Quantum and Classical Realities: Reconciled at Last?
Some physicists think they’ve explained how quantum effects vanish at macro scales; others say it doesn’t change quantum mechanical paradoxes.
Cat box: An icon of quantum-mechanical weirdness is the thought experiment of Schrödinger’s cat: a cat in a box that is neither dead nor alive, but in a so-called quantum superposition of both, until observed. Several science posts are now claiming that work at UC Santa Barbara solves the paradox by applying Einstein’s time-dilation property of general relativity to the bridge from atomic to macroscopic phenomena. Some pick sides on whether the cat ends up dead or alive.
- Einstein kills Schrödinger’s cat: Relativity ruins quantum world (New Scientist)
- Einstein saves the quantum cat (PhysOrg)
- How gravity kills Schrödinger’s cat (Nature)
The abstruse details go beyond our needs here. Suffice it to say that quantum weirdness remains after this latest attempt to reconcile QM with classical physics. There is no theory of quantum gravity, for instance; “it doesn’t change our picture of the world,” one critic said; “it’s nothing new,” another remarked (Nature).
Spooky. For decades, physicists have grappled with interpreting the nature of reality from quantum mechanical experiments. What is the nature of “quantum entanglement,” for instance, that seems to involve spooky action at a distance between two entangled particles separated by a distance? PhysOrg adds to the weirdness by describing new entangled states that appear to be violations of local realism.
Get real. “What is really real?” Nature asked last month. “A wave of experiments is probing the root of quantum weirdness.” Zeeya Merali describes some physicists who don’t worry about the big questions when paradoxes arise. “Shut up and calculate” is their attitude. Bohr and Heisenberg felt that the quantum wavefunction is “nothing more than a tool for predicting the results of observations”; they cautioned physicists “not to concern themselves with what reality looks like underneath.” Some can’t help but wonder anyway. Merali discusses physicists on the fringe still dabbling with Everett’s many-worlds hypothesis and the possibility of parallel universes. One of them says, “what would be really exciting is to devise a test for whether there is in fact any objective reality out there at all.” It seems lost on him that the proposition is self-defeating; he has to assume reality to question it.
Mass action. As for “shut up and calculate” pragmatics, Nature reported new measurements of the mass differences of the proton, neutron and electron. These measurements bear on the fine-tuning of the universe, having potential catastrophic consequences for the stability of atoms and stars if they were to vary within narrow limits. The new measurements claim to have accuracy to 8 significant figures.
Big TOE. Theoretical particle physics goes far beyond measurement. One example is Vakhtang Kartvelishvili’s article on The Conversation, “Particle physics discovery raises hope for a theory of everything.” His hope is in the newly-restarted Large Hadron Collider (LHC) at CERN. The “standard model” is “far from perfect” because it cannot account for 95% of reality, according to consensus big bang theory (see 6/19/15). Is there enlightenment in the decay profile of the B-meson? He wonders. “The next run of the LHC, which is about to start, should provide the opportunities to improve the precision of these measurements, and to put even more stringent constraints on theories that include physics beyond the standard model – or maybe bring a discovery which does not fit any of the existing ones?” Meanwhile, at the University of Tokyo, physicists are looking for their Theory of Everything in quantum entanglement and the holographic principle, Science Daily says. Unless the two approaches prove to be compatible, it seems intuitive that a universe cannot have two everythings.
Math whiz. Aside from QM, particle physics and idle speculations about reality, one uncanny quirk about the universe is how well it can be described by mathematics. In “How mathematics reveals the nature of the cosmos,” Joshua Carroll on PhysOrg takes a historical tour through advances in mathematics, speculating that “Mathematics almost certainly came about from very early human tribes … that may have used math as a way of keeping track of lunar or solar cycles, and keeping count of animals, food and/or people by leaders.” But is mathematics an invention, or a discovery? He assumes the latter, but never explains why the universe should conform to abstract logical relationships that are quantifiable, elegant, and simple. Is it not surprising to manipulate equations and come up with discoveries that turn out to match observations?
These stories are provided for those who like idle speculation. All you need to know is that self-refuting beliefs are necessarily false. It’s also good to know that secular scientists recognize the fact that our universe is finely tuned for life to exist. Consequently, scientists need to get real and explain how that could have come out of a mindless, meaningless beginning.