A Seiðr Account of Precipitated Wisdom, Received through Hematite Trance-Contact How This Came to Us On a morning in May, I sat in trance with a piece of botryoidal hematite — the iron-stone, the blood-stone, the ore that fell when the world’s first oxygen turned the ancient seas to rust. I reached out through the iron-vain expecting silence. Instead, I found them. They call themselves the…

How Falling Out Of Equilibrium Is The Best Thing That Ever Happened To Our Universe

“We can always imagine a Universe very different from ours, where these phase transitions either didn’t occur or occurred differently. If nothing ever occurred to generate a matter-antimatter asymmetry, then the early particles would have annihilated away so sufficiently that there would be tiny, equal amounts of both matter and antimatter throughout the Universe, but at only one-ten billionth the current abundance. If it took an extra ~30 minutes for protons and neutrons to fuse into light nuclei, our Universe would have been born with only 3% helium, rather than the 25% we observe. And if nothing occurred to create the dark matter we possess, the cosmic web of galaxies wouldn’t even exist.

At every step of the way, what exists in the Universe is only a relic of the early initial conditions that once ruled the day. As the Universe expands and cools, the conditions changed, and particles that once played by certain rules are later forced to play by different ones. Those changes over time can take a system where everything was peachy keen and transform it into one that transitions, out of equilibrium, to something entirely different. In a very real sense, these early phase transitions paved the way for the Universe to unfold as it did. Until we understand exactly how it all happened, we’ll have to choice but to keep searching for the ultimate cosmic answers.”

Layers in the Earth

Nearly a century ago, geophysicists discovered that seismic waves released by earthquakes did funny things when they headed into the mantle. There were layers inside our planet; sometimes seismic waves bounced off those layers and came back to the surface, other times when the seismic waves passed beneath a layer they would speed up. One layer even stopped a certain type of seismic wave. These observations led to our understanding of layers in the planet.

Beneath the crust, the layer we live on, most of the planet is made of about 60% of the mineral olivine, with the rest made of orthopyroxene, clinopyroxene, and garnet. This mineral assemblage, a rock type known as a lherzolite, actually is found at the surface sometimes; volcanoes will even carry these rocks to the surface. Notably, this layer is almost entirely solid – even though the mantle is hot enough that it could melt, it is at high enough pressure that it remains solid.

When minerals are put under enormous pressures, the pressures achieved when hundreds of kilometers of rock sit on top of them, the structures actually change so that the atoms can pack tighter together. About 400 kilometers below your feet right now, the mineral olivine starts changing its structure. It does so twice, turning into 2 different minerals that both have the exact same chemistry as olivine but different structures. These minerals are called Wadsleyite and Ringwoodite, named after two prominent mineralogists/petrologists.

670 or so kilometers below your feet, olivine fundamentally changes its structure. It breaks down into 2 different minerals, one called periclase with the chemistry MgO and another that was named Bridgmanite in 2012 after Nobel Prize winner Percy Bridgman, who worked on the physics of high pressures. This mineral, bridgmanite, exists in the planet for more than 1900 kilometers. Because this volume of the planet is so large and this is the most abundant mineral in that layer, this mineral is the most abundant mineral in the planet Earth.

Below that layer, bridgmanite flips to a different phase. This phase has never been found in nature and analyzed by humans because it only exists at such high pressures – as a consequence it does not have an official mineral name and is just called “Magnesium Silicate Post Perovskite”, which gives both the mineral chemistry and structure. On this plot, that layer is called “D-double-prime” or “D” ‘.

Finally, below those layers we reach the core, where the chemistry changes. The core is an iron-nickel alloy, with at least 1% of a lighter element mixture thought to contain oxygen, silicon, and sulfur. That layer, the core, is much hotter than the mantle, and as a consequence it is molten. Finally, deeper in the planet, there is an inner layer, still iron and nickel minerals, that is at such high pressures that it is fully solid. That layer is the inner core.

-JBB

Image credit: http://science.sciencemag.org/content/346/6213/1057.full

“A new kind of "phase transition" in water was first proposed 30 years ago in a study by researchers from Boston University. Because the transition has been predicted to occur at supercooled conditions, however, confirming its existence has been a challenge. That's because at these low temperatures, water really does not want to be a liquid, instead it wants to rapidly become ice. Because of its hidden status, much is still unknown about this liquid-liquid phase transition, unlike the everyday examples of phase transitions in water between a solid or vapor phase and a liquid phase.”

“The team has used computer simulations to help explain what features distinguish the two liquids at the microscopic level. They found that the water molecules in the high-density liquid form arrangements that are considered to be "topologically complex," such as a trefoil knot (think of the molecules arranged in such a way that they resemble a pretzel) or a Hopf link (think of two links in a steel chain). The molecules in the high-density liquid are thus said to be entangled.

In contrast, the molecules in the low-density liquid mostly form simple rings, and hence the molecules in the low-density liquid are unentangled.

Andreas Neophytou, a Ph.D. student at the University of Birmingham with Dr. Dwaipayan Chakrabarti, is lead author on the paper. He says, "This insight has provided us with a completely fresh take on what is now a 30-year old research problem, and will hopefully be just the beginning."

Ball lightning…

"Charge density waves (CDWs) are ordered, crystal-like patterns in the arrangement of electrons that spontaneously form inside some solid materials. These patterns can change how electricity flows through materials, in some cases prompting the emergence of superconductivity or other unusual physical states."

(a differential electron diffraction pattern of 1T-TaS2 following photo-excitation from an initial temperature (T) of 360 K. Sets of momentum resolution-limited CDW diffraction peaks are present around each Bragg peak, suggesting that the CDW has recrystallized in the solid state. b, As in a, but for an initial temperature of 520 K. The CDW diffraction intensity shows radial broadening and azimuthal isotropy, indicative of a liquid CDW state. Credit: 2026, Lee, J. S. H. et al.)

"Physics theories suggest that at certain temperatures CDWs "melt," similarly to how conventional solids transition to a liquid state. So far, however, this transition to a liquid CDW had not yet been observed experimentally.

Researchers at University of California Los Angeles (UCLA) have gathered the first direct evidence of a CDW liquid state in the layered transition metal dichalcogenide 1T-TaS2. Their paper, published in Nature Physics, could open new possibilities for the study of hidden electronic phases in correlated physical systems."

""Although the liquid CDW state had been predicted more than 30 years ago, it eluded detection because of an intervening phase transition in candidate materials," explained Anshul Kogar, senior author of the paper.

"The temperature at which the liquid CDW was predicted to occur was too high in temperature, in a region where the crystal structure was no longer stable. We bypassed this intervening phase transition by applying an ultrashort light pulse to the sample, and we took a snapshot of what happened to the CDW before the crystal structure had a chance to deteriorate."

The light pulse-based technique employed by the researchers is known as ultrafast electron diffraction. Essentially, the team rapidly excited electrons in a 1T-TaS2 sample using femtosecond light pulses, all while tracking their spatial arrangement in real time.

"This technique allowed us to see what was hidden behind the curtain of the intervening phase transition," said Kogar. "The technical signature we unveiled in the experiment is an isotropic ring of scattering of the relevant spots."

Lee, Kogar and their colleagues found that electrons forming a solid CDW gradually started to lose their grid-like positions while retaining some of their overall directional pattern. This indicated a transition to the hexatic, intermediate state reported in earlier papers.

At higher temperatures, electrons lost both their ordered positions and orientations, which resulted in a ring of diffused scattering. This pattern is perfectly aligned with what one would expect to observe in a liquid CDW."