Upper limit found for quantum world

February 24, 2016 by Erik Arends, Leiden Institute of Physics
The red line shows the upper limit for parameters rc (margin on location) and λ (frequency of wave function collapse per atomic mass unit). The black dotted line gives the expectation for Oosterkamp’s next experiment. The purple ball estimates the values based on the fact that electrons definitely behave quantum mechanically around large molecules. In the end, the goal is to found the values for both parameters. This completes the formula for the boundary between the quantum and macroscopic world. For a given size and mass, this formula tells which laws apply to the object. Credit: Leiden Institute of Physics

The quantum world and our world of perception obey different natural laws. Leiden physicists search for the border between both worlds. Now they suggest an upper limit in a study reported in Physical Review Letters.

The laws of the quantum domain do not apply to our everyday lives. We are used to assigning an exact location and time to objects. But fundamental particles can only be described by probability distributions—imagine receiving a traffic ticket for speeding 30 to 250 km/h somewhere between Paris and Berlin, with a probability peak for 140 km/h in Frankfurt.

Boundary

Because the laws are completely different in both worlds, a clear boundary might exist between them. Size and mass could then be used to determine whether an object obeys quantum or macroscopic laws, but the edge of this boundary is elusive. Leiden physicist Tjerk Oosterkamp and his research group have now established established an upper limit for quantum phenomena, closing in on the answer.

'We keep excluding values, so that we slowly close in on the boundary's location,' says Oosterkamp. 'If we only have a small area left, we can better design our experiments to see what is happening at the edge of the .'

Parameters

According to a certain , you can describe a particle's position with a probability distribution that sometimes spontaneously collapses. In that case, its position is, indeed, determined precisely, within a certain margin. This margin and how often the spontaneous collapse occurs are the two parameters that physicists seek. If they determine those, they have a complete formula to define a strict border between quantum and macro.

Oosterkamp has now determined an upper limit on these parameters of 31 collapses per year per atomic mass unit with a margin around 10 nanometers, to 1 collapse per 100 years with a margin of 1 micron. For their next measurement, the researchers expect fewer collapses, so they can define an even stricter upper limit.

Explore further: Solving hard quantum problems—everything is connected

More information: Upper bounds on spontaneous wave-function collapse models using millikelvin-cooled nanocantilevers, A. Vinante, M. Bahrami, A. Bassi, O. Usenko, G. Wijts, and T.H. Oosterkamp, Physical Review Letters , 2016. arxiv.org/abs/1510.05791

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13 comments

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Hyperfuzzy
1 / 5 (1) Feb 24, 2016
does not two worlds disprove one or both?
Phys1
1 / 5 (1) Feb 24, 2016
Have to agree with fuzzy here.
Quantum Magician
5 / 5 (1) Feb 24, 2016
The quantum world and our world of perception obey different natural laws.

No. -__-

We just use different approaches (tools/models) to describe them. Because even despite the massive advances in all fields of science in the last ~100 years, we still don't fully understand what the *bleep* is really happening "down there" ...
Botopfbber
3 / 5 (1) Feb 24, 2016
This can only tell us what sets of equations to use and does nothing to combine them both while it may define a border we still have to define rules to both. Maybe we are still to dumb to understand whats really going on, I hope someday we do better then this.
Colbourne
1 / 5 (1) Feb 25, 2016
Quantum theory supports the idea that our universe is actually a "computer simulation" running on some kind of computer. Rather than spending the resources to calculate everything precisely, the "programmer" made approximations so that only important calculations were performed exactly and less relevant calculations were only calculated generically.
This shows that even with a computer the size of the universe , it is not fast enough !!!
Botopfbber
1 / 5 (1) Feb 25, 2016
I think if maybe we stop telling our kids what can and can't be done maybe in a thousand generations or so we will bridge the math gap .... but I feel a "computer simulation" approach at looking at all this is like saying the earth is held up on the backs of turtles .... we still don't know what dark mater and energy is just like we didn't know the earth is round.
Steelwolf
1 / 5 (1) Feb 25, 2016
With the way that the Quantum Level works, it almost seems to necessitate the idea that if Anything Exists, then Everything Must Exist: If Anything is Possible (as Quantum Physics is slowly showing us) then Everything Must Happen, at some place and at some point in Time (even if it has to be on it's own different timeline). The whole idea of not only Infinity, but Multiple Infinities gives rise to an infinite number of possibilities, and thus every possible combination is going to be replicated Somewhere in Nature. Thus, yes, either quantum science shows there are more than one Universe, under those laws, or We would not exist. Seeing as how we DO appear to exist, it would seem that these other planes, and I would assume other intelligent beings (possibly of a higher quanta intelligence wise than we) and expect that they have their sciences refined to a much finer point than our own. At that point, which is natural effect and which is artificially induced, at whatever scale possible?
Whydening Gyre
4.3 / 5 (3) Feb 25, 2016
Quantum theory supports the idea that our universe is actually a "computer simulation" running on some kind of computer. Rather than spending the resources to calculate everything precisely, the "programmer" made approximations so that only important calculations were performed exactly and less relevant calculations were only calculated generically.
This shows that even with a computer the size of the universe , it is not fast enough !!!

What if - the Universe IS the computer? running a sim of itself, ON itself?
And - I'm learning that, if you step back far enough, EVERYthing is quantum..:-)
dirk_bruere
5 / 5 (2) Feb 25, 2016
This appears to be a determination of the degree to which a system can be isolated from its surroundings
torbjorn_b_g_larsson
1 / 5 (1) Feb 25, 2016
Decoherence is the way classical systems emerge out of QP systems, so not much new here.

On the thread, these two theories are compatible as a case of emergence (cf a flowing liquid, say, out of assemblies of molecules), the point of emergence is exactly that we can't predict its characteristics from underlying physics (Gödel/Turing/AIT incompleteness if you will: http://inference-...ferently ), and the type of physics is agnostic on the computer simulation idea.

[FWIW, my 2c on simulation is"forgeddaboudid", when we increase resolution we should eventually see deviations from simplest possible physics. Simulation is a sort of non-grounded - and always unquantified - "machina in machina" idea.]
Whydening Gyre
5 / 5 (1) Feb 25, 2016
This appears to be a determination of the degree to which a system can be isolated from its surroundings

It's a measurement of boundary.
KBK
1 / 5 (1) Feb 26, 2016
There is no law in science, folks (^article).

Stop using the physiological social hierarchy emotional trigger of conformity by using the word law.
Azrael
1 / 5 (1) Feb 29, 2016
I'm surprised that I'm surprised.

Nothing in the comments about "water striders" on the "surface" "observing with it's own ripples".

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