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 Skywatcher Skyliner 150P Dobsonian questions
- MartinJH
- · Replies 11 ·
Graduate How Does the Solar Wind's Protective Role Affect Astronomical Observations?
- unerkennbar
- · Replies 2 ·
Graduate What happens when two black holes' event horizons touch?
- mdmaaz
- · Replies 50 ·
Graduate The bounce and many universe theories
- wolram
- · Replies 9 ·
Graduate Are There Other Universes Beyond Our Own?
- revo74
- · Replies 26 ·
Undergrad Could the acceleration of expansion (of the universe) be an optical illusion?
- pdxfetal
- · Replies 7 ·
Undergrad Planets - Effective Temperature vs Actual Temperature
- ExcessRed
- · Replies 2 ·
High School Is it possible to truly escape Earth's gravitational pull?
- nfong
- · Replies 1 ·
Undergrad Can There Be a Stable Figure-Eight Orbit Between Earth and the Moon?
- TheAwkwardEng
- · Replies 1 ·
Graduate Quasars with high redshift in nearby galaxies
- Shenstar
- · Replies 26 ·
Graduate Brian Greene: Hidden Reality Book
- Lino
- · Replies 4 ·
Graduate Can We Identify the Center of Our Expanding Universe?
- Reclamist
- · Replies 13 ·
Undergrad Asteroids and the formation of planets
- Yaymy
- · Replies 3 ·
Finding a quasar image with a blue gamma ray beam from a TV program
- QuarkCharmer
- · Replies 6 ·
Undergrad What Happens if a Supernova's Gamma Rays Reach Earth?
- Shenstar
- · Replies 5 ·
Undergrad Did time move slower in the early universe due to gravitational time dilation?
- Shakes
- · Replies 3 ·
Graduate Ballon expansion vs raisin bread expansion
- enotstrebor
- · Replies 26 ·
Graduate The boundaries between individual universes
- mdmaaz
- · Replies 2 ·
Graduate Computing the halo mass function and the SFH
- matteo86bo
- · Replies 2 ·
Graduate Anti-matter vs matter at creation.
- hakon
- · Replies 15 ·
Graduate Halton Arp's prediction about connected galaxies and redshift
- Yesifeed
- · Replies 75 ·
Graduate Orbital effect of a sudden change to G
- enotstrebor
- · Replies 3 ·
High School Where can I find equatorial coordinates of celestial objects?
- e2m2a
- · Replies 4 ·
High School Position of Sun at noon between the Equator and Tropic of Cancer
- dobry_den
- · Replies 1 ·
Graduate What Are the Best Resources for Researching Dark Energy?
- phys lover199
- · Replies 2 ·
Undergrad Can We Go "Outside the Universe"?
- narrator
- · Replies 29 ·
Graduate Uniform redshift in inflationary model?
- toliynyk
- · Replies 2 ·
Graduate Questions on Redshift, Hubble’s Law, spacetime expansion and the standard model
- johnmartin
- · Replies 21 ·
High School I was watching Stephen Hawking Into the universe and he was talking
- Redwit
- · Replies 12 ·
High School If earths rotation stoped, the moon would be released.
- cvjacques
- · Replies 81 ·
Graduate Can distant galaxies have recession velocities greater than c?
- Alain De Vos
- · Replies 7 ·
Undergrad Perpetual Motion: Is Cosmos an Endless Machine?
- force5
- · Replies 26 ·
Graduate Would Einstein's relativity and physics hold outside our universe or in a multiverse?
- khotsofalang
- · Replies 14 ·
Graduate If gravitation is mediated via particle doesn't it mean thatthis
- vlad777
- · Replies 15 ·
Graduate Equation for the energy of Hawking Radiation
- Uranium235
- · Replies 1 ·
Graduate Does the universe have an overall rotation?
- novop
- · Replies 5 ·
High School What happen to gravity in the center of earth
- jsm6252
- · Replies 12 ·
Graduate Why do scientists believe white holes are impossible?
- Ultrastar 1
- · Replies 63 ·
Graduate Did the basic laws of physics also evolve after BB?
- octelcogopod
- · Replies 2 ·
Graduate Robertson-Walker metric and time expansion
- grelf
- · Replies 54 ·
Graduate Why Do Planets with the Same Orbital Period Have the Same Average Density?
- abcd8989
- · Replies 3 ·
Graduate Does velocity increase gravitation?
- little bang
- · Replies 3 ·
Undergrad How long could it take for the Earth to be in the exact same place as it was?
- SitPlutoSit
- · Replies 7 ·
Graduate Could Dinosaurs Weigh Less Due to Ancient Gravitational Forces?
- Premiummind
- · Replies 9 ·
Graduate Is Our Universe Based on Finite Geometry?
- mikfig
- · Replies 1 ·
Graduate Magnetism and Ampere-Maxwell's law
- e2m2a
- · Replies 7 ·
What is dark matter?
- Cbray
- · Replies 6 ·
Graduate Is LQC compatible with dark energy?
- skydivephil
- · Replies 1 ·
Graduate Chasing the edge of the universe?
- PapaJacky
- · Replies 1 ·
Does peace occur before real space travel ?
- Physics-Learner
- · Replies 94 ·
Stargazing What is the advantage of a binocular telescope (such as the LBT)?
- LBT
- · Replies 1 ·
High School How Long Does Earth Rotate Around the Earth-Moon Barycentre?
- freedom6446
- · Replies 3 ·
Undergrad Emission line in spectrum of a sun
- Kawakaze
- · Replies 1 ·
Graduate What happens if light hits the boundary of an expanding universe?
- Werg22
- · Replies 66 ·
Graduate How do collisions affect the evolution of objects in the Oort cloud?
- mersecske
- · Replies 2 ·
Graduate Matter creation, dark energy, and the possibility of a Big Crunch
- Laotzi
- · Replies 6 ·
High School Clarification needed on attached diagram
- RhodesMedia
- · Replies 10 ·
Graduate Why ignore proton-electron reactions in early universe equilibrium
- Davide82
- · Replies 9 ·
Graduate The Value of the Cosmological Constant
- Chronos
- · Replies 13 ·
Graduate Theorists predicted the big bang to expand faster than the speed of light
- AstrophysicsX
- · Replies 12 ·
Graduate How often do small asteroids reach the Earth's solid surface?
- mersecske
- · Replies 23 ·
Graduate Can a star with a black hole core be stable?
- magic9mushroo
- · Replies 6 ·
Graduate What is the total mass of the heliosphere approximately? And its
- mersecske
- · Replies 1 ·
Graduate How Do CMBR Variations Differ Across Planets?
- db1uover
- · Replies 2 ·
Undergrad Why do different galaxies have different redshifts?
- EMFsmith
- · Replies 1 ·
Undergrad Why does gravity make things spin?
- Tarnix
- · Replies 40 ·
Undergrad How to Calculate Angular Diameter of a Galaxy with a Given Diameter?
- P-Jay1
- · Replies 2 ·
Graduate The properties of light over time/distance
- agent83
- · Replies 4 ·
Graduate Spacetime, like an isometric weather map?
- narrator
- · Replies 2 ·
Graduate Calculating the density of a HII region
- bcx
- · Replies 2 ·
Undergrad What Data is Needed to Understand the Formation of Black Hole Jets?
- LewMcCoy
- · Replies 42 ·
Undergrad Big Bang Theory: Is Everything Energy?
- JeremyL
- · Replies 3 ·
Mars Age Two to Four Million Years?
- joesmith
- · Replies 9 ·
Graduate Will the speed of light change in the Universe's distant future?
- Lost in Space
- · Replies 12 ·
Graduate Space expansion vs. time speeding up
- miselaineeous
- · Replies 1 ·
Graduate Is the Universe's Expansion Rate Actually Slowing Down?
- saywhat
- · Replies 3 ·
Graduate Missing mass found in galaxy filaments
- narrator
- · Replies 1 ·
Undergrad Star density, outside our galaxy
- narrator
- · Replies 11 ·
Graduate Is Dark Energy Tearing Us Apart Atom by Atom?
- Chaos' lil bro Order
- · Replies 2 ·
Graduate When will we be able to image the Oort cloud?
- Loren Booda
- · Replies 1 ·
Graduate Does my Big Bang model of gravitational collapse and explosion match mainstream theory?
- Waddi
- · Replies 13 ·
Graduate Is GRB090429b at the Edge of the Observable Universe?
- Lookup
- · Replies 7 ·
Stargazing Most powerful telescope system of the future?
- Oldfart
- · Replies 31 ·
Graduate Are MERCURY and Swift N-Body codes still in common use?
- zhermes
- · Replies 7 ·
Graduate What are the properties of electron gas in the Sun?
- mersecske
- · Replies 5 ·
Undergrad Is AMS-02 Truly a Game-Changer in Space Exploration?
- SubTachyon
- · Replies 5 ·
Undergrad History of cosmology theories and current research
- narrator
- · Replies 6 ·
High School Why doesn't the Moon spin on its axis?
- RichD
- · Replies 61 ·
Undergrad Distribution of planets material
- mersecske
- · Replies 10 ·
Graduate Cold Dark Matter vs Hot Dark Matter
- cp05
- · Replies 7 ·
Undergrad Do star and H-atom distributions differ in the Milky Way on large scales?
- mersecske
- · Replies 1 ·
Undergrad What does it mean to say the universe is flat?
- albroun
- · Replies 22 ·
Undergrad Atmospheric Surface Pressure and Density
- arakish
- · Replies 1 ·
Undergrad What determines the ratio of asteroid impact rates between Mars and Earth?
- mersecske
- · Replies 4 ·
Undergrad What is the binding energy needed to shatter Earth by asteroid impact?
- mersecske
- · Replies 8 ·
Undergrad Simulation of formation of a solar system
- mersecske
- · Replies 1 ·
Graduate Why Does Angular Diameter Distance Decrease After Redshift z=1.5?
- semiserious
- · Replies 3 ·
Graduate Can we see the Big Bang by looking far enough into space?
- Jussi
- · Replies 4 ·
Graduate Deriving the Relation for Escape Velocity from a Proto-Star Cloud
- trina1990
- · Replies 2 ·
Graduate Cosmological Models Predicting Heat Death of the Universe
- Cosmo Novice
- · Replies 8 ·