A team of researchers has made a groundbreaking discovery that challenges established physics by directly measuring the temperature of atoms in extremely hot materials. The breakthrough, published in Nature, uses a novel method that measures the speed of atoms, allowing scientists to overcome decades-long limitations in understanding warm dense matter.
For nearly a decade, this team worked to develop a method to circumvent the usual challenges of measuring extreme temperatures. Led by Tom White and Bob Nagler, researchers at SLAC National Accelerator Laboratory and partner institutions used a laser to superheat solid gold to an astonishing 19,000 kelvins – more than 14 times its melting point.
Their innovative technique involves sending a pulse of ultrabright X-rays through the superheated sample, which scatters off vibrating atoms, revealing their speed and temperature. This method has already led to significant changes in our understanding of the world, including overturning four decades of established theory on superheating.
The researchers discovered that rapid heating prevented the gold from expanding, allowing it to retain its solid state. This finding suggests that there may not be an upper limit for superheated materials if heated quickly enough. The team believes their method can be applied throughout the field and is poised to revolutionize our understanding of complex systems like fusion reactors.
This breakthrough has significant implications for research on fusion power plants, where scientists aim to replicate the conditions deep inside planets. With their new technique, researchers can now pinpoint atom temperatures from 1,000 to 500,000 kelvins, enabling more accurate design and analysis of fusion targets.
The discovery is a testament to the power of scientific collaboration and innovative thinking. As Nagler noted, “If our first experiment using this technique led to a major challenge to established science, I can’t wait to see what other discoveries lie ahead.”
Source: https://phys.org/news/2025-07-superheated-gold-entropy-catastrophe-method.html