The Observable Universe

This is a hard-core popular science novel. Readers seeking entertainment should stay away.

Information about this "K·HT_Studio" can be found in Volume One.

Special note: Everything in this book is intended solely for popular science education. Readers may use it too, but please do not use it for commercial purposes!!! [Future volumes may cover other topics, such as animals, pets, and plants.]

Observational cosmology relies on repeatable, verifiable measurements, simplifying the universe into a spacetime metric and its energy components. Telescopes, satellites, and large-scale surveys collect photons and particles through channels such as electromagnetic waves, neutrinos, and gravitational waves. Redshift, parallax, standard candles, gravitational lensing, the distribution of galaxies, and anisotropies in the cosmic microwave background place the Hubble constant at around 70 km/s/Mpc, with baryonic matter making up 5%, cold dark matter 25%, and dark energy 70%. Fitting the data to the ΛCDM model predicts a universe 13.8 billion years old, and provides a history of inflation, accelerated expansion, and the formation of large-scale structures. Future observations with larger samples, greater precision, and multiple messengers will test the dark energy equation of state, neutrino mass, and theories of gravity, continuing to refine humanity's objective description of the universe through evidence.

Some of the material in this book was sourced through searches by the following AI tools:

(Used only for research, not for creative writing)

Deep Seek, Yuanbao

Studio in charge: K·HT_Studio

Studio lead/editor-in-chief: Travel

Key members:

K·HT_Tang

K·HT_Qingjixian

K·HT_Hudie