Issue #48 ~ The discovery of quantum mechanics in 1925 was followed by a fierce debate about its meaning and implications. And this debate still rages on, but there have been many twists and turns since the early days. This blog is about the twists that I think are about to happen.
Thank you Vlatko. I appreciate your engage on this platform. I believe there is increasing evidence of quatum phenomena in biological systems leaving aside Sir Roger Pentrose's ideas. i believe taht studying large scale quatum phenomena will give us clues toward unification. My personalinsight/belief is of a recursive dynamic universe where planks constant rescales under certain conditions , avoiding singularity type conditions and making quatum phenomena possible at macroscales. The first hint of this is the apparent variability in the cosmological constant. If proves tur then all constants by definition via Einsteins equations become variable as well.
Fascinating post, and I really enjoyed listening to your linked talk as well. I'm a biologist by background so can't make any incisive comments about the physics, but just had a question - if chorophyll absorbing photons is a quantum process does that mean that everytime we look at a plant we are then entangled with it? By eating a plant and gaining its energy are we also entangled? Wouldn't this then mean that we are immensely entangled with pretty much everything around us? The mind boggles...
Thanks for sharing your thoughts here and I look forward to the new book!
Don't confuse organization with self-organization, Vlatko. As you rightly say in the article, the complexities between a mirror and a living being are not of the same order. But by the way, where does the degree of complexity appear in quantum equations???
Please note that the famous Aspect experiment that claimed to have demonstrated nonlocality in entanglement, is statistically flawed. Allow me to present a short description of the statistical analysis of Aspect's experiment.
The x is angle(a,b) in the interval [0,2π).The, a, is Alice's instrument parameter vector. The, b, is Bob's instrument parameter vector. The angle is measured in the plane orthogonal to the A-S-B axis. This “orthogonal to the A-S-B in the plane variation of x" is sufficient variation for understanding the statistics of the experiment. Obviously, x is a part of the random variable X describing the event “x,≠” in the measurement. The x is entirely free to have any value in [0,2π), in order to maintain Einstein conditions.
For more details:
A.Aspect, P.Grangier and G. Roger, Phys.Rev.Lett., 49, 91-94 (1982).
Note furthermore that the experiment is embedded in classical probability theory. E.g. the law of large numbers to estimate the probability space behind the Bell correlation formula.
Aspect then requires:
1. cos(x) = P(x,=) - P(x,≠)
1a. P(x,=)=N(x,=)/N
1b. P(x,≠)=N(x,≠)/N
1c. N(x,=)=N(x,+,+)+N(x,-,-)
1d. N(x,≠)=N(x,+,-)+N(x,-,+)
1e. N=N(x,=)+N(x,≠)
The + and - denote the polarization states measured in the experiment. Formula 1 is, in fact, the question of whether or not the measurement results in P(x,=), and, P(x,≠) can reproduce the quantum correlation cos(x). It's the hypothesis
H0: measurements of polarization in entangled pairs of photons can produce the quantum correlation
Then,
2. cos(x)=1-2sin²(x/2), x in [0,2π)
3. P(x,=)+P(x,≠)=1
This reformulates the hypothesis H0 into:
4. P(x,≠)= sin²(x/2), x in [0,2π)
Let us write F(x)=sin²(x/2).
The left-hand in 4. is a data probability (estimate) determined by nature. But, the right-hand isn't a probability function, F(x). It isn't monotone non-descending for x in [0,2π).
5. For x in [0,2π), the alleged probability density is derived from point 4. via f(x)=dF(x)/dx. But observe, f(x)=(1/2)sin(x), x in [0,2π), isn't a probability density. It is not positive definite for x in [0,2π).
I agree that there is a problem with defining what it means to be macroscopic. I believe that the whole universe is quantum and that such a boundary does not exist at the fundamental level. Of course, it might exist technologically speaking, for all practical purposes, in that we might not be able to conduct quantum interference experiments beyond certain scales. You can also think of boilogical processes as amplifiers of quantum information, however, it is possible that most of them as, again for all practical purposes, classical (meaning that quantum features are simply washed away by the complexity of the system).
Very interesting! But I think there's a problem with the concept of "macroscopic". As far as I know, there is no way to define an objective boundary separating "macroscopic" from "microscopic" in terms of number of atoms. So the whole notion of "macroscopic entanglement" seems slightly unscientific to me.
I have developed my own interpretation of QM, in which this problem is solved: I call it the "sensorial interpretation", and its central premise is that physical reality is reducible to sensations experienced by living organisms (not only humans). According to this, there is nothing mysterious in macroscopic entanglement, like in the example of the mirror: the mirror might be in an entangled state of recoiled/stationary, but the difference between those states is undetectable to our senses. If we make it detectable (make a measurement), the entanglement will disappear. The same applies to atoms responding to magnetic fields, etc.
This interpretation also predicts that macroscopic entanglement cannot occur in living systems.
If anyone is interested, I can share more details of my "sensorial interpretation". It may sound like a crazy idea, but it can be tested (I think) using a relatively simple double-slit experiment.
Thanks you Vlatko, very clear description of the experiment. If macroscopic entanglement occurs in living systems, then all possibilities do happen, right?
I think that "all possibilities do happen" only applies to the many-worlds interpretation. In other interpretations of QM, the entanglement eventually disappears, either by spontaneous collapse, or when a "measurement" happens. Different interpretations disagree about what constitutes a measurement, but that's a whole other can of worms :)
So if I have this right a bunch of photons are chucked at a mirror. Some photons reflect, and some transmit. Surely the equivalent of the half alive & half dead cat is that after a couple of photons, half the momentum of a single reflection should be imparted to the mirror until a measurement is conducted to see what really happened. Is this accessible with current experimental methods?
Thank you Vlatko. I appreciate your engage on this platform. I believe there is increasing evidence of quatum phenomena in biological systems leaving aside Sir Roger Pentrose's ideas. i believe taht studying large scale quatum phenomena will give us clues toward unification. My personalinsight/belief is of a recursive dynamic universe where planks constant rescales under certain conditions , avoiding singularity type conditions and making quatum phenomena possible at macroscales. The first hint of this is the apparent variability in the cosmological constant. If proves tur then all constants by definition via Einsteins equations become variable as well.
Fascinating post, and I really enjoyed listening to your linked talk as well. I'm a biologist by background so can't make any incisive comments about the physics, but just had a question - if chorophyll absorbing photons is a quantum process does that mean that everytime we look at a plant we are then entangled with it? By eating a plant and gaining its energy are we also entangled? Wouldn't this then mean that we are immensely entangled with pretty much everything around us? The mind boggles...
Thanks for sharing your thoughts here and I look forward to the new book!
Sara
Don't confuse organization with self-organization, Vlatko. As you rightly say in the article, the complexities between a mirror and a living being are not of the same order. But by the way, where does the degree of complexity appear in quantum equations???
Please note that the famous Aspect experiment that claimed to have demonstrated nonlocality in entanglement, is statistically flawed. Allow me to present a short description of the statistical analysis of Aspect's experiment.
The x is angle(a,b) in the interval [0,2π).The, a, is Alice's instrument parameter vector. The, b, is Bob's instrument parameter vector. The angle is measured in the plane orthogonal to the A-S-B axis. This “orthogonal to the A-S-B in the plane variation of x" is sufficient variation for understanding the statistics of the experiment. Obviously, x is a part of the random variable X describing the event “x,≠” in the measurement. The x is entirely free to have any value in [0,2π), in order to maintain Einstein conditions.
For more details:
A.Aspect, P.Grangier and G. Roger, Phys.Rev.Lett., 49, 91-94 (1982).
Note furthermore that the experiment is embedded in classical probability theory. E.g. the law of large numbers to estimate the probability space behind the Bell correlation formula.
Aspect then requires:
1. cos(x) = P(x,=) - P(x,≠)
1a. P(x,=)=N(x,=)/N
1b. P(x,≠)=N(x,≠)/N
1c. N(x,=)=N(x,+,+)+N(x,-,-)
1d. N(x,≠)=N(x,+,-)+N(x,-,+)
1e. N=N(x,=)+N(x,≠)
The + and - denote the polarization states measured in the experiment. Formula 1 is, in fact, the question of whether or not the measurement results in P(x,=), and, P(x,≠) can reproduce the quantum correlation cos(x). It's the hypothesis
H0: measurements of polarization in entangled pairs of photons can produce the quantum correlation
Then,
2. cos(x)=1-2sin²(x/2), x in [0,2π)
3. P(x,=)+P(x,≠)=1
This reformulates the hypothesis H0 into:
4. P(x,≠)= sin²(x/2), x in [0,2π)
Let us write F(x)=sin²(x/2).
The left-hand in 4. is a data probability (estimate) determined by nature. But, the right-hand isn't a probability function, F(x). It isn't monotone non-descending for x in [0,2π).
5. For x in [0,2π), the alleged probability density is derived from point 4. via f(x)=dF(x)/dx. But observe, f(x)=(1/2)sin(x), x in [0,2π), isn't a probability density. It is not positive definite for x in [0,2π).
I agree that there is a problem with defining what it means to be macroscopic. I believe that the whole universe is quantum and that such a boundary does not exist at the fundamental level. Of course, it might exist technologically speaking, for all practical purposes, in that we might not be able to conduct quantum interference experiments beyond certain scales. You can also think of boilogical processes as amplifiers of quantum information, however, it is possible that most of them as, again for all practical purposes, classical (meaning that quantum features are simply washed away by the complexity of the system).
Very interesting! But I think there's a problem with the concept of "macroscopic". As far as I know, there is no way to define an objective boundary separating "macroscopic" from "microscopic" in terms of number of atoms. So the whole notion of "macroscopic entanglement" seems slightly unscientific to me.
I have developed my own interpretation of QM, in which this problem is solved: I call it the "sensorial interpretation", and its central premise is that physical reality is reducible to sensations experienced by living organisms (not only humans). According to this, there is nothing mysterious in macroscopic entanglement, like in the example of the mirror: the mirror might be in an entangled state of recoiled/stationary, but the difference between those states is undetectable to our senses. If we make it detectable (make a measurement), the entanglement will disappear. The same applies to atoms responding to magnetic fields, etc.
This interpretation also predicts that macroscopic entanglement cannot occur in living systems.
If anyone is interested, I can share more details of my "sensorial interpretation". It may sound like a crazy idea, but it can be tested (I think) using a relatively simple double-slit experiment.
Thanks you Vlatko, very clear description of the experiment. If macroscopic entanglement occurs in living systems, then all possibilities do happen, right?
Hi Christine,
I think that "all possibilities do happen" only applies to the many-worlds interpretation. In other interpretations of QM, the entanglement eventually disappears, either by spontaneous collapse, or when a "measurement" happens. Different interpretations disagree about what constitutes a measurement, but that's a whole other can of worms :)
So if I have this right a bunch of photons are chucked at a mirror. Some photons reflect, and some transmit. Surely the equivalent of the half alive & half dead cat is that after a couple of photons, half the momentum of a single reflection should be imparted to the mirror until a measurement is conducted to see what really happened. Is this accessible with current experimental methods?