A new quantum uncertainty relation has been discovered that might mess with the temperature of your morning joe.
Is your coffee slightly too hot or slightly too cold? It could be both. (Photo: Julius Schorzman/Wiki Commons)
Are you particular about the temperature of your coffee? Does that first sip fresh off the griddle need to be that perfect degree of hot?
Well, there's some quantum physics news that might just make your efforts to attain that perfect sip of coffee futile. A new uncertainty relation has been discovered that raises serious doubts about the precision with which temperature can be measured, reports Phys.org.
In quantum physics, there's something called the uncertainty principle, which posits a fundamental limit to the precision with which certain pairs of physical properties of a particle can be known. This is why quantum physicists must often deal in probabilities when checking the results of their measurements, because precision is elusive.
This can lead to some bizarre thought experiments, such as the famous paradox of Schrödinger's cat, which involves a cat in a quantum booby-trapped box that is both alive and dead at the same time, at least until someone tries to open the box and check on the cat.
That thought experiment relies on the uncertainty relation about the radioactive decay of an atom (which is what triggers the booby trap on the cat). Similarly, though, we might also imagine Schrödinger's coffee, sitting on the griddle (perhaps while Schrödinger himself is pondering the fate of his poor cat), unsipped.
It turns out that getting measurements of when that coffee reaches the perfect temperature might be similarly impossible.
Researchers with University of Exeter recently attempted to create precise quantum thermometers capable of measuring temperatures at nanoscales. What they found was that under certain circumstances, the uncertainty in temperature readings are prone to fluctuations predicted by quantum theory. Specifically, tiny thermometers can be in a superposition between different temperatures, e.g. 90.5°C and 89.5°C, in the same way that Schrödinger's cat can be stuck in a superposition between being dead or alive.
"In addition to thermal noise that is present when making a temperature measurement, the possibility of being in a superposition means that quantum fluctuations influence of how we observe temperature at the nanoscale," explained Harry Miller, first author of the paper.
This is the first time that quantum uncertainty has been found to apply to the accuracy of temperature measurements. It could lead to new and profound ways of thinking about how thermodynamic laws apply, or don't apply, at the smallest scales.
Unfortunately, it also means that measuring the absolutely perfect cup of coffee might be unattainable. At least, until you take a sip.
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