Join in expert discussion on the topics of Astronomy, astrophysics and cosmology. This may include discussion on celestial objects, space, and the physical universe as a whole. Mainstream science only.
Threads
Undergrad Why do we distinguish spacetime curvature from spatial curvature?
- Ranku
- · Replies 18 ·
Insights Do Black Holes Really Exist? - Comments
- PeterDonis
- · Replies 73 ·
Undergrad Proton decay at the end of the Universe
- Gary Menzel
- · Replies 13 ·
Undergrad How fast must Voyager travel to leave the solar system?
- SPB COOPERATOR
- · Replies 4 ·
High School Why Do We See Darkness in a Universe Full of Stars?
- Joe30174
- · Replies 15 ·
Undergrad The Hubble constant − constant in what way?
- JimJCW
- · Replies 18 ·
Undergrad How long would it take the Universe to generate an Earth-like chemistry?
- BillTre
- · Replies 8 ·
Undergrad Why does mass of observable universe match distance squared in early universe model?
- dedocta
- · Replies 5 ·
Undergrad Spatial flatness and cosmological constant
- Ranku
- · Replies 5 ·
Graduate Why are B mode values used to disfavor power law potentials in Planck 2015?
- JD_PM
- · Replies 1 ·
Graduate Patterns in extragalactic stellar trajectories near the Milky Way
- Prez Cannady
- · Replies 2 ·
Undergrad Are some cosmic rays iron nuclei?
- swampwiz
- · Replies 7 ·
Undergrad Changing curvature as a universe evolves
- Will Learn
- · Replies 36 ·
Undergrad What happens to the material not involved in the core collapse of a supernova?
- MarkL
- · Replies 4 ·
High School Vertical lift question (Lift a roof from beneath with limited space)
- Kelly1214
- · Replies 10 ·
Undergrad Some questions about baryogenesis
- Barry-O-Genesis
- · Replies 1 ·
High School Mass and Surface Gravity of a Dyson Sphere
- Drakkith
- · Replies 9 ·
Stargazing Indonesian Punggur meteorite, 1.2g high iron breccia from January 2021
- davenn
- · Replies 36 ·
Undergrad Quantum Astronomy - well sort-of
- Tom.G
- · Replies 0 ·
Graduate Angular power spectrum dependence in redshift z and k
- fab13
- · Replies 5 ·
High School How Do Black Hole Animations Capture Optical Effects?
- anorlunda
- · Replies 5 ·
Undergrad How do I properly plot the solar spectrum and handle the flux of Arcturus?
- AlphaCrucis
- · Replies 3 ·
Undergrad Are all the celestial systems in the universe on a big plate?
- ronald_dai
- · Replies 13 ·
Undergrad Can three observers all be at the center in an isotropic universe?
- curioushuman
- · Replies 23 ·
Undergrad Protecting Earth from a red giant Sun with a Dyson sphere
- swampwiz
- · Replies 20 ·
High School Is Colonizing White Dwarf Systems Feasible for Interstellar Travelers?
- Jupiter60
- · Replies 7 ·
High School Jupiter's pole storms - potential relation?
- sea212
- · Replies 1 ·
How Black Holes Work: The Onion Explains
- vela
- · Replies 3 ·
Graduate Do relativistic effects make the age of the universe moot?
- Andy DS
- · Replies 14 ·
High School Can distant attractors outside our observable universe influence us indirectly?
- ronald_dai
- · Replies 15 ·
Graduate Looking for sources of information on Black Holes
- Lilian Sa
- · Replies 7 ·
Undergrad Comoving distance of a CMB photon over time
- JimJCW
- · Replies 39 ·
High School 2D Model of the Universe as an expanding ball
- darkdave3000
- · Replies 4 ·
Collector's Item For Space Buffs
- anorlunda
- · Replies 8 ·
Graduate Quintessence field equation of state
- fhenryco
- · Replies 3 ·
High School Need your advice how to start learning astronomy
- kevlevrone
- · Replies 17 ·
High School Gravitational fields affecting each other?
- Buckethead
- · Replies 21 ·
High School Is it a Meteorite? Las Vegas Hiker Finds 81.7g Object
- kolleamm
- · Replies 6 ·
Undergrad Will stars on the other side of the galaxy affect gravity here?
- KurtLudwig
- · Replies 10 ·
Undergrad New Paper Claims Primordial Black Holes Don't Explain Dark Matter
- ohwilleke
- · Replies 20 ·
Undergrad Are Cosmic Rays Actually Neutrinos?
- swampwiz
- · Replies 4 ·
High School Term for an end state of expansion?
- Huck Mucus
- · Replies 3 ·
High School Viewing distant celestial objects
- happyhacker
- · Replies 22 ·
High School If the universe is infinite or repeats, can "I" exist again?
- moonglow500
- · Replies 2 ·
Undergrad Coude Spectrograph vs Cassegrain?
- AlphaCrucis
- · Replies 3 ·
Undergrad Does Penrose's conformal cyclic cosmology have observational evidence?
- fresh_42
- · Replies 6 ·
Graduate Distances between observers using the Lightone7 calculator
- Bandersnatch
- · Replies 17 ·
What quirky tradition do astronauts have before launching into space?
- nduka-san
- · Replies 5 ·
Space travellers can run but they can't hide
- DaveC426913
- · Replies 11 ·
Undergrad Does the external field effect prove MOND over dark matter?
- kodama
- · Replies 1 ·
High School What Would Happen if the Earth Stopped Rotating?
- mincam
- · Replies 31 ·
Undergrad Do brown dwarfs cool to near absolute zero and solidify?
- Thecla
- · Replies 14 ·
Undergrad How can one see the noise in the Fourier Domain (Nyquist Frequency)?
- AlphaCrucis
- · Replies 6 ·
Graduate Discrepancy in Jorrie’s LightCone7-2017-02-08 Cosmo-Calculator
- JimJCW
- · Replies 15 ·
High School Request for an up to date list of cosmological theories
- Tanelorn
- · Replies 11 ·
Undergrad How to find the distance from a star to the center of the Milky Way Galaxy?
- Michael_L
- · Replies 8 ·
High School How do cosmology theories become accepted as mainstream?
- Tanelorn
- · Replies 5 ·
High School How common are total eclipses in the universe?
- mincam
- · Replies 21 ·
High School Did gamma radiation redshift into the cosmic microwave background?
- Jimmy87
- · Replies 42 ·
High School Can a Planet Have a Moon that Never Casts a Shadow?
- mincam
- · Replies 19 ·
Undergrad Do inhomogeneities in matter affect cosmic evolution through backreaction?
- Ranku
- · Replies 10 ·
Undergrad Strange radio signal from Proxima Centauri
- DavidCummings
- · Replies 14 ·
Undergrad Is the Ecliptic Plane the Same as the Apparent Path of the Sun?
- KurtLudwig
- · Replies 2 ·
Undergrad Questions about Isotropy in Our Universe and Implications
- Buzz Bloom
- · Replies 6 ·
Undergrad What is the astronomy reason for no UHF channel 37?
- swampwiz
- · Replies 35 ·
High School Has there ever been a planet-planet eclipse (i.e., observed from Earth)?
- swampwiz
- · Replies 17 ·
High School Does matter accumulate in Earth's gravity well?
- TimeSkip
- · Replies 38 ·
Undergrad Solar chromosphere: inter-conversion of Ca I, Ca II, role of photons
- jordankonisky
- · Replies 2 ·
Undergrad What is a "temperature distribution" in a stellar photosphere?
- AlphaCrucis
- · Replies 1 ·
Undergrad Which forces maintain the shape of the Milky Way?
- KurtLudwig
- · Replies 16 ·
High School 'A Brief History of Time' question on gravity
- Nitram
- · Replies 4 ·
High School Mars Landing, How instantaneous communication was possible
- NTesla
- · Replies 10 ·
Graduate Description of Titan and Potential Approaches to its Exploration
- BillTre
- · Replies 2 ·
High School What force keeps the planets orbiting normally?
- r731
- · Replies 10 ·
Undergrad How do Limb-Darkening curves differ at two different wavelengths?
- AlphaCrucis
- · Replies 1 ·
Undergrad Why is Mars not considered a "full-fledged" planet?
- swampwiz
- · Replies 9 ·
High School "Snow" on comet 67P/Churyumov-Gerasimenko is actually stars
- Keith_McClary
- · Replies 4 ·
Undergrad Are there more Pulsars than we observe?
- saddlestone-man
- · Replies 6 ·
Stargazing Will the supernova explosion of Betelgeuse influence the Earth?
- TimeSkip
- · Replies 2 ·
Undergrad How to compute the expansion of this congruence?
- LCSphysicist
- · Replies 7 ·
Undergrad What is the current status of the Hubble-tension?
- eaglechief
- · Replies 8 ·
High School Tidal locking for planets of K type (orange) dwarf stars
- Cerenkov
- · Replies 2 ·
Undergrad Will the Sun end as a Type 1a supernova?
- swampwiz
- · Replies 9 ·
Undergrad When was the matter density equal to the vacuum energy density?
- LeoChan
- · Replies 2 ·
Graduate What are the parameters that are the same in CMB data for multiple models?
- Arman777
- · Replies 8 ·
High School How the Earth's Magnetic field deflects the solar wind
- kimbyd
- · Replies 5 ·
Undergrad Follow an object into a black hole
- Psnarf
- · Replies 12 ·
Undergrad What are the key characteristics of rivals to inflation in cosmology?
- jake jot
- · Replies 14 ·
Undergrad Stellar nucleosynthesis and the supernova cycle
- swampwiz
- · Replies 1 ·
Stargazing Where to find more material about LORENE software?
- Leonardo Machado
- · Replies 1 ·
High School Value of G Changing Over Time?
- colin lowing
- · Replies 22 ·
Graduate Solve Stellar Structure with Lane-Emden Equation
- wasi-uz-zaman
- · Replies 2 ·
High School Next Generation Planetary Missions Hunt for Gravitational Waves
- veraamorim
- · Replies 1 ·
High School How much solar wind mass reaches Earth's surface?
- jovanovic_oliver
- · Replies 12 ·
Stargazing Is There a Common Pattern in Einstein Crosses?
- Buckethead
- · Replies 6 ·
Undergrad Dark Energy's Effect on Black Holes
- DarK_OmEgA
- · Replies 13 ·
High School Planetary debris found in white dwarf atmospheres
- lomidrevo
- · Replies 5 ·
Undergrad Why do papers still treat Fermi's paradox as unresolved after 2008?
- sbrothy
- · Replies 45 ·
Undergrad What differences exist between ancient and modern galaxies seen in Hubble Deep Field?
- seabass101
- · Replies 6 ·
Undergrad What is the rate of ejecta deposited between planets?
- swampwiz
- · Replies 7 ·