In a collider ring on Long Island, physicists have turned a long standing thought experiment into hard data, watching new particles emerge from what once looked like empty space. By tracing the birth of quarks and entire matter–antimatter pairs back to the quantum vacuum, they are testing how far the universe’s “nothingness” can be pushed before it reveals its hidden structure. The result is not philosophical wordplay but a set of measurements that show how fields, fluctuations and light itself can be coaxed into becoming tangible matter.
At the heart of this work is a new way of using a particle collider, not only to smash protons together but to probe the vacuum as an active medium that stores energy, information and even correlations between particles that have yet to exist. I see these experiments as the clearest sign so far that the vacuum is not a backdrop for physics, it is one of the main actors.
From “empty” space to a seething quantum vacuum
For most of classical physics, a vacuum was simply the absence of stuff, a region stripped of air, dust and radiation. Quantum theory replaced that picture with a more unsettling one, in which fields fill all of space and even the lowest energy state is restless, with fleeting excitations that appear and vanish too quickly to be seen directly. In this view, what we call empty space is already threaded with potential, a kind of latent matter that can be promoted into real particles if enough energy is focused into a small region, a point that modern physicists have now begun to track experimentally.
The shift from a bare void to a structured vacuum has been building for decades, as theorists argued that Nothing, in the everyday sense, is a misnomer for a state that is in fact filled with fluctuating fields and virtual particles. Descriptions of this “rich structure” emphasize that the vacuum behaves less like an empty container and more like a medium with its own properties, a perspective captured in work that speaks of Nothing as a dynamic participant in physical processes rather than a blank stage.
RHIC’s new trick: turning virtual quarks into real particles
The Relativistic Heavy Ion Collider, better known as the Relativistic Heavy Ion Collider or RHIC, at Brookhave National Laboratory was built to slam together ions as heavy as that of gold, recreating droplets of early universe matter. In its latest configuration, the same machine has been used more delicately, letting the ions graze past each other so that their intense electromagnetic fields interact without a direct crash, a setup that lets researchers probe how quark pairs emerge from the vacuum and then bind into particles that can be detected, extending earlier RHIC breakthroughs on antimatter.
In these runs, detectors pick up strange quarks and their partners that can be traced back to the quantum vacuum rather than to the incoming ions themselves, a reconstruction that relies on following their decay patterns and spin orientations. Researchers describe this as the first time they have been able to see directly that the quarks making up certain particles are coming from the vacuum, in other words from a state that was previously only a field filled with virtual particles, a claim laid out in detail by Brookhaven scientists.
Spin correlations: fingerprints of matter from “nothing”
What makes these events so compelling is not just that new particles appear, but that their internal properties carry a memory of how they were born. When quark–antiquark pairs are pulled out of the vacuum, theory predicts that their spins should be aligned in a specific way, forming spin triplet states in their own rest frame. Recent measurements of lambda and antilambda particles at RHIC show that their spins are correlated in precisely this fashion, a pattern that researchers interpret as evidence that the pair emerged together from the same quantum fluctuation, a conclusion highlighted in new spin studies.
The same work suggests that this quantum linkage may hint at a deeper entanglement between the newly formed particles, with their spins tending to point in the same direction even after they have separated. That kind of correlation is hard to explain if the quarks were simply knocked loose from the colliding ions, but it follows naturally if they were born as a pair from the vacuum itself, a view that has been reinforced by analyses of spin correlations in these events.
Breit–Wheeler in the lab: making matter from light alone
Alongside the quark studies, RHIC has also been turned into a factory for a different kind of creation event, one that Albert Einstein and later theorists could only imagine. By accelerating gold ions to nearly the speed of light, the collider generates electromagnetic fields so intense that they can be treated as beams of real photons, and when these fields graze past one another, pairs of photons can collide and transform into electron–positron pairs without any other intermediary, a process that was recently demonstrated in gold runs.
This reaction, known as the Breit–Wheeler process after Gregory Breit and John A. Wheeler, was predicted in 1934 but had never been cleanly observed in a single laboratory experiment until these collider studies. By analyzing the angles and energies of the outgoing electron and positron, researchers have found strong evidence that they are indeed seeing matter and antimatter created from collisions of real photons, confirming a key piece of quantum electrodynamics that Scientists and others have long sought, and prompting detailed discussions of how Corrected interpretations of pair production at RHIC fit into the broader story of energy converting into matter, as debated in Corrected community posts.
How colliders turn the vacuum into a laboratory
What makes RHIC’s recent work distinctive is that it treats the vacuum itself as the object of study, not just the particles that pass through it. In the quark experiments, researchers effectively stretch the color field between separating quarks until it becomes energetically favorable for the vacuum to spawn a new quark–antiquark pair, a process that has been described as turning one long flux tube into two shorter ones, with virtual pairs in the vacuum spontaneously appearing and then annihilating unless they are pulled apart, an image developed in Yet discussions of confinement.
In the photon–photon collisions, the collider is used in a different mode, turning its heavy ions into sources of intense light that can be focused and overlapped in a controlled way. That approach has been described as the World’s first particle collider configuration to show matter emerging from “nothing” in the quantum vacuum, with the resulting particles reconstructed from how they decay and how their spins line up, a narrative that has been popularized in coverage of the World experiment.
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