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 If a star is 10 light years away, was it 10 light years away 10 years ago?
- thetexan
- · Replies 12 ·
Graduate Will CMB ever stop being detected on Earth
- Sleve123
- · Replies 7 ·
Graduate Why is Ice More Prevalent in Comets than in Early Planetary States?
- skeleton
- · Replies 2 ·
Graduate Singularity-free oscillatory model of the Big Bang and inflation
- wolram
- · Replies 3 ·
Graduate Thermal statistics in the hot universe
- Accidently
- · Replies 1 ·
Graduate Could a black hole be akin to a tornado in a vacuum?
- TheSnitch
- · Replies 2 ·
Graduate Is there a quanta associated with dark energy?
- ensabah6
- · Replies 1 ·
Undergrad Is the Net Flux from an Isotropic Source Zero?
- ed2288
- · Replies 1 ·
Undergrad Order and harmony vs disorder and chaos.
- revo74
- · Replies 6 ·
Could the entire universe be rotating like a galaxy?
- DarioC
- · Replies 10 ·
Graduate Galaxy Rotation Curves: Impact of Angle on Velocity and Shape
- TrickyDicky
- · Replies 1 ·
Graduate Reversed Gravity: Antigravity Effects on Spacetime
- abuguchie
- · Replies 5 ·
High School Rainbows in Space: Can We See Light Refraction?
- Dave13
- · Replies 1 ·
Undergrad Equation for the sun's apparent path accounting for Earth's axial tilt
- alech4466
- · Replies 2 ·
Gigantic Full Worm Moon this Weekend
- PhanthomJay
- · Replies 17 ·
Undergrad Reasonable mass and surface gravity of fictional planet based on radius
- FtlIsAwesome
- · Replies 15 ·
High School US federal government should increase space exploration beyond the mesosphere
- Khanguy
- · Replies 40 ·
Graduate How can hawking radiation escape?
- revnaknuma
- · Replies 1 ·
Graduate Universe - bubbles of Dark Matter?
- mikewday
- · Replies 9 ·
Graduate Was cosmic inflation just a temporary phase in the early universe?
- bobsmith76
- · Replies 4 ·
Graduate Did Hawking's multiple histories theory break down at Planck scale?
- ajazz
- · Replies 20 ·
Undergrad Jovian Moons: Is a Small Jovian a Moon of a Larger One?
- FtlIsAwesome
- · Replies 1 ·
Undergrad When the sun becomes a black dwarf
- Dremmer
- · Replies 24 ·
Graduate Do wormholes allow for time travel and travel to other dimensions?
- deltabourne
- · Replies 10 ·
Graduate What Happens if a Scale Model of the Sun Weighs as Much as the Real Sun?
- lvanb
- · Replies 3 ·
High School Can you really balance a silver dollar on edge during the vernal equinox?
- Philosophaie
- · Replies 5 ·
Graduate What color would a neutron star appear up close?
- FtlIsAwesome
- · Replies 2 ·
High School Positioning of the artificial satellite
- aqua_s
- · Replies 4 ·
Graduate Is Energy Truly Conserved in an Expanding Universe?
- zeromodz
- · Replies 3 ·
Undergrad Space saver compartments with mechanical crank device
- davidbdix
- · Replies 5 ·
Undergrad Doppler Shift at Right Angles Confusion
- racshot65
- · Replies 7 ·
Graduate Variable light speed and speical relativity
- Mr. Burns
- · Replies 5 ·
Graduate Calculating the Hubble Constant at Different Redshifts
- Epistimonas
- · Replies 3 ·
Graduate Naked singularities and traversable wormholes
- FtlIsAwesome
- · Replies 6 ·
High School Travel in Space: Electric or Fuel?
- Karoka
- · Replies 4 ·
What colors would you see descending through Uranus' atmosphere?
- GoodUniverse
- · Replies 43 ·
Graduate Is the fate of black dwarfs to become neutron stars without proton decay?
- Dremmer
- · Replies 4 ·
High School EDIT: Guys I just need someone to take me under their wing for a
- Cbray
- · Replies 1 ·
Size comparison, from the moon to the largest known star
- Forestman
- · Replies 1 ·
Graduate Evidence for spatial variantion of the fine structure constant
- exponent137
- · Replies 4 ·
Undergrad How did the planets acquire their spin?
- Forestman
- · Replies 30 ·
Graduate When do gravitationally bound objects start separating due to dark energy?
- chris2112
- · Replies 1 ·
Graduate Questions About Time Before the Big Bang
- HMS
- · Replies 98 ·
Graduate Is my analysis of star observations in Orion accurate?
- omoplata
- · Replies 7 ·
Graduate Does the Big Bang Theory Contradict the First Law of Thermodynamics?
- onlyatheory
- · Replies 2 ·
Undergrad Why do retrograde satellites require more velocity than prograde ones?
- luckis11
- · Replies 10 ·
Graduate Pulsating variable star mathematics question
- bcheero
- · Replies 1 ·
Graduate Spherical star in a hydrostatic equilibrium
- ted1986
- · Replies 5 ·
Undergrad Velocity of a star for Doppler Spectroscopy
- skydivephil
- · Replies 2 ·
Graduate The degree of order in the Universe
- revo74
- · Replies 5 ·
Graduate Coliding Galaxies: A Highly Ordered Event?
- revo74
- · Replies 5 ·
Gliese 581g, 20 light-years away
- waht
- · Replies 66 ·
Graduate How did the big bang ever stop being a black hole?
- AdrianMay
- · Replies 43 ·
Graduate Puzzle of scalar dynamic in the early universe
- Accidently
- · Replies 10 ·
High School What would happen if the Earth become completely solid?
- ExNihilo
- · Replies 8 ·
Graduate Is the speed of gravitational field creation equal to its removal?
- sciencecrazy
- · Replies 2 ·
Graduate Calculating Moon's Total Kinetic Energy
- termina
- · Replies 2 ·
Graduate What is the meaning of expansion in Loop Quantum Cosmology?
- TrickyDicky
- · Replies 29 ·
High School How do private space companies make money on exploration?
- Nano-Passion
- · Replies 21 ·
Graduate Measuring Distances Across Billions of Light Years
- superpaul3000
- · Replies 4 ·
Graduate Dark Energy Theory Gets Boost From New Measurements
- Tanelorn
- · Replies 1 ·
Graduate Simulating Galactic Evolution in a Game
- Bob65536
- · Replies 4 ·
Graduate Getting the hubble constant from time delay in a gravitational lens
- cegec
- · Replies 5 ·
First law of thermodynamics and theism
- onlyatheory
- · Replies 1 ·
Graduate Initial state of the Universe (order or chaos)
- revo74
- · Replies 2 ·
High School Movement of spaceships versus spacewalkers
- Animyr
- · Replies 3 ·
Graduate Is a Constant Velocity Dispersion a Solution to the Jeans Equations of Galaxy?
- victoria13
- · Replies 1 ·
Graduate Can we travel between different spacetimes if they exist?
- Dremmer
- · Replies 1 ·
Japan's Seismic Activity Altered the Earth's Axis
- ladykrimson
- · Replies 1 ·
Did the Sun Go Dark Last Night?
- KartAnimal29
- · Replies 13 ·
Graduate Looking for defunct papers/theories
- Beer w/Straw
- · Replies 3 ·
Graduate Requirements for Light Speed Travel (as we understand now)
- wcdrotar
- · Replies 6 ·
Graduate What happens to mass when it approaches the speed of light?
- nukeman
- · Replies 11 ·
Graduate Why Is There More Matter Than Antimatter in the Universe?
- ownedbyphysics
- · Replies 3 ·
Graduate What Energy Sources Could Sustain a Refuge in an Expanding Universe?
- kriku
- · Replies 7 ·
Undergrad A manned mission to Mars and its obstacles
- ladykrimson
- · Replies 5 ·
Graduate Does the Event Horizon of a Black Hole Only Form on the Equitorial Plane?
- Khan Wolf
- · Replies 10 ·
Undergrad How quickly will the Sun expand as it becomes a red giant?
- ladykrimson
- · Replies 22 ·
Undergrad What happens to entropy in a cyclical universe?
- sci-guy
- · Replies 15 ·
Graduate Could All Matter Be Curved Space Itself?
- CosmicVoyager
- · Replies 4 ·
Graduate How does the 'atmosphere' of the sun affect ligth from stars passing behind it.
- BernieM
- · Replies 23 ·
High School Position of stellar bodies in space.
- PrincePhoenix
- · Replies 5 ·
Graduate How do phase shift parameters affect summer solstice date prediction?
- littlewombat
- · Replies 1 ·
Undergrad Could the Big Bang really have happened in an instant?
- cragar
- · Replies 12 ·
Undergrad Is space made up of individual units?
- CosmicVoyager
- · Replies 7 ·
Graduate Can a Maximally Rotating Black Hole be Defined by the Kerr Metric?
- Imax
- · Replies 10 ·
Undergrad How Does the Gravitational Slingshot Effect Propel Objects?
- Ali Asadullah
- · Replies 4 ·
Undergrad Are antimatter and dark matter the same thing?
- pibb
- · Replies 13 ·
Graduate The eccentricity of binary stars' orbits
- shirin
- · Replies 7 ·
Graduate Total radiation flux from a star
- Radu094
- · Replies 4 ·
Graduate Cyclic Universe, Big Rip version
- Dmitry67
- · Replies 11 ·
Undergrad Do Wormholes Exist in Our Universe or Just in Apples?
- abhiroop_k
- · Replies 12 ·
Graduate What is the critical density of the Universe using hubble's constant?
- damasgate
- · Replies 1 ·
Graduate How is Hubble's equations H(t) = 2/3 t^-1 derived?
- damasgate
- · Replies 1 ·
Undergrad Can galaxies separate at speeds faster than the speed of light?
- iamBevan
- · Replies 5 ·
Graduate What is the definition of adiabatic CMb spectrum in simple inflationary models?
- skydivephil
- · Replies 5 ·
Graduate Gravitational properties of event horizons in quantum vs supermassive black holes
- John15
- · Replies 19 ·
Graduate Doesn't the big bang model rule out an infinite universe?
- CosmicVoyager
- · Replies 21 ·
Graduate What Happens Inside a Black Hole Beyond the Event Horizon?
- super_kangaro
- · Replies 16 ·
Graduate Why did space expand at the big bang if all forces neutralized?
- CosmicVoyager
- · Replies 2 ·