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 Is dark matter a superfluid?
- wolram
- · Replies 8 ·
Black hole in binary system 8000 light years away
- Jimster41
- · Replies 3 ·
Graduate Why isnt the universe full of quark stars?
- Mustang11
- · Replies 11 ·
Graduate Planetoid formation, spherical or not.
- anorlunda
- · Replies 3 ·
Undergrad How Do We Determine the Original Color of Light from Distant Galaxies?
- Gilad Barnea
- · Replies 15 ·
High School Does the Sun's core spin on an axis like Earth's?
- BottomHat
- · Replies 3 ·
Graduate FRW metric, convention misunderstanding?
- AstroPhysWhiz
- · Replies 1 ·
Graduate Why is gravity considered weak if it has universal reach?
- Jamie Harper
- · Replies 15 ·
Graduate Hubble constant evolution in flat LCDM with simplified equations
- Jorrie
- · Replies 7 ·
Are Helios Quantum 5 binoculars worth the investment?
- and7barton
- · Replies 9 ·
Graduate What does cosmic event horizon mean for our universe model?
- Omega0
- · Replies 60 ·
Graduate Can mathematical models in cosmology describe reality without observational evidence?
- wolram
- · Replies 27 ·
Graduate Why constant expansion makes distant galaxies recede faster
- valenumr
- · Replies 53 ·
Graduate I have always wondered if Photons are magnetic and if so are
- allybee
- · Replies 8 ·
Graduate Evolution of Life-Supporting Elements
- Aaron8547
- · Replies 5 ·
Graduate Q: Measured changes in the CMB radiation?
- Joe Ciancimino
- · Replies 1 ·
Graduate High resolution observations of dark matter?
- Martin Sallberg
- · Replies 2 ·
High School Why does the Earth have a tilt but the moon doesn't?
- somebodyelse
- · Replies 3 ·
Graduate Coordinate conditions in cosmology
- TrickyDicky
- · Replies 4 ·
Undergrad Could We Hear the Sun If Sound Waves Travelled Through Space?
- Gerinski
- · Replies 6 ·
Graduate Black holes swallow space and time?
- mickael alain
- · Replies 1 ·
Graduate Effect of high intensity electric and magnetic fields on gravity
- bwana
- · Replies 1 ·
Graduate Simple explanation of the Boltzmann Brain paradox
- Graeme M
- · Replies 1 ·
Undergrad Saving images with WCS coordinates in SAOImage ds9
- TheWonderer1
- · Replies 4 ·
Undergrad Origin of Galaxies and Super Massive Black Holes
- lavinia
- · Replies 27 ·
Undergrad Why does gravity collapse and stars explode?
- Josh S Thompson
- · Replies 13 ·
Graduate Why must dark matter interact weakly?
- newjerseyrunner
- · Replies 9 ·
Graduate Something about calculating the Age of the Universe
- JohnnyGui
- · Replies 132 ·
Graduate Collapsars vrs. QM degeneracy pressure
- Helios
- · Replies 4 ·
Undergrad Hubble's Law and Hubble's Constant
- tanvi
- · Replies 4 ·
Graduate Do geodesics of measure zero allow past-eternal inflation?
- slatts
- · Replies 5 ·
Graduate Earth moon motions, distance etc.
- Vrbic
- · Replies 3 ·
Graduate Is a Black Hole's Entropy Truly Lost?
- Quds Akbar
- · Replies 9 ·
High School What is a black hole and why can't light escape from it?
- PhyStudent20
- · Replies 4 ·
Graduate How do we know black holes exist beyond the theory of relativity?
- wolram
- · Replies 23 ·
Graduate New approach to cosmological bulk viscosity
- craigi
- · Replies 2 ·
Graduate What Other Theories Exist for Modifying Gravity Besides Mond?
- wolram
- · Replies 5 ·
Graduate Dark matter, Mach's ether and the QCD vacuum
- wolram
- · Replies 1 ·
Graduate Thermodynamics at the apparent horizon of the universe
- Chronos
- · Replies 8 ·
Graduate CMB at 50: Princeton early universe panel discussion
- palmer eldtrich
- · Replies 2 ·
Graduate From RTN reference frame to ECI and orbital elements
- GNCstudent
- · Replies 2 ·
Graduate Kinetic equilibrum and chemical equilibrium
- karlzr
- · Replies 4 ·
Graduate Where did the initial conditions for the Big Bang come from?
- Robert P
- · Replies 10 ·
Undergrad Solar System barycenter - Orbit of planets
- Andrew1955
- · Replies 62 ·
Graduate Isn't space expansion logically required?
- Gerinski
- · Replies 74 ·
Nice lunar and planetary conjunction
- davenn
- · Replies 11 ·
Milky Way Composite: Vacation Night Photo
- Andy Resnick
- · Replies 2 ·
Graduate Do neutron stars, pulsars, magnetars etc. have weather?
- Alex299792458
- · Replies 6 ·
Graduate How Can we Find the Escape velocity of a black hole
- J Venkatesh
- · Replies 52 ·
Graduate I don't understand what is the meaning of phase? (phase space, phase point, etc)
- TimeRip496
- · Replies 1 ·
High School Why do planets and stars flicker?
- Josh S Thompson
- · Replies 14 ·
High School Large, Persistent Eclipse/Shadow On Earth?
- alphareign
- · Replies 3 ·
Graduate Size of the visible/observable universe
- DiracPool
- · Replies 8 ·
Undergrad What Are the Physical Components of Space?
- alasange
- · Replies 40 ·
Graduate What Does Lambda Represent in Cosmology's Expanding Universe Model?
- Jimster41
- · Replies 10 ·
High School Pushing asteroids off course with spacecraft engines
- JohnMConley
- · Replies 36 ·
Undergrad What materials can a star produce before dying?
- Ranguna
- · Replies 35 ·
Undergrad How do gravity assist maneuvers increase probe velocity?
- toesockshoe
- · Replies 3 ·
High School Why does the moon orbit the sun?
- avito009
- · Replies 4 ·
Graduate Are Universal Oscillations Causing Changes in Cosmological Expansion?
- Berenices
- · Replies 8 ·
Graduate Geo Coronal Absorption Frequency
- neilparker62
- · Replies 3 ·
Graduate Does the universe appear solid from a sufficient distance?
- Mike Moores
- · Replies 7 ·
Undergrad Why are most craters on Ceres nearly circular?
- Borek
- · Replies 5 ·
Graduate How Does the Expansion of the Universe look?
- Berenices
- · Replies 5 ·
Graduate How to know there is a frequency shift?
- ShayanJ
- · Replies 10 ·
Graduate Does universe expansion separate photons, traveling parallel?
- art pletcher
- · Replies 15 ·
Undergrad Intensity of light along the iridium flare
- jojotank
- · Replies 5 ·
Undergrad Cosmological Expansion: Is There a Limit?
- Subrata Paul
- · Replies 1 ·
Undergrad Distance of GJ 436b to GJ 436 - doesn't work out.
- Ikon Rahu
- · Replies 1 ·
Graduate 800+ ultra-diffuse galaxies in Coma cluster
- marcus
- · Replies 2 ·
Undergrad What Causes Radio Blackouts During Space Capsule Descent?
- Dr Wu
- · Replies 9 ·
Graduate Graviton vs Einstein's Curvature of Spacetime
- ScientificMind
- · Replies 8 ·
Universe Splitter iPhone App: Randomly Split Universe?
- dilletante
- · Replies 3 ·
High School What happens to sound from a supernova explosion?
- Subrata Paul
- · Replies 5 ·
Graduate Like spacetime -- can sound be taken as a fifth dimension?
- Subrata Paul
- · Replies 2 ·
Undergrad Has the Value of G Constant Changed Recently?
- Tony Stark
- · Replies 6 ·
Graduate Spatial Expansion Interpretation with Quantum Graphity Model
- Feeble Wonk
- · Replies 8 ·
Graduate Does Infinity mean 'potential' Infinity?
- tom aaron
- · Replies 7 ·
Undergrad How do different bodies in the Solar System affect Earth's gravitational pull?
- Gaz1982
- · Replies 4 ·
Undergrad How did Kepler derive his laws WITHOUT law of gravitation?
- Hansa
- · Replies 11 ·
Graduate Baryon oscillation peak a cosmological standard ruler
- wolram
- · Replies 2 ·
Graduate Higgs Bosson, manipulate gravity, 4 dimensional space.
- Mixander
- · Replies 3 ·
Graduate Determining The Size and Age of Our Universe
- Scott WKreiger
- · Replies 8 ·
Undergrad Why sunrise times vary more than sunset times with latitude
- Agreegate
- · Replies 5 ·
Graduate Are there current efforts on ritz-type cosmology?
- sebastian_1
- · Replies 1 ·
Graduate What force is needed to overcome expansion?
- rede96
- · Replies 7 ·
Graduate Sobral CR7 galaxy at redshift 7 and population III stars
- marcus
- · Replies 10 ·
What Does the Observable Universe Look Like?
- Kanov
- · Replies 4 ·
High School What happens when rotation flips you upside down in a rotating habitat?
- cbrons
- · Replies 8 ·
Graduate Speed of light inside a black hole
- Gerinski
- · Replies 4 ·
Undergrad Can you understand the 5th dimension without fully grasping the 4th?
- Bollini Mouli
- · Replies 4 ·
Graduate Argument of the Perihelion Projection
- Philosophaie
- · Replies 2 ·
High School What absorbs Ultraviolet radiation?
- Alex299792458
- · Replies 7 ·
Graduate Could Velocity Exceed c in Comoving Worldlines?
- Omega0
- · Replies 41 ·
Stargazing How to make a homemade reflecting telescope
- Vishal Das
- · Replies 2 ·
Undergrad Where is my calculation of sun angle incorrect?
- AWoods
- · Replies 15 ·
Undergrad Astronomers report finding earliest stars that enriched cosmos
- diogenesNY
- · Replies 3 ·
Graduate Is Time Measured Differently Due to Time Dilation Since the Big Bang?
- Tanelorn
- · Replies 6 ·
Graduate Effect of Rotation on the Earth and Planetary Disk(s)
- Mazin Nasralla
- · Replies 8 ·
Graduate How Do Planetary Distances Influence Retrograde Motion Durations?
- RingNebula57
- · Replies 3 ·