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
Can You Spot All the Galaxies in This Virgo Supercluster Photo?
- Andy Resnick
- · Replies 8 ·
Graduate Trajectory opimization: Fast preview algorithm
- Profiler
- · Replies 1 ·
Undergrad Can Kepler's 2nd Law be applied to more than one planet?
- Overt
- · Replies 6 ·
Graduate Other evidences of the Galaxys' Acceleration
- meTheNaive
- · Replies 1 ·
Graduate What does it mean by a flat universe?
- Happiness
- · Replies 13 ·
Undergrad Does the barycenter or the sun sit at the focus in Kepler's first law?
- RisingSun361
- · Replies 1 ·
Graduate Can We Harness Black Holes for Faster Flybys?
- Dr Wu
- · Replies 2 ·
Graduate Four random quasars in a straight line?
- jimgraber
- · Replies 6 ·
Graduate When can globular clusters be considered collisionless?
- kderakhshani
- · Replies 4 ·
Graduate Distances for classical objects vs. photons
- TRB8985
- · Replies 10 ·
Graduate Can you have an antimatter black hole?
- Philjhinson
- · Replies 18 ·
Graduate Friedmann equation reformulated for volume growth rate instead of distance
- marcus
- · Replies 18 ·
Helpful websites about astronomy and cosmology
- Phobos
- · Replies 144 ·
High School Are Galaxies in Hubble Telescope Photos of Clusters?
- synfiniti
- · Replies 2 ·
Graduate Can Anti Matter Galaxies and Black Holes Exist Together?
- Stephanus
- · Replies 12 ·
Graduate Center of mass - cant find error in derivation
- Kyouran
- · Replies 13 ·
Graduate Questions on the Lyman Alpha Profile
- neilparker62
- · Replies 33 ·
Undergrad Can light pressure affect the motion of galaxies?
- nitsuj
- · Replies 3 ·
Graduate Do clocks measure conformal time?
- jcap
- · Replies 5 ·
High School Is Time an Illusion? A 13-Year-Old's Take on the Block Universe Concept
- Canutej24
- · Replies 4 ·
Graduate Conformal symmetry of FRW spacetime
- jcap
- · Replies 1 ·
Undergrad Calculating an Escape from Earth's Gravity: Can It Be Done?
- Salvador
- · Replies 4 ·
Graduate Intuition Behind Scale Invariance Power Spectrum
- center o bass
- · Replies 1 ·
Graduate Penrose's cyclic universe - question
- hammock
- · Replies 2 ·
Graduate Why isn't everything expanding in an expanding universe?
- Happiness
- · Replies 51 ·
Insights Animating Black holes and Singularities - Comments
- edguy99
- · Replies 5 ·
Graduate Killing vectors and momentum conservation
- jcap
- · Replies 13 ·
Undergrad Does the Universe Have its Own Clock and Period?
- Atlas3
- · Replies 30 ·
High School Proof that the moon is closer to Earth than the sun
- Rabbani
- · Replies 33 ·
Undergrad Could you send an object into space completely without fuel?
- rumborak
- · Replies 18 ·
High School Why does the moon appear rotated from Gibraltar to Auckland?
- Andrew1955
- · Replies 17 ·
Graduate Inside the big bang were their other sub big bangs?
- tlain123
- · Replies 4 ·
Graduate Does Chiral EM Asymmetry Imply Matter-Antimatter Asymmetry?
- ohwilleke
- · Replies 2 ·
Graduate Relationship betwen ##Ω_k## and ##k##
- Quarlep
- · Replies 3 ·
Graduate Expanding universe - some thoughts
- Whitefire
- · Replies 13 ·
Graduate Universe density in Hyperbolic Universe
- Quarlep
- · Replies 14 ·
Graduate Litterature on Statistical Homogeneity and Isotropy
- center o bass
- · Replies 1 ·
Graduate Upper bound on the Inflation's e-foldings
- Trifis
- · Replies 3 ·
Graduate CMB , Spherical Harmonics and Rotational Invariance
- center o bass
- · Replies 4 ·
Graduate Referance Frame Calculating Newtonian Friedmann Equation
- Quarlep
- · Replies 18 ·
Graduate What is the cause of space expansion in the universe?
- Stephanus
- · Replies 3 ·
Graduate Gravitational wave E modes: inflation versus recombination
- Frank Einstein
- · Replies 1 ·
Graduate General differential equation solution for Kepler Problem
- Steve Jones
- · Replies 4 ·
Graduate How do galaxies die? Contradictions between two papers
- Novanglus
- · Replies 1 ·
High School Question on Comet 67P tail in Rosetta image
- ehilge
- · Replies 12 ·
Undergrad Where is a supernova at distance modulus 48 compared to the Hubble radius?
- Kairos
- · Replies 27 ·
Undergrad Confirmation on the Effect of Solar Irradiance
- ecastro
- · Replies 7 ·
Graduate Lyman Series Wavelengths - measurement standard?
- neilparker62
- · Replies 0 ·
Graduate Did the universe come from nothing and where is the energy?
- Stephanus
- · Replies 7 ·
Graduate M31 halo paper - question on metallicity
- jim mcnamara
- · Replies 1 ·
Graduate Can we be sure about there was nothing before big bang?
- Lightermahn
- · Replies 5 ·
Graduate Are galaxies accelerating away, and can we feel cosmic acceleration?
- Stephanus
- · Replies 10 ·
Graduate Will the time will eventually stop like a snapshot?
- Lightermahn
- · Replies 2 ·
High School Can two celestial bodies orbit each other eternally without external influence?
- Stephanus
- · Replies 5 ·
Graduate Compatibility of General Relativity with SO(3)
- Ans
- · Replies 3 ·
Graduate In Need of Some (Measurable) Illumination
- Dr Wu
- · Replies 10 ·
Graduate If space is curved, could it be detected
- newjerseyrunner
- · Replies 26 ·
Graduate Is "heavy nothing" already infinite or is it expanding?
- slatts
- · Replies 7 ·
Graduate Does the Universe Have a Preferred Frame of Reference?
- Stephanus
- · Replies 2 ·
Graduate Is the mass of the universe finite (collection of objects)?
- King Solomon
- · Replies 53 ·
Graduate Detecting the presence of other universes
- Happiness
- · Replies 10 ·
Graduate Does Relativity Alter Our Perception of Galaxies?
- Low-Q
- · Replies 5 ·
Graduate How seriously do physicists take Boltzmann brains?
- RyanJones
- · Replies 9 ·
What will happen if our sun color blue?
- Dr.ahmad adnan
- · Replies 15 ·
Graduate Can We See CMB Again If Universe Expands at a Constant Rate?
- CassiopeiaA
- · Replies 15 ·
Graduate Radio astronomical receiving system
- ansenko
- · Replies 5 ·
Graduate Can Dark Energy Be Described as a Force?
- Quarlep
- · Replies 3 ·
Graduate Cosmological model without dark matter or dark energy
- wolram
- · Replies 1 ·
Graduate What's the universe radius function
- Quarlep
- · Replies 10 ·
Graduate Earth's velocity wrt CMB gives the centre of the universe?
- Happiness
- · Replies 3 ·
Undergrad How can I know if two stars came from the same cluster?
- Frank Einstein
- · Replies 4 ·
Graduate Measuring Gravitational Redshift due to Galaxies without GR
- quantumfoam
- · Replies 4 ·
Graduate How Far Can We Detect Faint Celestial Objects Near Our Solar System?
- Dr Wu
- · Replies 6 ·
Graduate Baryon number conservation in early universe when T<m
- karlzr
- · Replies 8 ·
Undergrad Find Radial Velocity of Galaxies
- Quarlep
- · Replies 3 ·
Graduate What if expansion rate of a universe is the speed of light?
- Burtay Mutlu
- · Replies 8 ·
Graduate Could universe expansion result from gravity contracting the cosmic web filaments?
- Scott444
- · Replies 6 ·
Undergrad Is the CMB evidence that we're at the center of the universe?
- ScienceIsFun
- · Replies 6 ·
Graduate Cosmic strings account for primordial SMBH production?
- Chronos
- · Replies 2 ·
Graduate What do E and B mode patterns represent in CMB polarization?
- fairy._.queen
- · Replies 11 ·
Graduate Very Large Halo Around the Andromeda Galaxy
- Tanelorn
- · Replies 3 ·
Stargazing Can I Make My Own 8 Telescope with These Required Instruments?
- Harshil
- · Replies 2 ·
Graduate Can time be a periodic function in GRFE?
- Atlas3
- · Replies 15 ·
Graduate If the universe has a spin, was it causing the similar
- Burtay Mutlu
- · Replies 1 ·
Undergrad Calculating Star and Planet Positions in the Night Sky: A Mathematical Approach
- Harshil
- · Replies 5 ·
Undergrad Is the expansion of the universe similar to an explosion?
- thetexan
- · Replies 10 ·
High School How much energy radiates from Jupiter?
- Ans
- · Replies 4 ·
Graduate Does the total mass plus energy plus gravity equal zero?
- Stephanus
- · Replies 7 ·
Undergrad If we consider the universe as bounded but infinite
- Atlas3
- · Replies 13 ·
Undergrad Gravity moving toward the center of the Sun?
- brains3234
- · Replies 20 ·
Graduate How does a particle's kinetic energy vary with a(t)?
- Buzz Bloom
- · Replies 33 ·
Is there any physicists i could email?
- veronicap
- · Replies 2 ·
Undergrad Expansion of space in our neighborhood
- virgil1612
- · Replies 9 ·
Graduate Finding sources for primordial neutrino density and temperature
- Buzz Bloom
- · Replies 16 ·
Graduate Can the expansion of space affect the speed of light?
- Ghostcrown
- · Replies 4 ·
Graduate Are Krauss's claims in 'A Universe from Nothing' disproven?
- Thomas Moore
- · Replies 13 ·
Graduate Gamow peak and nuclear reaction rate
- wieblinger
- · Replies 2 ·
High School What Would Happen if I Threw My Watch into a Black Hole?
- Emmanuel_Euler
- · Replies 10 ·
Graduate Farthest observable object and how space expands
- Stephanus
- · Replies 12 ·
Graduate Lightcone 1.0 basic redshift article development
- Mordred
- · Replies 14 ·