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
High School Picture of the Day: Gas Swirling Around a Black Hole
- wolram
- · Replies 2 ·
Undergrad How to differentiate Doppler shift from star emission
- semc
- · Replies 5 ·
High School What is containing the Universe?
- Spin2win
- · Replies 63 ·
Undergrad Question on the Derivation of Temperature/Scale Factor Relation
- TRB8985
- · Replies 3 ·
High School Measuring the Universe's expansion rate
- Cimion
- · Replies 12 ·
Undergrad Possibility of a quasar jet laser impacting Earth directly
- FelixLudi
- · Replies 17 ·
Graduate Coriolis Drift of Discrete Objects
- Sooty
- · Replies 3 ·
High School Formation of Supermassive Black Holes
- RandomPhysicist
- · Replies 3 ·
Graduate Calculation of the "lightness number" for solar sails
- Val---
- · Replies 1 ·
High School Why the multiverse makes no sense to me
- Mlesnita Daniel
- · Replies 10 ·
High School ESA image of alleged Mars plume: is it real?
- fizzy
- · Replies 12 ·
High School Rough probability that aliens would visit the Earth?
- consuli
- · Replies 45 ·
High School Calculating solar irradiance at each planet?
- bbbl67
- · Replies 10 ·
Undergrad Detect exoplanets by yourself with the cheapest equipment
- alberto91
- · Replies 5 ·
High School What would the universe be like with less mass and energy?
- Ethan Deibert
- · Replies 2 ·
Undergrad Is the universe spherical and shaped like a bubble or is it flat?
- Aidan345733
- · Replies 27 ·
Undergrad Mathematical Proof of Elliptical Orbits
- Celso
- · Replies 4 ·
Undergrad Is the universe expanding or stretching? (adding space vs stretching distance)?
- Mr J
- · Replies 8 ·
High School Rare Earth hypothesis, Gaian bottleneck, and the Drake equation
- Aidan345733
- · Replies 1 ·
Undergrad Time dilation vs. the Doppler effect
- Exidor
- · Replies 13 ·
High School Bose Stars (dark matter in origin)
- unusually_wrong
- · Replies 1 ·
High School Earth's orbit around the sun -- looking for an equation
- Romanko
- · Replies 6 ·
High School Can the moon orbit be used as perpetual motion?
- Enniss
- · Replies 5 ·
High School Conundrum thinking about crossing an Event Horizon
- Grinkle
- · Replies 32 ·
Undergrad Can I Simulate Planetary Accretion with Disksim?
- KarenRei
- · Replies 1 ·
Undergrad Stacking NGC 7741 images with fewer than 6 stars for alignment
- starstruck_
- · Replies 19 ·
High School Do we directly observe redshifted galaxies receding >c?
- Anthony111
- · Replies 17 ·
Undergrad Would a black hole made of dark matter differ from one made of ordinary matter?
- Spas Stoilov
- · Replies 14 ·
Undergrad Can dark matter be modeled as a gas?
- DanMP
- · Replies 2 ·
Undergrad Why does the Sun's spectrum show both continuous and absorption features?
- xoxo1001
- · Replies 9 ·
Undergrad Communicating about the LHC and Cosmology in a creative way?
- nicklas_m123
- · Replies 1 ·
High School Formation of Hyperion System: How Planets Form Far from Stars
- wolram
- · Replies 1 ·
High School Relationship between the age of the Universe and the Hubble horizon
- Anthony111
- · Replies 1 ·
Undergrad Resources to find Data/Models for Nonradial Pulsations of Va
- Samantha Martin
- · Replies 6 ·
Undergrad How can there be fluctuations in the inflaton field value?
- ForgeJB
- · Replies 6 ·
High School Do distant galaxies look younger because their light is older?
- Hans Nelsen
- · Replies 14 ·
Graduate Falsifications and constraints due to GW measurements
- Auto-Didact
- · Replies 19 ·
Undergrad How can you measure a galaxy's distance from time and diameter?
- StillLearningToronto
- · Replies 10 ·
High School Extrapolation back to T zero, before 1980
- Cerenkov
- · Replies 2 ·
Undergrad Does the Planck Length Experience Length Contraction at High Speeds?
- windy miller
- · Replies 2 ·
Undergrad CMB results cause the contradiction of big bang theory
- Jinsuk Kim
- · Replies 2 ·
High School Can Modified Newtonian Dynamics Explain Dark Matter?
- Elbraido
- · Replies 3 ·
Undergrad All current 'hints' towards Dark matter not being "matter"
- AlenKovac
- · Replies 4 ·
Undergrad C# Accurate Earth, Moon Sun visual model to predict eclipses
- TheGalaxyOfGold
- · Replies 2 ·
High School Where Does the Energy for the Expanding Universe Come From?
- KurtLudwig
- · Replies 8 ·
High School What is the cause of Cosmological redshift?
- itoero
- · Replies 30 ·
Undergrad Conservation of energy in an expanding universe
- windy miller
- · Replies 10 ·
High School How much of a star undergoes fusion?
- lavinia
- · Replies 24 ·
Graduate Estimating Displacement of Uranus Due to Neptune's Gravity
- jp40684
- · Replies 16 ·
Undergrad Calculating Earth's Orientation and Moon's Position at J2000.0
- TheGalaxyOfGold
- · Replies 4 ·
Graduate What is the dust-to-gas ratio in oxygen-poor galaxies?
- newgate
- · Replies 6 ·
Undergrad Computing a value of radius for a typical white dwarf
- fab13
- · Replies 5 ·
Undergrad Gravitational waves and the multiverse
- Kaustubh Namjoshi
- · Replies 3 ·
Undergrad Can red dwarfs truly convert 100% of their hydrogen?
- bbbl67
- · Replies 7 ·
Undergrad Comparing Julian day periods for Jupiter, lunar precession and Saros cycles
- fizzy
- · Replies 2 ·
Undergrad Why doesn't dark matter affect the solar system or fit standard models?
- LAP3141
- · Replies 22 ·
Undergrad What is the relationship between Julian Days and other observable time periods?
- fizzy
- · Replies 6 ·
Undergrad What is the shape of very massive stars?
- windy miller
- · Replies 9 ·
High School Dark Energy Fluids: Read the Latest Research
- wolram
- · Replies 3 ·
Undergrad How do gravity and entropy reconcile if gravity decreases entropy?
- Frank Peters
- · Replies 14 ·
Undergrad Can a crewed trip to Alpha Centauri complete in one human lifetime?
- rootone
- · Replies 73 ·
High School Why does Earth have a coherent magnetic field while the Sun's is disrupted by heat?
- BeedS
- · Replies 23 ·
High School Does discrete space resolve the information paradox in continuous space?
- DannyTr
- · Replies 28 ·
Stargazing Is there any material I can use for an aperture solar filter?
- nuffsed
- · Replies 4 ·
Undergrad What could cause a discrepancy in the Bias of a CCD
- starstruck_
- · Replies 9 ·
High School Why is the gravity of a neutron star stronger than that of its original star?
- Simon Peach
- · Replies 6 ·
Undergrad Does constant expansion create apparent acceleration between particles?
- RussB
- · Replies 1 ·
High School Black Holes -- What methods to use to find them?
- jha192001
- · Replies 8 ·
Undergrad Shortest trajectory for spacecraft from A to rotating body B
- VladZH
- · Replies 3 ·
High School What are these diagrams showing about GR?
- Cerenkov
- · Replies 17 ·
Graduate Current Status of Eternal Inflation
- ad infinitum
- · Replies 4 ·
High School Why don't man-made satellites drift away from the Earth?
- wywong
- · Replies 17 ·
Undergrad Understanding Penrose's large number
- windy miller
- · Replies 10 ·
High School Feasibility of a L1 Gravity Swing Cold Launch?
- hmmm27
- · Replies 18 ·
Graduate Integrating partial derivatives in a field equation
- Samson Ogaga Ojako
- · Replies 17 ·
High School Is the Universe Actually Infinite? A Philosophical Discussion
- DannyTr
- · Replies 26 ·
Undergrad Why does Mars have so much iron on it's surface?
- rootone
- · Replies 7 ·
Undergrad Is a Topopolis' Orbit Truly Unstable?
- DET
- · Replies 7 ·
Undergrad Clock signals in primordial power spectrum as test for inflation alternatives
- Spinnor
- · Replies 1 ·
High School Uranus and/or Neptune Lab ideas
- nmsurobert
- · Replies 11 ·
Undergrad Is any attention being given to Conformal Cyclic Cosmology?
- Ebanflo
- · Replies 6 ·
High School Standard Big Bang model vs Inflationary model
- Cerenkov
- · Replies 11 ·
High School The geometry of the expansion of space
- benorin
- · Replies 5 ·
Undergrad GW170817: Limits on D>4 Spacetime Dimensions
- fresh_42
- · Replies 2 ·
High School High School Astro Club: Teaching Astronomy in a City
- nmsurobert
- · Replies 2 ·
Undergrad Testing inflation against bouncing and ekpyrotic models
- windy miller
- · Replies 6 ·
High School Density of the early Universe contributing to the red-shift?
- D.S.Beyer
- · Replies 26 ·
Undergrad Variations in the speed of sound in a star
- fab13
- · Replies 5 ·
Undergrad What is it that forces an object down curved space time?
- vincent
- · Replies 11 ·
Undergrad Zero Active Mass in FRW cosmologies
- jcap
- · Replies 3 ·
High School Is right ascension only measured once a year?
- DonutLord
- · Replies 6 ·
Undergrad What is the Janus Universe and its implications for the arrow of time?
- windy miller
- · Replies 4 ·
High School What is Olbers' Paradox and how does it relate to the universe's structure?
- alejandromeira
- · Replies 2 ·
Undergrad Is there some prediction of the speed of rings?
- Prometeus
- · Replies 6 ·
Undergrad How to get state vector in 4-observation method of Gauss
- Jenab2
- · Replies 2 ·
Undergrad Is the expansion actually accelerating? Or does it just appear so?
- Inani Schroedinger
- · Replies 4 ·
Undergrad Why Do Astrophysicists Use νLν in Accretion Disk Emission Studies?
- Astroiaco
- · Replies 7 ·
High School Is the Universe a 3D Cut of a 4D object?
- Reapphil
- · Replies 10 ·
Undergrad Positions of distant supernova explosions false?
- kiki_danc
- · Replies 31 ·
Undergrad Neutron Stars mass and radii observation data
- Leonardo Machado
- · Replies 1 ·