A paper just published suggests a method that would easily test whether or not electron entanglement is measurable on the macroscopic scale.
“[The] idea is based on the third law of thermodynamics which states that the entropy at absolute zero is dependent only on the degeneracy of the ground state. This in turn implies that the specific heat capacity of a material must asymptotically approach zero as the temperature gets closer to absolute zero. But if particles within the material were entangled, Vedral and pals say this would not be the case.
That kind of thinking suggests a straightforward experiment: simply measure the heat capacity of a material as its temperature drops to zero. If it doesn’t asymptotically approach zero, then you’ve got some entanglement on your hands.”
Read the full article here.
Measuring the specific heat of a material is a straightforward experiment. Back when I was in graduate school, many of the basement labs were running cryogenic tests measuring the specific heat of samples being supplied by the research station over at DuPont. This experiment would just be a matter of “degree” (pun intended.)
In fact sufficient data may already exist – it’s just going to take some enterprising grad student to pull it out of the archives and analyze it differently than it was analyzed before.