Experiment Designed to Detect Quantum Vacuum Fluctuations
Nov 29, 2023
By Amal Pushp, Affiliate Physicist at the International Space Federation
Quantum Theory and Special Relativity combines remarkably in a framework known as Quantum Field Theory (QFT). According to this theoretical structure, all fundamental particles have an associated field and whenever a measurement takes place locally, the observed particles could be considered as results of certain excitations within the field. QFT has found remarkable applications in fields such as particle physics and condensed matter physics wherein it has been utilized to create precise physical models of subatomic particles and quasiparticles respectively.
A direct physical consequence of QFT is an exciting phenomenon known as quantum vacuum fluctuations or simply vacuum fluctuations. In principle, a classical description of vacuum suggests that it is completely devoid of any action however, the situation is not the same from a quantum worldview. The quantum vacuum is dynamic and can be described as a fluctuating field with temporary and spontaneous changes occurring at extremely small scales.
Consider a subatomic particle in a vacuum. Now the presence of vacuum fluctuations could be sensed through certain variations in the electromagnetic field of the particle, and this has essentially been realized experimentally. However, the direct presence of these fluctuations without the requirement of any particles has never been observed in practice. A recent proposal however aims to take on this challenge empirically [1]. The research proposal is led by a research group based at the Helmholtz-Zentrum Dresden-Rossendorf (HZDR) and their aim is to capture quantum fluctuations directly through a test utilizing the largest X-ray laser in the world namely, European XFEL.
The X-ray beam from the world's largest X-ray laser, the European XFEL, only becomes as clearly visible as in the photo in complete darkness and with an exposure time of 90 seconds. In 2024, the first experiments to detect quantum fluctuations in vacuum will take place here. Credit: European XFEL / Jan Hosan
Following is the mechanism by which the experiment is supposed to work. The laser emits brief and intense bursts of light into a stainless-steel chamber with reduced pressure. Primarily, the goal is to control vacuum fluctuations in a manner that seemingly transforms the polarization of an X-ray flash from the European XFEL, effectively altering its oscillation direction as if by magic. In the words of Prof Ralph Schützhold, a theorist at HZDR, “It would be like sliding a transparent plastic ruler between two polarizing filters and bending it back and forth”. The ruler basically corresponds to vacuum fluctuations in this analogy.
Given the faintness of the light signal, the likelihood of X-ray photons experiencing polarization change is minimal, posing a risk of failure. In response to this challenge, the researchers have devised an alternative strategy. They tend to introduce two optical laser pulses simultaneously into the vacuum chamber. The collision of these two optical pulses would result in the temporary creation of a "light crystal." Consequently, the X-ray pulse from the European XFEL would be deflected by this crystal, enhancing the probability of measuring the desired effect.
Furthermore, should the two optical laser pulses have distinct wavelengths, it could lead to a modification in the energy of the X-ray photons. This, once again, facilitates the measurement of the desired effect. While the project is presently in the planning phase, its realization holds the potential for substantial validation of theories such as quantum electrodynamics (QED) and promises advancements in technology.
Unified Science in Perspective-
In a recent paper, physicists Nassim Haramein, Dr. Cyprien Guermonprez and Dr. Olivier Alirol delve into the intriguing problem of zero-point field fluctuations and how it relates to the emergence of mass in the universe [2]. The authors discuss how the vacuum of space is not empty but is rather full of virtual particles that have measurable consequences, such as producing the Lamb shift of atomic spectra and modifying the magnetic moment for the electron. They also explore the relationship between vacuum fluctuations and the energy density of a system, and how this is related to the coherency of the vacuum fluctuations. The paper provides a thought-provoking and insightful look at the fundamental nature of vacuum fluctuations and their role in the emergence of mass.
It has also been speculated that the experimental proposal to test vacuum fluctuations might produce results that deviate significantly from theoretical predictions, potentially necessitating the formulation of new laws of physics. The new paper by our team is expected to be valuable in this endeavor.
References
[1] N. Ahmadiniaz et al, Detection schemes for quantum vacuum diffraction and birefringence, Physical Review D (2023). DOI: 10.1103/PhysRevD.108.076005
[2] Nassim Haramein, Cyprien Guermonprez, & Olivier Alirol. “The Origin of Mass and the Nature of Gravity”, (2023). DOI: 10.5281/zenodo.8381114
