Key baselines in the deep structure of the universe include:
- Universal Physical Laws: Physical laws are consistent throughout the observable universe. Gravity (as described by general relativity) and the laws of motion apply the same way to distant galaxies as they do in our local solar system, serving as a foundational, unchanging framework.
- Fundamental Constants: Constants such as the speed of light in a vacuum (), the gravitational constant (𝐺), and Planck’s constant (ℎ) are believed to remain fixed across all time and space, providing the “rules” that allow for the formation of complex structures.
- The Cosmic Microwave Background (CMB): This radiation, leftover from the Big Bang, fills all of space and is remarkably uniform. With a temperature of 2.7K, it serves as an almost absolute rest frame (a universal reference point) from which the velocity of celestial bodies can be measured.
- Fundamental Fields: The universe is structured by underlying fields, including quantum fields (the source of particle existence) and the Higgs field (which gives mass to particles).
- The Cosmic Web: On the largest scales, matter is organized into a, consistent “web-like” structure of filaments and voids, which acts as a structural baseline for how galaxies are distributed.
- The Fine-Structure Constant (𝛼): This “dimensionless” constant, measuring the strength of the electromagnetic interaction, is a key, stable value (approx. 1/137) that has remained consistent over billions of years, anchoring atomic structure.
While some theories speculate that these constants might vary slightly, observational data to date indicates they have remained constant over roughly 99.9973% of cosmic history.