Rice University researchers have taken the Universe’s temperature by measuring heat from quark-gluon plasma, a primordial substance created just after the Big Bang.
Using high-energy particle collisions, they tracked how this plasma formed and cooled over time. Their findings, showing temperatures between 2 and 3 trillion Kelvin, offer the most precise look yet at how the early universe evolved from pure energy into matter.
Measuring the Primordial Fireball
A team led by Rice University physicist Frank Geurts has achieved a breakthrough by measuring the temperature of quark-gluon plasma (QGP) at multiple points in its evolution. This exotic form of matter is thought to have filled the universe only millionths of a second after the big bang, the event that marks the beginning and expansion of the cosmos. The research, published October 14 in Nature Communications, sheds new light on how the early universe behaved under extreme heat and density.
For decades, scientists have sought reliable ways to measure temperatures in environments so extreme that no instrument could directly survive them. Geurts and his colleagues solved this problem by studying thermal electron-positron pairs created during high-speed heavy-ion collisions at the Relativistic Heavy Ion Collider (RHIC) at Brookhaven National Laboratory in New York. These emissions revealed the plasma’s internal temperature as it formed and cooled.
Earlier attempts at temperature measurements were often uncertain, influenced by factors such as whether they reflected the QGP phase itself or were skewed by Doppler-like effects caused by the plasma’s rapid motion.
“Our measurements unlock QGP’s thermal fingerprint,” said Geurts, a professor of physics and astronomy and co-spokesperson of the RHIC STAR collaboration. “Tracking dilepton emissions has allowed us to determine how hot the plasma was and when it started to cool, providing a direct view of conditions just microseconds after the universe’s inception.”
A New Thermal Window Into Nuclear Matter
Quark-gluon plasma is a unique state where quarks and gluons, the building blocks of protons and neutrons, exist freely rather than being bound inside particles. Its properties depend strongly on temperature, but previous approaches lacked the resolution and precision needed to probe the plasma’s interior without interference from its violent expansion. Because QGP can reach temperatures in the trillions of Kelvins, researchers needed a noninvasive method capable of capturing accurate, real-time readings.
“Thermal lepton pairs, or electron-positron emissions produced throughout the QGP’s lifetime, emerged as ideal candidates,” Geurts said. “Unlike quarks, which can interact with the plasma, these leptons pass through it largely unscathed, carrying undistorted information about their environment.”
Detecting these faint signals among countless other particles demanded exceptional sensitivity and meticulous data calibration.
Experimental Breakthrough at RHIC
To make this possible, the team enhanced the RHIC’s detection systems, fine-tuning them to identify low-momentum lepton pairs while filtering out background noise. They then tested the idea that the energy distribution of these pairs could directly reflect the plasma’s temperature. This method, known in theoretical discussions as a “penetrating thermometer,” combines emission data collected throughout the plasma’s lifespan to form an average temperature profile.
Despite the inherent challenges of limited statistical data and complex background interference, the researchers succeeded in obtaining one of the most accurate thermal measurements of quark-gluon plasma to date.
Mapping the Quark-Gluon Temperature Profile
The study revealed two distinct average temperatures depending on the mass range of the dielectron pairs: a lower temperature of approximately 2.01 trillion Kelvin in the low-mass region, predicted by theoretical models and consistent with freeze-out temperatures from hadronic probes, and a significantly higher temperature of about 3.25 trillion Kelvin in the higher pair mass region.
This difference indicates that thermal radiation from the low-mass range, which creates these dielectrons, is predominantly emitted later near the phase transition. In contrast, those from the higher mass range originate from the earlier, hotter stage of the QGP’s evolution.
“This work reports average QGP temperatures at two distinct stages of evolution and multiple baryonic chemical potentials, marking a significant advance in mapping the QGP’s thermodynamic properties,” Geurts said.
Implications for the Early Universe
By precisely measuring the temperature of the QGP at different points in its evolution, scientists gain crucial experimental data needed to complete the “QCD phase diagram,” which is essential for mapping out how fundamental matter behaves under immense heat and density, akin to conditions that existed moments after the big bang and are present in cosmic phenomena like neutron stars.
“Armed with this thermal map, researchers can now refine their understanding of QGP lifetimes and its transport properties, thus improving our understanding of the early universe,” Geurts said. “This advancement signifies more than a measurement; it heralds a new era in exploring matter’s most extreme frontier.”
Reference: “Temperature measurement of Quark-Gluon plasma at different stages” by STAR Collaboration, 14 October 2025, Nature Communications.
DOI: 10.1038/s41467-025-63216-5
Co-authors of this study include former Rice postdoctoral associate Zaochen Ye, now at South China Normal University; Rice alumnus Yiding Han, now at Baylor College of Medicine; and current Rice graduate student Chenliang Jin. Geurts’ U.S. Department of Energy Office of Science Award supported the study.
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5 Comments
“To make this possible, the team enhanced the RHIC’s detection systems, fine-tuning them to identify low-momentum lepton pairs while filtering out background noise. They then tested the idea…”
See, they’re looking through tunnel-vision tubes, cock sure “the idea” that they were told is true. That they are dealing with particles, that one guy’s ‘idea’ of Glons is true, that they act to stick similarly charged quarks together – as combination particles, protons and neutrons and that high temp makes them briefly blend together in a plasma. So their “idea” is perfectly formed – in their minds at the start. (very important)
They then go to an accelerator and produce a high-temp blast of absolute white noise – from which they use math to “filter” out what they don’t want and also leave figures they believe express the exact “idea” they came in with.
But it may be that every one of these people have been fooling themselves. This whole time.
That sounds bad – but think of the explosion of human knowledge if they started to understand what’s really going – !
VERY GOOD!
That are different blind people touching different parts of an elephant, and then thinking that they have verified the elephant’s appearance through their actions. They do not understand local and global, individual and general. Just as parity violation is widely promoted in physics today.
They claim that temperature is measured. How? The fact is that temperature is inferred based on theory, which is incomplete. They are trying to validate their theory based on that theory itself, a self-reference. Can we call it science?
VERY GOOD!
Exposing rampant pseudoscience requires more people and media participation. Although lifting the fig leaf may make some people feel disgusted, it is still necessary for scientific and social progress, as well as humanistic development. The purpose is also to make the public fully aware of the dirtiness and ugliness behind the grandiose appearance of certain so-called peer-reviewed publications.
VERY GOOD!
When we pursue the ultimate truth of all things, the space in which our bodies and all things exist may itself be the final and deepest puzzle we need to explore. This is not only the pursuit of physics, but also the most magnificent exploration of the origin of the universe by human reason.
Based on the Topological Vortex Theory (TVT), space is an uniformly incompressible physical entity. Space-time vortices are the products of topological phase transitions of the tipping points in space, are the point defects in spacetime. Point defects do not only impact the thermodynamic properties, but are also central to kinetic processes. They create all things and shape the world through spin and self-organization.
In today’s physics, some so-called peer-reviewed journals—including Physical Review Letters, Nature, Science, and others—stubbornly insist on and promote the following:
1. Even though θ and τ particles exhibit differences in experiments, physics can claim they are the same particle. This is science.
2. Even though topological vortices and antivortices have identical structures and opposite rotational directions, physics can define their structures and directions as entirely different. This is science.
3. Even though two sets of cobalt-60 rotate in opposite directions and experiments reveal asymmetry, physics can still define them as mirror images of each other. This is science.
4. Even though vortex structures are ubiquitous—from cosmic accretion disks to particle spins—physics must insist that vortex structures do not exist and require verification. Only the particles that like God, Demonic, or Angelic are the most fundamental structures of the universe. This is science.
5. Even though everything occupies space and maintains its existence in time, physics must still debate and insist on whether space exists and whether time is a figment of the human mind. This is science.
6. Even though space, with its non-stick, incompressible, and isotropic characteristics, provides a solid foundation for the development of physics, physics must still insist that the ideal fluid properties of space do not exist. This is science.
and go on.
Is this the counterintuitive science they widely promote? Compromising with pseudo academic publications and peer review by pseudo scholars is an insult to science and public intelligence. Some so-called scholars no longer understand what shame is. The study of Topological Vortex Theory (TVT) reminds us that the most profound problems in physics often lie at the intersection of different theories. By exploring these border regions, we can not only resolve contradictions in existing theories but also discover new physical phenomena and application possibilities.
Under the topological vortex architecture, it is highly challenging for even two hydrogen atoms or two quarks to be perfectly symmetrical, let alone counter-rotating two sets of cobalt-60. Contemporary physics and so-called peer-reviewed publications (including Physical Review Letters, Science, Nature, etc.) stubbornly believe that two sets of counter rotating cobalt-60 are two mirror images of each other, constructing a more shocking pseudoscientific theoretical framework in the history of science than the “geocentric model”. This pseudo scientific framework and system have seriously hindered scientific progress and social development.
For nearly a century, physics has been manipulated by this pseudo scientific theoretical system and the interest groups behind it, wasting a lot of manpower, funds, and time. A large amount of pseudo scientific research has been conducted, and countless pseudo scientific papers have been published, causing serious negative impacts on scientific and social progress, as well as humanistic development.
Complexity does not necessarily mean that there is no logical and architectural framework to follow. Mathematics is the language and tool that reveals the motion of spacetime, rather than the motion itself. Although the physical form of spacetime vortices is extremely simple, their interaction patterns are highly complex, and we must develop more and richer mathematical languages to describe and understand them.
The development of the Topological Vortex Theory (TVT) reflects a progression from concrete physical phenomena to abstract mathematical modeling and, ultimately, to interdisciplinary unification.
——Excerpted from https://t.pineal.cn/blogs/4569/An-Overview-of-the-Development-of-Topological-Vortex-Theory-TVT.