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
High School Would John notice the stick move or the sun go out first?
- Stupid_1
- · Replies 7 ·
Mysterious Martian 'Forests' Discovered
- Arch2008
- · Replies 2 ·
Graduate Does Earth need a giant moon for plate tectonics and mineral cycles?
- Jackobear
- · Replies 4 ·
Undergrad Why is Earth in the habitable zone but not other planets?
- nickwetz
- · Replies 5 ·
Graduate How do we know the universe is expanding from redshifts?
- aib
- · Replies 6 ·
High School The Moon moves away from the earth - Is the theory correct ?
- Bjarne
- · Replies 33 ·
Undergrad Could This Be a Nova or Supernova Seen on Dec 26?
- DMuitW
- · Replies 4 ·
Graduate Yes, that is correct. Thank you for pointing that out.
- aib
- · Replies 6 ·
Graduate The nature of the universe as interpreted quantum information
- Evolver
- · Replies 6 ·
Graduate Can dark matter WIMPs with different spins make degenerate clouds?
- Dmitry67
- · Replies 8 ·
Aurora borealis over India is it possible?
- Cowtipper
- · Replies 7 ·
Graduate Does Universe Pulse? Theory or Naive Guess?
- matt010nj
- · Replies 7 ·
Graduate The speed of sound of the inflaton field
- chronnox
- · Replies 1 ·
What Happens if Gamma Ray Bursts Hit Earth's Ozone?
- noblegas
- · Replies 5 ·
Graduate Seven questions on gravity, spacetime curvature, and universe shape
- DeadLeaf
- · Replies 1 ·
High School Is mathematics the same in other universes?
- Minus1
- · Replies 5 ·
Graduate Matter density in closed/open universe
- fab13
- · Replies 25 ·
Graduate How does a collapsing core become a black hole?
- durand
- · Replies 4 ·
Graduate How Do We Know the Cosmic Microwave Background Radiation Isn't Local?
- anya2
- · Replies 4 ·
Graduate Magnetic diffusivity : significance?
- !kx!
- · Replies 5 ·
Graduate Singularities, dark matter, and dark energy. A connection?
- Psycho0124
- · Replies 4 ·
High School Question: what exactly is a singularity?
- C.Braestrup
- · Replies 4 ·
Graduate Using stars random distribution to determine presence of gravity
- tmh556
- · Replies 3 ·
Graduate Do spiral galaxies appear spiral due to light travel time delays?
- abitdim
- · Replies 9 ·
Undergrad Can massive objects resist a black hole and can light pass through it?
- RustyBullet
- · Replies 12 ·
Graduate Does the Big Bang Model Support Instantaneous Inflation in an Infinite Universe?
- SW VandeCarr
- · Replies 16 ·
Graduate Orbital period decay and gravitational waves
- Ranku
- · Replies 15 ·
Graduate Why not use carbon nanotubes to conduct power up a space elevator tether
- danlgarmstron
- · Replies 9 ·
Undergrad Converting Intensity into magnitudes
- lavenderblue
- · Replies 1 ·
Graduate What is the relationship between information and consciousness in the universe?
- WaveJumper
- · Replies 1 ·
Graduate Neutron Star Collisions: Effects & Stages
- josh_c7
- · Replies 9 ·
Graduate Should the big bang theory be revised after galaxy HUDF-JD2?
- roland
- · Replies 10 ·
Graduate Hartle-Hawking Model (How the Universe Can Appear From Nothing)
- TimBowe
- · Replies 15 ·
High School One question [size of the universe]
- mtasquared
- · Replies 22 ·
Stargazing What is the bottom limit of telescopes and why can't they detect visible light?
- aster79
- · Replies 2 ·
Undergrad Can Black Holes Consume the Entire Universe?
- Aeronaut
- · Replies 2 ·
Graduate Does the Universe's Expansion Affect Time Travel?
- anvesh111
- · Replies 9 ·
Graduate Hubble Ultra Deep Field baby galaxy examination
- aib
- · Replies 7 ·
Graduate Nearby supernova risk discussed by Sigurdsson
- marcus
- · Replies 9 ·
Graduate T Pyxidis Supernova: Energy Release Compared to SN1054
- mheslep
- · Replies 2 ·
Graduate Why is the dark matter to baryonic matter ratio about 5:1?
- BillSaltLake
- · Replies 8 ·
Graduate Does orbital period decay from binary stars emit kinetic or potential energy?
- Ranku
- · Replies 5 ·
Graduate What space does the expanding universe expand into?
- RemoteSensor
- · Replies 2 ·
High School Is the Universe Expanding Without Boundaries?
- ssope
- · Replies 9 ·
Graduate Current CMB photon number density?
- denseguy
- · Replies 1 ·
High School Does the moon cause the flux and reflux of the tides?
- BogMonkey
- · Replies 6 ·
Undergrad How Do We Measure the Size of the Universe?
- paweld
- · Replies 6 ·
Graduate Effects of Magnetic fiedon the Dark Energy and Cosmic String
- pieas
- · Replies 1 ·
Graduate Gravity on the surface of Gliese 581 d
- horseshoe7
- · Replies 19 ·
High School How did universe start to expand
- crazco
- · Replies 9 ·
Fermi Telescope Spots Giant Explosion in Space
- Saturni
- · Replies 21 ·
Graduate How to calculate r.m.s radius of a N-body system?
- luxiaolei
- · Replies 1 ·
High School If the universe is infinite, does it mean that everything exists?
- Richard87
- · Replies 24 ·
Graduate Are Hubble's Sphere and the Universe's Age Coincidentally Similar?
- zeromodz
- · Replies 21 ·
Graduate Do black holes evaporate or go bang ?
- jimw
- · Replies 31 ·
High School See the Diffraction of Moon Light at Night
- pmehnati
- · Replies 3 ·
Undergrad What is inflation in big bang theory?
- edpell
- · Replies 28 ·
High School Paper on the physics of big bang: what should be included
- crazco
- · Replies 5 ·
Graduate Shouldn't All Black Holes Have EM Wave Halos?
- jobyts
- · Replies 1 ·
Possible misenterpretations of the known universe
- MrModesty
- · Replies 3 ·
Graduate A giganitc wavefuntion of the universe = determinism?
- roberto85
- · Replies 15 ·
Graduate Questions about string theory, multiverse, time travel, and black holes
- Sententia
- · Replies 2 ·
Graduate Cellular phones and reverse SETI
- Robot B9
- · Replies 9 ·
Graduate Is a flat universe better imagined as an expanding sphere or a cube?
- Holocene
- · Replies 20 ·
Graduate Does expanding space have a physics basis or is it just a mathematical construct?
- edpell
- · Replies 17 ·
What Are the Different Theories on the Creation of Our Universe?
- jessicadambra
- · Replies 1 ·
Graduate Understanding Magnitude Systems in Extragalactic Imaging
- ian2012
- · Replies 1 ·
Graduate Producing a CCD Image: Corrections, Calibration, Subexposures
- ian2012
- · Replies 2 ·
High School What is the Direction of Orbiting Planets around the Sun?
- albert1993
- · Replies 1 ·
Graduate Distinguishing between flatness
- Ranku
- · Replies 12 ·
Graduate Is a de Sitter universe compatible with dark energy?
- hurk4
- · Replies 7 ·
Graduate If Hubbles constant is decreasing?
- iidartzii
- · Replies 10 ·
Graduate Does any model predict the mass (or total energy) of the observable Universe?
- BillSaltLake
- · Replies 13 ·
Graduate Variation of Density Parameters with Redshift
- cepheid
- · Replies 4 ·
Graduate Accelerating Expansion: Is there a Positive Feedback Loop?
- edpell
- · Replies 1 ·
Graduate Universe expanding or time speeding up?
- CosmologyHobbyist
- · Replies 18 ·
Graduate Does vacuum energy density increase over time?
- Rubix
- · Replies 7 ·
Graduate Cosmological constant or dark energy or vaccum denisty/energy/energy density
- edpell
- · Replies 9 ·
Graduate Why doesn't infalling matter appear to cross the event horizon?
- Paul_Bartosik
- · Replies 7 ·
Graduate Is Space-Time Really a Woven Fabric?
- Darkroman
- · Replies 6 ·
Graduate Thermodynamics in Friedman World Models
- cepheid
- · Replies 2 ·
Graduate Expansion of space and looking back in time
- DARKSYDE
- · Replies 7 ·
Graduate Could dark energy have existed before the Big Bang?
- hurk4
- · Replies 17 ·
Graduate Could the Big Bang be a white hole in a larger universe?
- DaneBramage
- · Replies 8 ·
Undergrad How to calculate the orbit of a minor planet?
- neptunecs
- · Replies 2 ·
Undergrad Why Do Some Galaxies Have Warped Structures?
- Astronuc
- · Replies 5 ·
Undergrad Why is Neptune so difficult to see with the naked eye?
- Count Iblis
- · Replies 5 ·
Undergrad Is dark matter hiding in plain sight?
- mintparasol
- · Replies 38 ·
Graduate Is the Inertial Frame Defined by the Universe's Center of Mass Unique?
- edpell
- · Replies 5 ·
Fat Guy vs Skinny Guy: Universe Size Dependent?
- beeresearch
- · Replies 1 ·
Undergrad Does Gravity Affect Nuclear Reactions in Space?
- comsat
- · Replies 5 ·
Graduate The Conundrum of the Speed of Light and the Expanding Universe
- Emu
- · Replies 4 ·
Undergrad Does the universe have an edge beyond which there's complete vacuum?
- um0123
- · Replies 27 ·
Undergrad Does gravity eventually slow the universe's expansion?
- Cloengaa
- · Replies 3 ·
Undergrad Are LMC, SMC approaching the Milky Way ?
- Widdekind
- · Replies 2 ·
Undergrad Standard tests for qualifying radiation detectors for space
- parazit
- · Replies 2 ·
Graduate Why does gravity cause lower orbit speed at smaller radii?
- Bjarne
- · Replies 18 ·
Graduate Evidence for pre Big Bang physical universe?
- Tiapan
- · Replies 31 ·
Undergrad Death of Mars: How a Volcano Could Trigger Planetary Extinction
- MarsWTF
- · Replies 2 ·
Undergrad Calculating Kinetic Energy for Rotating Planets
- Bjarne
- · Replies 5 ·