# Quantum Physics Reveals Fundamental Limits to Material Transparency Theoretical research demonstrates that no material can achieve perfect, permanent light transparency. - **Source:** [Scientific American Content: Global](https://brifing.si/source/4f066134-e06d-4415-87ef-305e3dc2aba6) - **Published:** 2026-11-07 - **Topic:** [science](https://brifing.si/c/science) - **Original article:** - **On Brifing:** https://brifing.si/s/9bf84bc7-5a03-4339-8b38-7a66662d3230 ## The Myth of Transparency Researchers previously believed that materials could eventually be engineered to achieve perfect transparency. However, theoretical physicists have now proven that absolute transparency is physically impossible. Even the most advanced materials inevitably lose some light as it passes through them, due to underlying quantum processes that are inherent to all matter. ## Quantum Light-to-Sound Conversion The core mechanism involves a quantum process where light waves are converted into sound waves. As photons interact with the atomic nuclei of a material, they impart energy that triggers tiny, quantum mechanical vibrations. This energy transfer ensures that light will eventually fade, regardless of how clear or inert the substance is. ## Superfluids as Ideal Models Physicists modeled these interactions using superfluid helium, which is cooled to near absolute zero. In this state, atoms move without friction, making the liquid exceptionally clear. While superfluid helium is currently the closest substance to perfect transparency, the research indicates that even here, light eventually loses energy over extreme distances. ## Universal Physical Limitations Angelo Esposito and his colleagues suggest that this limitation is universal for all materials, not just superfluids. By applying theoretical frameworks originally developed to study dark matter, the team concluded that light attenuation is a fundamental rule of nature. This discovery establishes a precise, unavoidable boundary for optical engineering and material science. ## Distance and Light Decay While the loss of light is inevitable, the rate of decay can be incredibly slow in specific conditions. In a perfect superfluid, light could theoretically travel across the entire diameter of the Earth before becoming noticeably fainter. Despite this vast distance, the eventual fading of photons remains a constant, unavoidable physical reality. ## Expert Perspective on Findings Borna Salehian, a physicist at the Swiss Federal Institute of Technology Zurich, praised the study for identifying a fundamental limitation set by nature. Such theoretical work is essential for understanding the boundaries of physical systems. The findings were shared as a preprint on arXiv.org, inviting further academic scrutiny and peer review. ## Comparison to Existing Materials Current record-holding materials, such as the gels developed at the University of Colorado Boulder, are highly effective at bending light. However, these materials are designed for thin applications, as their transparency diminishes significantly with thickness. The new research explains why increasing the depth of any material inevitably leads to greater light absorption. ## Implications for Future Optics This research shifts the focus from achieving perfect transparency to managing unavoidable light loss in optical systems. By defining the fundamental limits of light transmission, scientists can better optimize fiber-optic technologies and high-precision sensors. Understanding these quantum constraints is vital for the next generation of advanced optical and communication infrastructure. ## Sources covering this story - https://www.scientificamerican.com/article/nothing-can-be-fully-transparent-physicists-discover/ — --- _Summary written by Brifing from the original reporting. Copyright in the original article belongs to its publisher; read the full piece at the link above._