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 Responding to a PhD astronomer's claim of scant evidence for the Big Bang
- csmcmillion
- · Replies 19 ·
Graduate Did early galaxies at redshift 10 form in just 45 million years?
- PetTastic
- · Replies 2 ·
Graduate What is information in a black hole
- Astro.padma
- · Replies 12 ·
Graduate How close to constraining DE to simply be Lambda?
- marcus
- · Replies 0 ·
High School Why doesn't tidal force pull earth and moon together?
- AlonsoMcLaren
- · Replies 4 ·
High School Neutron Stars vs Black Holes: What's the Difference?
- jayaramas
- · Replies 4 ·
Graduate Theoretical scenario for star-forming with a calculation
- jcarper
- · Replies 21 ·
Graduate Can cyclical processes be compatible with the second law of thermodynamics?
- bill alsept
- · Replies 82 ·
Graduate What is expansion ? A thought experiment
- matthias31415
- · Replies 22 ·
Undergrad Why most of the galaxies are having two spiral arms only?
- jayaramas
- · Replies 5 ·
Graduate Is New Space Being Created Between Galaxies?
- skydivephil
- · Replies 8 ·
High School Practical uses of Manhattanhenge for a summer science project
- Ironside
- · Replies 3 ·
Graduate What are the main challenges in developing space-based solar power systems?
- shashankac655
- · Replies 2 ·
Graduate Time dilations and our perspective
- bill alsept
- · Replies 2 ·
Graduate Why can we see nearby luminous objects but only see distant supernovae as flashes?
- Alexroma
- · Replies 18 ·
Graduate Soft landiing an asteroid at the south pole
- khoopes01
- · Replies 24 ·
Graduate Universe cyclic model and energy loss
- mtanti
- · Replies 6 ·
Graduate Big Bang Theory and Shape of the Universe
- Vorde
- · Replies 6 ·
Graduate State Space control dervatives of input in B matrix.
- controlboy
- · Replies 1 ·
Graduate Ptolemy reduces to Kepler as Epicycles → ∞?
- Geremia
- · Replies 18 ·
Graduate Age of the Universe - is it meaningful?
- Saddlestone
- · Replies 22 ·
Graduate Geometric entropy in loop quantum cosmology bounce models
- marcus
- · Replies 6 ·
Undergrad Does the universe have a center of mass?
- kahwawashay1
- · Replies 26 ·
Undergrad How is the degree of vacuum in the Universe measured?
- Yuri B.
- · Replies 4 ·
Graduate Using Black holes to view our solar system
- elegysix
- · Replies 1 ·
Graduate Is there any way how to dispove that universe is a computer simulation?
- No-where-man
- · Replies 12 ·
Undergrad Does VLBI use the same formula as question 2 on telescope baseline?
- s3a
- · Replies 6 ·
Graduate Is the Energy of the Universe Really Zero?
- da_willem
- · Replies 20 ·
Graduate Increasing the mass of the moon (via pancake theory)
- Princedragon
- · Replies 5 ·
Graduate Do convective instabilities in supernovae explain the neutron star–black hole mass gap?
- Chronos
- · Replies 11 ·
Stargazing Why are Radio Telescopes less detailed?
- Vorde
- · Replies 5 ·
Stargazing Telescope for my astronomy class next semester
- HeLiXe
- · Replies 2 ·
Graduate Hubble constant depend on expansion model?
- johne1618
- · Replies 3 ·
Graduate Why did the universe expand if gravity was so strong at the Big Bang?
- cragar
- · Replies 4 ·
Graduate Are the Outer Bands of Galaxies Moving Faster Than the Speed of Light?
- DaddyJax
- · Replies 10 ·
Undergrad Our solar system and center of Milky way
- ahmediukas
- · Replies 7 ·
Graduate Failure to calculate equation of time and declination of the sun
- dwaynie
- · Replies 4 ·
Undergrad The Universe: A Mobius Strip of Possibilities?
- infinitea
- · Replies 2 ·
Graduate No Obvious Objects Produce Gamma Rays
- Dotini
- · Replies 3 ·
Undergrad Need a good textbook for astrophysics
- achuthan1988
- · Replies 1 ·
Undergrad Is Hubble Constant Really Constant?
- jayaramas
- · Replies 5 ·
Graduate Those Jets from the poles of black holes
- Daniel Batt
- · Replies 9 ·
Undergrad Newtons of an exploding Supernova
- Physics quest
- · Replies 14 ·
Graduate Buckshot spread pattern in vacuum of space
- scorpiooooooh
- · Replies 8 ·
Undergrad Could an all water planet theorhetically exist?
- larrybud
- · Replies 20 ·
Have I seen the layers of parallel universes.
- datacloud
- · Replies 14 ·
Graduate What happens to a star hit directly by a gamma ray burst?
- Astroboy123
- · Replies 13 ·
Graduate Space-time created ahead of matter - how far?
- Saddlestone
- · Replies 37 ·
Graduate Why Even Talk About Gravitons Even Existing?
- NYSportsguy
- · Replies 43 ·
Undergrad Converting solar and lunar RA/Dec to Earth surface latitude/longitude
- Gannet
- · Replies 14 ·
Graduate Nature of Dark Energy and a cracker in the sand
- Hammer76
- · Replies 21 ·
High School Queen's song '39 - the only pop song about relativity?
- Saddlestone
- · Replies 3 ·
Graduate How do black holes radiate if nothing can escape?
- 2sin54
- · Replies 4 ·
Graduate Parameters in U.S. Naval Observatory's sun equation of time algorithm
- dwaynie
- · Replies 7 ·
Undergrad Why Does Lithium Stay on the Surface of the Sun?
- sawtooth500
- · Replies 4 ·
Graduate How can we know the current state of distant galaxies if we only see their ancient light?
- Ut-Napishtim
- · Replies 10 ·
Graduate Average value of sin(i) in radial velocities (exoplanets)
- cahill8
- · Replies 1 ·
Undergrad Force that the Earth exerts on the Moon
- Poppinkrey
- · Replies 7 ·
Graduate Finding a cosmology presentation topic for my background level
- Cluelessluke
- · Replies 1 ·
Graduate Can we find objects beyond 13.8 billion light-years from the Big Bang?
- shashankac655
- · Replies 26 ·
I'm writing a novel involving worm holes and asteroids/meteors
- Haendelrsz
- · Replies 3 ·
Graduate How realistic is a time compression vacation destination with a high rate?
- nemorosa
- · Replies 11 ·
Graduate Conflict between reionization and the most distant object
- thenewmans
- · Replies 6 ·
Graduate Can Laser-Pushed Solar Sails Achieve Near Light Speed by Circling Back?
- udtsith
- · Replies 9 ·
High School What is a parallel universe and how does it relate to physics?
- VaibhavP
- · Replies 5 ·
Graduate Acceleration of two bodies in circular orbit provided by own gravity
- Ry122
- · Replies 2 ·
Graduate Why the early universe didn't collapse into a black hole?
- shazdeh
- · Replies 18 ·
Graduate State Space Analyis - the 'B' matrix
- phiby
- · Replies 2 ·
Undergrad Could Protons and Electrons Explain the Big Bang's Origins?
- aherrera
- · Replies 7 ·
Graduate Calculation of a planet's mass via wavelengths
- Poppinkrey
- · Replies 2 ·
Undergrad Effects of dark energy on our solar system
- VaibhavP
- · Replies 6 ·
Graduate Why don't some galaxies contain antimatter?
- Delta2
- · Replies 5 ·
Graduate Universe's full cycle: explosion - implosion
- Yuri B.
- · Replies 1 ·
Stargazing Spectra Optics telescope 1400X150 questions
- Gliese123
- · Replies 23 ·
Graduate Why does the moon have apogee and perigee if its orbit is circular?
- Ry122
- · Replies 1 ·
Graduate Proof of Red Shift that indicates Expansion
- Buckeye
- · Replies 26 ·
Graduate Electro-Gravity ideas, Dark Energy
- happienumber
- · Replies 7 ·
Graduate Crab pulsar gamma rays above 100 GeV challenge current models
- Dotini
- · Replies 4 ·
Graduate Do all pulsars have a Pulsar wind nebula?
- StephanJ
- · Replies 1 ·
Graduate What percentage of solar energy is converted to solar neutrinos?
- jayaramas
- · Replies 2 ·
Graduate Cyclic Universe - Fixed in Size but Divided into 8 Sections
- Buckeye
- · Replies 7 ·
Undergrad How do neutrinos behave near a black hole?
- jayaramas
- · Replies 5 ·
Graduate How many dimensions compose reality?
- Duhoc
- · Replies 15 ·
Graduate Dark matter or variable gravity?
- slooper2112
- · Replies 13 ·
Graduate Arp 220 (UGC 9913, IC 4553) and Supernovae
- Astronuc
- · Replies 1 ·
Graduate Why general relativity fails at cosmological scales
- skylark53
- · Replies 10 ·
Graduate Converting spectrum into velocity space
- Piano man
- · Replies 5 ·
Graduate Explanation for gravity and mass?
- IvorGeorge
- · Replies 1 ·
Graduate How Does Earth's Helical Trajectory Affect Its Calculated Speed Through Space?
- TrickyDicky
- · Replies 6 ·
Undergrad Any difference between type 1a supernovae and a novae
- srikar97
- · Replies 8 ·
Undergrad Should space exploration be only the developed world’s adventure?
- shashankac655
- · Replies 113 ·
Undergrad What are the requirements for interstellar travel at different speeds?
- Jon0815
- · Replies 4 ·
Graduate What Are the Flaws in Stenger's Argument on the Origins of Order?
- bobsmith76
- · Replies 3 ·
Graduate Can Regular Matter and Dark Matter Be the Same Thing in Higher Dimensions?
- raid1000
- · Replies 1 ·
Graduate How do I measure the distance of a galaxy using conventional terms?
- Skolon
- · Replies 8 ·
High School Why does the same sun angle look so different between summer and autumn?
- DaveC426913
- · Replies 14 ·
Graduate Greatest cosmic energy detected by Veritas
- TrickyDicky
- · Replies 1 ·
Graduate What is the Geometry of Spacetime Near the Big Bang?
- Imax
- · Replies 17 ·
Graduate How Can I Use the Two-Point Correlation Function to Compare Image Structures?
- mikeph
- · Replies 6 ·
Graduate What causes the sinusoidal waviness in UARS orbital altitudes below 570 km?
- jna
- · Replies 15 ·