Scientists have discovered gold is far less predictable than previously thought. When rapidly heated to an astonishing 18,700 degrees Celsius – 14 times beyond its standard melting point – the precious metal resisted liquefaction for a fraction of a second, maintaining its solid structure. This entirely unexpected result, published in *Nature*, overturns long-standing predictions about the temperature limits of solids and may force a reassessment of how matter behaves under extreme conditions.
The key to the study, led by the University of Nevada, USA with participation from Italy’s University of Padova, lies in the extreme speed of the heating process, similar to phenomena occurring in asteroid collisions or nuclear reactors. To superheat tiny gold samples beyond their expected limit, the research team, headed by Thomas White, employed intense, ultra-short X-ray laser pulses lasting just 45 femtoseconds (one femtosecond is one millionth of a billionth of a second).
When heating occurs this rapidly, atoms lack sufficient time to transition immediately into a liquid state, leaving the material intact initially. While this phenomenon of superheating solids was known, scientists previously believed it could only push the melting limit by about 3 times. This time, however, that limit was surpassed by a factor of 14. The gold remained solid for over 2 picoseconds (one picosecond is one thousandth of a billionth of a second), a duration significant enough to prompt researchers to reconsider existing models.
“This measurement not only exceeds the limits previously predicted,” stated the study authors, “but also suggests a much higher threshold for superheating solids.” The implications are profound: it’s possible that some solids might not have a melting point at all, at least when heated via such extreme processes.
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