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 Scalar field in Expanding Universe EOM
- ChrisVer
- · Replies 13 ·
Graduate Couldn't the universe be finite if Omega =1?
- Athanasius
- · Replies 86 ·
Graduate Ratio of matter to radiation density
- Ranku
- · Replies 6 ·
Undergrad Will the Universe Shrink and Reignite Life?
- vrmuth
- · Replies 21 ·
Graduate Is dimensionless singularity truly dimensionless?
- No-where-man
- · Replies 70 ·
High School Structure of galaxy and the laws behind it
- shivakumar06
- · Replies 3 ·
High School How do clouds and ground charge differences cause lightning during rain?
- shivakumar06
- · Replies 3 ·
Graduate Interaction of three black holes
- shivakumar06
- · Replies 1 ·
Undergrad Can Black Holes Be Broken Apart?
- shivakumar06
- · Replies 2 ·
Undergrad What causes some stars to emit radio waves?
- shivakumar06
- · Replies 1 ·
Undergrad Where Do Electrons Go in the Plasma State of Stars?
- shivakumar06
- · Replies 2 ·
Graduate Is Dark Energy Actually the Pull of Black Holes?
- rhyshanan
- · Replies 8 ·
Graduate Did Matter Exist Before Time? - Hartle-Hawking State
- Mayank_Jha
- · Replies 1 ·
Graduate Properties of Matter in Vacuum (Space)
- sshai45
- · Replies 1 ·
Graduate Gerald Shroeder and the age of the universe
- Onestone
- · Replies 6 ·
Graduate Could Black Holes Expand in Negative Dimensions and Create a Negative Universe?
- swaroop
- · Replies 5 ·
Did anyone see the Beast asteroid fly by Earth today?
- Creator
- · Replies 19 ·
Graduate If equal matter and antimatter formed at the Big Bang, why is there more matter now?
- shounakbhatta
- · Replies 9 ·
What Are Some Recommended Astronomy Books for Laypersons?
- cjackson
- · Replies 5 ·
Graduate The black Hole Wars - Losing Information in the Hawking Radiation
- m_robertson
- · Replies 9 ·
Graduate Simple explanation of the lunar highlands problem
- D H
- · Replies 1 ·
Graduate 2-point correlation functions for curvature perturbations
- WannabeNewton
- · Replies 12 ·
High School Scale and size of the observable universe
- kyphysics
- · Replies 11 ·
Graduate Why matter hasn't unified with spacetime like space unified with time
- Yoozer
- · Replies 2 ·
Graduate Mass required for a closed universe.
- duordi134
- · Replies 16 ·
Undergrad Hubble constant measurement of 222 km/s/Mpc versus the standard 70
- chasrob
- · Replies 6 ·
High School Unidentified Constellation: Deciphering Star Patterns and Their Meanings
- Ritzycat
- · Replies 5 ·
Undergrad Can Black Holes Increase in Mass?
- Nova
- · Replies 5 ·
Graduate Must (Ve) expansion of the universe be C?
- bobie
- · Replies 56 ·
Graduate Implications of the divisibility of time for the study of the big bang
- Toppy123
- · Replies 1 ·
Graduate Final State of the universe 10^ googal plex^ googal?
- biocarb6
- · Replies 1 ·
Simulated Universe: Who or What is the Creator?
- binaryverse
- · Replies 1 ·
Graduate Does lensing explain the Hubble tension and close the universe?
- Chronos
- · Replies 4 ·
Undergrad Will DECIGO launch in 2027 if it's still in proposal stage?
- skydivephil
- · Replies 4 ·
Graduate Numerical Facts about the Milky way's halo
- majormuss
- · Replies 2 ·
Graduate Inclination of Equatorial North Pole relative to Galactic Equator
- fizixfan
- · Replies 8 ·
Graduate Gravitational attraction on the cosmic scale?
- Vincentius
- · Replies 42 ·
Graduate Why does a singularity have to exist?
- eldred
- · Replies 3 ·
Graduate Why Are Statistical Significance Maps Used in Cosmic Ray Anisotropy Studies?
- vaart
- · Replies 3 ·
Graduate Is the Universe's Shape Spherical or Hyperbolic?
- elusiveshame
- · Replies 8 ·
Undergrad Is the CMB a Distorted Image of the Early Universe?
- Doctor
- · Replies 8 ·
Graduate If every event is governed by one or more laws
- iDimension
- · Replies 6 ·
High School 40,000 years taken for light to reach here?
- adjacent
- · Replies 16 ·
Graduate If black holes don't exist then neither does the cosmic horizon?
- nuclearhead
- · Replies 3 ·
Graduate How does BICEP2 evidence affect Penrose's critique of inflation's initial conditions?
- twistor
- · Replies 12 ·
Undergrad What do we exactly mean by space is expanding?
- Yashbhatt
- · Replies 47 ·
Graduate How do you measure redshift z for stars and galaxies?
- bobie
- · Replies 17 ·
Martians observe Mercury solar transit
- Creator
- · Replies 3 ·
Undergrad Is Space Within Atoms Also Stretched by the Big Bang?
- vijayst
- · Replies 25 ·
Stargazing Whats an innovative idea for a nuclear telescope?
- Praetorian
- · Replies 2 ·
How to identify that light in the sky
- Greg Bernhardt
- · Replies 10 ·
Graduate Can someone explain why we need inflation?
- nuclearhead
- · Replies 21 ·
Graduate What if there is no Dark Matter?
- Elizabeth90125
- · Replies 11 ·
High School Focal length short and long. Which to choose?
- Tyrion101
- · Replies 7 ·
Graduate Dark matter distribution around black holes.
- majormuss
- · Replies 5 ·
Stargazing Celestron Powerseeker 60AZ Telescope
- PhysicoRaj
- · Replies 4 ·
Tracking the International Space Station
- Borg
- · Replies 9 ·
Graduate Is Saturn's 63rd Moon Being Born?
- PhysicoRaj
- · Replies 2 ·
Graduate Possible research topics for high redshift galaxies and AGN
- Cptn.Shelly
- · Replies 4 ·
Undergrad Stars Creating Elements Heavier than Iron
- SYahoo
- · Replies 4 ·
High School Can a body in space form a sphere?
- iwant2beoz
- · Replies 14 ·
Graduate A layman with an idea, foolish perhaps
- Deuterium1971
- · Replies 7 ·
Undergrad Voids inside atoms and voids in space?
- Monkey71Miaman
- · Replies 2 ·
Undergrad How can Google Sketchup simulate Sun and Earth movement for seasonal changes?
- thedy
- · Replies 5 ·
Graduate Speed of Light Affecting Objects' Appearances?
- connorp
- · Replies 5 ·
High School Why can the moon block the sun so precisely during eclipses?
- cosmosmike
- · Replies 7 ·
Graduate Rate of expansion of the universe
- TonyB178
- · Replies 4 ·
Graduate Is the expansion accelerating or decelerating?
- Yashbhatt
- · Replies 10 ·
Graduate How Did Scientists Miscalculate the Distance of UDFj-39546284?
- bobie
- · Replies 16 ·
Undergrad Conics and Beyond: Understanding Trajectories in Multiple Gravitational Fields
- Jhenrique
- · Replies 1 ·
Graduate Traces of Theia Found on The Moon
- anorlunda
- · Replies 6 ·
What is your favourite episode of Cosmos: A Space-time Odyssey?
- interhacker
- · Replies 14 ·
High School Kepler-10c mega-Earth is 17 times heavier than Earth
- Greg Bernhardt
- · Replies 3 ·
Undergrad Why is Andromeda redshifted if we're approaching it?
- dm4b
- · Replies 4 ·
Graduate Concordance value of Hubble growth rate (2014)
- marcus
- · Replies 3 ·
Graduate Questions on Hubble's law and Friedmann equation
- kdlsw
- · Replies 2 ·
Graduate Tidal Acceleration and planetary rotation
- AotrsCommander
- · Replies 4 ·
Cosmos: A Spacetime Odyssey 2014 TV series discussion
- berkeman
- · Replies 118 ·
Graduate GRB datasets with redshift and distance modulus measurements
- kosmolog
- · Replies 6 ·
Graduate Is Kolmogorov complexity the only measure of randomness?
- Duhoc
- · Replies 8 ·
Undergrad How long until Earth drifts too far from the Sun as the universe expands?
- kenny1999
- · Replies 13 ·
Undergrad If the universe is expanding, how can 2 galaxies collide?
- Lethal_Firefly
- · Replies 6 ·
Graduate Can Space Curve Without Mass or Energy?
- Duhoc
- · Replies 18 ·
Graduate Information conservation and Big Bang
- anorlunda
- · Replies 18 ·
Graduate Question concerning density of dark energy
- CosmicTheorist
- · Replies 2 ·
High School Is the fabric of space displaced by a mass object in it?
- webboffin
- · Replies 8 ·
Graduate How Does the Velocity of Distant Stars Relate to the Mass of the Universe?
- cosmosmike
- · Replies 2 ·
Graduate Non-anthropic String Theory Landscape and Finite Universes
- twistor
- · Replies 9 ·
Graduate Five Cepheids Detected on the Other Side of the Galaxy
- CygnusX-1
- · Replies 2 ·
Graduate Is the concept of finite mass-energy in the universe outdated?
- Jobrag
- · Replies 2 ·
Graduate Need rebutal for plasma EU theory
- tanzanos
- · Replies 1 ·
Graduate Friedmann's Acceleration Equation
- johnnnyboy92
- · Replies 3 ·
Graduate Could Supermassive Black Holes At The Center Of Galaxies Be Wormholes?
- stevebd1
- · Replies 1 ·
Graduate How does a nebula form from a neutron star
- kdlsw
- · Replies 5 ·
Graduate Is Inflation Eternal Into the Past?
- saleh
- · Replies 4 ·
Graduate DeSitter and AntiDeSitter Universe
- Quantizer
- · Replies 4 ·
Graduate Conservation of Energy in the Universe at Large
- Islam Hassan
- · Replies 13 ·
Graduate Can a Big Rip occur in a flat universe?
- Islam Hassan
- · Replies 3 ·
High School Is Saturn the Night Object in Photos?
- DennisN
- · Replies 20 ·
Graduate Did Electrons Form Before Quarks? Chronology of Universe's Reheating Phase
- avito009
- · Replies 6 ·