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 Time from big bang / size of universe
- Pjpic
- · Replies 5 ·
Stargazing Why Not Leave Hubble in Space Until It Fails?
- Majo18
- · Replies 2 ·
Graduate Gravitational Lensing or Inferior Mirage?
- 6nqpnw
- · Replies 3 ·
High School Are Phantom Planets Counterbalancing Our Solar System?
- scott_sieger
- · Replies 14 ·
Graduate Instead of a space elevator a well
- brad50
- · Replies 12 ·
Undergrad Are Sedimentary Layers the Cause of Banding on Asteroid Vesta?
- DoggerDan
- · Replies 2 ·
Undergrad Light in intergalctic space/ voids
- JLA727
- · Replies 5 ·
Graduate A Problem with (Almost) Universal Red Shift
- jaston
- · Replies 3 ·
Graduate Lower mass limit for neutron stars?
- Reedbeta
- · Replies 5 ·
Graduate Why dark matter can not collapse into a blackhole?
- magnetar
- · Replies 6 ·
Graduate Is the Motion of Dark Matter Subhalos Random or Patterned?
- kadiliissaar
- · Replies 1 ·
Graduate Could the Moon be the cooled remains of a planets core?
- Jack23454
- · Replies 10 ·
High School First orbit of an asteroid this month (around Vesta, with ion drive)
- marcus
- · Replies 9 ·
Graduate Thermal sunyaev-zeldovich effect
- as_if_iqbal
- · Replies 1 ·
Graduate Inflation and entropy as information explain past hypotesis?
- matteo210
- · Replies 6 ·
Graduate Can someone explain to me exactly what is meant by vanishing dimensions theory?
- L.J.Tibbs
- · Replies 1 ·
Graduate Dimensions that are not space dimensions nor time dimensions.
- Dremmer
- · Replies 14 ·
Graduate Z ~ 1.6; star formation and angular diameter distance peak coincidence?
- zhermes
- · Replies 1 ·
New Mars rover launch 2011 (Curiosity, YouTube, eta August 2012))
- marcus
- · Replies 3 ·
Graduate Alfven Waves Drive Coronal Heat + Solar Wind
- Dotini
- · Replies 2 ·
Graduate How Does Pressure Influence Nebulae in N-Body Simulations?
- NeuroFuzzy
- · Replies 1 ·
Graduate Predicting the Location of a Star Within an Image
- tentheory
- · Replies 1 ·
Undergrad How much force is needed to move a planet.
- Debt
- · Replies 11 ·
Undergrad Pluto's new moon discovered in July 2011
- Drakkith
- · Replies 8 ·
Graduate Vacuum Energy: Gravitational Attraction or Repulsion?
- tenchotomic
- · Replies 2 ·
Graduate What is the significance of water vapor around distant black holes?
- JonDE
- · Replies 5 ·
Undergrad Kronberger 61 and Planetary Nebulae
- Astronuc
- · Replies 1 ·
Undergrad Can we ever explore distant star systems given the speed of light limit?
- adilsyyed
- · Replies 24 ·
High School Why have we just noticed an asteroid in Earth's orbit?
- Neandethal00
- · Replies 16 ·
Undergrad Is weightlessness in orbit just a result of horizontal velocity?
- ranjit_k
- · Replies 7 ·
Stargazing Which are the top telescope producers
- Ahmadsh
- · Replies 10 ·
Graduate Super Novae and emission of electromagnetic waves and gravitation wavefronts
- hammock
- · Replies 22 ·
Graduate What is the Significance of the K Line of Ca II in 1934POMic?
- venkypunjabi
- · Replies 1 ·
Graduate Detecting a Dipole in the Handedness of Spiral Galaxies at Redshift z ~ 0.04
- bcrowell
- · Replies 5 ·
Graduate Why is fine-tuning considered a problem if life has no physical significance?
- laifuthegreat
- · Replies 3 ·
High School Space Expansion/Time Travel (#IMAN00B)
- Fluxhavok
- · Replies 3 ·
Graduate Cosmic horizon of 42-billion light-years?
- MACHO-WIMP
- · Replies 1 ·
Graduate Would a Deimos/Phobos orbital resonance affect Mars?
- barycenter
- · Replies 1 ·
Graduate Why is there no consensus on the big rip?
- zeromodz
- · Replies 13 ·
Graduate CMB, The Horizon Problem and a comment on BH's
- superg33k
- · Replies 36 ·
Graduate Observational evidence for bottom-up structure formation
- ad510
- · Replies 2 ·
Undergrad How to Get Intense Light Star for Spectrum Analysis
- sadegh4137
- · Replies 2 ·
Graduate Do we see galaxies the way they really are ?
- nomisrosen
- · Replies 12 ·
Graduate Can quantum observation explain the fine-tuning of universal constants?
- Thedirtpoet
- · Replies 6 ·
Graduate The Big Bounce and the Parity Problem
- JonDE
- · Replies 8 ·
Undergrad Stefan-boltzmann solved for temperature?
- ~jet
- · Replies 8 ·
Undergrad Illuminated fraction of the Moon
- JeffOCA
- · Replies 5 ·
Graduate What causes the cold spot in the cosmic microwave background?
- Gravitons
- · Replies 32 ·
Stargazing Observing the sun with Newton telescope
- Alain De Vos
- · Replies 10 ·
Undergrad How long does sunlight take to reach over a semicircular hill?
- alankar
- · Replies 10 ·
Graduate How Can Redshift be Expressed as a Function of DM in an Empty Universe Model?
- Aztral
- · Replies 35 ·
Graduate What is the impact of light particles on the universe's weight and energy?
- YoungDreamer
- · Replies 8 ·
Undergrad ET phone home or anywhere really
- deathtical
- · Replies 14 ·
Graduate What do the colors and bright line in the Planck CMB image represent?
- YoungDreamer
- · Replies 9 ·
Graduate Moving Phobos to join Deimos for single moon.
- barycenter
- · Replies 53 ·
Undergrad If motion is relative, were both geocentric and heliocentric models right?
- Swapnil
- · Replies 17 ·
Graduate Our Universe Is A Closed Electron In A Far Grander Universe We Can Never See?
- Silverbackman
- · Replies 20 ·
Undergrad The universe is expanding wait, really?
- SuperM4ssive
- · Replies 5 ·
Undergrad If the universe is infinite, does that mean that everything exists somewhere?
- Richard87
- · Replies 145 ·
Graduate Bayesian analysis of abiogenesis probability given Earth's early life
- marcus
- · Replies 3 ·
Graduate Universal expansion vs energy conservation
- martix
- · Replies 15 ·
Undergrad What is dark flow in galaxy clusters?
- Gravitons
- · Replies 1 ·
Undergrad Speed of light is it really constant?
- deathtical
- · Replies 5 ·
Free software for calculating sunset and sunrise times
- facenian
- · Replies 4 ·
Graduate More on PI Early Universe Videos
- skydivephil
- · Replies 5 ·
Graduate Resources for Friedmann equation problem sets
- jacdiam89
- · Replies 5 ·
Graduate Bouncing universes and anti matter.
- wolram
- · Replies 3 ·
Undergrad Difference between a Gravity Well and a Black Hole
- Dave Hooley
- · Replies 20 ·
Graduate Could the combined gravity of the Universe create an event horizon?
- YoungDreamer
- · Replies 12 ·
Graduate Releasing the object from Space Elevator
- Eagle9
- · Replies 5 ·
Graduate Could dark matter have repulsive gravity properties?
- YoungDreamer
- · Replies 36 ·
Graduate Why is the Big Bang treated as untouchable in cosmology?
- deathtical
- · Replies 38 ·
Undergrad Why Are U-B and B-V Values Important in Studying Stars and Clusters?
- randa177
- · Replies 4 ·
Graduate Could the Big Bang have destroyed evidence of what caused it?
- Godswitch
- · Replies 15 ·
Graduate Physics puzzle: A 1 radius 7 billion K temp. ball is activated inside Jupiter
- jcarper
- · Replies 5 ·
Undergrad Could gravity affect human evolution?
- YoungDreamer
- · Replies 3 ·
A better name for what we call the Big Bang
- Tanelorn
- · Replies 1 ·
Graduate Tidal Locked to a Red Dwarf? What Would the Calendar Look Like?
- Nick Writes
- · Replies 9 ·
Stargazing Upgrading my telescope, need advice.
- Vorde
- · Replies 6 ·
Graduate What caused the big bang?
- owr
- · Replies 18 ·
Graduate Radio Astronomy. Baselines and Fringes, Interferometry
- solarblast
- · Replies 4 ·
High School What Causes the Illusion of Planets Moving Backwards in the Sky?
- Philosophaie
- · Replies 3 ·
Undergrad Is Nemesis a Real Companion Star to Our Sun?
- YoungDreamer
- · Replies 6 ·
Undergrad Calculating Gravitational Energy
- Bravodhan
- · Replies 5 ·
Graduate Position angle of Moon's bright limb (formula)
- JeffOCA
- · Replies 5 ·
Graduate Steinhardt's crit of inflation (PIRSA video)
- marcus
- · Replies 21 ·
Graduate How does the jetstream of particles manage to escape from the blackhole?
- mdmaaz
- · Replies 12 ·
Undergrad Black Holes Schwarzschild radius
- Cbray
- · Replies 7 ·
High School Some questions about the Universe and its expansion.
- JerryClower
- · Replies 10 ·
Undergrad Dark energy - Expansion of the universe
- teddd
- · Replies 10 ·
Graduate Why aren't the <v^2> and <vr^2> curves different in my Hernquist model?
- LordV
- · Replies 1 ·
Graduate Black holes: zero volume and infinite density
- lovenugget
- · Replies 6 ·
Graduate Do sound vibrations from plate tectonics (earthquakes) attract asteroids?
- dreamerregina
- · Replies 2 ·
Graduate 12 min orbit white dwarfs found Best target for gravitational waves
- MTd2
- · Replies 4 ·
Stargazing Why do Blanco telescope blue filters transmit blue light?
- randa177
- · Replies 8 ·
Is the JWST Doomed? Scientists Speak Out Against Budget Cuts
- Tanelorn
- · Replies 1 ·
Undergrad Calculating gravitational acceleration between Earth and Sun for N-body simulation
- braindeaduser
- · Replies 6 ·
Graduate Into what shape does an orbiting sphere get distorted by tidal forces?
- Paulibus
- · Replies 4 ·
Graduate How Do Thermodynamics and Branes Influence the Universe's Origin?
- alex_j
- · Replies 3 ·
Graduate How does the universe handle paradoxes caused by time travel?
- soryy708
- · Replies 2 ·