From: mk_thisisit
Humanity invests significant resources to determine if physics, particularly its fundamental constants, remains consistent across the observed universe [00:00:09]. This inquiry into the constancy of fundamental parameters gives rise to a cascade of deep scientific questions [00:00:21].
The Standard Model and its Parameters
The Standard Model of particle physics, which describes the structure of reality, is built upon quantum field theory [02:01:59]. Instead of discrete particles, the model views them as excitations of quantum fields [02:17:56]. This model contains approximately 20 parameters, or fundamental constants, whose values are determined experimentally [03:28:44]. There is no overarching theory that predicts the exact values of these constants [03:35:47].
A key feature of these fundamental constants is that they are dimensionless, meaning their values do not depend on the system of units chosen for measurements [03:44:03]. They primarily represent ratios of elementary particle masses and the strengths of fundamental interactions, such as the electromagnetic interaction, characterized by the fine structure constant [03:49:10].
It is important to note that the speed of light, while fixed in the SI unit system, is not considered a fundamental constant in the same way. It is used to define the measure of length based on the extremely precise atomic clocks [05:07:44].
Testing Consistency Across Time and Space
A major scientific question is whether these fundamental constants are truly constant, or if they can vary over time or exhibit spatial gradients [04:06:58]. The scientific community is intensely focused on verifying if the physics at the edges of the observed universe is the same as locally [04:16:11].
Scientists conduct ultra-precise experiments to test the constancy of these parameters. One method involves using optical atomic clocks to measure the fine structure constant. Recent experiments have shown that if this constant oscillates in time, its oscillation is extremely small, with its value fixed to at least 15 significant digits [14:04:13]. This research has significantly advanced previous knowledge [14:37:04].
Currently, no changes in fundamental constants have been measured [13:07:11]. Detecting any flow in time or inhomogeneity in space of a fundamental constant would undoubtedly be a Nobel Prize-winning discovery [13:19:08].
The Anthropic Principle and Life’s Dependence
An intriguing observation born from understanding quantum theory is that if fundamental constants were altered even slightly, life as we know it might not exist [07:07:10]. For instance, a minimal change could prevent proteins from folding correctly, making life impossible [04:33:04]. This suggests that life can only function within a strictly defined set of fundamental constants [04:49:03].
However, interpreting this “perfect matching” of constants to allow for life is a complex matter [08:21:40]. It could be that a more general model, beyond the current Standard Model, might predict the values of these constants, thus resolving the mystery and moving beyond an anthropocentric view [08:38:08]. This is a significant challenge in understanding the origin of life and physical constants.
Ultra-Precise Spectroscopy of Molecular Hydrogen
A groundbreaking experiment in Toruń, Poland, aims to trap molecular hydrogen, a feat never before achieved on Earth [13:30:11]. This project involves developing advanced laser and photonic technologies in cryogenic conditions to perform ultra-precise spectroscopy of molecular hydrogen [14:53:07].
Molecular hydrogen is chosen because it is the smallest and simplest molecule in nature [19:55:00]. Unlike many other atoms and molecules, molecular hydrogen interacts extremely weakly with electric and magnetic fields, making traditional laser cooling and trapping methods ineffective [16:32:00]. To overcome this, researchers must create an ultra-strong laser field within an optical cavity, reaching average optical power levels of nearly a megawatt [18:21:00]. This will enable the system to be isolated from the environment, allowing for extremely precise measurements [15:57:04].
The goal is to test quantum theory at an unprecedented level of accuracy, specifically exploring whether it extends beyond atomic physics to molecular physics [19:17:00]. Such ultra-accurate measurements allow scientists to test the Standard Model and probe for “new physics” beyond its current scope [02:56:00].
Quantum Vacuum and New Physics
Even in seemingly empty space, the quantum vacuum is permeated by oscillating quantum fields, where virtual particles are constantly created and annihilated [02:47:33]. Simple molecules like hydrogen are influenced by this quantum vacuum and feel its zero oscillations [02:55:00]. Ultra-accurate measurements allow researchers to probe this interaction and, potentially, discover unknown physics if the Standard Model proves incomplete in certain corners [02:58:00]. Such experiments are crucial in the ongoing quest to find the limits of the Standard Model and potentially reveal a deeper understanding of reality [32:37:04].