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 Erosion of comet with Dark Matter.
- daumphys
- · Replies 13 ·
Graduate Where Did the Big Bang Occur?
- hoshang
- · Replies 7 ·
High School Could an ~12ft rocket launch some sort of probe into space
- Turtle^2
- · Replies 19 ·
Graduate Connecting two points in the Universe?
- elsiear
- · Replies 6 ·
Graduate How could the universe arise from vacuum fluctuations?
- girl914
- · Replies 29 ·
Undergrad Is it possible I saw a luminous cosmic ray track?
- jselin
- · Replies 2 ·
Graduate How Can We Quantify Homogeneity in Physical Systems?
- skippy1729
- · Replies 3 ·
High School Why Can't We See Stars Beyond Earth?
- DeepSpace9
- · Replies 13 ·
Graduate Is accelerated expansion creating energy
- friend
- · Replies 14 ·
Undergrad How Long Do Black Holes Last Before Vaporizing?
- thequestioner
- · Replies 9 ·
Undergrad Pluto's New Moon and Potential Collision Risks for New Horizons Probe
- jarroe
- · Replies 6 ·
Graduate Observable universe expansion and macroscale quantum physics
- skepsys82
- · Replies 2 ·
Undergrad How Do You Calculate Angular Separation of Stars Using Different Coordinates?
- TheSource007
- · Replies 3 ·
Graduate Can objects be redshifted to the point of becoming invisible?
- 1MileCrash
- · Replies 1 ·
Undergrad How Does the Gravitational Force Equation Change with 1/r^3?
- nearc
- · Replies 1 ·
RIP - Sally Ride - first American woman in space
- Astronuc
- · Replies 7 ·
Graduate How Did the First Proton Emerge from the Big Bang?
- Alain De Vos
- · Replies 14 ·
Excellent Exoplanet Illustration
- Ryan_m_b
- · Replies 27 ·
Graduate Does the number of galaxies change with time?
- jmd_dk
- · Replies 13 ·
High School Half of moon fluctuates in luminosity and hue randomly, why?
- sonoffeanor
- · Replies 3 ·
Why does the sun appear larger near the horizon?
- tahayassen
- · Replies 4 ·
Undergrad Is the Drake Equation Overestimating Intelligent Life in the Universe?
- Stu21
- · Replies 18 ·
Graduate Could a Star Collapse into a Quark Star Instead of a Black Hole?
- AbsoluteZer0
- · Replies 3 ·
High School Looking further and further into the past?
- pwdrmntainski
- · Replies 2 ·
Graduate Fields permeating spacetime - aether?
- jnorman
- · Replies 3 ·
High School What Is the Diameter of the Observable Universe?
- Myslius
- · Replies 9 ·
Undergrad Does time move faster while measured from space or from earth?
- Rorkster2
- · Replies 10 ·
Graduate If the moon was vapourised, would it recondense or get blown away by solar wind?
- jetwaterluffy
- · Replies 8 ·
Stargazing How Do I Choose the Right Optical Lenses for Building a Telescope?
- DrCy
- · Replies 4 ·
Stargazing Problem about calculating focal length of a telescope
- Blacky&Imy
- · Replies 2 ·
Undergrad Why are galaxies colliding if they all moved outward from the Big Bang?
- Grimstone
- · Replies 24 ·
Undergrad Why don't galaxies and solar systems expand with space?
- Brook
- · Replies 21 ·
Graduate Is Newton's Law a Result of Constant Volumetric Expansion?
- MDEarl
- · Replies 19 ·
Graduate Interstellar Medium Around Sol / Interstellar Ramscoop
- MattRob
- · Replies 7 ·
Graduate Is eternal inflation possible in LQC?
- MathematicalPhysicist
- · Replies 23 ·
Undergrad 10 light years but destroyed 6000 years ago?
- heartyface
- · Replies 7 ·
Graduate Dark matter/Dark antimatter Asymmetry?
- alemsalem
- · Replies 6 ·
Graduate How is energy/matter density distributed through the universe?
- Rorkster2
- · Replies 4 ·
Graduate Why are weakly interacting particles proposed as dark matter candidates?
- someGorilla
- · Replies 3 ·
Undergrad What is the width of the Lagrange points?
- CowedbyWisdom
- · Replies 1 ·
Graduate How much mass does 'Dark Matter' and 'Nothing' (empty space) have?
- Rorkster2
- · Replies 6 ·
Graduate Is the proper distance the shortest distance in FLRW universe?
- andrewkirk
- · Replies 7 ·
Graduate Why Doesn't Dark Energy Expand Galaxies?
- g.lemaitre
- · Replies 30 ·
Undergrad Good Introductory Book/Article to Dark Energy?
- charmander
- · Replies 4 ·
Graduate Proposed dark matter detector - how does it work?
- Roo2
- · Replies 11 ·
Graduate Can Space Expand Faster Than the Speed of Light?
- DARKSYDE
- · Replies 10 ·
Undergrad Do scientists know why planets orbit stars on the same dimentional plane?
- Rorkster2
- · Replies 4 ·
Graduate Why Doesn't the Comoving Hubble Length Always Increase?
- alialice
- · Replies 9 ·
Graduate Size/Mass of a planet needed in order to have a molten core or a magnetic field?
- jarroe
- · Replies 3 ·
Undergrad Speed Of Light In Relation To The Size Of The Universe
- CowedbyWisdom
- · Replies 8 ·
Undergrad When did astronomers determine gas giants lack solid surfaces?
- mopc
- · Replies 4 ·
Graduate Kepler's Equation and its choices
- solarblast
- · Replies 9 ·
High School How many degrees of view is cosmic microwave background?
- Rorkster2
- · Replies 3 ·
Graduate Why doesn't the Big Rip tear apart objects if rulers expand with space?
- weinie
- · Replies 23 ·
High School How do you define a planet's rotation?
- skiller
- · Replies 12 ·
Graduate Where does a neutron star's black body spectrum peak?
- alialice
- · Replies 2 ·
Graduate Major astronomical discovery for a sci-fi film plot
- closecall17
- · Replies 7 ·
Graduate Did all 10^80 particles exist after the first 3 minutes?
- g.lemaitre
- · Replies 15 ·
Undergrad What happens to you if you get pulled into a black hole?
- DrPhy
- · Replies 26 ·
Graduate How is it possible to live past the event horizon?
- spacetimedude
- · Replies 19 ·
Graduate Creating Artificial Gravity for Spacecraft Travel
- Robert_K
- · Replies 5 ·
High School Night sky and supernova questions
- Government$
- · Replies 9 ·
Undergrad How is molecular hydrogen detected?
- JDoolin
- · Replies 95 ·
Undergrad Angular momentum and eccentricity
- Alexrey
- · Replies 2 ·
Graduate Is life the goal of the universe or merely a side effect?
- Graal
- · Replies 17 ·
Graduate Is the universe 13.7 Billion years old? There seems to be a contradiction
- surajt88
- · Replies 48 ·
Graduate An Infinite Lapse of Time is Impossible and Unscientific
- james.goetz
- · Replies 43 ·
High School Pluto's color changes as it makes its closest approach?
- jarroe
- · Replies 1 ·
Jumping into a earthcenter tunnel
- schiz0ai
- · Replies 4 ·
Undergrad Speed through the universe we are moving?
- jarroe
- · Replies 4 ·
Undergrad Why doesn't cosmic expansion affect our solar system?
- Ikon Rahu
- · Replies 37 ·
Graduate What is the system of angular units used by astronomers of Venus?
- kapella
- · Replies 2 ·
Graduate Could we see Earth 75.2 years ago using light from a supermassive black hole?
- kevpatts
- · Replies 6 ·
High School Two bright yellow lights over Connecticut on July 10th
- Aero51
- · Replies 4 ·
Graduate Can Negative Changes in Entropy Occur in the Universe?
- Aero51
- · Replies 26 ·
High School Is the Universe Really Flat and What Lies Above or Below the Earth?
- Erik B
- · Replies 3 ·
Undergrad Is omega = 1.0000... misleading for ideally flat space?
- jerusalem
- · Replies 56 ·
Graduate CERN particle announcement related to dark matter / energy?
- Lino
- · Replies 6 ·
Graduate Why Are Galaxies Rushing Apart According to Weinberg's First Three Minutes?
- g.lemaitre
- · Replies 5 ·
Graduate Other dimensions have been proven .
- jarroe
- · Replies 15 ·
Graduate How accurate can we measure shifts in the EM spectrum?
- Bjarne
- · Replies 11 ·
Undergrad Calculating orbits of moons, when both the planet and star are involved.
- sydan
- · Replies 8 ·
Graduate How Flat is Our Universe Really?
- marcus
- · Replies 5 ·
Graduate Does a Space Warp Bubble Move Through Space or Does Space Move Around It?
- jarroe
- · Replies 3 ·
Graduate Questioning Hubble's Law: Does the Expanding Universe Theory Hold Up?
- khurramc
- · Replies 3 ·
Graduate Cosmological expansion vs. stretching
- Neuroglider
- · Replies 36 ·
Graduate Dark energy related to 10-dimensional universe
- vened
- · Replies 2 ·
Graduate Could the Universe Have Regions of Expansion and Collapse?
- coolcalx
- · Replies 27 ·
Graduate Post big bang matter/energy distribution
- jarroe
- · Replies 2 ·
Graduate Can black holes be disintegrated from a sufficiently powerful explosion?
- Bararontok
- · Replies 34 ·
Graduate Imposssible to see light that left a star 13.4 billion yrs ago
- aboro
- · Replies 20 ·
Graduate Dark Matter - How strong is it at a galaxy periphery?
- Bjarne
- · Replies 1 ·
Graduate Why is a gravitational field negative energy ?
- andrewkirk
- · Replies 5 ·
Undergrad Is gravitational force ever truly zero anywhere in the universe?
- Lino
- · Replies 10 ·
Undergrad How can we observe galaxies beyond 13.8 billion light-years away?
- TheSwamper
- · Replies 7 ·
Graduate Would the universe be the same if it was reset?
- ResolutE
- · Replies 27 ·
Undergrad Calculating distance from redshift
- chris1969
- · Replies 6 ·
Graduate In what sense is the standard model enormously successful
- g.lemaitre
- · Replies 14 ·
Undergrad Dark matter is the thread connecting galaxy clusters
- arabianights
- · Replies 3 ·
Graduate Plotting planetary movements through space
- Rakky
- · Replies 8 ·