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 Are There Laws Governing the Passage of Time?
- thedragonbook
- · Replies 3 ·
Graduate Twinkle, twinkle, little star
- Andy Resnick
- · Replies 4 ·
Graduate The Big Bang and CP Violation: Where Did the Mass Go?
- Khursed
- · Replies 4 ·
Graduate Effect of the Galactic plane on the COBE CMBR measurements
- Tanelorn
- · Replies 7 ·
Undergrad How fast is the universe expanding and is it accelerating?
- michael879
- · Replies 27 ·
Graduate Does Fine Structure Constant Vary From Place to Place?
- Dotini
- · Replies 13 ·
Graduate Gleise 581g; does it exist and could it harbor life?
- vanvlizr
- · Replies 12 ·
Undergrad Does Energy Gravitate? Answers Here
- wolram
- · Replies 3 ·
Graduate Particles (The Universe) Popping Up Into Existence
- RobinSky
- · Replies 7 ·
Graduate Is Space Infinite While Matter is Finite?
- shifty88
- · Replies 14 ·
Undergrad Which elements/compounds can be liquid on Venus?
- Ontophile
- · Replies 3 ·
Graduate How Can I Identify Elements in Jupiter's Absorption Spectrum?
- Jahne7
- · Replies 1 ·
Graduate Could time exist outside our universe before the Big Bang?
- revo74
- · Replies 8 ·
What Higher Dimensions Feel Like
- Hirams_bro
- · Replies 6 ·
Graduate How gravitational potential effects mass?
- new_r
- · Replies 5 ·
Undergrad Measurement of Galaxy Rotation: How Long Does it Take?
- jayaramas
- · Replies 4 ·
High School Light year, explanation required?
- optical mouse
- · Replies 27 ·
Graduate Missing Matter - Is anything really Missing
- yogi
- · Replies 15 ·
Graduate Zero-energy_universe doesnt add up
- granpa
- · Replies 2 ·
Graduate How fast can you accelerate by running in a low-density space environment?
- vityav
- · Replies 8 ·
Undergrad How feasible you think Nemesis theory is
- Chewy0087
- · Replies 5 ·
Stargazing Quick and Easy Telescope Measurments?
- Willis666
- · Replies 4 ·
Graduate Determining the dominant body in a basic planetary system simulation
- TheHarvesteR
- · Replies 7 ·
Undergrad Can the Drake equation estimate intelligent alien civilizations?
- PhysicsPost
- · Replies 32 ·
Stargazing How can I safely view a solar eclipse?
- PhysicsPost
- · Replies 1 ·
Solar system on my date of Birth
- sabrina82
- · Replies 11 ·
Graduate Is the Universe Losing Mass Through Stellar Energy Conversion?
- jayaramas
- · Replies 1 ·
Graduate Why do so many people claim cyclic models brake down due to entropy?
- lukesfn
- · Replies 2 ·
Graduate The Raisin Bread Analogy Question
- Julius Caesar
- · Replies 36 ·
What is the best book on cosmology for all levels of knowledge?
- think
- · Replies 4 ·
Graduate Is the Center of the Milky Way Not What We Think?
- kjensen
- · Replies 11 ·
Graduate Creation of space what exactly does this mean
- matthias31415
- · Replies 20 ·
Graduate Black holes, dark matter, the expansion of the universe, and unifying theories.
- robertfergus
- · Replies 4 ·
Graduate Is the Big Bang Misunderstood as an Explosion in Static Space?
- Imax
- · Replies 2 ·
Graduate What is the ultimate fate of a massive star in space?
- PhysicsPost
- · Replies 1 ·
Graduate The limit of the observable universe
- mrspeedybob
- · Replies 8 ·
Undergrad Possible energy sources that a lunar base might have as an option
- MonserrateM
- · Replies 4 ·
Graduate Calculating density from CMB data
- skippy1729
- · Replies 3 ·
Undergrad Are orbital planes generally parallel on large scales?
- mrspeedybob
- · Replies 3 ·
High School Why does Earth have one sun and moon while other planets have more?
- rijaalu
- · Replies 4 ·
Has something new been discovered in astronomy?
- Fusiontron
- · Replies 1 ·
Graduate How to Accurately Convert FK5 to Altitude and Azimuth?
- Scott S
- · Replies 1 ·
High School What distance will a traveler cover if they walk in a southwesterly direction?
- luiseduardo
- · Replies 6 ·
Graduate Can Mic Oscillations Replace Dark Energy in Cosmic Expansion Models?
- wolram
- · Replies 1 ·
Graduate Questions Regarding The Expansion of The Universe
- RobinSky
- · Replies 17 ·
Virgin Galactic - the first step?
- narrator
- · Replies 7 ·
Graduate Can quantum randomness explain the big bang without a cause?
- GarryS
- · Replies 116 ·
Undergrad The size of the universe, and what we can see.
- TheSwamper
- · Replies 4 ·
Undergrad Why aren't stars in a star cluster attracted to each other?
- texasblitzem
- · Replies 25 ·
Graduate Exponential expansion and Higgs mechanism
- lark
- · Replies 15 ·
Graduate Elliptical Orbit's curvature the same at opposite ends of semi-major axis?
- bahamagreen
- · Replies 9 ·
Graduate We Know Less About CDM Than We Did Before
- Dotini
- · Replies 6 ·
Undergrad The sun moves through space, right?
- phinds
- · Replies 8 ·
High School Benefits of a lunar base and whether silicon can be transported to Earth
- MonserrateM
- · Replies 44 ·
Undergrad Will Pluto Crash into Neptune?
- Philosophaie
- · Replies 8 ·
Graduate Question: Regarding Stellar Spectroscopy Equipment.
- Jahne7
- · Replies 1 ·
Undergrad Do different light frequencies bend equally through gravitational lenses?
- jayaramas
- · Replies 1 ·
Undergrad How to simulate planets orbit curce around the sun ?
- kjensen
- · Replies 36 ·
High School Is Velocity Consistent in Planetary Orbits?
- AakashPandita
- · Replies 14 ·
Stargazing Choosing a Telescope: Orion vs Celestron
- Willis666
- · Replies 2 ·
Undergrad Why do scientists believe the expansion of the universe is accelerating?
- sdemjanenko
- · Replies 11 ·
High School If Universe is Expanding at an Accelerated Rate Why
- ronholton
- · Replies 22 ·
Undergrad Formation/Expansion of Red Giant
- Guni22
- · Replies 3 ·
Graduate Why doesn't dark matter collapse to black hole density?
- bigmig
- · Replies 26 ·
Graduate Can a spaceship land on a pulsar?
- bostonnew
- · Replies 7 ·
High School Is Dark Matter Just Unseen Water Vapor?
- nmk
- · Replies 9 ·
Undergrad Could the Universe's Expansion be Compared to Oil on Water?
- pilgrum90
- · Replies 3 ·
Graduate How can we measure time before the Big Bang?
- kings7
- · Replies 26 ·
Undergrad What is the estimated energy output of the Milky Way?
- jayaramas
- · Replies 1 ·
Graduate A question based on Lawrence Krauss' explanation
- TRB8985
- · Replies 3 ·
Graduate What if light speed wasn't the limit?
- narrator
- · Replies 10 ·
Undergrad Why are galaxies shaped like spirals?
- jayaramas
- · Replies 1 ·
Undergrad What are some applications of lasers in astrophysics research?
- d3nat
- · Replies 7 ·
Graduate Why can't varying gravitational G with distance explain flat galaxy rotation curves?
- hkyriazi
- · Replies 38 ·
Graduate Quantum fluctuations and Spacetime
- DonSmith
- · Replies 3 ·
High School Andromeda Galaxy colliding with the Milky Wa
- zytyxx
- · Replies 14 ·
Undergrad Star to black hole same mass/gravity?
- narrator
- · Replies 4 ·
Undergrad Questions about Galactic Rotation
- LaurieAG
- · Replies 11 ·
Undergrad What is the Smallest Possible Size of a Black Hole?
- jayaramas
- · Replies 9 ·
Undergrad Is Gliese 581d a Goldilocks planet?
- narrator
- · Replies 52 ·
Graduate What would Fermi say now about his 'paradox'?
- udtsith
- · Replies 1 ·
Graduate Why are planetary orbits so circular?
- oldman
- · Replies 34 ·
Graduate Accelerating expansion of universe is an illusion
- bohm2
- · Replies 44 ·
Graduate Responding to a PhD astronomer's claim of scant evidence for the Big Bang
- csmcmillion
- · Replies 19 ·
Graduate Did early galaxies at redshift 10 form in just 45 million years?
- PetTastic
- · Replies 2 ·
Graduate What is information in a black hole
- Astro.padma
- · Replies 12 ·
Graduate How close to constraining DE to simply be Lambda?
- marcus
- · Replies 0 ·
High School Why doesn't tidal force pull earth and moon together?
- AlonsoMcLaren
- · Replies 4 ·
High School Neutron Stars vs Black Holes: What's the Difference?
- jayaramas
- · Replies 4 ·
Graduate Theoretical scenario for star-forming with a calculation
- jcarper
- · Replies 21 ·
Graduate Can cyclical processes be compatible with the second law of thermodynamics?
- bill alsept
- · Replies 82 ·
Graduate What is expansion ? A thought experiment
- matthias31415
- · Replies 22 ·
Undergrad Why most of the galaxies are having two spiral arms only?
- jayaramas
- · Replies 5 ·
Graduate Is New Space Being Created Between Galaxies?
- skydivephil
- · Replies 8 ·
High School Practical uses of Manhattanhenge for a summer science project
- Ironside
- · Replies 3 ·
Graduate What are the main challenges in developing space-based solar power systems?
- shashankac655
- · Replies 2 ·
Graduate Time dilations and our perspective
- bill alsept
- · Replies 2 ·
Graduate Why can we see nearby luminous objects but only see distant supernovae as flashes?
- Alexroma
- · Replies 18 ·
Graduate Soft landiing an asteroid at the south pole
- khoopes01
- · Replies 24 ·
Graduate Universe cyclic model and energy loss
- mtanti
- · Replies 6 ·