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M. Svrˇ cek
14 The Second Quantum Floor
The transition from classical to microscopic quantum physics is nicely distinguished
if one compares the Rutherford and the Bohr atomic models. In the former an electron
needs to accelerate its movement in order to achieve a higher energy level around
the nucleus. In the Bohr model there is no need for any movement or acceleration;
all electrons occupy certain quantum states and transitions to another level occur by
way of quantum jumps.
In addition to the microscopic quantum domain, mentioned above and which we
name the first quantum floor, one also has the whole scale of megascopic phenomena,
operating on a second quantum floor. Surprisingly we are here in a similar situation
compared to a century ago. The microscopic quantum description all of a sudden has
become insufficient. Note that we have repeatedly discussed this issue in previous
sections, e.g. for transitions between isomers and distorted J-T states in molecules,
and in superconductors, and found that microscopic tunnelling, represented by the
direct movement of elementary particles, is entirely outside the scope of the given
problem. We need an additional concept of megascopic quantum jumps appearing
either on the microscopic or the macroscopic level, which is in a similar relation to
microscopic tunnelling as the concept of microscopic quantum jumps, in the Bohr
model, relates to the classical electronic movement in the Rutherford model.
Concentrating briefly on superconductivity and its megascopic origin, we recapitulate the three main reasons why superconductivity does not have any microscopic
explanation, see also Sects. 9 and 11:
(1) Every microscopic theory must result in Born’s rule for the probabilities related
to the density and the velocity of the superconducting carriers, and these quantities have to be experimentally measurable. But as we know, they are in principle
non-measurable.
(2) No microscopic theory allows us to avoid the universal concept of Bloch states
for the description of superconducting carriers. It means that the carrier mass
must take the effective mass of the electrons into account. This, however, is
in direct contradiction with measurements of the London moment, where only
bare electronic masses are reported.
(3) According to the second form of van Fraassen’s argument, asymmetry cannot arise ex nihilo. Although we know that the original asymmetry around the
superconductor can be present in the form of an external magnetic field, no
microscopic theory is able to explain the Meissner effect mechanism, when the
superconductor is cooled below the critical temperature and the constant magnetic field cannot bring about any acceleration of the superconducting carriers.
It means that a microscopic theory is unable to implement the original asymmetry, and this fact contradicts the mentioned second form of the van Fraassen
argument.
Nevertheless, superconductors can be described macroscopically on the quantum
level. The concept of macroscopically-occupied quantum states was proposed by
M. Svrˇ cek
14 The Second Quantum Floor
The transition from classical to microscopic quantum physics is nicely distinguished
if one compares the Rutherford and the Bohr atomic models. In the former an electron
needs to accelerate its movement in order to achieve a higher energy level around
the nucleus. In the Bohr model there is no need for any movement or acceleration;
all electrons occupy certain quantum states and transitions to another level occur by
way of quantum jumps.
In addition to the microscopic quantum domain, mentioned above and which we
name the first quantum floor, one also has the whole scale of megascopic phenomena,
operating on a second quantum floor. Surprisingly we are here in a similar situation
compared to a century ago. The microscopic quantum description all of a sudden has
become insufficient. Note that we have repeatedly discussed this issue in previous
sections, e.g. for transitions between isomers and distorted J-T states in molecules,
and in superconductors, and found that microscopic tunnelling, represented by the
direct movement of elementary particles, is entirely outside the scope of the given
problem. We need an additional concept of megascopic quantum jumps appearing
either on the microscopic or the macroscopic level, which is in a similar relation to
microscopic tunnelling as the concept of microscopic quantum jumps, in the Bohr
model, relates to the classical electronic movement in the Rutherford model.
Concentrating briefly on superconductivity and its megascopic origin, we recapitulate the three main reasons why superconductivity does not have any microscopic
explanation, see also Sects. 9 and 11:
(1) Every microscopic theory must result in Born’s rule for the probabilities related
to the density and the velocity of the superconducting carriers, and these quantities have to be experimentally measurable. But as we know, they are in principle
non-measurable.
(2) No microscopic theory allows us to avoid the universal concept of Bloch states
for the description of superconducting carriers. It means that the carrier mass
must take the effective mass of the electrons into account. This, however, is
in direct contradiction with measurements of the London moment, where only
bare electronic masses are reported.
(3) According to the second form of van Fraassen’s argument, asymmetry cannot arise ex nihilo. Although we know that the original asymmetry around the
superconductor can be present in the form of an external magnetic field, no
microscopic theory is able to explain the Meissner effect mechanism, when the
superconductor is cooled below the critical temperature and the constant magnetic field cannot bring about any acceleration of the superconducting carriers.
It means that a microscopic theory is unable to implement the original asymmetry, and this fact contradicts the mentioned second form of the van Fraassen
argument.
Nevertheless, superconductors can be described macroscopically on the quantum
level. The concept of macroscopically-occupied quantum states was proposed by