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 Does Asymmetry in Spacecraft Flyby Trajectories Cause Unexpected Energy Gains?
- Zman
- · Replies 1 ·
Graduate Stable Blackhole: Radius Dependence
- hurk4
- · Replies 3 ·
High School What Causes the Colorful Cross in Photos of Sirius?
- pixel01
- · Replies 3 ·
Graduate Is the edge of the universe the begging of time
- John Creighto
- · Replies 2 ·
Graduate Can two planets orbit on opposite sides of a star?
- Nentuaby
- · Replies 6 ·
Undergrad How Can You Capture Star Spectra for Astronomical Analysis?
- MonsieurWise
- · Replies 3 ·
Undergrad Is Space Infinite? - What Do You Think?
- cragar
- · Replies 15 ·
Graduate Is the universe's expansion rate constant, accelerating, or decelerating?
- cam875
- · Replies 7 ·
Graduate We know that there are opposites all around us with energy, you have
- redhedkangaro
- · Replies 14 ·
High School Bright star low in the west sky after sunset: Venus or another planet?
- blimkie.k
- · Replies 1 ·
Graduate Could the Big Bang Have Been A Cyclical Event?
- WhoWee
- · Replies 2 ·
Graduate Can our Nuclear weapons destroy a Neutron Star?
- Zdenka
- · Replies 10 ·
Undergrad How was Voyager 2 used to determine the orbits of Uranus and Neptune?
- Zman
- · Replies 1 ·
Stargazing 8 inch dobsonian focusing issue with 30mm eyepiece
- Sheneron
- · Replies 60 ·
Graduate String/ M theory and Dark Matter
- SammyB
- · Replies 1 ·
Graduate Where did all the matter in the universe come from?
- cam875
- · Replies 9 ·
Graduate Can Dark Energy Be the Sole Source of Gravity?
- JinChang
- · Replies 18 ·
Graduate What happens if a cosmic ray proton with 10^20 eV hits the brain?
- fluidistic
- · Replies 11 ·
High School Why do planets attract objects if rotation creates outward gravity?
- Diddas
- · Replies 12 ·
Graduate A Star's Life, (Full Explanation)
- menergyam
- · Replies 9 ·
Graduate Would reversing gravity cause a black hole to fly apart?
- VelociBlade
- · Replies 24 ·
Graduate Calculating the luminosity density of the universe
- IRNB
- · Replies 1 ·
Graduate What theories explain the universe's edge and membrane interactions?
- Djrob99
- · Replies 11 ·
Graduate Can an Observer Safely Enter and Observe the Singularity Inside a Black Hole?
- davidschmid10
- · Replies 6 ·
Graduate Does light in a reflecting box get redshifted by cosmic expansion?
- Yoo
- · Replies 18 ·
Does the Universe Operate on Mathematical Logic?
- th3plan
- · Replies 18 ·
Graduate Effects of Tensor + Scaler gravity
- captn
- · Replies 5 ·
Graduate How Does Space-Time Influence the Fall of an Apple?
- thinker93
- · Replies 5 ·
High School Water plumes from Enceladus's south pole detected by Cassini
- wolram
- · Replies 5 ·
Graduate Space Expansion and Light question
- hagendaz
- · Replies 5 ·
Graduate Why does infalling matter appear frozen at the event horizon?
- Charlie G
- · Replies 6 ·
Graduate Is Dark Energy Usable for Energy Extraction?
- Coin
- · Replies 25 ·
Graduate Why include -xi*H in the equation of state?
- odd-socks
- · Replies 2 ·
Graduate Could the universe be inside a black hole?
- Nel
- · Replies 1 ·
Undergrad Why do distant galaxies move away faster in an expanding universe?
- electerr
- · Replies 7 ·
Graduate Super hubble and subhorizon fluctuations
- aristurtle
- · Replies 2 ·
High School Direction of the gravtional force on the earth
- tnutty
- · Replies 3 ·
Undergrad Equation to find the speed of a distant star
- DeepSeeded
- · Replies 11 ·
Why does Betelgeuse look redder tonight?
- scupydog
- · Replies 11 ·
Graduate Can Inter-Universe Energy Transfer Create New Realities?
- CozmicScott
- · Replies 2 ·
Graduate What happens to a Black hole when they die?
- Rashid
- · Replies 17 ·
Graduate Studying the formation of the very first stars
- marcus
- · Replies 0 ·
Undergrad Is the Sun's Gravity Enough to Propel Objects to the Corona?
- lubuntu
- · Replies 11 ·
Graduate Black Holes have no gravity below the event horizon? - How can that be?
- Dusty_Matter
- · Replies 19 ·
When will the next naked eye comet appear?
- Stratosphere
- · Replies 12 ·
Undergrad Could the Universe Be Collapsing Without Our Knowledge?
- ONON
- · Replies 3 ·
Undergrad Sir Author Eddington and Einstein's GTR
- plutoisacomet
- · Replies 3 ·
Graduate Can Black Holes Decay and How Does This Affect Their Event Horizon?
- Haibara Ai
- · Replies 4 ·
Fantastic astrophotograpy book now out
- turbo
- · Replies 1 ·
Undergrad Why Is a Single Wavelength Used to Calculate Hubble's Diffraction Limit?
- TheMan112
- · Replies 8 ·
Asteroid 2009 DD45: Close Approach to Earth March 2nd
- Waveform
- · Replies 2 ·
Graduate Does gravitational lensing prevent accurate measurements of cosmic distances and age?
- christian_dude_27
- · Replies 15 ·
Graduate How Do We Know Time, Space, and Matter Were Created in the Universe?
- redhedkangaro
- · Replies 4 ·
Undergrad What would happen to Earth's orbit if it increased in mass or lost velocity?
- GordonDengyo
- · Replies 2 ·
Graduate What will happen to Earth when hit by a Neutron Star at the Speed of Light?
- Zdenka
- · Replies 41 ·
Undergrad Can we photograph a black hole directly?
- dtmmfam
- · Replies 9 ·
Graduate HII regions, on-the-spot approximations
- sarahrose
- · Replies 2 ·
High School Why Aren't Meteors Heated by Friction?
- pixel01
- · Replies 2 ·
High School How gravity make planet to rotate?
- freeman1879
- · Replies 8 ·
High School Is the Orion Skyquest XT8 a good first telescope for planetary observation?
- Charlie G
- · Replies 6 ·
Undergrad Space in an Atom: What is the Nature of this Space?
- vibjwb
- · Replies 3 ·
Graduate Why is k constant in the Friedmann equation?
- wolfram
- · Replies 5 ·
Graduate Is Discrete Scale Relativity the Missing Piece of Einstein's Part III?
- Knecht
- · Replies 2 ·
Stargazing in Georgia: Left or Right?
- kimhen1
- · Replies 3 ·
Graduate Do cosmological maps account for galaxy motion and look-back time?
- discord73
- · Replies 5 ·
Undergrad Can someone explain curved space time?
- Djrob99
- · Replies 7 ·
Graduate Gravity has to have an effect on time,when gravity can curve space ,it
- monty37
- · Replies 8 ·
High School Are There Stars Made of Something Other Than Hydrogen?
- discord73
- · Replies 11 ·
Astrophysicist Jobs: What's Available?
- wiiyogi
- · Replies 2 ·
Undergrad Calculating Orbital Velocity for a Satellite Orbiting Earth
- .:Endeavour:.
- · Replies 2 ·
Graduate How much does dust affect light from high redshift quasars?
- oldman
- · Replies 3 ·
Graduate Accelerating Universe Expansion: Big Bang or Repulsive Force?
- Chalk
- · Replies 2 ·
Graduate Big bang, little bangs, or sontaneous creation?
- Peter Watkins
- · Replies 14 ·
Graduate Is the Cosmic Microwave Background a Picture of the Universe's Past?
- electerr
- · Replies 5 ·
High School Is 2009 Really the Year of Astronomy?
- mjsd
- · Replies 5 ·
Graduate Sun's Corona Paradox: Temperature Defying Laws of Thermodynamics
- Je m'appelle
- · Replies 3 ·
Graduate Can We Detect Moons Around Earth-Sized Exoplanets?
- 888eddy
- · Replies 5 ·
Graduate A Structure Larger than the Sloan Great Wall?
- Petradog
- · Replies 5 ·
Graduate Balloon analogy for relativistic motion in expanding FRW spacetime
- Ich
- · Replies 1 ·
Graduate Could a Moon Be Transformed into a Mini Sun?
- bcohen1
- · Replies 3 ·
High School Do the planets' gravity move the Sun?
- Oscar Wilde
- · Replies 8 ·
Undergrad What is singularity? [Black Hole ]
- jasmine
- · Replies 15 ·
Undergrad Is this the approximate gravity of Mars?
- .:Endeavour:.
- · Replies 3 ·
Graduate How can the Friedmann equation predict energy density if expansion rate varies?
- electerr
- · Replies 3 ·
Graduate Singularity - Black Hole or Naked
- mathman
- · Replies 19 ·
Graduate Converting monochromatic flux between wavelength and frequency
- constellation
- · Replies 1 ·
Graduate Friction in space as approaching light speed
- Jackslap
- · Replies 25 ·
Graduate Observing antiquark annihilation
- gtring
- · Replies 1 ·
Graduate What caused the big bang?
- hadeka
- · Replies 19 ·
Undergrad Is the Red-Shift of Galaxy Spectra Evidence for the Expanding Universe?
- Peter Watkins
- · Replies 6 ·
Undergrad Is the Big Crunch Inevitable in the Fate of Our Universe?
- Ollie_G
- · Replies 3 ·
Graduate Could tying a generator to a distant galaxy create perpetual energy?
- AxelBoldt
- · Replies 19 ·
Undergrad Can Aliens Observe Plato Lecturing in Academia?
- grasp
- · Replies 12 ·
Stargazing Kepler Telescope is so productive?
- pixel01
- · Replies 9 ·
Undergrad Does Physics Predict How the Universe Will End?
- JeffNYC
- · Replies 4 ·
Graduate Universe expansion in 4D spacetime: what does outward mean?
- ronald_dai
- · Replies 1 ·
Graduate How Do Large Galaxy Fluctuations Challenge Standard Cosmological Models?
- wolram
- · Replies 12 ·
Undergrad Why Do Orbits Take an Elliptical Shape?
- koolraj
- · Replies 2 ·
Graduate Friction necessary for planet formation?
- AxelBoldt
- · Replies 3 ·