One Discovery published in the magazine Nature put one of the pillars of physics in check. Scientists managed to provoke the overheating of gold, leading it to extreme temperatures without the metal to lose its solid structure.
This is a feat that challenges the so-called “entropy catastrophe”, theory accepted as a thermodynamic limit for over four decades.
The study was conducted by Bob Nagler of the US Department of Energy at the Slac National Accelerator Laboratory, in partnership with Tom White, an associate professor at Nevada University. In addition, she had researchers from various international institutions, such as European XFel, as well as the universities of Queen’s, Columbia, Princeton, Oxford, California and Warwick.
Theory knocked down? Understand what the “catastrophe of entropy” is
Since the 1980s, theoretical models maintain that By raising the temperature of a solid, atomic vibrations would become so intense that its structure would collapse, inevitably leading to fusion. This phenomenon was described as an entropy catastrophe, a kind of thermodynamic limit that established the maximum point where a material could remain solid.
To challenge this limit, The physicists used ultra -rare lasers who warmed very thin layers of gold in trilliones. This speed caused the electrons to absorb energy before the crystalline grid had time to disorganize.
Soon after, high-intensity x-ray beams recorded the atomic behavior of the material, proving that gold was overheated but still solid.
Gold, whose conventional melting point is 1,064 ° C, was brought to temperatures up to 19,000 Kelvin (about 18,700 ° C), ie, more than 14 times above the limit provided for classic physics. Previous models estimated that a solid could not remain stable at temperatures three times higher than its melting point.
Why did the overheated gold remained solid?
The differential was the speed. Ultra -rare warming did not give time for the atoms to reorganize in liquid state. The energy was placed so fast that the crystalline structure was “frozen” in its place, creating an extreme solid state by some trilliones of a second – enough time to challenge the established theory.
Physicists used ultra-brilliant X-rays to measure atom vibration right after laser firing. This technique of atomic accuracy allowed to accompany the behavior of gold under conditions that were previously considered unattainable.
Theoretical limits of physics should be rethought
Observation contradicts the forecast of entropy catastrophe and shows that models on the stability of matter under extreme conditions need to be revised.
Em useTom White, Associate Professor of Physics at the University of Nevada and one of the authors of the study, states that the results do not violate the laws of thermodynamicsBut they reveal that when the process is fast enough, classical physics cannot keep up with the speed of change.
Research opens the way for advances in areas such as nuclear fusion, modeling of planetary interiors and the study of hot dense matter found in giant stars and planets. It can also help to understand extreme impact phenomena such as asteroid collisions or nuclear reactor failures.
Can other materials also display similar behavior?
Scientists believe yes. The expectation is that other metals and compounds submitted to these extreme experiments can reveal unexpected propertiesforcing science to update graphs and models that describe how matter behaves in the domain of the most energetic and unexplored nature.
For Slac’s Bob Nagler, this is just the beginning: “If our first experiment using this technique has already challenged established science, I can barely wait to see that other findings await us.”
