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
Stargazing Best Telescope Under $400: Top Picks and Recommendations for US Shoppers
- Littlejenny
- · Replies 4 ·
Undergrad What force causes planets to orbit instead of colliding?
- Kothar
- · Replies 15 ·
Undergrad What Was the Resolving Power of Green Bank's 300-ft Telescope?
- sbarb25
- · Replies 2 ·
Undergrad Taking picture of stars from weather balloon
- Space_launch
- · Replies 2 ·
Graduate Can a planet around a brown dwarf stay stable for billions of years?
- dysfunction
- · Replies 2 ·
Graduate Cosmic Radiation - how is our sun's speed calculated?
- lenfromkits
- · Replies 2 ·
High School How to estimate the length of a month
- Owen-
- · Replies 5 ·
High School Does an accelerating object in space need a force to stop?
- vanwykm
- · Replies 1 ·
High School Why do planets in a solar system orbit on the same plane?
- Electricblue2
- · Replies 2 ·
Graduate Can black holes allow us to break the speed of light?
- Grimstone
- · Replies 5 ·
High School Understanding Sun Storms: Causes, Intensities, and Time Periods
- 2rashmi1993
- · Replies 4 ·
Do Parallel Universes Really Exist?
- anvesh111
- · Replies 28 ·
Undergrad Is the 14 billion year age of the universe based on observation or assumption?
- Vexa
- · Replies 7 ·
Undergrad What is the chemical makeup of stars and how does it affect their lifespan?
- food4thought
- · Replies 7 ·
Undergrad Water in moon ejecta plume (Lcross report 22 Oct.)
- marcus
- · Replies 2 ·
Graduate Can a much larger universe with continuing inflation explain large-scale structure?
- Tanelorn
- · Replies 4 ·
Graduate Black hole gravational pull vs neutron star ?
- Moviemann345
- · Replies 2 ·
Undergrad Can I Pursue an Astrophysics Masters/PhD in the USA with a Mathematics Degree?
- buddhikapriya
- · Replies 4 ·
Graduate Inflation Theory: Matter-Antimatter Annihilation Concept
- endverse
- · Replies 5 ·
Graduate Period-Luminosity Relationship of Type I Cepheids - Need Better Formula
- Desmos
- · Replies 2 ·
Graduate Must a Hot Jupiter be relatively young?
- jscroft
- · Replies 2 ·
Graduate Is dark energy actually zero-point energy?
- jimjohnson
- · Replies 4 ·
Graduate Testing time dilation with a spinning object in space
- jreelawg
- · Replies 6 ·
High School Does the earth translate around the sun?
- nonequilibrium
- · Replies 7 ·
Graduate Why Do Disk Galaxies Appear to Spin Despite Irregular Redshift Patterns?
- TrickyDicky
- · Replies 8 ·
Undergrad What Are the Competing Theories in Astrophysics: Dark Matter vs MOND?
- Ironside
- · Replies 1 ·
Graduate Galaxy at redshift z=8.6 (the actual paper)
- marcus
- · Replies 1 ·
Graduate How Is the Distance to the CMB Measured and How Does It Relate to Its Structure?
- AutoToAlek
- · Replies 2 ·
Graduate Does the universe need an escape velocity?
- jhe1984
- · Replies 12 ·
Graduate How Do Critical Density and CMB Irregularities Explain the Universe's Shape?
- leatherneckpa
- · Replies 2 ·
CERN scientists eye parallel universe breakthrough
- Gaius Baltar
- · Replies 2 ·
Stargazing Increasing the resolving power of a telescope
- Idoubt
- · Replies 1 ·
High School Could Gliese 581 Be Our Next Habitable Planet?
- AfRoMaNn
- · Replies 2 ·
Undergrad How is measuring Redshift possible?
- timbreman
- · Replies 8 ·
High School Ideas for High School Astrophysics Course Syllabus
- kungfuscious
- · Replies 8 ·
Undergrad Signal reception interval for starship traveling at 0.8c to Alpha Centauri
- Aurealis
- · Replies 7 ·
Graduate What are the limits of interstellar travel?
- skippy1729
- · Replies 44 ·
Undergrad *Quick moon question - (about orbit)
- nukeman
- · Replies 6 ·
Undergrad Formation of Stars: How Gas Spins to Fuel Birth
- Sniperman724
- · Replies 2 ·
Undergrad Is this angular size calculation correct?
- nukeman
- · Replies 1 ·
Undergrad Universe Origin: How Could Galaxy be 13B Light Years Away?
- Trimike
- · Replies 1 ·
Graduate Does gravitational time dilation affect stellar redshift measurements?
- temoisio
- · Replies 10 ·
Graduate Superstring Cosmology: Compactifying 7 Dimensions
- Kevin_Axion
- · Replies 5 ·
Undergrad How do I normalize the likelihood distribution?
- aymer
- · Replies 8 ·
Undergrad Is the Big Bang Theory Debunked?
- phoenixthoth
- · Replies 55 ·
Stargazing Pictures I took at a 2.5m telescope in the Canary Islands
- kungfuscious
- · Replies 1 ·
Undergrad Do wormholes exist and can they be created?
- 2rashmi1993
- · Replies 6 ·
Graduate Could Dark Energy be Caused by a Slow Shift in the Base State?
- Upisoft
- · Replies 3 ·
Undergrad Calculating the Earth-Sun distance during perihelion
- nukeman
- · Replies 9 ·
Graduate Inflation and initial conditions
- skydivephil
- · Replies 2 ·
Graduate What happens when a medium elliptical galaxy collides with a dwarf elliptical?
- TrickyDicky
- · Replies 2 ·
Stargazing What is the Best Catadioptric Telescope for Portability and Versatility?
- procq
- · Replies 4 ·
Undergrad Greenwich Mean Timt, GMT and Universal Coodinated Time, UT
- Philosophaie
- · Replies 2 ·
How do I protect an astronomy idea from being taken by others?
- nukeman
- · Replies 16 ·
Undergrad Are the crossed objects in the Hubble Ultra Deep Field nearby stars or distant galaxies?
- AdkinsJr
- · Replies 3 ·
Stargazing Heyy, i've had a telescope before and know how to use them.Has
- nickthrop101
- · Replies 3 ·
High School Is Earth’s orbit far from circular?
- nukeman
- · Replies 1 ·
Stargazing What Are the Best Telescope Models Within the £100-£250 Range?
- nickthrop101
- · Replies 1 ·
Graduate Faster than Light Travel Side Effects
- Ultrastar 1
- · Replies 17 ·
Undergrad Black holes giving birth to stars?
- discord73
- · Replies 1 ·
Graduate How Do Stars Achieve Their Massive Sizes?
- discord73
- · Replies 1 ·
Graduate What are the Current Main Research Topics in Astrophysics?
- ahmadfadl92
- · Replies 1 ·
High School Shading moon phases as viewed from space above the North Pole
- nukeman
- · Replies 13 ·
High School Is the Waning Crescent Visible Near the Horizon?
- nukeman
- · Replies 4 ·
High School What would happen if you fell into a black hole?
- wangdang
- · Replies 5 ·
Undergrad How would tides change if the moon were twice as far away?
- kay89
- · Replies 11 ·
Stargazing Aug 21st, 2017, a total solar eclipse will cross the US
- Ivan Seeking
- · Replies 29 ·
Graduate Dark matter and keplerian revolution
- TrickyDicky
- · Replies 19 ·
High School The Grand Design - Stephen Hawking and Leonard Mlodinow
- yarixen
- · Replies 5 ·
Graduate What Causes Hypervelocity Stars to Eject from Black Holes?
- shnazzybox
- · Replies 1 ·
Graduate How do I find Earth's motion with gravity from both the Sun and Mars?
- Sakriya
- · Replies 12 ·
Undergrad Calculating Gravities for Math to the Moon
- nution
- · Replies 2 ·
Undergrad From physics how can we figure out how old the earth and the universe is?
- dcderek24
- · Replies 7 ·
Graduate Can a "Dead Universe" be Revived?
- geordief
- · Replies 8 ·
Undergrad Astrometry and Elliptical orbits
- Mu naught
- · Replies 4 ·
Graduate How is the Final Velocity of Star Movements Calculated?
- lenfromkits
- · Replies 1 ·
Undergrad Can We Reach the Moon with a Slow, Steady Launch?
- nution
- · Replies 9 ·
Undergrad How Can We Determine the Size of a Black Hole?
- fillipeano
- · Replies 4 ·
Undergrad Could Heat Exchange Be the Reason Behind Earth's Spin?
- JamiePocock
- · Replies 3 ·
Undergrad Strange wikipedia entry about the sun's core
- Fanaval
- · Replies 3 ·
Graduate The infinite possobilities presented by the infinite amount of probabilities
- dr.probable
- · Replies 14 ·
High School Why are solar eclipses so short compared to lunar eclipses?
- nukeman
- · Replies 3 ·
Graduate Negative pressure and dark energy
- relativityfan
- · Replies 10 ·
Graduate Why smaller particles come together
- A Dhingra
- · Replies 6 ·
Graduate Colliding Black Holes: Will the Smaller Get Pulled In?
- Worzel
- · Replies 4 ·
Undergrad Define/explain this gravity calculation (picture)
- nukeman
- · Replies 4 ·
John Huchra Dies at 61; Maps Altered Ideas on Universe
- diogenesNY
- · Replies 1 ·
Graduate Can FLRW metric be taken to describe stretching in time rather than space?
- themos
- · Replies 2 ·
Graduate Quasar Alignment to Cosmic Strings
- Kevin_Axion
- · Replies 5 ·
Graduate Expanding present time formula for matter-dominated universe at Ω₀ = 1
- knightq
- · Replies 8 ·
Graduate Can a QM/GR overlap provide a breakthrough in understanding gravity?
- Ran out of sp
- · Replies 3 ·
Undergrad How can all galaxies see other galaxies if some started on the outer edge?
- jimjohnson
- · Replies 5 ·
Graduate What caused the expansion of the universe for the 1st 7 billion years?
- mysearch
- · Replies 10 ·
Graduate What is the relationship between mathematical structures and real existence?
- PhanthomJay
- · Replies 8 ·
Graduate Is the Expansion of the Universe Driven by Mass?
- wolram
- · Replies 22 ·
Graduate What is the energy of the galactic magnetic field? (E/c^2)
- MTd2
- · Replies 1 ·
Graduate Plotting Intensity in Airy Pattern of Telescope - 1D
- theneedtoknow
- · Replies 1 ·
Graduate Is the cosmological constant a ratio of dark energy to gravity?
- Ikoro
- · Replies 18 ·
Graduate Testing Newtonian gravity with NGC 1851 and NGC 1904
- inflector
- · Replies 19 ·
Graduate If Big Crunch = True, then Reincarnation = True?
- SeventhSigma
- · Replies 18 ·