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 Direction in Space: Do We Launch Straight Up from the North and South Poles?
- elusiveshame
- · Replies 3 ·
High School What is Stellar Flux and How Does it Affect Solar Wind?
- EpicAll Rounder
- · Replies 3 ·
Space Engineers sandbox game discussion
- Greg Bernhardt
- · Replies 1 ·
Graduate Do quantum fluctuation particles create gravitational effect?
- BernieM
- · Replies 11 ·
Graduate Why does surface area of an Event Horizon increase?
- avito009
- · Replies 6 ·
Graduate Sagittarius A* and its event horizon
- EinsteinKreuz
- · Replies 5 ·
Undergrad Is space a fourth-dimensional object that expands?
- SaniT404
- · Replies 7 ·
Graduate Could Dark Matter Be the Source of Anomalous X-ray Emissions?
- jim mcnamara
- · Replies 4 ·
Witnessing Geminids: Slower Meteor Shower Speed
- Jonathan Scott
- · Replies 4 ·
Graduate Physical meaning of max. proper distance at time of emisson
- AlephClo
- · Replies 10 ·
Graduate Entering a black hole theoretically of course
- LightPiercing
- · Replies 26 ·
Graduate How Does Entropy Influence Hawking Radiation in Black Holes?
- avito009
- · Replies 3 ·
Graduate Can you see all timelines of a finite universe from outside it?
- Vivek des
- · Replies 7 ·
Undergrad Energy cannot be created. Then where did it all come from?
- Symmetry777
- · Replies 70 ·
Graduate Why Is the Universe Not Symmetrical?
- Ozgen Eren
- · Replies 39 ·
Undergrad Is the tetrahedron the building block of the universe?
- ben krempp
- · Replies 12 ·
Graduate Accumulated environmental damage to Hubble main mirror
- Ganesh Ujwal
- · Replies 2 ·
Latest Smoothed Sunspot Number posted 8 Dec '14 at SWPC
- Doug Huffman
- · Replies 2 ·
Undergrad Sgr. A* - Mathematical calculations
- AlexNis
- · Replies 5 ·
Graduate Constants linked to the observable universe, not whole
- liometopum
- · Replies 22 ·
Undergrad How to Calculate the Distance Between Mars and Earth?
- MMS
- · Replies 12 ·
Graduate Understanding Horizon Distance in Axion Cosmology Model
- ChrisVer
- · Replies 11 ·
Graduate Disappearance of dark matter since the Big Bang
- !Jon Snow!
- · Replies 3 ·
Graduate Naive Question regarding Galaxy Rotation Curves
- Loudzoo
- · Replies 4 ·
Capturing Stars with Mobile Devices: Fact or Fiction?
- liometopum
- · Replies 5 ·
Graduate Dark Matter and extra dimensions
- CaptDude
- · Replies 12 ·
Undergrad Did Biosphere 2 discoveries inform design of the ISS or other manned spaceflight?
- Ganesh Ujwal
- · Replies 2 ·
Graduate Cosmic rest frame, proper distances and comoving distances
- resurgance2001
- · Replies 1 ·
Can mirrors reflect cosmic rays?
- Physics_Chris
- · Replies 5 ·
Undergrad Why is the Sun's core power density only 276 W/m³ if my calculation gives 3.42×10^7 W/m³?
- stinsonbr
- · Replies 31 ·
Undergrad Why does the Soyuz cover its main engine?
- Ganesh Ujwal
- · Replies 3 ·
Undergrad Why doesn't ISS pass over the polar regions?
- Ganesh Ujwal
- · Replies 1 ·
Graduate Understanding Hawking Radiation: Energy Subtracted from Black Holes
- jaydnul
- · Replies 3 ·
Graduate Why Is Asteroid Composition Highly Varied?
- anorlunda
- · Replies 9 ·
High School Why is the Solar System Flat Instead of Spherical Like Atomic Structures?
- hafiz ns
- · Replies 14 ·
Undergrad Uncertainty of planetary orbital period
- Jack21222
- · Replies 2 ·
High School Why if we put Saturn in water, it will float?
- LeilaTesla
- · Replies 3 ·
Graduate Find the mass of a black hole from just its radius?
- Lamdbaenergy
- · Replies 6 ·
Graduate Field equations Einstein-Gauss-Bonnet action
- Nick2014
- · Replies 4 ·
High School The Fascinating Ponzo Illusion: How Our Brain Distorts the Size of the Moon
- LeilaTesla
- · Replies 1 ·
Graduate Is Inflation the Only Solution to the Homogeneity Problem in Cosmology?
- the_pulp
- · Replies 8 ·
CoffeeShop Astrophysics public lectures in Milwaukee
- Dennis Roscoe
- · Replies 32 ·
Undergrad How Much Declination Do Stars Need for a Luck City at Latitude 35°?
- walter1998
- · Replies 2 ·
Graduate Van Flandern's paper on "Speed of Gravity", question.
- damianpaz
- · Replies 20 ·
Graduate Expanding universe and thermodynamics
- Paul Howard A
- · Replies 30 ·
Undergrad Would We See Solar Events Speed Up While Traveling to the Sun?
- Filip
- · Replies 19 ·
Graduate Why Are We Here Right Now Instead of Billions of Years Later?
- Jeroen Bruijns
- · Replies 10 ·
Undergrad What is the fate of the universe?
- Unnickporser
- · Replies 20 ·
Undergrad Escaping earth's atmosphere with a balloon
- Dead Fish
- · Replies 8 ·
Undergrad What is the correlation between the age and size of the universe?
- somebodyelse
- · Replies 4 ·
Graduate Smolin dispelling false impressions of the singularity
- Doug Huffman
- · Replies 1 ·
Graduate Is the Weyl Curvature Hypothesis a Viable Alternative to Inflation?
- twistor
- · Replies 5 ·
Undergrad Gravitational Binding Energy vs total mass energy
- tacsec
- · Replies 8 ·
High School Does the Solar System spin around an axis and if so where is it?
- Darkan9el
- · Replies 17 ·
Graduate Is Interstellar Travel Possible with Current Propulsion Technology?
- dfinch
- · Replies 3 ·
Best Camera for deep space object
- SpaceNerdz
- · Replies 5 ·
Graduate If spacetime is flat, how can objects orbit in different directions?
- Quds Akbar
- · Replies 13 ·
Graduate How can black holes have electrical charge, and spin?
- Lamdbaenergy
- · Replies 5 ·
Graduate Why does a star explode outward after core collapse rather than oscillate?
- jaydnul
- · Replies 9 ·
Graduate Observational data for evolution of Hubble rate
- Sudesh Kumar
- · Replies 3 ·
Graduate Anything actually physically infinite within the universe?
- camilus
- · Replies 4 ·
High School Understanding Acceleration and its Impact on Time and Velocity - A Question
- Jared Adams
- · Replies 9 ·
Undergrad Why does orbital velocity increase closer to the sun?
- Jimmy87
- · Replies 4 ·
Graduate Could the mass of a singularity be described as an empty set
- Quds Akbar
- · Replies 13 ·
Graduate Relativistic Degrees of freedom g(T)
- ChrisVer
- · Replies 9 ·
Graduate Do you know Dragan Hajdukovic's models work?
- Lino
- · Replies 2 ·
Graduate Are there any particles with all the properties of a WIMP
- Quds Akbar
- · Replies 9 ·
Undergrad A few very specific questions about Venus
- Andy Weightman
- · Replies 3 ·
High School Can we decrese the timegap of space telsecope images?
- Vphysics2013
- · Replies 6 ·
Graduate Apparent Birghtness And Absolute Brightness
- Plutonium88
- · Replies 1 ·
Graduate Detection of motion of non characterised particles
- vin300
- · Replies 4 ·
Graduate Simple thought Experiment, Straight Line between 2 Distant Points
- ricardo81
- · Replies 7 ·
High School Why do planets orbit in ellipses rather than polygons?
- kay
- · Replies 2 ·
Graduate Centrifugal Spaceship Accelerator
- dfinch
- · Replies 1 ·
Graduate Universe's Informational Content and the Big Bang
- ricardo81
- · Replies 13 ·
Graduate Saha equation (experiment verification?)
- ChrisVer
- · Replies 11 ·
Undergrad Van Allen Belt: Why are electrons generally further out?
- gauss44
- · Replies 1 ·
Using gravity to suck matter from a star (Lexx)?
- 04qWIGk3
- · Replies 2 ·
Graduate Does inflation create new space and violate conservation laws?
- Fabio Sachs
- · Replies 4 ·
Graduate Variations Séculaires des Orbites PlanétairesVSDOP87
- Philosophaie
- · Replies 1 ·
Graduate Is there vacuum at the Event Horizon of a Black Hole?
- avito009
- · Replies 1 ·
Undergrad Is matter inside spacetime or part of spacetime itself?
- Watari
- · Replies 1 ·
Graduate Visual perspective at the speed of light:
- Lamdbaenergy
- · Replies 3 ·
Graduate Difference between orbital mechanics and astrodynamics ?
- thor36
- · Replies 2 ·
Graduate Do black holes continuously grow by absorbing matter?
- tonyxon22
- · Replies 20 ·
Graduate Is there any evidence for MACHOs or WIMPs being Dark Matter?
- Quds Akbar
- · Replies 1 ·
Graduate Hawking Radiation From Black Holes:
- Lamdbaenergy
- · Replies 10 ·
Graduate Why stealth technology fails in space
- TrueGormagon
- · Replies 7 ·
Graduate Does superconductivity recreate the vacuum properties of outer space?
- kuro-hi
- · Replies 29 ·
Graduate What determines the mass of a gravitational singularity?
- Quds Akbar
- · Replies 6 ·
Graduate The scale factor in flat FRW model
- TrickyDicky
- · Replies 53 ·
High School About the size, brightness and distance of celestial objects
- tonyxon22
- · Replies 11 ·
High School Why is space cold if the sun radiates energy everywhere?
- Salvador
- · Replies 5 ·
Graduate How to Measure Perpendicular Peculiar Velocity in Galaxy Simulations?
- sketos
- · Replies 7 ·
If you could meet the person who is the authority on brown and white dwarfs
- GiantSheeps
- · Replies 2 ·
Undergrad Can a star with thousands of solar masses be formed?
- nicolauslamsiu
- · Replies 11 ·
High School What is the role of gas density in determining friction in space?
- avito009
- · Replies 5 ·
Graduate What Factors Influence the Density of a Hydrogen Cloud in Space?
- BOAS
- · Replies 3 ·
Graduate Entropy of the initital state of the universe
- revo74
- · Replies 8 ·
Graduate Is Space-Time a Continuum or a Physical Object?
- TrickyDicky
- · Replies 47 ·