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 The Inflationary and The Big Bang Theory
- yazanhomsi
- · Replies 2 ·
High School Presenting to middle-schoolers on black holes - suggestions?
- Ghostcrown
- · Replies 4 ·
Graduate Age of Universe in Planck normalized units
- Filipe Salles
- · Replies 2 ·
Undergrad Why do galaxies rotate in a flat disc and how is angular momentum conserved?
- JohnnyGui
- · Replies 17 ·
Graduate How can we calculate universe diameter at a given time
- Quarlep
- · Replies 40 ·
Undergrad Who First Conceived the Idea of the Cosmological Principle?
- yazanhomsi
- · Replies 3 ·
Undergrad Difference between Cosmology and Astrophysics/Astronomy
- Salman Ranjha
- · Replies 6 ·
Graduate Novel idea for space travel (launch track around the moon)
- udtsith
- · Replies 22 ·
Yay, starting my Astronomy MSc this month
- sunrah
- · Replies 1 ·
Graduate Zwicky's dark matter discovery: how did he determine galactic equilibrium?
- Earnest Guest
- · Replies 1 ·
Graduate Apple and Worm: Patching holes in spacetime game
- diegzumillo
- · Replies 5 ·
Undergrad How Can Empty Space Be Curved?
- Hankb
- · Replies 3 ·
Graduate Why do so many galaxies in a cluster have near zero velocity
- Earnest Guest
- · Replies 2 ·
Graduate Improved MOND Model for Galaxy Cluster Kinematic Data
- Earnest Guest
- · Replies 4 ·
Undergrad I'm not sure where to start with very basic cosmology
- astralarcher
- · Replies 5 ·
Graduate Does dark matter only appear around visible mass in space maps?
- Tony Stark
- · Replies 7 ·
Undergrad Could a personal magnet protect a human from space radiation?
- Algren
- · Replies 6 ·
Graduate The age of the Universe in a denser region of TimeSpace
- gavrosh
- · Replies 9 ·
Graduate Does multiverse really explain fine-tuning?
- abc5
- · Replies 57 ·
Graduate Reappearance of matter from a horizon
- ontodva
- · Replies 11 ·
Graduate Can the Universe's Acceleration be Measured in m/s^2 Instead of m/s/pc?
- H-S-D
- · Replies 5 ·
Graduate Does cosmological expansion affect the Planck length?
- Jimster41
- · Replies 15 ·
Graduate Total mass-energy v nature of forces, particles
- tempus
- · Replies 5 ·
Undergrad How do I assign colors to images by wavelength in Aladin?
- Illogical
- · Replies 7 ·
Simulation of New Horizons arrival day at Pluto
- tony873004
- · Replies 6 ·
Undergrad Elliptical Orbit of Sun Around Milky Way
- iLe0
- · Replies 5 ·
Will Humans ever completely understand the universe?
- Shano
- · Replies 5 ·
Graduate Homogeneity and isotropy in Big Bang model
- Goddar
- · Replies 15 ·
Graduate LCDM Model best value of ##Ω_k##
- RyanH42
- · Replies 9 ·
High School A little solar activity this week
- davenn
- · Replies 2 ·
Undergrad Confusion About the Physics of Orbiting Bodies
- ScientificMind
- · Replies 10 ·
Undergrad Blackbody Radiation and the Inverse Square Law
- ecastro
- · Replies 14 ·
Graduate Cosmic acoustics -- why no intermediate waves on CMB map
- jordankonisky
- · Replies 12 ·
Undergrad Did time have a definite beginning, or is t=0 meaningless?
- Isaac0427
- · Replies 13 ·
Undergrad Can time exist without space and vice versa
- Niaboc67
- · Replies 1 ·
Graduate Why does the dark matter ratio differ between the universe and the Milky Way?
- RyanH42
- · Replies 3 ·
Graduate Implications of SMBH Entropy on DM
- michael879
- · Replies 2 ·
High School Why did the universe expand if it was below its Schwarzschild radius at 20 minutes?
- Stephanus
- · Replies 13 ·
Graduate IceCube sees astrophysical neutrinos
- marcus
- · Replies 7 ·
Jupiter with four moons captured handheld and on tripod
- Glenstr
- · Replies 13 ·
Graduate Is the CMB Data Showing that We are the Center of the Universe?
- abc5
- · Replies 7 ·
Undergrad If the universe is a simulation, on what does it run?
- Stoney Pete
- · Replies 6 ·
Graduate Are We an Early Intelligent Species in the Universe?
- Chronos
- · Replies 3 ·
Graduate Interaction Between Light and Black Holes
- ScientificMind
- · Replies 10 ·
Undergrad Traveling to space aging more slowly is true?
- praveena
- · Replies 11 ·
High School Does Space Really Contain Nothing?
- mklaben15
- · Replies 7 ·
Graduate Over what scale is curvature measurable
- newjerseyrunner
- · Replies 4 ·
RIP Jacob Bekenstein (Black Hole Entropy)
- George Jones
- · Replies 4 ·
Graduate How Does the Casimir Force Relate to the Expansion of the Universe?
- ComaBerenices
- · Replies 1 ·
Undergrad How do we know galaxies are exactly where we see them?
- Armando Valle
- · Replies 7 ·
Undergrad Minimum possible warning for deadly comet/asteroid
- bland
- · Replies 8 ·
High School How to convert Ohms to luminosity?
- Nancee_K
- · Replies 15 ·
Stargazing What is the difference between linear and angular magnitude in telescopes?
- Sobhan
- · Replies 9 ·
Graduate Is there an implied spherical shell mass external to the universe
- Dukon
- · Replies 19 ·
Graduate Acceleration of Universe: centrifugal force?
- petermoose
- · Replies 3 ·
Graduate Hydrogen/Helium Emission Spectra Temperature Dependence
- Albertgauss
- · Replies 2 ·
Graduate Gamma ray bursts (GRB) and distribution of life
- marcus
- · Replies 5 ·
Graduate The metric tensor: definition, equations and properties
- Greg Bernhardt
- · Replies 2 ·
Graduate How do we know everything in the universe is matter? (versus antimatter)
- rumborak
- · Replies 7 ·
Graduate How is expansion manifested physically?
- ash73
- · Replies 33 ·
Undergrad Distances in km/s vs mega parsecs or light years
- BWV
- · Replies 9 ·
Graduate What cosmic "wind" is beign referenced?
- Lino
- · Replies 4 ·
High School Have we ever observed galaxies colliding?
- Sobhan
- · Replies 7 ·
Graduate Can we use counter-rotating rings to generate power on space
- Wilki_22
- · Replies 8 ·
Undergrad Where to start learning cosmology
- Entr0py
- · Replies 12 ·
Ready to Watch the Perseid Shower? Join Me for a Clear Sky Viewing!
- Dembadon
- · Replies 24 ·
Graduate Does Gravity Cause Heat Flow to the Center of the Earth?
- Chas Tennis
- · Replies 4 ·
Graduate Earth mimics supernovae with TGFs. No one knows how.
- Dotini
- · Replies 4 ·
Graduate Is vacuum acceleration directly proportional to distance?
- 69911e
- · Replies 4 ·
High School How is the Big Bang compatible with an infinite universe?
- member 529879
- · Replies 53 ·
Graduate How Far Can We Exclude Alien EM Broadcasts in Our Light Cone?
- BWV
- · Replies 10 ·
How big is an object in empty space?
- =SJ=
- · Replies 19 ·
Graduate Can a micro black hole be created Past the horizon of a large black hole
- jovcevskiigor
- · Replies 13 ·
Undergrad Why isn't the Oort Cloud shaped like a disk?
- GiantSheeps
- · Replies 13 ·
Graduate Expected rate of change, if at all, of nature's constants
- hideelo
- · Replies 4 ·
Graduate Is the equation c²/r²=πGρ_Λ correct for cosmological scales?
- RyanH42
- · Replies 6 ·
High School Solar day and the amount of Earth's rotation
- james gander
- · Replies 5 ·
Graduate What is the edge of the universe and what lies beyond?
- Stephanus
- · Replies 4 ·
High School Questions regarding to the Accelerating universe from Novice
- endless
- · Replies 9 ·
Graduate The too-big-to-fail problem in Milky Way dark matter simulations
- wolram
- · Replies 8 ·
Graduate Primordial gravitational wave constraints from Planck 2015
- Garth
- · Replies 4 ·
Graduate How many Hubble Spheres are in the universe?
- quantumfunction
- · Replies 5 ·
Graduate Is the Universe Flatter Than We Thought?
- Chronos
- · Replies 2 ·
Physical cosmology learning sites
- Entr0py
- · Replies 4 ·
Graduate Why Can't We See Beyond the Cosmic Horizon Despite Observing the Oldest Light?
- yazanhomsi
- · Replies 6 ·
Insights Approximate LCDM expansion in simplified math (part 4)
- Jorrie
- · Replies 14 ·
Graduate What Determines the Fate of Our Universe?
- gianeshwar
- · Replies 9 ·
Graduate Why dark matter distribution is so different in galaxies?
- RyanH42
- · Replies 28 ·
Graduate Questions about black holes and wormholes
- hnn
- · Replies 12 ·
Graduate Dark Matter Primer: Overview and Updates
- wolram
- · Replies 1 ·
Graduate Dark Matter density given specific location
- RyanH42
- · Replies 27 ·
Graduate Dark matter and Antimatter-matter
- RyanH42
- · Replies 12 ·
High School How do scientists determine that distant galaxies exist?
- praveena
- · Replies 11 ·
Graduate Is dark matter distrubition always near galaxies?
- RyanH42
- · Replies 5 ·
Graduate Can silicon burning halt before iron, and what are neutron star mass limits?
- Stephanus
- · Replies 33 ·
Graduate Dark energy and cosmological constant
- yazanhomsi
- · Replies 11 ·
Graduate A Question Regarding Black Holes
- Mkbul
- · Replies 13 ·
Graduate What is math showing inflation solves horizon problem?
- Buzz Bloom
- · Replies 6 ·
Graduate Is R_h=ct a more accurate cosmological model than wCDM/LCDM?
- wolram
- · Replies 7 ·
Graduate Derivation of Gott's formula for size of observable universe
- Buzz Bloom
- · Replies 4 ·