to those arising for quantum particles. Recently, these results have been revisited (Andersen et al. , Phys. Rev. E, vol. 92 (1), 2015, 013006; Batelaan et al. , J. Phys.: Conf. Ser. , vol. 701 (1), 2016, 012007) and contested (Andersen et al. 2015; Bohr, Andersen & Lautrup, Recent Advances in Fluid Dynamics with Environmental Applications , 2016, Springer, pp. 335–349). We revisit these experiments with a refined experimental set-up that allows us to systematically characterize the dependence of the dynamical and statistical behaviour on the system parameters. The system behaviour is shown to depend strongly on the amplitude of the vibrational forcing: as this forcing increases, a transition from repeatable to unpredictable trajectories arises. In all cases considered, the system behaviour is dominated by a wall effect, specifically the tendency for a drop to walk along a path that makes a fixed angle relative to the plane of the slits. While the three dominant central peaks apparent in the histograms of the deflection angle reported by Couder & Fort (2006) are evident in some of the parameter regimes considered in our study, the Fraunhofer-like dependence of the number of peaks on the slit width is not recovered. In the double-slit geometry, the droplet is influenced by both slits by virtue of the spatial extent of its guiding wave field. The experimental behaviour is well captured by a recently developed theoretical model that allows for a robust treatment of walking droplets interacting with boundaries. Our study underscores the importance of experimental precision in obtaining reproducible data. -
#616 by SeeShells on 14 Oct, 2018 02:13
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Famous Experiment Dooms Alternative to Quantum Weirdness
Not sure if it Dooms it. I'd noticed that in their experiment they used a droplet that is just a particle not a wave and particle
https://www.quantamagazine.org/famous-experiment-dooms-pilot-wave-alternative-to-quantum-weirdness-20181011/
https://journals.aps.org/pre/abstract/10.1103/PhysRevE.92.013006
In a thought-provoking paper, Couder and Fort [Phys. Rev. Lett. 97, 154101 (2006)] describe a version of the famous double-slit experiment performed with droplets bouncing on a vertically vibrated fluid surface. In the experiment, an interference pattern in the single-particle statistics is found even though it is possible to determine unambiguously which slit the walking droplet passes. Here we argue, however, that the single-particle statistics in such an experiment will be fundamentally different from the single-particle statistics of quantum mechanics. Quantum mechanical interference takes place between different classical paths with precise amplitude and phase relations. In the double-slit experiment with walking droplets, these relations are lost since one of the paths is singled out by the droplet. To support our conclusions, we have carried out our own double-slit experiment, and our results, in particular the long and variable slit passage times of the droplets, cast strong doubt on the feasibility of the interference claimed by Couder and Fort. To understand theoretically the limitations of wave-driven particle systems as analogs to quantum mechanics, we introduce a Schrödinger equation with a source term originating from a localized particle that generates a wave while being simultaneously guided by it. We show that the ensuing particle-wave dynamics can capture some characteristics of quantum mechanics such as orbital quantization. However, the particle-wave dynamics can not reproduce quantum mechanics in general, and we show that the single-particle statistics for our model in a double-slit experiment with an additional splitter plate differs qualitatively from that of quantum mechanics.
http://iopscience.iop.org/article/10.1088/1742-6596/701/1/012007
We provide support for the claim that momentum is conserved for individual events in the electron double slit experiment. The natural consequence is that a physical mechanism is responsible for this momentum exchange, but that even if the fundamental mechanism is known for electron crystal diffraction and the Kapitza-Dirac effect, it is unknown for electron diffraction from nano-fabricated double slits. Work towards a proposed explanation in terms of particle trajectories affected by a vacuum field is discussed. The contentious use of trajectories is discussed within the context of oil droplet analogues of double slit diffraction.
http://math.mit.edu/~bush/wordpress/wp-content/uploads/2017/12/Pucci-Slits-2017.pdf
Couder & Fort ( Phys. Rev. Lett. , vol. 97, 2006, 154101) demonstrated that when a droplet walking on the surface of a vibrating bath passes through a single or a double slit, it is deflected due to the distortion of its guiding wave field. Moreover, they suggested the build-up of statistical diffraction and interference patterns similar to those arising for quantum particles. Recently, these results have been revisited (Andersen et al. , Phys. Rev. E, vol. 92 (1), 2015, 013006; Batelaan et al. , J. Phys.: Conf. Ser. , vol. 701 (1), 2016, 012007) and contested (Andersen et al. 2015; Bohr, Andersen & Lautrup, Recent Advances in Fluid Dynamics with Environmental Applications , 2016, Springer, pp. 335–349). We revisit these experiments with a refined experimental set-up that allows us to systematically characterize the dependence of the dynamical and statistical behaviour on the system parameters. The system behaviour is shown to depend strongly on the amplitude of the vibrational forcing: as this forcing increases, a transition from repeatable to unpredictable trajectories arises. In all cases considered, the system behaviour is dominated by a wall effect, specifically the tendency for a drop to walk along a path that makes a fixed angle relative to the plane of the slits. While the three dominant central peaks apparent in the histograms of the deflection angle reported by Couder & Fort (2006) are evident in some of the parameter regimes considered in our study, the Fraunhofer-like dependence of the number of peaks on the slit width is not recovered. In the double-slit geometry, the droplet is influenced by both slits by virtue of the spatial extent of its guiding wave field. The experimental behaviour is well captured by a recently developed theoretical model that allows for a robust treatment of walking droplets interacting with boundaries. Our study underscores the importance of experimental precision in obtaining reproducible data.
"Quote"
BM is about particles and these particles are guided by Schrödinger’s wave
function. Thus in BM the situation is “wave and particle” rather than
“wave or particle”." "End Quote"
http://www.mathematik.uni-muenchen.de/~bohmmech/BohmHome/files/Frequently_Asked_Questions_about_Bohmian_Mechanics.pdf
I would recommend taking some time and watching this series of videos on BM.
My Very Best,
Shell -
#617 by Monomorphic on 14 Oct, 2018 11:11
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I'd noticed that in their experiment they used a droplet that is just a particle not a wave and particle
There is a wave in the silicone oil bath. The droplet bounces around and is guided by this pilot wave. Couder and Fort's 2006 experiment claimed to produce the same interference patterns as the classic double slit experiment. This was presented as a macroscopic analogue of the particle and guiding wave from Bohmian Mechanics (BM). However, those interference patterns have not been replicated, and analysis of the pilot wave suggests that it cannot interfere with itself as suggested by BM.
Of course, the bouncing droplet is not really quantum mechanical so it is not surprising this is the outcome. It will be interesting to see what was the cause of these previous interference patterns. The paper mentions that it may take certain frequencies or a certain amount of noise. That sounds familiar!
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#618 by SeeShells on 14 Oct, 2018 12:48
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The bouncing oil droplet is only a analogy used to show how pilot waves might act not a true representation of BM.I'd noticed that in their experiment they used a droplet that is just a particle not a wave and particle
There is a wave in the silicone oil bath. The droplet bounces around and is guided by this pilot wave. Couder and Fort's 2006 experiment claimed to produce the same interference patterns as the classic double slit experiment. This was presented as a macroscopic analogue of the particle and guiding wave from Bohmian Mechanics (BM). However, those interference patterns have not been replicated, and analysis of the pilot wave suggests that it cannot interfere with itself as suggested by BM.
Of course, the bouncing droplet is not really quantum mechanical so it is not surprising this is the outcome. It will be interesting to see what was the cause of these previous interference patterns. The paper mentions that it may take certain frequencies or a certain amount of noise. That sounds familiar!
This is an article in The Physics arXiv Blog where the object are larger than an electron (which isn't hard to do considering the electrons size
)
https://medium.com/the-physics-arxiv-blog/physicists-smash-record-for-wave-particle-duality-462c39db8e7b
QuoteOf course, nobody has seen the quantum superposition of a baseball or anything anywhere near that size. The experiment would be impossibly difficult. But physicists have seen this wave-particle duality for protons, atoms and increasingly large molecules such as buckyballs.
And that raises an interesting question: how big an object can physicists observe behaving like a wave? Today, Sandra Eibenberger at the University of Vienna in Austria and a few pals say they’ve smashed the record for a quantum superposition by observing wavelike behavior in giant molecules containing over 800 atoms.
My Very Best,
Shell
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#619 by Mark7777777 on 21 Oct, 2018 19:50
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I'm just checking this thread still accepts posts -- since it hasn't had any for 8 days -- a record I think.
)