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 Quantized space-time and redshift.
- turbo
- · Replies 30 ·
Graduate Does a Black Hole Have a Greater Gravitational Field Than Its Original Star?
- JV
- · Replies 5 ·
High School Why do Earth, Moon, and Venus have different numbers of craters?
- S. Dilly
- · Replies 3 ·
Graduate Has Gravity Probe B been a waste of money?
- Garth
- · Replies 41 ·
Undergrad Space vs Energy: Can Volume Exist Without Energy?
- force5
- · Replies 36 ·
Graduate Does Meson Exchange Cease in Neutron Stars at Sub-Femtometer Distances?
- kurious
- · Replies 10 ·
Graduate Rubber Sheet, Heavy Sphere & Gravity: Explained
- anand
- · Replies 9 ·
Graduate Is Hawking’s new idea on Black Hole original or adopted?
- shashi
- · Replies 14 ·
High School Could This Be the First Photo of an Extrasolar Planet?
- meteor
- · Replies 1 ·
Graduate Gravity constant G = 3(H^2)/[4pi(e^3)ρ].
- Nigel
- · Replies 2 ·
Graduate Alternate dimensions or Universes
- Gale
- · Replies 13 ·
High School Do nearby stars have an effect on the Sun and its planets?
- Erus
- · Replies 2 ·
Graduate No, this is not a question for biologists.
- kjones000
- · Replies 8 ·
Graduate Will New Objects Appear in the Sky as Time Passes?
- Gerinski
- · Replies 19 ·
Graduate The Sun's X-file Under The Spotlight
- Ivan Seeking
- · Replies 2 ·
Graduate The Infinite Universe Expands is Inaccurate
- Imparcticle
- · Replies 6 ·
Graduate CIPA - a fantastic Zero Point Energy website
- turbo
- · Replies 5 ·
Graduate How Does Infinity Become Smaller? | Hawking
- veryyoung
- · Replies 3 ·
Graduate Mystery of Dark Energy: Unravelling the GR Expansion of Universe
- quasar987
- · Replies 71 ·
Graduate Does the universe dance in forms?
- plum
- · Replies 27 ·
Graduate Was Space Present Before the Big Bang or Did It Expand with the Universe?
- Harveyf
- · Replies 83 ·
High School Creating a VB6 Orbit Simulator: Tips & Advice
- walter
- · Replies 17 ·
Undergrad Are Cosmic Rays Particles or Radiation?
- RAD4921
- · Replies 2 ·
Undergrad Universe Expansion Speed: Einstein's Theory Impacted?
- Stonefeather
- · Replies 20 ·
Undergrad Cosmic background radiation - alternative proposal
- zforgetaboutit
- · Replies 55 ·
What do you think will be the fate of the universe?
- Gold Barz
- · Replies 43 ·
Stargazing Did You Guide Your Moon Shot?
- check
- · Replies 5 ·
High School What kinds of space rays are detectable on earth
- Imparcticle
- · Replies 3 ·
Undergrad What is the formula for calculating delta v for escape velocity?
- tony873004
- · Replies 3 ·
Graduate I've yet to understand the finite universe
- plum
- · Replies 11 ·
Undergrad Chances of aliens finding Earth disappearing
- Ivan Seeking
- · Replies 18 ·
Undergrad Black Hole Implosion or Supernova Explosion - Which is More Powerful?
- dave19903652
- · Replies 6 ·
Graduate Calculating The Event Horizon of a Supermassive Black Hole
- Vast
- · Replies 2 ·
Undergrad Strange SETI Signal from ~1000 LY
- Ivan Seeking
- · Replies 9 ·
Graduate Could Quantum Gravity Predict a Long-Distance Invariant Scale?
- marcus
- · Replies 7 ·
High School Planets Orbit Sun: Why Same Direction?
- Ezekiel.
- · Replies 5 ·
Undergrad How Fast Is the Milky Way Moving Relative to the Cosmic Background Radiation?
- kingofjazz
- · Replies 3 ·
Undergrad Could Geostationary Satellites End Up Gathering Over the Indian Ocean?
- kurious
- · Replies 11 ·
Graduate Is there a mechanism for reproducing universes?
- Vast
- · Replies 9 ·
Graduate Could Sedna be a trapped rogue planet
- mee
- · Replies 5 ·
Mysterious signals from 1000 light years away
- Adam
- · Replies 1 ·
Undergrad Elliptical Orbits: How They Work & Math Behind Them
- daveed
- · Replies 1 ·
Graduate Star formation and distribution in spiral galaxies
- hellfire
- · Replies 3 ·
Graduate Is the Orion Trapezium Exploded from a Pre-Stellar Body?
- juan avellaneda
- · Replies 1 ·
Undergrad Why is gravity always attractive?
- HIGHLYTOXIC
- · Replies 17 ·
Graduate Flat geodesics mediate spacetime
- Loren Booda
- · Replies 16 ·
Undergrad Elliptical Orbits: Simple Explination & Gaining Energy
- Cyrus
- · Replies 9 ·
High School Possible terrestrial extrasolar planet found
- Phobos
- · Replies 11 ·
High School Question: Jupiter and Saturn at 200x?
- VantagePoint72
- · Replies 12 ·
High School What is Dark Energy? | Learn About Universe
- no idea
- · Replies 3 ·
Graduate Entropy of a Star: Calculating Sun & Neutron Stars
- kurious
- · Replies 3 ·
Graduate Is Our Universe Just One Bubble in a Multiverse?
- sol2
- · Replies 9 ·
Graduate Hyperbolic, Parabolic or Elliptical Orbit?
- cj
- · Replies 1 ·
Fate Of Universe - Hindus, Buddhists & Mayans Right?
- Gold Barz
- · Replies 17 ·
High School You Are the Centre of the Universe
- The Binary Monster
- · Replies 37 ·
High School Expert Help on Understanding Seasons with Perpendicular Earth's Axis
- S. Dilly
- · Replies 5 ·
Graduate Should PF Have a Separate Quantum Gravity Forum?
- marcus
- · Replies 15 ·
Stargazing What Telescope Should I Buy Under $700?
- VantagePoint72
- · Replies 4 ·
Graduate Curved or Flat? Decoding the Distance Measurements in Space
- asprin
- · Replies 2 ·
Undergrad Questions About Black Holes - Answers for Non-Physics Students
- UglyEd
- · Replies 8 ·
Graduate Doubts and Unease: Physics Articles Troubling Ben
- The Binary Monster
- · Replies 5 ·
Graduate The Big Leak, Universe Equilibrium, Time
- Erus
- · Replies 2 ·
Graduate Celestial Die Hards: Escape Velocity at 1 Planck Length
- kjones000
- · Replies 1 ·
Undergrad Is the Parallax Method Still the Most Widely Used for Measuring Star Distances?
- neoweb
- · Replies 4 ·
High School Weightlessness in the Center of The Earth?
- hexrd
- · Replies 10 ·
Graduate Your weight on a Space Elevator ?
- MonstersFromTheId
- · Replies 8 ·
Stargazing Looked through a telescope for the first time
- JasonRox
- · Replies 17 ·
Undergrad Why Do Variable Stars Like R Hydra Exhibit Unique Color Changes?
- juan avellaneda
- · Replies 5 ·
Graduate Can dark energy prevent neutron stars from collapsing into black holes?
- kurious
- · Replies 4 ·
Graduate Unruh: Loop Quantum Cosmology paper (new)
- marcus
- · Replies 9 ·
Burning Man 2004- The Vault of Heaven
- setAI
- · Replies 5 ·
Searching for Aliens: Are We Alone in the Universe?
- Gold Barz
- · Replies 11 ·
Graduate Is G truly a constant in the equation F(M,m,r)=GMm/rr?
- Gonzolo
- · Replies 5 ·
Graduate QG plasma and gamma ray bursters
- kurious
- · Replies 18 ·
Graduate Neutron Star Properties: Density, Pressure, and Acoustical Velocity
- Orion1
- · Replies 12 ·
Building an Observatory for Your Astronomy Club: Tips and Considerations
- Gale
- · Replies 5 ·
High School What is Dark Matter and is it a reputable concept in astronomy and cosmology?
- alexkerhead
- · Replies 7 ·
Graduate Are there multiple theories for the origin of dark matter and dark energy?
- salsero
- · Replies 66 ·
Undergrad Why Does Gamma Ray Take 1M Years to Reach Star Surface?
- CBR600RR
- · Replies 8 ·
Undergrad Is the Moon's Gravity Calculation Correct?
- Oops
- · Replies 9 ·
Graduate On the general curvature of space.
- quasar987
- · Replies 15 ·
Graduate Does Universe Expansion Influence Galaxy Clustering?
- PoPpAScience
- · Replies 9 ·
High School Why do Mercury and our Moon not spin?
- kichigai
- · Replies 14 ·
Graduate Origin of Cosmic Rays and GRB (new paper by A.Dar)
- marcus
- · Replies 6 ·
Stargazing Schmidt-Cassegrain Telescope Image Quality - Karl's Questions
- EIRE2003
- · Replies 33 ·
High School What Does Newton's Gravitation Constant Represent?
- Ygmaince241
- · Replies 9 ·
Graduate Creation, Re-Creation and re-Generation of The Universe
- mitch@crowfamily.us
- · Replies 14 ·
Graduate Is MOND Valid in Describing Universal Expansion Beyond 10^26 Metres?
- kurious
- · Replies 5 ·
Graduate The Denouement of Blue Supergiants
- Simfish
- · Replies 1 ·
Undergrad Formula for sunset/rise times, moonrise/set and phases
- Goats Dont Shave
- · Replies 2 ·
Graduate Expansion/contraction same thing?
- RAD4921
- · Replies 1 ·
Graduate Baez on Dark Energy vs Cos.Const.
- marcus
- · Replies 5 ·
Undergrad Doppler Effect: Does Light Obey the Rule?
- bart0211
- · Replies 2 ·
Graduate What is the significance of the Chandrasekhar boundary in neutron star research?
- canopus
- · Replies 3 ·
Graduate Three Dimensional Space in the Forth Dimension
- Physicsfreek
- · Replies 1 ·
Graduate Expanding & Contracting Universe: Black Hole Integration?
- Blueplanetbob
- · Replies 13 ·
High School The Solar Phenomena: Prominences, Flares, and CMEs
- daveed
- · Replies 3 ·
Graduate Everything you wanted to know about Dark Matter
- Olias
- · Replies 1 ·
Graduate The Origin of the Universe: Reexamining the Big Bang Theory
- employee #416
- · Replies 87 ·
High School Why does light travel at light speed?
- jackpot337
- · Replies 62 ·