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 Another cluster collision shows dark matter separation like the Bullet Cluster
- marcus
- · Replies 21 ·
Undergrad What Would Happen if You Cut the Earth in Half?
- Schoomy
- · Replies 6 ·
Undergrad Finding historical weather data for astronomy observation sites
- natski
- · Replies 7 ·
High School Energy and momentum flux in the sun and Newton's 3rd law.
- Spinnor
- · Replies 2 ·
Graduate How to Fix an Error with the Setup of IDL/Healpix?
- Lyuokdea
- · Replies 1 ·
Undergrad How Far Can a 300 mm Telescope Resolve a Double Star Separated by 10 AU?
- radiosource
- · Replies 1 ·
Graduate Energy density of massive neutrinos
- nicksauce
- · Replies 3 ·
Graduate Calculating Neutrino Binding in Gravitational Potentials
- Spinnor
- · Replies 3 ·
Graduate Cosmologists' claims about brain size and intelligence
- SF
- · Replies 18 ·
Undergrad How would gravity change if Earth rotated faster?
- Warmacblu
- · Replies 22 ·
Graduate A god switchs off the nuclear fires in our sun tonight, do I have to worry?
- Spinnor
- · Replies 7 ·
Graduate Gravity and developments in GR after WMAP 5 year data
- Wallace
- · Replies 42 ·
Graduate How do we accurately measure the speed of light without frames of reference?
- Yadukrishnan
- · Replies 3 ·
Graduate How does special relativity treat past, present, and future?
- Descartz2000
- · Replies 2 ·
Graduate What is the boundary of the observable universe in the Milne universe?
- micomaco86572
- · Replies 5 ·
Graduate Are L4 and L5 Lagrange Points Stable with M1/M2 ≥ 24.96?
- E92M3
- · Replies 1 ·
Graduate The equation of state of radiation
- micomaco86572
- · Replies 5 ·
Undergrad Conflicting estimates for universe size vs observable universe
- Hasu
- · Replies 18 ·
High School Does Altair complete its precession cycle through the zodiac in about 67 years per degree?
- mabs239
- · Replies 11 ·
Graduate I need to shield Earth's Gravitational force.
- frozenguy
- · Replies 1 ·
Graduate Could gravitational waves form interference patterns?
- evanghellidis
- · Replies 27 ·
Graduate Why Do Distant Galaxies Appear Further Apart Than Expected?
- S.Vasojevic
- · Replies 27 ·
Graduate Rigidity of 3D beam structures with closed loops
- topcomer
- · Replies 35 ·
Graduate How Do Photons from Very Old Galaxies Reach the Hubble Telescope?
- bkilkerr
- · Replies 1 ·
Graduate Is Gravitational Shear Limited to Gravitational Lensing?
- beech
- · Replies 1 ·
Graduate Big Bang: Definition of Universe Area
- Pjpic
- · Replies 5 ·
Graduate How Does Time Dilation Impact the Calculated Age of the Universe?
- ravisastry
- · Replies 4 ·
Undergrad How do we date stars by helium production if they form from helium-rich clouds?
- adkinje
- · Replies 17 ·
Undergrad Stars and planets made out of antimatter?
- SpaceGuy50
- · Replies 24 ·
Graduate What are the flaws in this critique of dark matter theory?
- Galteeth
- · Replies 30 ·
Graduate Energy of a mass orbiting a black hole at distance r
- zzzaaaappp
- · Replies 1 ·
Sky Color on Planet Orbiting Zeta Tucanae (F9V, CI 0.576)
- dsisk559
- · Replies 2 ·
Graduate Did the universe expand from a point?
- murrdpirate0
- · Replies 5 ·
High School What Can We Learn About the Zodiac Constellations on October 20th?
- mabs239
- · Replies 3 ·
Graduate How is orbital energy transferred between celestial bodies?
- dschmidt12
- · Replies 4 ·
High School Why do planets of our solar system orbit in rings not spheres?
- Schoomy
- · Replies 2 ·
Graduate Big Bang - No Single point of Expansion
- earamsey
- · Replies 67 ·
Graduate Stuff I always wondered about astrophysics
- FayeKane
- · Replies 51 ·
Graduate Dark energy might be modif'n of GR different from cosmo constant.
- marcus
- · Replies 21 ·
Graduate Cosmic micro-wave background, also cosmic gravitation-wave background?
- Spinnor
- · Replies 8 ·
High School Difference between axial tilt and inclination
- Philosophaie
- · Replies 7 ·
Undergrad Gravitational Attraction: Could Dark Matter be Explained?
- mviswanathan
- · Replies 7 ·
Undergrad How can you estimate mass of star?
- dsisk559
- · Replies 1 ·
High School What is the Law of Gravity and Why Do Masses Attract?
- Bjarne
- · Replies 6 ·
Undergrad Books on Astrophysics/Nucleosynthesis
- bgreer76
- · Replies 1 ·
Graduate Does cosmic microwave background radiation have a preferred direction?
- Mihael@@/&
- · Replies 6 ·
Graduate Understanding Spacetime: Clarifying Misconceptions and the Role of Gravity
- Simon76
- · Replies 1 ·
Undergrad Which textbook explains the CMB temperature calculation?
- micomaco86572
- · Replies 14 ·
Undergrad Does Earth's eccentricity change?
- DaveC426913
- · Replies 6 ·
Graduate Will Black Dwarfs Become Iron Stars in 10^1500 Years?
- SpaceGuy50
- · Replies 9 ·
Graduate Could a supermassive black hole have caused the Big Bang?
- qmpash
- · Replies 27 ·
What would you throw in a black hole?
- Pattonias
- · Replies 59 ·
High School Can Pluto Twinkle Like Stars from Earth?
- Loren Booda
- · Replies 13 ·
Graduate Ellipticals vs. spirals colliding
- Loren Booda
- · Replies 5 ·
New Calculated Trajectory for the Apophis asteroid
- CFDFEAGURU
- · Replies 4 ·
Graduate Did inflation give matter its properties like mass and size?
- Cosmicon
- · Replies 9 ·
Graduate Where do Quantum corrections matter?
- Galteeth
- · Replies 8 ·
High School Does the solar system orbit in a plane or oscillate up and down through the galaxy?
- greyfox
- · Replies 13 ·
Graduate Unit transformation of Cosmological Constant ?
- icarus2
- · Replies 5 ·
Graduate Which of 4 Universe Scenarios Do You Believe In?
- Dmitry67
- · Replies 6 ·
Graduate Antimatter's role in the architecture of the universe
- Carid
- · Replies 36 ·
Undergrad Does the Cosmos Have a Preferred Direction?
- madkid
- · Replies 4 ·
Undergrad Astroid Toutatis year 2012 has effects on Earth and moon
- RT4765
- · Replies 14 ·
Undergrad How is sea level defined when tides constantly change it?
- Philosophaie
- · Replies 10 ·
Undergrad What Is the Weak Field Limit?
- keepitmoving
- · Replies 5 ·
Graduate Why is it customary to assume that the vacuum energy contribution is neglible?
- Galteeth
- · Replies 13 ·
Undergrad What Catastrophe Could Render Earth Uninhabitable in 40-60 Years?
- Steve Walmsle
- · Replies 9 ·
High School If I run towards the cosmic horizon will I see it receding
- xMonty
- · Replies 9 ·
Graduate CFD and MHD methods for astrophysics Ph.D. research
- HossamCFD
- · Replies 15 ·
Graduate How to Plan a Mission from LEO to the Itokawa Asteroid?
- brash
- · Replies 4 ·
Graduate Space Elevator Vehicle: Acceleration After Cable Release
- nuclear tan
- · Replies 3 ·
Undergrad Is Aeronautics the Future for Aspiring Astrophysicists?
- vorcil
- · Replies 1 ·
Graduate How does the event horizon of a Schwarzchild black hole nucleate and develop?
- oldman
- · Replies 22 ·
Graduate Does expansion of space violate conservation of energy?
- S.Vasojevic
- · Replies 31 ·
Undergrad Why do physicists claim the universe came from nothing?
- AdkinsJr
- · Replies 6 ·
Graduate Theoritically how far can one see in the universe
- mviswanathan
- · Replies 29 ·
Undergrad Sidereal Time: Clarifying Contradictory Definitions
- Starproj
- · Replies 1 ·
Undergrad Can Light Really Be Trapped by a Black Hole?
- re-undefined
- · Replies 14 ·
Graduate Gravitational slingshot as a weapon
- fillindablank
- · Replies 9 ·
Graduate Black Hole Energy/Galactic Plane
- NIXSIX5
- · Replies 3 ·
Undergrad Why is it difficult to imagine nothingness and infinity?
- ElaMiNaTo
- · Replies 12 ·
High School Why do planets rotate on their axes?
- kashiark
- · Replies 12 ·
Graduate Is space warped, or is matter expanding?
- Modman
- · Replies 6 ·
Undergrad Does Doppler effect change the energy of emitted light?
- neurobio
- · Replies 11 ·
Graduate Space Expansion: Is Gravity the Cause?
- keepitmoving
- · Replies 2 ·
High School What are the major differences between the 8 planets of our solar system?
- Databank
- · Replies 3 ·
Graduate What size must a black hole be to reverse universal expansion?
- Cosmicon
- · Replies 12 ·
Undergrad Why Are Galaxies Accelerating Away?
- prysdieheer
- · Replies 38 ·
Graduate The Reissner-Nordstrom metric
- Orion1
- · Replies 3 ·
Seeing Earth from space for $148
- Borek
- · Replies 7 ·
Graduate Hypothetical space station orbiting inside a plasma torus
- Pennarin
- · Replies 2 ·
High School Some quesitons about Sun and Earh
- cshum00
- · Replies 5 ·
Undergrad Is there something that Sun actually absorbs?
- looka
- · Replies 16 ·
High School What does it mean when we say the universe is expanding?
- Rubix
- · Replies 5 ·
Undergrad How can I calculate the tilt of the Earth using trigonometry?
- Philosophaie
- · Replies 1 ·
Graduate What can be detected in chunk of vacuum?
- looka
- · Replies 10 ·
Graduate Why does power spectrum is calculated at the radiation/matter epochs?
- chronnox
- · Replies 1 ·
Graduate What happens when two black holes collide?
- Pjpic
- · Replies 31 ·
High School Why do astronauts describe the smell of space as strong, metallic, and unique?
- WhoWee
- · Replies 10 ·
Graduate Problems with big bang theory and cosmological expansion
- PhoenixByrd
- · Replies 26 ·