Mystery AtlasScientific Theories & Frontiers
Cosmology
The universe's biggest open questions — dark matter, dark energy, the multiverse, the Big Bang and what preceded it — and how cosmologists weigh the evidence.
Questions
What Is Dark Energy?
What dark energy is: the 1998 discovery of accelerating expansion, the cosmological constant vs. quintessence, and the 2024-25 DESI evolving-dark-energy hint.
Question
What Is Dark Matter?
What dark matter is: the evidence for unseen mass in galaxies, the leading particle explanation, the MOND alternative, and why neither is confirmed.
Question