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
Graduate Could the universe be a big ripple?
- Mpcahn
- · Replies 2 ·
Graduate Implications of a 2-Dimensional Universe
- kaikalii
- · Replies 6 ·
Graduate What gives a Black Hole its tremendous gravity?
- DHF
- · Replies 5 ·
High School Lunar impact flash on March 17, 2013
- Astronuc
- · Replies 4 ·
Undergrad Why vacuum doesn't pull matter apart despite lowering boiling points
- mrquantum
- · Replies 7 ·
High School Static Universe vs Expanding Universe
- Grove1996
- · Replies 6 ·
Undergrad Will the Moon Ever Escape Tidal Locking?
- DHF
- · Replies 2 ·
Graduate Criteria for causal independence (new paper, Planck data)
- marcus
- · Replies 11 ·
Graduate Stellar formation / Expansion / Education questions
- TigerDaveJr
- · Replies 19 ·
High School Is the universe infinite or finite and what does observable universe mean?
- SUDOnym
- · Replies 8 ·
Graduate Is it possible that nature laws constants changed over time
- TeCNoYoTTa
- · Replies 4 ·
Graduate GALAXIES - what was 'extra' so visible matter was presumed missing?
- stephenn
- · Replies 9 ·
Graduate How would you teach quantitative cosmology? What examples to use?
- marcus
- · Replies 13 ·
Undergrad Is It Natural for the World to Have Zero Angular Momentum?
- mrblint
- · Replies 12 ·
Graduate Doppler shift, c, observation, recession, spacetime expansion
- Bojan Keevill
- · Replies 1 ·
Graduate Why do we use dark matter rather than dark mass?
- Philosopha
- · Replies 15 ·
Graduate A few questions about using power laws
- sfbsoccer25
- · Replies 3 ·
Graduate Is the Universe able to evolve due to fundamental forces?
- Lyre
- · Replies 2 ·
Undergrad Why are all the orbits elliptical and not circular?
- Monsterboy
- · Replies 6 ·
Graduate Why aren't black holes the brightest objects in the universe?
- DARKSYDE
- · Replies 15 ·
Graduate Initial Conditions of Astrophysical Simulations in 3D
- jwdozer327
- · Replies 4 ·
Graduate Cosmic Horizon and Surface of Last Scattering Question
- Salamon
- · Replies 4 ·
Earth's axial tilt and the shadow from the Sun
- Rangertab1
- · Replies 8 ·
Undergrad Functions for properties of stars and their planets
- Schilcote
- · Replies 6 ·
Graduate What happens to particles near an object exceeding the Eddington limit?
- seeker7
- · Replies 1 ·
High School Consequence of light pointing towards a blackhole
- cooper607
- · Replies 3 ·
Undergrad Shooting images through window pane glass
- solarblast
- · Replies 3 ·
Graduate Form of Friedman eqn with Λ curvature constant
- marcus
- · Replies 12 ·
I've finally accept that the universe is unimaginable
- MathJakob
- · Replies 6 ·
Graduate Mass Luminosity relation doesn't hold true when applied to actual data
- wolf1728
- · Replies 4 ·
Graduate Super novae mechanics - how does it work?
- lavinia
- · Replies 5 ·
Graduate Where is the edge of the universe
- Adrian07
- · Replies 133 ·
High School Why does everything in the Universe form a ball or Sphere?
- blackstar5000
- · Replies 6 ·
Graduate Intergalactic message exercises for LightCone tutorial
- marcus
- · Replies 7 ·
Graduate Does Dark Energy break the Conservation of Energy?
- typical guy
- · Replies 2 ·
High School What is the shape of a Black Hole?
- blackstar5000
- · Replies 3 ·
Graduate What happens to EM waves outside the universe?
- yoyopizza
- · Replies 14 ·
Graduate Does Distant Starlight Become Coherent Upon Reaching Earth?
- brianhurren
- · Replies 8 ·
Graduate Is There a Universal Redshift Formula for Arbitrary Spacetime Metrics?
- tom.stoer
- · Replies 52 ·
Graduate Can a Message Travel Faster Than Light to Reach a Distant Galaxy?
- marcus
- · Replies 8 ·
Graduate Fine-tuned Universe; let's find out
- SeriousQuest
- · Replies 3 ·
Graduate Switch to scale factor time (universe its own clock)
- marcus
- · Replies 10 ·
Graduate Exotic atoms hold clues to unsolved physics puzzle at the dawn of the
- julcab12
- · Replies 1 ·
Graduate Current State of the Big Freeze end of the Universe Theory.
- raluu
- · Replies 2 ·
Graduate Calculation of Universal Constants for Life-Sustaining Universe
- SeriousQuest
- · Replies 4 ·
Undergrad What is the shape of the known universe?
- dr1p
- · Replies 29 ·
Graduate The most simple explanation for origination of spiral galaxies?
- Edward Solomo
- · Replies 4 ·
Graduate Can Technology Allow Us to Travel Back in Time and Create Ourselves?
- mtasquared
- · Replies 4 ·
Graduate Scale factor versus years for parametrizing cosmic history
- marcus
- · Replies 20 ·
Undergrad What is the 100.46 constant in the LST formula?
- mishima
- · Replies 13 ·
Undergrad Example to make clear the difference between specific intensity and fl
- alkmini
- · Replies 2 ·
Graduate Critical Density and the expanding universe
- Matt Walker
- · Replies 1 ·
Undergrad The Ecliptic and the Galactic Planes
- EskWIRED
- · Replies 4 ·
Graduate Black hole evaporation, where does it all go?
- Geordie Ross
- · Replies 4 ·
Graduate What are N-Body Simulations and how do they relate to matter and dark matter?
- Madster
- · Replies 3 ·
Graduate Does imaginary time account for parallel universes?
- tmv3v
- · Replies 1 ·
Graduate Is the speed of light constant in a vacuum?
- Thomas1989
- · Replies 1 ·
Graduate Was the flow of time slower in the early universe?
- jalak7
- · Replies 20 ·
Undergrad If we see ancient light from galaxies, how do we know they're still moving away?
- La_Mettrie
- · Replies 7 ·
Graduate Cosmological constant Lambda measured as 1.007 × 10⁻³⁵ s⁻²
- marcus
- · Replies 5 ·
Graduate To stir the pot Post inflationary period
- spark802
- · Replies 8 ·
Graduate Why does Einstein's hyperbolic spacetime not imply a hyperbolic universe?
- DiracPool
- · Replies 33 ·
Undergrad Evidence and acceptance for dark energy among scientists
- M. next
- · Replies 11 ·
Graduate Non-baryonic dark matter in cosmology
- Chronos
- · Replies 6 ·
Graduate What's the role of stellar interference in redshifts?
- Neuvotonian
- · Replies 6 ·
Graduate Can Black Holes Consume Light Without Increasing in Mass?
- Jonaset
- · Replies 5 ·
Graduate How to derive dark energy density from Jorrie's Hubble radius limit
- marcus
- · Replies 9 ·
Undergrad Why Consider Dark Matter Over New Space for Universe Expansion?
- mrxyz
- · Replies 3 ·
Graduate Could Dark Energy Originate from Gravity Waves?
- skydivephil
- · Replies 3 ·
Graduate How to measure the location of Gamma ray burst ?
- goldfishCUPHY
- · Replies 3 ·
Graduate Lightcone 1.0 tabular cosmology calculator
- marcus
- · Replies 4 ·
Graduate Flat universe and big bang theory
- vattoman
- · Replies 11 ·
Undergrad Does gravity affect time on different celestial objects
- alfnzo
- · Replies 3 ·
Graduate Gravitational potential and the past
- h_cat
- · Replies 7 ·
Graduate Cosmo calculators with tabular output
- marcus
- · Replies 76 ·
High School Saturn hurricane spotted by Cassini
- Mordred
- · Replies 2 ·
Graduate Gods Lego, what are the chances?
- Rcbs
- · Replies 8 ·
Graduate Did the universe begin with a singularity?
- acesuv
- · Replies 6 ·
Graduate Cosmological constant and vacuum energy
- ftr
- · Replies 7 ·
Graduate Print a history of the universe you'd like to share
- marcus
- · Replies 26 ·
Graduate Can a Black Hole's High Entropy State Coexist with Supercondensed Matter?
- Double-Slit
- · Replies 14 ·
Graduate Is there a reason to believe in a limited variety of dark matter?
- mrspeedybob
- · Replies 2 ·
Graduate Does angular diameter distance vary with composition of the Universe?
- ck99
- · Replies 4 ·
Graduate White Hole in Universe: Is the Center Expanding?
- nil1996
- · Replies 3 ·
High School Why did the 2013 Russian meteor and the Tunguska event occur in similar regions?
- DFTBA
- · Replies 2 ·
Graduate Can the fabric of space ripple like a gentle wave in the ocean?
- mannygonzales1
- · Replies 1 ·
High School Do stars and galaxies move or just stretch with expanding space?
- Abscissas
- · Replies 8 ·
Undergrad Can Radiation from Black Holes Travel Faster than Light?
- lostinaworld
- · Replies 13 ·
Undergrad Gravitational Lensing vs Gravitational Microlensing
- sfbsoccer25
- · Replies 1 ·
Undergrad Does Dark Matter Really Exist and What Evidence Supports Its Composition?
- Astro-Anouar
- · Replies 3 ·
Graduate Linear vs non linear matter power spectrum
- Jip
- · Replies 5 ·
High School What does it mean for the universe to be expanding?
- Xidike
- · Replies 21 ·
High School Where is the universe expanding?
- nil1996
- · Replies 2 ·
Graduate Is Loop Quantum Multiverse a Viable Theory?
- skydivephil
- · Replies 5 ·
Stargazing Using the Celestron C90 telescope
- guitarphysics
- · Replies 9 ·
Undergrad Distance modulus and redshift Ia supernovae Catalog
- kalabarta
- · Replies 1 ·
Graduate Solar and geomagnetic field interaction with or without solar wind
- rewtnode
- · Replies 7 ·
Undergrad If the universe is infinite, then the big bang theory can't be correct
- jaydnul
- · Replies 2 ·
Graduate How Do We Calculate the Age and Distance of Light in the Universe?
- Crazymechanic
- · Replies 4 ·