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 does redshift indicate that space-time is expanding
- LSulayman
- · Replies 7 ·
Undergrad Understanding Orbital Mechanics and the Concept of Sustained Circular Orbit
- thetexan
- · Replies 5 ·
Graduate Why is an infinitely small point required for the big bang?
- BernieM
- · Replies 12 ·
Undergrad Time of last scattering - what was it like
- chris1969
- · Replies 13 ·
Stargazing What can a 100 cm focal length telescope with CCD camera resolve?
- umciukas
- · Replies 1 ·
Graduate Is the sun a black hole for low frequency radiation?
- MikeGomez
- · Replies 5 ·
Graduate How to change a star's luminosity
- Ken G
- · Replies 4 ·
Graduate How to evaluate apparent field of a telescope and CCD camera system
- umciukas
- · Replies 1 ·
Undergrad Does Light Take Longer to Reach Us Through a Gravitational Lens?
- scupydog
- · Replies 4 ·
High School Ecliptic, Celestial equator and horizon?
- atomqwerty
- · Replies 3 ·
Graduate Why the universe needs a prime mover but God doesn't
- CyberShot
- · Replies 9 ·
Graduate Redshift and Universal Expansion
- BruceNakagawa
- · Replies 6 ·
Undergrad What Is the Shape and Expansion of the Universe?
- LSulayman
- · Replies 1 ·
Graduate Why doesn't dark matter fall into black holes ?
- Robin
- · Replies 4 ·
Graduate Inhabiting gaseus planets (such as Jupiter,
- MathematicalPhysicist
- · Replies 2 ·
Graduate Why could matter escape the enormous gravity at the Big Bang's start?
- Dinosky
- · Replies 12 ·
Graduate Looking for simple answers gravity and time
- pw_jamison
- · Replies 18 ·
Graduate Is expansion a result of gravity?
- binbots
- · Replies 3 ·
Undergrad Which model of the Universe is most accurate according to Alan Watts?
- LSulayman
- · Replies 6 ·
Graduate What's a natal kick in reference to astrophysics?
- golmschenk
- · Replies 2 ·
Graduate Is time stopped inside a black hole?
- CosmicVoyager
- · Replies 24 ·
Undergrad Why is the Milky Way a bared galaxy?
- Imax
- · Replies 5 ·
Graduate Matter Falling to a Black Hole's Event Horizon
- Jonathan Cohn
- · Replies 5 ·
Graduate What will the universe be composed of
- jc09
- · Replies 5 ·
Graduate How long does it take a black hole to gain seven billion solar masses?
- poeteye
- · Replies 11 ·
Undergrad What is the relevance in knowing that the universe for example is expanding?
- LSulayman
- · Replies 24 ·
Graduate Consequences of Chicxulub impact
- Godspanther
- · Replies 26 ·
Graduate A new cosmological model (re are we living in a black hole)
- johne1618
- · Replies 9 ·
Graduate Timing of the big bounce in eternal inflation
- skydivephil
- · Replies 4 ·
Undergrad In which direction in the sky are we headed?
- dotancohen
- · Replies 10 ·
Graduate What is the trigonometric parallax of a binary system?
- shirin
- · Replies 4 ·
Graduate How Large Could a Virga-Style Enclosure Be Before Collapsing?
- qraal
- · Replies 4 ·
Graduate How Do Atoms in Collapsing Stars Remain Stable Before Becoming Singularities?
- tanzanos
- · Replies 3 ·
Undergrad Extraterrestrial sky color based on atmospheric composition and sun color
- FtlIsAwesome
- · Replies 4 ·
High School Orbital mechanics assignment: Newton's gravitation and Kepler's laws
- LukeyD
- · Replies 1 ·
Graduate What is Accretion Induced Collapse and its Relationship with Type IA Supernovae?
- ibysaiyan
- · Replies 4 ·
Graduate Does logic hold true outside our reality (spacetime)?
- mitcho
- · Replies 3 ·
Undergrad What is the Angular Extent of Trigonometric Parallax?
- mahsa
- · Replies 4 ·
Undergrad Olbers Paradox and The Sherwood Forest
- Acili
- · Replies 12 ·
Graduate What caused cosmic inflation to stop?
- iamaelephant
- · Replies 2 ·
Graduate Critical Density: What Is It and Where Does It Come From?
- LSulayman
- · Replies 3 ·
Undergrad How are different types of orbits numerically categorized?
- chzbuhsqured
- · Replies 2 ·
Carl Sagan's pale blue dot photograph and human perspective
- planethunter
- · Replies 3 ·
Graduate Value for redshift change in acceleration
- jc09
- · Replies 1 ·
Undergrad Calculating Acceleration Due to Gravity in a Galaxy
- Bjarne
- · Replies 1 ·
Graduate 'Normal universe' a special case?
- BernieM
- · Replies 11 ·
Undergrad Can planets orbit around black holes?
- Dremmer
- · Replies 27 ·
Undergrad Retrograde Motion: How Tilting of Moon Affects Revolution
- warpatato
- · Replies 2 ·
Graduate Orbital velocity for material ejected from a spinning rubble pile asteroid
- higginsdj
- · Replies 3 ·
Undergrad Where can I find theoretical isochrones?
- alexgmcm
- · Replies 2 ·
Graduate Force on a dust particle from solar radiation
- UniPhysics90
- · Replies 1 ·
Graduate What gave rise to cosmic inflation of the early Universe?
- Soumya_M
- · Replies 4 ·
Graduate What Are the Common Misconceptions About the Big Bang Theory?
- zonde
- · Replies 24 ·
Ideas for a creative astronomy class project
- nukeman
- · Replies 6 ·
Graduate Bad astronomy in massive star luminosity
- Ken G
- · Replies 24 ·
Graduate Is Gravitomagnetism attractive does it have important long range attraction?
- ensabah6
- · Replies 2 ·
Graduate Is the Universe a Black Hole?
- johne1618
- · Replies 1 ·
Graduate Theorize Possible Colonization on Europa
- mrudis65
- · Replies 9 ·
Undergrad Evidence that the Universe is Expanding?
- zketrouble
- · Replies 5 ·
Undergrad Find FWHM: Pixel Values, Gaussian Curve, Standard Deviation
- bugra
- · Replies 3 ·
Undergrad How many pages of astrophysics textbooks can you absorb in a day?
- Simfish
- · Replies 3 ·
Graduate How would you create a traversable wormhole from singularities or quantum foam?
- TheTraveler
- · Replies 16 ·
High School What is the Earth's orbital speed around the sun?
- rhenretta
- · Replies 10 ·
Graduate Shape, structure, and nature of the universe - questions/theories
- E-8
- · Replies 1 ·
Stargazing What did the January 4th, 2010 eclipse look like?
- Borek
- · Replies 2 ·
Undergrad Why does the Moon orbit the Earth rather than the Sun?
- Ryker
- · Replies 6 ·
Graduate Does vacuum energy gravitate and cause the universe to accelerate?
- TrickyDicky
- · Replies 7 ·
High School Is Betelgeuse Really Over 100,000 Times Brighter Than the Sun?
- Kittel Knight
- · Replies 1 ·
Graduate What happened to all the Anti-Matter
- Tanelorn
- · Replies 18 ·
Graduate Relationship between galaxy size and black hole density
- chris2112
- · Replies 4 ·
High School Did Mercury and Gemini use the same capsule?
- dotancohen
- · Replies 4 ·
Graduate Proof that our solar system will leave the milky way.
- zeromodz
- · Replies 7 ·
Graduate Black Holes: growth affected by Higgs or Dark energy/matter
- JustinLevy
- · Replies 3 ·
Graduate Realspace and redshift space correlation function questions
- 1ytrewq
- · Replies 3 ·
Graduate Do quantum fluctuations in empty space create daughter universes in eternal inflation?
- mrspeedybob
- · Replies 3 ·
Graduate Temporal finitism is wrong in assuming the beginning of time.
- apst
- · Replies 28 ·
Graduate How generalizable is simulation/model research?
- Simfish
- · Replies 1 ·
Graduate What Role Do Dark Matter Filaments Play in Cosmology?
- Alfrez
- · Replies 1 ·
Undergrad Does lumpiness mean order or disorder in cosmology?
- andresordonez
- · Replies 2 ·
Graduate Why is there still mostly hydrogen in pop I and II stars?
- DaleSwanson
- · Replies 3 ·
Undergrad Can Black Holes Actually Emit Radiation?
- subhendu001
- · Replies 1 ·
Graduate Do galaxy rotation rates vary, and are identical spins connected by wormholes?
- leonstavros
- · Replies 6 ·
Undergrad When was Dark Matter Proposed After the Big Bang?
- Deepak247
- · Replies 4 ·
Undergrad Why Aren't Concrete Spacers Required In Foundations?
- DaleSwanson
- · Replies 1 ·
Graduate How Do Coiled Magnetic Fields in Black Holes Create Jets?
- danh0000
- · Replies 1 ·
Graduate Dark matter, dark energy, and the Kerr metric?
- Imax
- · Replies 11 ·
Graduate Understanding Black Hole Singularity
- DLuckyE
- · Replies 35 ·
High School Balloon within a balloon question
- mikdes
- · Replies 4 ·
Stargazing Any suggestions for a good set of binoculars around $30?
- itsthemac
- · Replies 4 ·
Winter is better for stargazing? Is it true?
- banbianlian
- · Replies 9 ·
Graduate Dark Matter - what's the mystery?
- elginz
- · Replies 11 ·
Undergrad Does Dark Matter Affect the Speed of Light?
- sreekant
- · Replies 3 ·
Graduate Could Inflation Create a Universe from a Pre-Existing De-Sitter Vacuum State?
- dude01
- · Replies 1 ·
Graduate This is the question which is asked in this content.
- UniPhysics90
- · Replies 1 ·
Graduate How does the comoving Hubble radius solve the horizon problem in de Sitter inflation?
- torus
- · Replies 4 ·
Graduate Is redshift unreliable as a measuring tool?
- azzkika
- · Replies 14 ·
Undergrad How Does Gravity Affect Light in Black Holes?
- The legend
- · Replies 7 ·
Undergrad How Did the Moon Achieve Orbit Without an Orbital Burn?
- Oldfart
- · Replies 2 ·
Graduate Isn't a Cosmos Made from Nothing Self-Consistent?
- wawenspop
- · Replies 19 ·
Graduate Finding Longitudinal Data of Star Magnitudes in Surveys
- theneedtoknow
- · Replies 1 ·