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 Doppler effect vs expansion effect on wavelength
- rogerperkins
- · Replies 2 ·
High School Questions About Things in Orbit and Why They Don't Descend
- oneamp
- · Replies 7 ·
Graduate Synchronization of time impossible?
- chowyunfat321
- · Replies 9 ·
Undergrad Kepler's 2nd.law and calculation
- shounakbhatta
- · Replies 4 ·
Graduate Could an eliptical galaxy exist with an axis of rotation?
- ilikescience94
- · Replies 4 ·
Graduate First detection of pop III stars?
- Chronos
- · Replies 2 ·
Graduate Are FLRW metrics with scale factor in space and time equivalent?
- tartaneto
- · Replies 3 ·
Graduate Titan's atmosphere vs temperature.
- tanzanos
- · Replies 1 ·
Undergrad Calculating HZ for Contact Binary Systems
- ckirmser
- · Replies 3 ·
Graduate Is Our Universe Truly a Hologram?
- Avichal
- · Replies 4 ·
Undergrad How Large Can a Planet be and Still Have Earth's Mass?
- Yae Miteo
- · Replies 11 ·
Graduate Does Time Cease to Exist Without Matter?
- phinds
- · Replies 171 ·
Undergrad Satellites in various orbits above the earth exploded?
- oneamp
- · Replies 11 ·
Graduate What is Plasma-Fire and Why is it So Dangerous?
- xthomasbhx
- · Replies 9 ·
Graduate Pre-inflationary spatial curvature
- timmdeeg
- · Replies 13 ·
Undergrad Electromagnetic waves vs the laws
- drew737
- · Replies 11 ·
Graduate How does the mass of a black hole compare to its accretion disk?
- EskWIRED
- · Replies 7 ·
Graduate Why do BAOs create wiggles in the power spectrum?
- Madster
- · Replies 2 ·
Graduate What force overcomes cosmic expansion between galaxies?
- awcrowe
- · Replies 1 ·
Graduate Where have all the neutrinos gone?
- Paulibus
- · Replies 7 ·
Undergrad Deteriorating Orbits of Satellites and Objects
- TSjames
- · Replies 2 ·
Undergrad What other elements could compose a terrestrial planet?
- Yae Miteo
- · Replies 14 ·
Graduate Deriving fate of the universe from Friedman's equations
- andrewkirk
- · Replies 3 ·
What is the bright, changing light in the southwestern sky in France?
- willis hallis
- · Replies 10 ·
Undergrad Why don't velocities add up to exceed the speed of light?
- YbNvS
- · Replies 7 ·
Graduate Could life arise on a brown dwarf?
- Chronos
- · Replies 2 ·
High School Planet HD 106906 b in most distant orbit ever observed
- Greg Bernhardt
- · Replies 6 ·
Graduate Infinite universe from a finite start
- timpeac
- · Replies 14 ·
High School What would happen to a human body exposed to space without a spacesuit?
- kalidas1992
- · Replies 5 ·
Graduate I still don't understand singularities
- MathJakob
- · Replies 5 ·
Are there road traffic rules in Space?
- tinypositrons
- · Replies 3 ·
Graduate How Does a Dark Matter Halo Relate to the Clusters of Galaxies We Observe?
- sketos
- · Replies 2 ·
Graduate CMB anisotropies and the ISW effect
- Chronos
- · Replies 2 ·
Graduate Largest reflection angle in Chandra X-ray telescope optics
- ExoP
- · Replies 1 ·
Undergrad How Does the Oberth Effect Work?
- sanman
- · Replies 3 ·
Graduate Meta Materials as Cosmic Ray Shielding for Spacecraft?
- Ian J.
- · Replies 3 ·
Undergrad Is constant planetary alignment (syzygy) possible ?
- B0b-A
- · Replies 7 ·
Graduate Scaling the Universe: How Would it Affect Physics?
- kfx
- · Replies 2 ·
High School Why do planets orbit the sun along the same paths?
- kalidas1992
- · Replies 3 ·
Graduate Earth's Atmosphere Without Magnetic Field & Geology
- willstaruss22
- · Replies 11 ·
High School Why does sunlight cool down traveling through space?
- kalidas1992
- · Replies 3 ·
Graduate Maximum velocity of ISON and some other stuff
- ilikescience94
- · Replies 24 ·
Graduate When was the CMB radiation detected today actually emitted?
- xdrgnh
- · Replies 9 ·
Undergrad How do Planets generate electromagnetic waves?
- junk0
- · Replies 16 ·
Stargazing Will the James Webb telescope see past the big bang?
- Herbascious J
- · Replies 7 ·
Graduate Boltzmann's multiverse and fluctuations
- erotavlas
- · Replies 14 ·
Graduate How are dark matter, general relativity, and standard model related?
- nortonian
- · Replies 11 ·
Graduate Is There a Different Event Horizon for Dark Matter?
- bubbie
- · Replies 1 ·
Undergrad Does the center of the galaxy intersect the ecliptic?
- Pjpic
- · Replies 1 ·
Graduate Evidence of Orbiting Black Holes?
- EskWIRED
- · Replies 3 ·
Graduate Why is there any residual angular momentum left over from the big bang
- taylrl3
- · Replies 1 ·
Graduate Prevalence of Earth-size planets orbiting Sun-like stars
- Chronos
- · Replies 9 ·
Undergrad Solar eclipse - magnitude and albedo
- Numeriprimi
- · Replies 1 ·
Graduate Is the Universe Expanding Through Space or is Space Itself Expanding?
- CWatters
- · Replies 12 ·
Anybody here keeping track of ison
- nil1996
- · Replies 10 ·
Graduate How does matter form into galaxies during the cooling down period?
- Fabo
- · Replies 16 ·
High School Time lapse image of Comet ISON, what looks like snow?
- Spinnor
- · Replies 3 ·
Graduate How Do You Calculate Delta V in a 1-D Gravitational Field?
- Ashiataka
- · Replies 1 ·
Undergrad Can a Running Tap Water Basin Be an Analogy for a Black Hole Event Horizon?
- shounakbhatta
- · Replies 6 ·
Graduate Is the Quantum Vacuum in Deep Space the Same as on Earth?
- kye
- · Replies 21 ·
Graduate Can Super Inflation Explain the Planck Anomalies?
- skydivephil
- · Replies 5 ·
Graduate Why is GRB 130427A so bright at 3.6 billion light years?
- |Glitch|
- · Replies 7 ·
Graduate Dark matter build up near Black holes, thoughts?
- Fermifaq
- · Replies 11 ·
Graduate Where Does Gravity Get Its Energy From?
- Ramone420
- · Replies 9 ·
Graduate Hawking radiation and its significance
- shounakbhatta
- · Replies 14 ·
Graduate What was the primordial composition of U isotopes in solar system?
- snorkack
- · Replies 23 ·
Undergrad Gravity, center of planets, stars
- Mr.Bomzh
- · Replies 5 ·
Undergrad Cygnus X1: Date of Highest Excursion
- sscran
- · Replies 3 ·
High School Can we see new stars appearing as light reaches us from beyond the particle horizon?
- BOAS
- · Replies 22 ·
High School Can a Planet Collect Enough Mass to Become a Black Hole?
- Chitose
- · Replies 28 ·
Graduate Can gravitational redshift explain cosmological redshift?
- hb20007
- · Replies 12 ·
Graduate How Are Heavy Nuclei Produced in Black Hole Jets?
- anorlunda
- · Replies 7 ·
Undergrad Calculating Apparent Magnitude of The Moon
- luuurey
- · Replies 1 ·
Undergrad Space Cold: Is a Vacuum of Space Really Cold?
- jaydnul
- · Replies 2 ·
Undergrad Why do sources give different ages for the first radiation in the universe?
- Toldox
- · Replies 9 ·
Undergrad Earth's shadow in the atmosphere
- marellasunny
- · Replies 1 ·
Graduate Orbit of figure eight 3 or more bodies
- renegade05
- · Replies 1 ·
High School Do i have this right now - mass of the universe
- wolram
- · Replies 5 ·
Graduate Is the Big Collapse a Black Hole?
- haael
- · Replies 5 ·
Graduate Could black holes be empty centers of spinning systems like hurricane eyes?
- taonut
- · Replies 2 ·
Graduate How do we know blackholes are dense? Could instead they be a vortex?
- taonut
- · Replies 20 ·
Graduate Can retrograde moons oscillate between approaching and receding due to tidal forces?
- P.Bo
- · Replies 2 ·
Hyperbolic Comet C-2012 S1 (ISON)
- Philosophaie
- · Replies 3 ·
Graduate Calculating Mass Density of the Universe with SDSS DR10 Quasar Catalog
- Chronos
- · Replies 4 ·
Undergrad Why are Black Holes such massive gravity pools?
- Rhadiel
- · Replies 4 ·
Graduate Star formation activity and SMBH activity
- sender33
- · Replies 2 ·
Undergrad Are there any analogies that are actually meaninful?
- MathJakob
- · Replies 7 ·
Graduate Universe finite or infinite during the first instance of inflation?
- Herbascious J
- · Replies 20 ·
Graduate Feedback and Control Theory applied to Cosmology and Particle Physics
- Tanelorn
- · Replies 4 ·
Graduate Can the Big Bang Theory Be Experimentally Verified in Modern Physics?
- bgq
- · Replies 2 ·
Graduate Velocity Cone in expanding universe
- say_cheese
- · Replies 2 ·
Graduate How large can gas giants grow before gaining mass instead of volume?
- Ian J.
- · Replies 21 ·
High School Layperson's question regarding earth's rotational wobble
- Glenstr
- · Replies 8 ·
Graduate Mass loss in relation to radius of a star
- Markus0003000
- · Replies 1 ·
Undergrad Why does the sun's radiation intensity decrease with distance?
- Remon
- · Replies 12 ·
Undergrad Dimensions - how many are there in universe?
- ananthu017
- · Replies 4 ·
Graduate Differentiating Redshift Type by Spectral Shift Signatures
- bitznbitez
- · Replies 30 ·
Graduate Is Motion Possible in a Continuous Space?
- JK423
- · Replies 41 ·
Graduate Calculating physical separation of 2 sources at unknown angle.
- BOYLANATOR
- · Replies 2 ·
Graduate Hells Angels bikie in a Beijing Opera Concert
- Sharky1
- · Replies 6 ·