Science

Needless to say, at 19,000 Kelvin, the solid gold sample blew past that boundary, heating up to more than 14 times its melting point, which is about 1,300 Kelvin. The team suggests the speed of the heating likely kept the gold from expanding. They blasted the gold to its record-setting temperature in just 45 femtoseconds, or 45 millionths of a billionth of a second.

“The thing that’s intriguing here is to ask the question of whether or not it’s possible to beat virtually all of thermodynamics, just by being quick enough so that thermodynamics doesn’t really apply in the sense that you might think about it

The team notes that the second law of thermodynamics, which states that disorder increases with time, still stands—their work did not disprove it. That’s because the gold atoms reached their extreme temperature before they had time to become disordered, White tells Nature’s Dan Garisto.

Even still, researchers are now faced with a question they had considered all but completely solved nearly four decades ago, per New Scientist: How hot can something really get before it melts? If a material is heated quickly enough, there might be no limit, per the SLAC statement.

Sort of reminds me of the energy-time version uncertainty principle: if an interval is short enough, energy fluctuations can be extremely high.

What I'd like to know here is what the duration threshold to would allow fusion to start is.

https://www.newscientist.com/article/2489578-gold-can-be-heated-to-14-times-its-melting-point-without-melting/

"White and his team fired a powerful laser at a 50-nanometre thick sheet of gold for 45 quadrillionths of a second..."

As a rank amateur I don't understand the other discussions here, but my thinking is that if a material is heated up for such a short period of time, and also only in a very small location ("The laser was focused to a spot approximately 100 µm in radius"), not across the whole mass, then the energy will dissipate across the mass of the material without building up enough to break the bonds and melt.

For me, what'd be more significant to know is how long it'd take for melting to occur/what's the tipping point.

So I've skimmed through the journal article and:

https://www.nature.com/articles/s41586-025-09253-y

"Notably, the temperatures exceed the proposed limit of 3Tm in both cases for over 2 ps. This time is approximately an order of magnitude longer than the characteristic phonon oscillation period and, thus, much longer than required for homogeneous melting"

So the gold did melt, just not instantaneously!

"Our experimental findings raise an important question about the ultimate stability limit for superheating."

Right so both news articles avoid stating that melting occured so far as to suggest it didn't and that was what was significant...oh well, reading the journal article was interesting at least!

One question of mine I didn't see was answered is, what significance do the xrays have on the temperature and time taken to melting?