Einstein saves the quantum cat

June 16, 2015, University of Vienna
Illustration of a molecule in the presence of gravitational time dilation. The molecule is in a quantum superposition of being in several places at the same time, but time dilation destroys this quantum phenomenon. Credit: Igor Pikovski, Harvard-Smithsonian Center for Astrophysics

Einstein's theory of time and space will celebrate its 100th anniversary this year. Even today it captures the imagination of scientists. In an international collaboration, researchers from the universities of Vienna, Harvard and Queensland have now discovered that this world-famous theory can explain yet another puzzling phenomenon: the transition from quantum behavior to our classical, everyday world. Their results are published in the journal Nature Physics.

In 1915 Albert Einstein formulated the theory of general relativity which fundamentally changed our understanding of gravity. He explained gravity as the manifestation of the curvature of space and time. Einstein's theory predicts that the flow of time is altered by mass. This effect, known as "gravitational ", causes time to be slowed down near a massive object. It affects everything and everybody; in fact, people working on the ground floor will age slower than their colleagues a floor above, by about 10 nanoseconds in one year. This tiny effect has actually been confirmed in many experiments with very precise clocks. Now, a team of researchers from the University of Vienna, Harvard University and the University of Queensland have discovered that the slowing down of time can explain another perplexing phenomenon: the transition from to our classical, everyday world.

How gravity suppresses quantum behavior

Quantum theory, the other major discovery in physics in the early 20th century, predicts that the fundamental of nature show fascinating and mind-boggling behavior. Extrapolated to the scales of our everyday life leads to situations such as the famous example of Schroedinger's cat: the cat is neither dead nor alive, but in a so-called quantum superposition of both. Yet such a behavior has only been confirmed experimentally with small particles and has never been observed with real-world cats. Therefore, scientists conclude that something must cause the suppression of quantum phenomena on larger, everyday scales. Typically this happens because of interaction with other surrounding particles.

The research team, headed by ?aslav Brukner from the University of Vienna and the Institute of Quantum Optics and Quantum Information, found that time dilation also plays a major role in the demise of quantum effects. They calculated that once the small building blocks form larger, composite objects - such as molecules and eventually larger structures like microbes or dust particles -, the time dilation on Earth can cause a suppression of their quantum behavior. The tiny building blocks jitter ever so slightly, even as they form larger objects. And this jitter is affected by time dilation: it is slowed down on the ground and speeds up at higher altitudes. The researchers have shown that this effect destroys the quantum superposition and, thus, forces larger objects to behave as we expect in everyday life.

Paving the way for the next generation of quantum experiments

"It is quite surprising that gravity can play any role in quantum mechanics", says Igor Pikovski, who is the lead author of the publication and is now working at the Harvard-Smithsonian Center for Astrophysics: "Gravity is usually studied on astronomical scales, but it seems that it also alters the quantum nature of the smallest particles on Earth". "It remains to be seen what the results imply on cosmological scales, where gravity can be much stronger", adds ?aslav Brukner. The results of Pikovski and his co-workers reveal how larger particles lose their quantum behavior due to their own composition, if one takes time dilation into account. This prediction should be observable in experiments in the near future, which could shed some light on the fascinating interplay between the two great theories of the 20th century, quantum theory and .

Explore further: How spacetime is built by quantum entanglement

More information: Universal decoherence due to gravitational time dilation, Nature Physics (2015) DOI: 10.1038/nphys3366

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not rated yet Jun 16, 2015
So molecules are relatively quantum?

You see a quantum, and I see a quanta....
1 / 5 (1) Jun 16, 2015
Sounds like they should get some experiments to that effect up on the ISS (preferrably a much longer way away - but that would be costly) and an identical setup down here on the ground to see how big the difference is.
Jun 16, 2015
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4 / 5 (2) Jun 16, 2015
The wave function W(x,y,z,t) is dependent on time but probability density WW* (W modulus) is stationary and independent on time allowing for solution of Schrodinger Equation instead of Dirac Equation for most applications of QM.

The transition between micro and macrocosm is a transition between quantum theory and classical theory type of description of reality, all are founded on different concepts or existence and identity and many others like causality.

It was elegantly put by Richard von Mises in his famous book " Probability Statistics and Truth, 1957 who pointed out that statistically measuring smaller and smaller number of molecules in the system, while transitioning from macro to micro scale causes an increasing of relative error. I other words transitioning from micro to macro we are loosing relative accuracy of measurements.
More discussion of that I found at:
5 / 5 (2) Jun 16, 2015
If Gravity did indeed affect the quantum 'jitter' of macroscopic objects, wouldn't it make more sense to suggest this is because their increase in mass, and not their altitude? We're already talking about microscopic affects, so wouldn't the mass of the macroscopic object play much more into the 'decoherence' of quantum effects, as opposed to it's altitude?
5 / 5 (1) Jun 16, 2015
So a small piece of graphene can become entangled with another small piece of that substance only if they'er both horizontal!
Whydening Gyre
not rated yet Jun 16, 2015
Sounds like they should get some experiments to that effect up on the ISS (preferrably a much longer way away - but that would be costly) and an identical setup down here on the ground to see how big the difference is.

Good idea. It COULD show a measurable scale/ratio difference...
not rated yet Jun 16, 2015
1 / 5 (2) Jun 17, 2015
run of clocks in micro and macro cosmos depends on energy density of quantum vacuum.
There is no such a phenomena as "time dilatation" as time is only a mathem,atical parameter of motion in space
1 / 5 (5) Jun 17, 2015
Dear Prof. Brukner,

reading report on your research

I'm informing you that there is no such phenomena in the universe as "time dilatation" because time is only a mathematical parameter of motion in space.

Clocks run slower of faster because of variable density of quantum vacuum which is origin of space curvature on GR. With Fiscaletti we publish that stuff.

Yours Sincerely, Amrit Srečko Šorli

Foundations of Physics Institute - FOPI
Jun 17, 2015
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Jun 17, 2015
This comment has been removed by a moderator.
not rated yet Jun 17, 2015
How exactly the decoherence times can be measured today? Within five percent of precission? IMO this measurement would be extremely difficult to implement in practice:

Experiments with 'meso-scopic' objects are relatively new,... but should allow investigation into quantifiablly 'observing' decoherence.

The large number of atoms required for the collapse mechanism to be effective also leads to strong decoherence.

I don't think the above is a 'gravitational collapse' theory,... but rather a decoherence mechanism. Of course decoherence is not 'collapse'.
not rated yet Jun 17, 2015
Anywallsocket seems to have it right. Gravity. Tiny equals miniscule gravity. We, made of atomic stuff, have a greater experience with gravity. And since we have yet to have an inkling as to what gravity is, Higgs bosun aside, were no better off.
not rated yet Jun 18, 2015
This almost seems to suggest that in the presence of an enormous gravitational gradient, like a neutron star, quantum behavior might be suppressed even at the atomic scale. And, as matter approaches an event horizon it's behavior should become more and more "classical".
1 / 5 (1) Jun 22, 2015
Gravitational time diltation has origin in energy density of quntum vacuum. Less vacuum is dense, smaller is velocity of changes. Inside Sch. radius density of vacuum isso low that particles become unstable and transform back in energy of quntum vacuum....dekoherence has orgin in low energy density of vacuum, see my book "The Physics of NOW.
5 / 5 (1) Jun 22, 2015
It seems that this is closely related to Roger Penrose's observation that the linearity of quantum entanglement is lost on entering into nonlinear spacetime,

Based upon the empirical operation of cloud chambers and theory, Penrose at the time of his 1989 book, The Emperor's New Mind, estimated this to occur when the difference of interaction of two potential histories reached that of the one graviton level (about an interaction difference with mass of 22 micrograms). This theory, and the observation by Stuart Hameroff's of the potential importance of the microtubule, has led to the Penrose–Hameroff orchestrated objective-reduction proposal for human mind-brain interaction, essentially quantum computation.

One might also add that nonlinearity is the starting point of deterministic chaos, and so we may be seeing here the actual nexus of where information source meets information sink. Or per Robert Lanza's Biocentricism theory, we might say the nexus of consciousness/reality.
not rated yet Jun 23, 2015
Relative and variable.
Time is a measure (or perception) of duration rather than an entity.
Applied over minute distances it disappears altogether. It is a side effect.
not rated yet Jul 01, 2015
by increasing the energy of matter in this manner (lasers presumably) has anyone attempted to measure if there is an increased attraction between 2 point sources?
not rated yet Jul 01, 2015
by increasing the energy of matter in this manner (lasers presumably) has anyone attempted to measure if there is an increased attraction between 2 point sources?
not rated yet Jul 01, 2015
internet prob sorry
not rated yet Jul 10, 2015
This article says – "Quantum theory, the other major discovery in physics in the early 20th century, predicts that the fundamental building blocks of nature show fascinating and mind-boggling behavior." It is difficult to accept.

Heisenberg has given a proof of Uncertainty Principle (UP) in one of his books. The original proof is exactly copied in here: QM chapter in Soul Theory at WordPress dot com. Take a look at the proof. I think very rarely any QM people has read the proof of UP carefully. The proof is completely wrong, and it has nothing to do with physics or nature.

In the proof Heisenberg makes two fatal errors: (1) He says position and momentum of a particle are related by Fourier Transform (FT). There is no validation of such an assumption by any experimental evidences. (2) He ignores the fact that FT uses infinity.

If you replace infinity in FT by any finite number, then the uncertainty will vanish. Thus UP must be wrong and so is QM.

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