Essay2003
Parallel Universes
Max Tegmark
Argues that four distinct, independently motivated levels of physical theory all predict some form of multiverse, so rejecting the idea outright is harder than it looks.
link checked 17 Sept 2026Cosmology
The universe as a single object with a history.
11 topics · 14 curated works
Topics
- 01Foundations & Overviews1
- 02Big Bang Cosmology2
- 03Cosmic Microwave Background1
- 04Cosmic Inflation1
- 05Dark Matter1
- 06Dark Energy2
- 07Large-Scale Structure1
- 08Primordial Nucleosynthesis1
- 09Cosmological Parameters1
- 10The Hubble Tension2
- 11Multiverse Hypotheses1
Reading in Cosmology
14A way in
Start here
No prior grounding assumed.
Parallel Universes
Max Tegmark · 2003
Argues that four distinct, independently motivated levels of physical theory all predict some form of multiverse, so rejecting the idea outright is…
+1 more at this level
Then
Assumes you know the vocabulary.
A Relation between Distance and Radial Velocity among Extra-Galactic Nebulae
Edwin Hubble · 1929
Shows that galaxies recede at speeds roughly proportional to their distance, the observation that founded the expanding-universe picture of the…
+2 more at this level
Go deeper
Primary sources and full treatments.
The Origin of Chemical Elements
Alpher, Bethe & Gamow · 1948
Proposes that the observed abundances of the light elements were fixed by nuclear reactions in the first minutes of a hot, dense early universe.
+8 more at this level
12 of 14 works
Talk2020
The End of Everything (Astrophysically Speaking)
Katie Mack (The Royal Institution)
Works through the physically possible endings of the universe — heat death, big rip, vacuum decay — and shows which are decided by the measured behaviour of dark energy.
link checked 17 Sept 2026Paper1929
A Relation between Distance and Radial Velocity among Extra-Galactic Nebulae
Edwin Hubble
Shows that galaxies recede at speeds roughly proportional to their distance, the observation that founded the expanding-universe picture of the cosmos.
link checked 17 Sept 2026FreeIntermediate
Paper1965
A Measurement of Excess Antenna Temperature at 4080 Mc/s
Penzias & Wilson
Reports an unexplained uniform radio hiss from every direction in the sky, the accidental discovery of the cosmic microwave background left over from the Big Bang.
link checked 17 Sept 2026FreeIntermediate
Series2008
Frontiers and Controversies in Astrophysics with Charles Bailyn
Charles Bailyn (YaleCourses)
Works through exoplanets, black holes and dark energy as live problems, showing what the observations actually constrain and where the field's confidence is not yet earned.
link checked 17 Sept 2026FreeIntermediate
Paper1948
The Origin of Chemical Elements
Alpher, Bethe & Gamow
Proposes that the observed abundances of the light elements were fixed by nuclear reactions in the first minutes of a hot, dense early universe.
link checked 17 Sept 2026FreeAdvanced
Paper1981
Inflationary Universe: A Possible Solution to the Horizon and Flatness Problems
Alan H. Guth
Proposes a brief period of exponential expansion in the very early universe to explain why the cosmos looks so uniform and so close to spatially flat.
link checked 17 Sept 2026FreeAdvanced
Paper1986
A Slice of the Universe
de Lapparent, Geller & Huchra
Maps a thin wedge of galaxy redshifts and finds them arranged in sheets and voids rather than smoothly, the survey that first showed the universe's large-scale structure as visibly bubble-like.
link checked 17 Sept 2026FreeAdvanced
Paper1998
Observational Evidence from Supernovae for an Accelerating Universe and a Cosmological Constant
Riess et al.
Finds distant supernovae fainter than a decelerating universe predicts, arguing the expansion of the universe is speeding up rather than slowing down.
link checked 17 Sept 2026FreeAdvanced
Paper2005
Particle Dark Matter: Evidence, Candidates and Constraints
Bertone, Hooper & Silk
Reviews the astrophysical and particle-physics evidence for dark matter and argues a weakly interacting massive particle remains the best-motivated candidate despite decades of null direct-detection results.
link checked 17 Sept 2026FreeAdvanced
Series2013
MIT 8.286 The Early Universe
Alan Guth (MIT OpenCourseWare)
Derives big bang cosmology from general relativity and thermodynamics, and sets out the horizon and flatness problems that motivated inflation, taught by the physicist who proposed it.
link checked 17 Sept 2026FreeAdvanced
Paper2018
Planck 2018 Results. VI. Cosmological Parameters
Planck Collaboration
Fixes the values of the six parameters of the standard cosmological model from the cosmic microwave background to sub-percent precision, and argues the simplest model still fits better than its rivals.
link checked 17 Sept 2026FreeAdvanced
In order written
1929 – 2021- 1948The Origin of Chemical ElementsAlpher, Bethe & Gamow
- 1965A Measurement of Excess Antenna Temperature at 4080 Mc/sPenzias & Wilson
- 1986A Slice of the Universede Lapparent, Geller & Huchra
- 2003Parallel UniversesMax Tegmark
- 2005Particle Dark Matter: Evidence, Candidates and ConstraintsBertone, Hooper & Silk
- 2008Frontiers and Controversies in Astrophysics with Charles BailynCharles Bailyn (YaleCourses)
- 2013MIT 8.286 The Early UniverseAlan Guth (MIT OpenCourseWare)
- 2018Planck 2018 Results. VI. Cosmological ParametersPlanck Collaboration
- 2020The End of Everything (Astrophysically Speaking)Katie Mack (The Royal Institution)
- 2021In the Realm of the Hubble Tension — a Review of SolutionsDi Valentino et al.