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 Are Cosmic Rays Just Electromagnetic Rays from Space?
- cowah22
- · Replies 1 ·
Graduate Faster than light expansion speeds are standard
- marcus
- · Replies 6 ·
Undergrad Did the universe expand faster than light during the Big Bang?
- scoobydoo
- · Replies 15 ·
Graduate Stability of cosmological models
- axlsaml1
- · Replies 3 ·
High School The Earth and its orbit around the sun
- njay22
- · Replies 20 ·
Graduate Why do we say black holes vanish if their mass decreases with hawking radiation?
- spidey
- · Replies 5 ·
Graduate The Pre-Big Bang Universe: The Origin of Matter and Energy from the Vacuum
- Habeeb03
- · Replies 3 ·
Graduate Curvature of space; curvaure of spacetime
- jonmtkisco
- · Replies 49 ·
Undergrad The Big Bang, and where it occured in space.
- _Mayday_
- · Replies 9 ·
Graduate Universe expanded faster than the speed of light?
- intel
- · Replies 1 ·
Graduate Could the universe have always existed rather than starting from nothing?
- wolram
- · Replies 69 ·
Graduate Can we predict when the universe will gravitationally collapse?
- wolram
- · Replies 4 ·
Graduate Can galaxies recede faster than light without violating special relativity?
- grmnsplx
- · Replies 12 ·
Where Can I Download M.V.Berry's 'Stability of the Solar System' Paper for Free?
- astronomia84
- · Replies 5 ·
Graduate How fast does the universe expand from the Hubble constant?
- Tachyonie
- · Replies 16 ·
Undergrad What is Dark Energy and How Does It Affect the Universe's Expansion?
- anonymoussome
- · Replies 5 ·
High School Are those shooting stars or satellites in the night sky?
- scarecrow
- · Replies 3 ·
Why did people predict the world would end in 2012?
- tkitchen
- · Replies 6 ·
Graduate Do Boltzmann brains form more easily than universes?
- MarkeD
- · Replies 2 ·
Graduate What are the different theoretical shapes of black holes?
- jlroitman
- · Replies 8 ·
Graduate Queston On The Theory Of Everything
- sudhirking
- · Replies 3 ·
Graduate Negative Acceleration in Black Holes
- humuus
- · Replies 4 ·
Graduate The fuzzball proposal for black holes
- wolram
- · Replies 1 ·
Graduate Visualizations without space-time or light
- wawens
- · Replies 35 ·
Graduate Angular momentum of an oblate spheroid
- stevebd1
- · Replies 4 ·
Graduate Does the information loss paradox depend on Hawking radiation existing?
- spidey
- · Replies 5 ·
Graduate Beckenstein Bound: Understanding Smolin's Entropy Bounds
- Coin
- · Replies 4 ·
High School How do we determine the age of the universe and Earth?
- jfrancis
- · Replies 7 ·
Graduate Have physicists rebutted E. Lester Smith's Intelligence Came First theory?
- asterias
- · Replies 3 ·
Graduate At the April APS meeting: curing cosmic singularities
- marcus
- · Replies 1 ·
Undergrad Dark energy sources for a cosmology paper
- Jared37
- · Replies 6 ·
Graduate Rotational kinetic energy and gravity
- stevebd1
- · Replies 3 ·
Graduate How Do Black Hole Masses Compare to Normal Matter in the Universe?
- CosmiCarl
- · Replies 5 ·
Undergrad What Keeps the Galaxy Intact?
- Peralta_Man
- · Replies 4 ·
Largest Known Star: Introducing Myself and Cosmology
- Star-Gazer
- · Replies 3 ·
Graduate Who the top quantum cosmology researchers are
- marcus
- · Replies 34 ·
Graduate Titius-Bode law, any analytical or numerical derivation?
- Ulysees
- · Replies 14 ·
Graduate Relativity or Relativistic Theromdynamics
- hagopbul
- · Replies 4 ·
Graduate Warm dense matter phase and early universe models before decoupling
- jal
- · Replies 5 ·
Undergrad Human versus robotic spaceflight
- D H
- · Replies 46 ·
Graduate Finding asteroid orbital period from equilibrium temperature of 200 K
- rodrigues
- · Replies 4 ·
Graduate Solar corona luminosity curve versus distance
- Eleftheria
- · Replies 2 ·
Undergrad Universe burnout-What's so hard about that
- Capernicus
- · Replies 17 ·
High School Everything is part of something bigger
- sudhirking
- · Replies 11 ·
Graduate Escaping the Impending Heat Death of the Universe: A Possibility or a Fantasy?
- hammertime
- · Replies 3 ·
Graduate Is There a Contradiction Between Entropy in Thermodynamics and Cosmology?
- josephpalazzo
- · Replies 8 ·
Just one irrefutable datum point
- wolram
- · Replies 1 ·
Graduate What Lies Beyond Our Universe? Physicists' Opinions
- lionell
- · Replies 2 ·
Graduate Universe doesn't equal Time travel
- runicle
- · Replies 5 ·
Undergrad What would happen to Earth without the moon?
- Ulysees
- · Replies 12 ·
High School Why don't we feel Earth's rotation if we're moving with it?
- mnhtapu
- · Replies 13 ·
Undergrad Gamma Ray burst in the Milkey Way
- talmans
- · Replies 12 ·
High School Why do rockets need engines to change direction in space?
- Ry122
- · Replies 7 ·
Graduate Snowplow model of a supernova remnant
- Tuugii
- · Replies 4 ·
High School Would the Moon keep rotating if Earth disappeared?
- Timoothy
- · Replies 14 ·
High School Demonstrating Moon's Lack of Internal Rotation
- Timoothy
- · Replies 10 ·
Graduate Universal quality of virial theorem
- giann_tee
- · Replies 1 ·
High School Finding a Local Star Like Ours: 10-50 LY Radius
- MDW
- · Replies 1 ·
Undergrad Have cosmology discoveries stalled since 2022?
- Chaos' lil bro Order
- · Replies 8 ·
High School How much energy does the sun produce per second?
- Holocene
- · Replies 5 ·
Undergrad Why is the Earth getting closer to the sun and the moon getting farther away?
- DM
- · Replies 5 ·
Undergrad Naked-Eye Visible GRB: Witnessing Halfway Across All Creation
- DaveC426913
- · Replies 5 ·
Undergrad Why don’t planet hunters find black holes?
- jimgraber
- · Replies 2 ·
High School Why do we see the near side of the moon only?
- anonymoussome
- · Replies 23 ·
Graduate Urban legends in authoritative astronomy
- Ken G
- · Replies 46 ·
High School Earth's Closest Approach to the Sun: Does the Date Change?
- Ulysees
- · Replies 4 ·
Graduate Can Early Dark Energy Affect Standard Rulers in Cosmology?
- wolram
- · Replies 1 ·
What are the limiting factors in this case
- mubashirmansoor
- · Replies 4 ·
Undergrad Why Does Earth's Axis Precess Like a Spinning Top?
- Ulysees
- · Replies 3 ·
Graduate Is the Entropy of Black Holes Measurable for Non-Exotic Black Holes?
- RasslinGod
- · Replies 6 ·
Graduate Good textbooks on modern cosmology ?
- smallphi
- · Replies 6 ·
Graduate How Do Interpretations of Hubble Expansion Differ Empirically?
- my_wan
- · Replies 5 ·
Graduate Minimum value of g for blackhole
- spidey
- · Replies 1 ·
Undergrad Light Entering Black Hole: Observed or Not?
- spidey
- · Replies 5 ·
Have You Read Weinberg's Cosmology Yet?
- superpoincare
- · Replies 9 ·
Undergrad How Are Black Holes Detected and Measured?
- shaan_aragorn
- · Replies 11 ·
Alternative idea on expanding universe
- W3pcq
- · Replies 12 ·
Undergrad Will a universe 96% dark matter eventually collapse or keep expanding?
- viridian
- · Replies 7 ·
Undergrad Relation between earth position in orbit and its tilt
- pixel01
- · Replies 5 ·
Graduate Is There a Universal Point Where All Moments in Time Exist Simultaneously?
- zengin
- · Replies 4 ·
Graduate Angular size, black body radiation, parallax and magnitude of 51 Pegasi
- SilverHammer
- · Replies 1 ·
High School Newbie question on atsrophotography
- Holocene
- · Replies 2 ·
Graduate Is the Secret Number to the Universe 10^122?
- SF
- · Replies 16 ·
High School A Beginner's Guide to Learning About Black Holes
- Owen-
- · Replies 9 ·
Graduate Estim. dark energy up by 3 percentage points. Any reaction?
- marcus
- · Replies 3 ·
Graduate Gravity for a stellar black hole
- stevebd1
- · Replies 26 ·
Undergrad Can two stars have the same apparent but different absolute magnitudes
- bse
- · Replies 6 ·
Graduate Superbubbles from shock waves from supernova or stellar winds?
- sarahrose
- · Replies 2 ·
Undergrad Earth/solar position vs spiral arms
- ray b
- · Replies 3 ·
Graduate Meaning of setting the scale factor equal to 1 at present epoch
- kdv
- · Replies 3 ·
High School Moon Preservation: What if a Spaceshuttle or Missile Hit It?
- h.g.Whiz
- · Replies 5 ·
How many people object to a big bang creation-like event?
- Chronos
- · Replies 9 ·
Undergrad What Material Makes Up Black Holes?
- pixel01
- · Replies 6 ·
Astronomy Videos: Collection by NGC6822 on YouTube
- drosser
- · Replies 1 ·
Anybody know anything about parallelogram mounts
- Saladsamurai
- · Replies 6 ·
Undergrad . Radio Spectroscopy -> Finding the doppler shift in a graph
- PhysicsHelp12
- · Replies 1 ·
Graduate Question from a fool about the big bang
- zengin
- · Replies 13 ·
Undergrad How did the universe expand 78 billion light years in 11-20 billion years?
- hedkrash
- · Replies 5 ·
Graduate Tired light vs. expanding universe
- ntdg634
- · Replies 2 ·
Undergrad What causes the equatorial bulge?
- Sheneron
- · Replies 10 ·