Laser light coherence offers a consistent approach

Researchers at the University of Basel have developed a new approach to applying thermodynamics to microscopic quantum systems.


In 1798, the officer and physicist Benjamin Thompson (a.k.a. Count Rumford) observed the drilling of cannon barrels in Munich and concluded that heat is not a substance but can be created in unlimited amounts by mechanical friction.


Rumford determined the amount of heat generated by immersing the cannon barrels in water and measuring how long it took the water to reach boiling. Based on such experiments, thermodynamics was developed in the 19th century. Initially, it was at the service of the Industrial Revolution and explained, physically, for instance, how heat can be efficiently converted into useful work in steam engines.

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A Thermometer for Measuring Quantumness

If there’s one law of physics that seems easy to grasp, it’s the second law of thermodynamics: Heat flows spontaneously from hotter bodies to colder ones. But now, gently and almost casually, Alexssandre de Oliveira Jr.(opens a new tab) has just shown me I didn’t truly understand it at all.


Take this hot cup of coffee and this cold jug of milk, the Brazilian physicist said as we sat in a café in Copenhagen. Bring them into contact and, sure enough, heat will flow from the hot object to the cold one, just as the German scientist Rudolf Clausius first stated formally in 1850. However, in some cases, de Oliveira explained, physicists have learned that the laws of quantum mechanics can drive heat flow the opposite way: from cold to hot.

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120 year old fundamental law of Universe that Einstein got wrong has been proven

A physics professor from the Universidad de Sevilla (University of Seville) has tackled a problem in thermodynamics that has been around for more than a century, offering a new proof that also challenges an idea once put forward by Albert Einstein.

José María Martín Olalla’s study, published in The European Physical Journal Plus, focuses on the Nernst heat theorem. This theorem, first stated in 1905, says that as temperature gets closer to absolute zero, the exchange of entropy (a measure of disorder) also gets closer to zero. 

In his paper, Martín Olalla shows that the theorem can be proven using only the second law of thermodynamics, which says that the entropy of the universe always increases.

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Physicist Solves 120-Year-Old Thermodynamics Puzzle and Corrects Einstein

A thermodynamics mystery dating back to 1905 has been resolved by University of Seville professor José María Martín-Olalla, who demonstrates that the Nernst theorem is inherently tied to the second law of thermodynamics. His reinterpretation corrects a long-standing assumption made by Einstein, reframing how physicists understand the behavior of entropy near absolute zero. Credit: SciTechDaily.com

The paper argues that the third principle of thermodynamics follows from the second principle, rather than being a separate or independent concept.

Professor José María Martín-Olalla of the University of Seville has published a paper addressing a thermodynamics problem that has remained unresolved for 120 years. In doing so, he corrects an idea proposed by Albert Einstein more than a century ago.

The paper links Nernst’s theorem, an experimental observation from 1905 stating that entropy exchanges approach zero as temperature approaches zero, directly to the second principle of thermodynamics. Published in The European Physical Journal Plus, the study extends the implications of the second principle, which states that entropy in the universe tends to increase.

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The Entropy of Quantum Entanglement

Bartosz Regula from the RIKEN Center for Quantum Computing and Ludovico Lami from the University of Amsterdam have shown, through probabilistic calculations, that there is indeed, as had been hypothesized, a rule of entropy for the phenomenon of quantum entanglement.


This finding could help drive a better understanding of quantum entanglement, which is a key resource that underlies much of the power of future quantum computers. Little is currently understood about the optimal ways to make effective use of it, despite it being the focus of research in quantum information science for decades.


The second law of thermodynamics, which says that a system can never move to a state with lower entropy, or order, is one of the most fundamental laws of nature, and lies at the very heart of physics. It is what creates the "arrow of time," and tells us the remarkable fact that the dynamics of general physical systems, even extremely complex ones such as gases or black holes, are encapsulated by a single function, its entropy.     READ MORE...

Time Reversal

A team of researchers from the University of Twente has successfully illustrated that quantum mechanics and thermodynamics can coexist by using an optical chip with photon channels. The channels individually showed disorder in line with thermodynamics, while the overall system complied with quantum mechanics due to the entanglement of subsystems, proving that information can be preserved and transferred. Credit: University of Twente

It seems quantum mechanics and thermodynamics cannot be true simultaneously. In a new publication, University of Twente researchers use photons in an optical chip to demonstrate how both theories can be true at the same time.

In quantum mechanics, time can be reversed and information is always preserved. That is, one can always find back the previous state of particles. It was long unknown how this could be true at the same time as thermodynamics. 

There, time has a direction and information can also be lost. “Just think of two photographs that you put in the sun for too long, after a while you can no longer distinguish them,” explains author Jelmer Renema.

There was already a theoretical solution to this quantum puzzle and even an experiment with atoms, but now the University of Twente (UT) researchers have also demonstrated it with photons. “Photons have the advantage that it is quite easy to reverse time with them,” explains Renema. 

In the experiment, the researchers used an optical chip with channels through which the photons could pass. At first, they could determine exactly how many photons there were in each channel, but after that, the photons shuffled positions.  READ MORE...

Time Crystal

Google’s quantum computer has been used to build a “time crystal” according to freshly-published research, a new phase of matter that upends the traditional laws of thermodynamics. 

Despite what the name might suggest, however, the new breakthrough won’t let Google build a time machine.

Time crystals were first proposed in 2012, as systems that continuously operate out of equilibrium. Unlike other phases of matter, which are in thermal equilibrium, time crystals are stable yet the atoms which make them up are constantly evolving.

At least, that’s been the theory: scientists have disagreed on whether such a thing was actually possible in reality. Different levels of time crystals that could or could not be generated have been argued, with demonstrations of some that partly – but not completely – meet all the relevant criteria. 

In a new research preprint by researchers at Google, along with physicists at Princeton, Stanford, and other universities, it’s claimed that Google’s quantum computer project has delivered what many believed impossible. 

Preprints are versions of academic papers that are published prior to going through peer-review and full publishing; as such, their findings can be challenged or even overturned completely during that review process. READ MORE