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 Is there a drag on Earth caused by its motion relative to the CMB rest frame?
- substitute materials
- · Replies 5 ·
High School Can a photon be made energetic enough to escape a black hole
- Leyzorek
- · Replies 9 ·
Undergrad Great attractor and the CMB dipole
- Chronos
- · Replies 6 ·
Undergrad Matter term in Friedmann’s equation
- Buzz Bloom
- · Replies 12 ·
Undergrad Is the Universe's Contraction Model Too Fine-Tuned to Be Plausible?
- palmer eldtrich
- · Replies 5 ·
Undergrad Why is there no "mid-Atlantic ridge" on other planets?
- Edward Barrow
- · Replies 15 ·
High School Could Planet Nine and black holes be dark matter?
- Physics_Kid
- · Replies 73 ·
High School How Difficult Will It Be to Remove Mars from the Planetary Protection Treaty?
- lifeonmercury
- · Replies 1 ·
Stargazing Handling blown-out bright stars when stacking DSLR sky photos
- sophiecentaur
- · Replies 26 ·
Undergrad When Does the Radiation Epoch Begin with a Scale Factor of ~t1/2?
- PeteSampras
- · Replies 1 ·
Undergrad When we observe distant galaxies, are we measuring their past properties?
- Arman777
- · Replies 15 ·
High School Is background radiation from beyond our galaxy?
- david graham
- · Replies 10 ·
Graduate Can two observers receding at 0.51c from a central observer see each other?
- MassNerd
- · Replies 2 ·
High School Why does Sirius A blink in many colors?
- parshyaa
- · Replies 31 ·
High School Everything is in motion, what is not?
- starseeker
- · Replies 12 ·
High School Can Planets Thrive in Binary Star Systems?
- lifeonmercury
- · Replies 6 ·
Graduate What keeps Rhea stable? Simulation shows Titan-assist escape
- D O
- · Replies 6 ·
High School Why do stars have different masses and maintain equilibrium?
- Brunolem33
- · Replies 8 ·
Stargazing How bright and large would the Sun appear from Pluto
- grandpa2390
- · Replies 4 ·
Undergrad Friedmann Equation Analysis, expansion of the universe?
- SmcWill
- · Replies 3 ·
Undergrad How is entropy defined for cosmological phenomena?
- Stephen Tashi
- · Replies 7 ·
High School Is expansion the same Throughout the Universe
- wolram
- · Replies 8 ·
Graduate Detection of the 3.5 keV line in X-ray observations
- phyzguy
- · Replies 1 ·
High School Is this Saturn photo real or an artist's rendition?
- larry909
- · Replies 9 ·
Undergrad Evolution of the Energy Density Parameters
- Jorrie
- · Replies 19 ·
Undergrad Current values for H0, Ωm, and ΩΛ in the ΛCDM model
- resurgance2001
- · Replies 3 ·
Undergrad Does chaotic inflation involve phase transition?
- Ranku
- · Replies 6 ·
Undergrad Integrating the Friedmann Equations
- Trixie Mattel
- · Replies 1 ·
High School Is The Holographic Universe Theory Gaining Popularity And Why?
- wolram
- · Replies 23 ·
Undergrad What is the Dipole Repeller and How Does it Affect Our Galaxy's Motion?
- Shellsunde
- · Replies 6 ·
Undergrad Is momentum conserved in the entire observable universe?
- Arman777
- · Replies 22 ·
Undergrad How can I have an image in space that I cannot reach out and feel with my hand?
- barryj
- · Replies 7 ·
High School Could Jet Engines Be Used for Space Travel?
- Borrah Campbell
- · Replies 37 ·
Undergrad Einstein's 1917 cosmological constant and static universe model
- Chronos
- · Replies 2 ·
High School Where Can I Find a Barycentric Solar System Ephemeris?
- Dale
- · Replies 4 ·
High School Visibility of Ceres, Uranus, and Neptune with $60 binoculars
- lifeonmercury
- · Replies 3 ·
High School What color would asteroids look if they were on Earth?
- Albertgauss
- · Replies 1 ·
Undergrad Level of unseen elastic scatterings
- snorkack
- · Replies 6 ·
Stargazing Formulas for camera obscura (correct sub forum?)
- Ravensong
- · Replies 3 ·
Undergrad Is proton decay considered in neutron star models (and LHC)?
- jarekduda
- · Replies 16 ·
High School On the post-main-sequence evolution
- Singlau
- · Replies 9 ·
High School Can gravitational lensing delays measure expansion faster than expected?
- wolram
- · Replies 4 ·
High School Why are there different types of supernovae?
- SethUzumaki
- · Replies 2 ·
Graduate Energy scale of Hubble constant for dark energy scalar field
- victorvmotti
- · Replies 8 ·
High School Why is my distance calculation half the standard ruler value?
- Discman
- · Replies 4 ·
Undergrad Electroweak symmetry breaking and quantum tunneling.
- Ranku
- · Replies 12 ·
High School Does the 2LOT rule out an eternal universe?
- orion1977
- · Replies 19 ·
High School Mass and free fall speed under gravity
- Orrin
- · Replies 2 ·
Graduate Lyman-alpha forest: why not Lyman-beta?
- astrolollo
- · Replies 5 ·
Graduate Is inflation self-sustaining through quantum fluctuations?
- Quds Akbar
- · Replies 1 ·
High School Why does Proxima Cen b have only a 1.5% chance of transiting Proxima Centauri?
- jordankonisky
- · Replies 5 ·
Undergrad What would it take to hear the Sun's sound from Earth?
- Gerinski
- · Replies 12 ·
Undergrad Inflation and Gaussian CBR pertubations
- Buzz Bloom
- · Replies 4 ·
High School What is the heaviest element that a star will fuse?
- Aizen
- · Replies 11 ·
High School What would happen if the Moon wasn't there?
- Adamchiv
- · Replies 21 ·
Graduate Why does the distortion zone shrink relative to larger black holes?
- Chris G
- · Replies 8 ·
High School How does Ram pressure kill galaxies
- wolram
- · Replies 6 ·
Graduate Is linear polarization not expected from an astrophysical maser
- TheCanadian
- · Replies 6 ·
Undergrad Different forms of energy density in inflation
- shinobi20
- · Replies 29 ·
Undergrad Rescaling the equation of motion of inflation
- shinobi20
- · Replies 3 ·
High School Does redshift of distant galaxies show they receded faster in the past?
- Alistair Bingham
- · Replies 4 ·
High School Speed of light within a black hole
- nettleton
- · Replies 25 ·
Graduate Throwing gravity and dark energy in the same basket
- #Thomas#
- · Replies 1 ·
High School Venus -- a more attractive target than Mars for human colonization?
- lifeonmercury
- · Replies 10 ·
High School Are There Constellations with Stars Close to Each Other?
- lifeonmercury
- · Replies 16 ·
Undergrad Particle distribution as a function of radius in astrophysics
- MMS
- · Replies 3 ·
Undergrad Are Finite Universe Models Plausible Despite Flat Curvature?
- durant35
- · Replies 2 ·
Stargazing What sort of camera would you use?
- BL4CKB0X97
- · Replies 10 ·
Undergrad Constraints on Dark Matter in the Solar System
- Buzz Bloom
- · Replies 14 ·
Undergrad Can Spacetime be a Reference Frame?
- Arman777
- · Replies 23 ·
Undergrad Why is the DM density near the sun so small?
- Buzz Bloom
- · Replies 2 ·
Undergrad How Does the Lyman Break Drop-Out Technique Identify High Redshift Galaxies?
- resurgance2001
- · Replies 2 ·
Undergrad How to know what proposal to write for observation?
- Phys12
- · Replies 1 ·
High School Is the Universe Inside a Black Hole?
- Will K
- · Replies 28 ·
High School Is the Big Bang Just an Event in an Existing Space/Time Fabric?
- Physics_Kid
- · Replies 1 ·
Undergrad Growing food in space - a 3rd concept
- Al_
- · Replies 1 ·
Undergrad Estimate the number of CMB photons in 0.25-litre
- rano jojo
- · Replies 6 ·
High School Relating Gravitational Field Strength and Mass
- taetae
- · Replies 5 ·
High School How would I calculate how much light is being bent in a certain area?
- Verideth
- · Replies 1 ·
High School Top 3 candidates in our solar system to host microbial life from Earth
- lifeonmercury
- · Replies 6 ·
Undergrad Which is better to colonize: Mars, the Moon, or Deimos?
- Al_
- · Replies 1 ·
High School Why do black holes have infinite density, mass, and gravity?
- science_rules
- · Replies 9 ·
Undergrad Using gravitational lensing to detect dark energy effects
- Chronos
- · Replies 3 ·
Graduate Human behavior and conflict management on long-duration space missions
- houlahound
- · Replies 8 ·
Graduate Chandrasekhar Mass - White Dwarf
- Leonardo Machado
- · Replies 2 ·
High School How will Mars colonists keep time and organize their calendar?
- lifeonmercury
- · Replies 9 ·
High School Do hot Jupiters violate Kepler's laws?
- jordankonisky
- · Replies 4 ·
Undergrad Where did the Dark Energy (or similar mechanism) come from?
- Bolhuso
- · Replies 4 ·
Undergrad Was the big bang singularity infinite in size?
- CaptDude
- · Replies 14 ·
High School Evolving Dark Energy: A Missed Revolution?
- Chronos
- · Replies 1 ·
High School Can human brains visualize higher dimensions?
- Simon Peach
- · Replies 10 ·
Undergrad Qs re dark matter when all baryonic matter is in black holes
- Buzz Bloom
- · Replies 18 ·
Undergrad A multiple-impact origin for the Moon
- Buzz Bloom
- · Replies 3 ·
Graduate Can white dwarfs have iron cores?
- 21joanna12
- · Replies 26 ·
Undergrad Structure of Earth, pressure and density model
- Jenab2
- · Replies 2 ·
Undergrad Why dark matter and ordinary matter account for 96% of the universe's mass
- Johnsmith123
- · Replies 11 ·
Undergrad Why does particle dark matter fit the observations better than modified gravity?
- SD das
- · Replies 3 ·
Undergrad Is the Strange Star's Composition Similar to a Bose-Einstein Condensate?
- FallenApple
- · Replies 1 ·
Undergrad How Can I Graph Hubble Term vs. Inflaton Using Mathematica?
- shinobi20
- · Replies 8 ·
High School Dark matter can be cold warm or hot
- wolram
- · Replies 2 ·