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 Is the coasting universe consistent with observed comoving recession velocities?
- jonmtkisco
- · Replies 4 ·
Undergrad How do we know that the universe expands?
- kasse
- · Replies 3 ·
Graduate Determinism from least action and minimal state change
- Faith In Reas
- · Replies 10 ·
High School Have you heard anything about AstroTech's low-cost Ritchey-Chrétien scopes?
- chemisttree
- · Replies 4 ·
High School What is the speed of the moon's motion?
- Timoothy
- · Replies 8 ·
Undergrad When is the next 13.00 Local Sidereal Time for a UK observer?
- Ulysees
- · Replies 5 ·
Graduate Accelerating Universe,rate Of Acc Data Needed
- 69911e
- · Replies 2 ·
High School Do other planets have magnetic fields?
- mdnazmulh
- · Replies 10 ·
Graduate How Can Galaxies Move Away from Each Other Yet Still Have Filaments?
- kasse
- · Replies 3 ·
Graduate Assume that on earth we see something 1 billion light years away
- mathman
- · Replies 7 ·
High School Mining asteroids for space construction materials
- Phy6explorer
- · Replies 8 ·
Building Paralleogram Mount/What is the name of this Part?
- Saladsamurai
- · Replies 8 ·
Graduate Why does gravity break down in galactic rotation curves?
- meemoe_uk
- · Replies 7 ·
Graduate How to use the metric formula for a curved sphere in cylindrical coordinates
- Niles
- · Replies 11 ·
Graduate Does the rotating black hole have a double or single photon sphere?
- stevebd1
- · Replies 4 ·
Graduate Question regarding the big bang theory
- kasse
- · Replies 5 ·
Undergrad Microwave radiation proves what?
- boomerang
- · Replies 17 ·
Undergrad Does the Universe have a centre?
- boomerang
- · Replies 15 ·
Undergrad Why Is There Lightning on Venus?
- pixel01
- · Replies 4 ·
High School Why Are All Planets in the Same Plane?
- aetherguy881
- · Replies 8 ·
Where Does the Universe Reside?
- Phy6explorer
- · Replies 6 ·
Undergrad How are mass calculations done in the weightless environment of space?
- nuby
- · Replies 5 ·
Graduate Confirmation of any water on the moon?
- zankaon
- · Replies 1 ·
Graduate Does Dust Scattering Alter the Cosmic Background Radiation Spectrum at z < 100?
- hellfire
- · Replies 1 ·
Undergrad How to Calculate the Flattening of a Rotating Planet?
- natski
- · Replies 11 ·
Graduate Can we use our own Sun to travel through space?
- Blueprint
- · Replies 24 ·
Is cosmology an extension of creation science?
- W3pcq
- · Replies 19 ·
Graduate Does matter expand within spacetime or does spacetime itself expand?
- Opiacy
- · Replies 6 ·
To scale animation of solar system
- nuby
- · Replies 2 ·
Undergrad Why are we still looking at Mars?
- Snazzy
- · Replies 9 ·
Official version of Big Bang 2008
- jal
- · Replies 7 ·
High School Is the earth the centre of the solar system?
- boomerang
- · Replies 2 ·
Graduate Island universe eventually true?
- Loren Booda
- · Replies 6 ·
Graduate Does a black hole have a temperature profile?
- foolosophy
- · Replies 2 ·
Graduate Why doesn't space expand within gravitationally bound systems?
- shelanachium
- · Replies 21 ·
Graduate WMAP cold spot and void in the universe
- cmantzioros
- · Replies 1 ·
Where to Find Free Astrophysics Books Online?
- TheUmer
- · Replies 1 ·
Graduate What's the fastest space pulls apart from itself?
- Chaos' lil bro Order
- · Replies 6 ·
What is the Intriguing Theory of Null Physics?
- stewartcs
- · Replies 10 ·
High School Why do the sun and moon look bigger when rising and setting?
- dane502
- · Replies 5 ·
Graduate Applying the Virial Theorem to Stellar winds
- JimLad
- · Replies 2 ·
Graduate How Do Astrophysicists Measure Solar Mass Loss?
- japam
- · Replies 4 ·
High School Understanding Spectral Index: A Plain Explanation
- Sanjay87
- · Replies 1 ·
Undergrad Can artificial gravity be created without spinning or massive objects?
- Tachyonie
- · Replies 9 ·
Graduate Evidence for the Inflationary Period?
- Chaos' lil bro Order
- · Replies 2 ·
Graduate Does the Cosmic Background Radiation Provide an Absolute Frame of Reference?
- shelanachium
- · Replies 1 ·
Graduate Why Isn't Dark Energy Considered a Fundamental Force?
- kuahji
- · Replies 1 ·
Graduate Logical Positivism versus Cosmology
- lwb
- · Replies 6 ·
Graduate Gravitationally bound, ionized cloud of hydrogen
- Loren Booda
- · Replies 5 ·
Graduate Cauchy horizon in a Kerr rotating black hole
- stevebd1
- · Replies 5 ·
Undergrad Viewing size of Galaxies 7 Billion light years away?
- Remo Aviron
- · Replies 5 ·
Graduate Hardness of Neutronium: Estimating Magnitude
- jquark
- · Replies 5 ·
Graduate Ray of light travelling through universe (applying cosmological principle)
- keks
- · Replies 1 ·
Graduate Is the Accelerating Expansion of the Universe Caused by Energy Conversion?
- Jackrell
- · Replies 11 ·
Undergrad Calculating Fuel Needed for Geosynchronous Orbit
- Inquiring_Mike
- · Replies 9 ·
Graduate Baryon Asymmetry: Why is Matter More Abundant?
- spidey
- · Replies 1 ·
High School How Long Does it Take the Moon to Orbit the Earth?
- hashshashin71
- · Replies 4 ·
Graduate Is the concept of a creator necessary if the universe has always existed?
- Dertulm01
- · Replies 4 ·
Undergrad Early Warning against Killer -Asteroids - current state, ideas
- Oberst Villa
- · Replies 19 ·
Graduate Void expansion rate and cosmic acceleration.
- jonmtkisco
- · Replies 3 ·
Undergrad What is the Significance of a Secular Timescale?
- Simfish
- · Replies 3 ·
Graduate Will dark energy overcome dark matter?
- hobobobo
- · Replies 1 ·
Graduate Dark Matter Detection: Earth's Orbit and Its Interactions with the Solar System
- SF
- · Replies 4 ·
Graduate Question regarding about Ωbaryonic/DM/DE
- hobobobo
- · Replies 7 ·
Graduate Is There Really No Edge to Space, Only an Edge to Time?
- Liger20
- · Replies 17 ·
Graduate Congratulations to all the PF gurus
- meteor
- · Replies 15 ·
Graduate A Theory on the possible fate of the universe
- gabrielh
- · Replies 10 ·
Graduate Black holes, frame dragging and the effect on gravity
- stevebd1
- · Replies 6 ·
Graduate What would happen to time if all movement were parallel?
- Loren Booda
- · Replies 3 ·
Apophis Strikes Earth: Odds still 1 in 45,000
- Brad_Ad23
- · Replies 5 ·
Undergrad How to find data on Earth, planets, motions
- giann_tee
- · Replies 1 ·
Graduate What Are the Different Horizons and Distance Scales in Cosmology?
- hobobobo
- · Replies 7 ·
Undergrad Is the Root 2 Relationship Valid for Orbital Mechanics on the Moon?
- spud three
- · Replies 18 ·
Undergrad How did Hubble identify Cepheid variables in distant galaxies?
- Holocene
- · Replies 6 ·
Undergrad How Do Scientists Measure Distance Using Standard Candles?
- hobobobo
- · Replies 3 ·
Graduate Cosmological models with expansion and global rotation
- wolram
- · Replies 22 ·
Undergrad Ratio between Semi major and Velocity
- phi-lin good
- · Replies 3 ·
Undergrad Rotational Motion of Celestial Body
- Harmony
- · Replies 2 ·
Undergrad Apophis to impact earth in 2036?
- Ivan Seeking
- · Replies 54 ·
Graduate Void phenomenon in galaxy simulations with halo occupation model
- marcus
- · Replies 1 ·
Graduate I Know Why We Will Never Come Across A Wormhole
- sudhirking
- · Replies 2 ·
Graduate What Happens to Time and Space at the Event Horizon of a Black Hole?
- tribdog
- · Replies 19 ·
Graduate Loeb's perspective on emergence of structure
- marcus
- · Replies 3 ·
Graduate Do Laws of Physics Break Beyond the Event Horizon in Kerr Black Holes?
- spidey
- · Replies 4 ·
Undergrad Torque caused by/due to a galaxy's spin
- seroth
- · Replies 1 ·
Graduate How Does Hubble's Constant Relate to Universe Inflation and Horizon Changes?
- hobobobo
- · Replies 2 ·
Graduate Can space expand faster than light during inflation?
- hobobobo
- · Replies 1 ·
Graduate What Happens to Infalling Matter as a Black Hole Evaporates?
- michaeljohn
- · Replies 16 ·
High School What Causes Multi-Colored Stars to Twinkle in the Night Sky?
- NerfMonkey
- · Replies 3 ·
Graduate Can an Earth-like planet have a stable synchronous moon?
- shelanachium
- · Replies 25 ·
Undergrad Will a Toy Top Keep Spinning in Space?
- l0rca
- · Replies 2 ·
Undergrad Orbiting space station is observed to remain always vertically above
- Ed Quanta
- · Replies 6 ·
Graduate Wien's law predicts 10 microns, but Earth's emission peaks at 18 microns
- natski
- · Replies 9 ·
Stargazing Telescope alteration (Russ or turbo-1)
- Saladsamurai
- · Replies 48 ·
Undergrad Will voyager 1 or 2 pass the heliopause
- brett812718
- · Replies 1 ·
Graduate Gravitational attraction of bodies
- Nabeshin
- · Replies 3 ·
Graduate Could a dark matter particle discovery have practical applications?
- leftyguitarjo
- · Replies 1 ·
Graduate Is expansion only a factor in empty space?
- Tbeer
- · Replies 17 ·
Graduate Artificial Stars: Dream or Possibility?
- Antonio Jimenez
- · Replies 4 ·
Graduate Does the light-year distance to the CMB equal the age of the universe?
- CosmiCarl
- · Replies 5 ·