Astronomy, Astrophysics, Cosmology Forum

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

Undergrad Just how dark is Pluto from orbit? How about Saturn?

  • wedouglas
  • · Replies 9 ·
Replies
9

Undergrad Position and angle of Earth/Moon/Sun and timing

  • TouTorp
  • · Replies 1 ·
Replies
1

High School Can I see stars through the moon?

  • paddys09
  • · Replies 13 ·
Replies
13

Undergrad Could Ice Form Inside the Sun?

  • nefertum
  • · Replies 4 ·
Replies
4

Undergrad What is the Scientific Understanding of Gravity?

  • Backus
  • · Replies 21 ·
Replies
21

Interesting simulation of a spiral galaxy evolution.

  • Spinnor
  • · Replies 5 ·
Replies
5

Undergrad What Determines the Diameter of a Moon Halo?

  • jmvizanko
  • · Replies 1 ·
Replies
1

Graduate Fundamental Cosmology conference (Stockholm, November 2012)

  • marcus
  • · Replies 0 ·
Replies
0

High School Did Mars Once Have Flowing Water?

  • shifty88
  • · Replies 14 ·
Replies
14

Graduate What is the distance needed for a rocket to reach a velocity of 0 on Planet X?

  • scoop91
  • · Replies 6 ·
Replies
6

Graduate Can Shock Waves Initiate Protostar Formation?

  • hunt_mat
  • · Replies 3 ·
Replies
3

Undergrad Apparent size of comets in images from the SOHO satellite

  • Ostsol
  • · Replies 4 ·
Replies
4

Graduate How can the Universe be flat and accelerating in its expansion?

  • *FaerieLight*
  • · Replies 2 ·
Replies
2

High School What is the age of the universe in billions?

  • ofeyrpf
  • · Replies 9 ·
Replies
9

Graduate Another nail in the coffin of alternative redshift theories

  • Chronos
  • · Replies 8 ·
Replies
8

Graduate Is My Proper Time the Same as Cosmological or Conformal Time?

  • johne1618
  • · Replies 2 ·
Replies
2

Graduate Looking for other proof of expanding universe.

  • grounded
  • · Replies 75 ·
3
Replies
75

Graduate Is Heat Death or the Big Rip Inevitable in an Open Universe?

  • wolram
  • · Replies 20 ·
Replies
20

Graduate Understanding Spectra Shifts of Distant Stars

  • Ezio3.1415
  • · Replies 10 ·
Replies
10

Undergrad Big Bang Questions: How Far, How Long, Possible?

  • guitarphysics
  • · Replies 3 ·
Replies
3

Graduate Energy in co-moving co-ordinates?

  • johne1618
  • · Replies 7 ·
Replies
7

Graduate Difference between the Higgs field and the Inflaton field?

  • friend
  • · Replies 7 ·
Replies
7

Graduate Periodicity in the mass of planets?

  • Morgaen
  • · Replies 5 ·
Replies
5

Graduate I'm sure this has been asked before, but: Universes colliding with each other

  • mustang19
  • · Replies 16 ·
Replies
16

High School Life in the Early Universe: Origins and Evolution

  • GoodUniverse
  • · Replies 38 ·
2
Replies
38

Graduate Cosmological constant from first principles

  • Chronos
  • · Replies 9 ·
Replies
9

Undergrad Is Retro-Rocket Still a Relevant Term for Slowing Down Satellites?

  • Smileyxx
  • · Replies 14 ·
Replies
14

Graduate Consequences of a negative mass universe

  • olso4051
  • · Replies 5 ·
Replies
5

High School Can a person catch an object in space and stop it without being pulled along?

  • Ivan452
  • · Replies 1 ·
Replies
1

Graduate Determining Mass/Density of Universe: How Accurate?

  • mysearch
  • · Replies 10 ·
Replies
10

Graduate Does Light Exist Outside Time?

  • mugenshiyo
  • · Replies 8 ·
Replies
8

Undergrad Can someone explain abberation of starlight?

  • Pharaoness
  • · Replies 3 ·
Replies
3

Graduate Could the Formation of Great Voids be Explained by Ordinary Laws of Motion?

  • codex34
  • · Replies 4 ·
Replies
4

Undergrad How Does the Moon Influence Earth's Rotation and Orbit?

  • Rick James
  • · Replies 4 ·
Replies
4

Oceans vs Outer Space: Colonization & Resources

  • Monsterboy
  • · Replies 14 ·
Replies
14

Graduate Observable Universe and Black Holes

  • sefer
  • · Replies 3 ·
Replies
3

Graduate Vogt-Russell Theorem: Learn & Model Stellar Structures

  • po6
  • · Replies 2 ·
Replies
2

Undergrad The universe and its matters: finite or infinite?

  • nemoover
  • · Replies 6 ·
Replies
6

Graduate Temperature of planets from their Luminosities at specific wavelengths.

  • mystupidmouth
  • · Replies 12 ·
Replies
12

Graduate Spacetime Crystal: Theory & Possibility

  • Light Bearer
  • · Replies 4 ·
Replies
4

Graduate Evidence of Cosmic Backround Radiation cooling

  • Bill Minerick
  • · Replies 5 ·
Replies
5

Graduate Gravity Assist Oberth Effect Sun

  • Albertgauss
  • · Replies 4 ·
Replies
4

Graduate Simple argument for a linear cosmology

  • johne1618
  • · Replies 10 ·
Replies
10

Graduate Dark Matter as possible ground state for all matter

  • Bill Minerick
  • · Replies 2 ·
Replies
2

Graduate Why does our universe/dimension follow the laws that it does?

  • Niaboc67
  • · Replies 2 ·
Replies
2

Undergrad Is Dark Rift a Rotating Cloud or a Dust Belt Surrounding the Galactic Center?

  • ShayanJ
  • · Replies 4 ·
Replies
4

Graduate Higgs Boson and Dark Matter / Dark Energy

  • Velcro
  • · Replies 11 ·
Replies
11

Graduate Jupiter and Saturn - Back and Forth in the Early Solar System?

  • lpetrich
  • · Replies 3 ·
Replies
3

Graduate Co-moving density should be constant?

  • johne1618
  • · Replies 14 ·
Replies
14

Graduate Perfect cosmological principle in co-moving co-ordinates

  • johne1618
  • · Replies 4 ·
Replies
4
Replies
8

Graduate Many Worlds + Anthropic Principle

  • kamikaze762
  • · Replies 21 ·
Replies
21

Graduate A question about our prodominently matter universe.

  • Dappy
  • · Replies 1 ·
Replies
1

Graduate How did gravity build astronomical objects that rotate?

  • Paulibus
  • · Replies 31 ·
2
Replies
31

Graduate Does the Milky have a QSO? What is the observational evidence concerning QSOs?

  • betzalel
  • · Replies 24 ·
Replies
24

Graduate Universe was the size of our solar system after 1 sec

  • kjamha
  • · Replies 15 ·
Replies
15

Undergrad Backwards Orbiting Moon: Impact and Visibility with Earth's Rotation

  • DeepSpace9
  • · Replies 17 ·
Replies
17

Graduate How would Earth mass loss theoretically affect its orbital mechanics?

  • mofobro
  • · Replies 12 ·
Replies
12

Undergrad Red Shift: Questions About Light & Big Bang

  • gway22
  • · Replies 2 ·
Replies
2

Undergrad Is the Expansion of the Universe Slowing Down?

  • NWH
  • · Replies 15 ·
Replies
15

Graduate Oldest most distant Galaxy discovered to date

  • Tanelorn
  • · Replies 24 ·
Replies
24

Undergrad Do You Know Why Stars Have Different Colors?

  • gmax137
  • · Replies 13 ·
Replies
13

Graduate Is This Fomalhaut's Debris Disk?

  • Drakkith
  • · Replies 4 ·
Replies
4

Graduate How Are Fluid Solutions Used in Astrophysics and Cosmology?

  • shounakbhatta
  • · Replies 19 ·
Replies
19

Graduate How is mass distribution understood within the LCDM cosmological model?

  • mysearch
  • · Replies 5 ·
Replies
5

Graduate Angular Velocity of a Nebula Accretion Disk

  • Vodkacannon
  • · Replies 1 ·
Replies
1

Graduate How much space mining would begin to affect earth

  • VegaMan
  • · Replies 8 ·
Replies
8

Graduate Creating artificial ultradense objects by ablation implosion?

  • monstermacina
  • · Replies 23 ·
Replies
23

Graduate The Kantian Wall - The Meaning of Space, Time, and Mass in Modern Physics

  • arupel
  • · Replies 1 ·
Replies
1

Graduate Big Bang inflation/expansion vs centre of universe vs Speed of light query

  • learningmore
  • · Replies 28 ·
Replies
28

Graduate The First Law of Thermodynamics VS. The Universe Created from Nothing

  • B.M.Gray
  • · Replies 16 ·
Replies
16
Replies
1

Graduate Origin of Matter: Theory Explaining Creation

  • wasteofo2
  • · Replies 66 ·
3
Replies
66

Graduate What does it mean that time is expanding?

  • darrenr
  • · Replies 10 ·
Replies
10

Graduate How to Generate Accurate Initial Conditions for Simulating Galaxy Dynamics?

  • fab13
  • · Replies 2 ·
Replies
2

Graduate Do Solar Systems with Eccentric Planets Have More Stable Orbits?

  • Philosophaie
  • · Replies 29 ·
Replies
29

Undergrad Q about moon and sun tides, energy related to comet strikes and the mass water?

  • aw07
  • · Replies 1 ·
Replies
1

Undergrad Is the Expansion of the Universe a Fact or a Possibility?

  • DeepSpace9
  • · Replies 9 ·
Replies
9

Graduate Is Spacetime Capable of Tearing or Breaking Down?

  • r.hackett
  • · Replies 3 ·
Replies
3

Graduate Direct detection of dark matter tendrils?

  • ivorax
  • · Replies 7 ·
Replies
7

What is the heaviest thing in the universe?

  • markf
  • · Replies 8 ·
Replies
8

Graduate Source of magnetic field of Neutron stars.

  • lindloda
  • · Replies 2 ·
Replies
2

Graduate How Does a 3.5D Perspective Enhance Our Understanding of Spacetime Expansion?

  • Faradave
  • · Replies 17 ·
Replies
17

Graduate Heat Interactions with Non-Normal Matter

  • danielu13
  • · Replies 4 ·
Replies
4

Undergrad How do you calculate declination and Right Ascension from Earth Coordinates?

  • Brynjolf
  • · Replies 3 ·
Replies
3

Graduate Understanding Rotation Curves: A Study of Galactic Density and Derivatives

  • Dan_
  • · Replies 1 ·
Replies
1

High School A theory about the beginning of the universe

  • Ultimation
  • · Replies 7 ·
Replies
7

Graduate Understanding the Zero Energy Principle of the Universe

  • johne1618
  • · Replies 39 ·
2
Replies
39

Graduate Isotropic and homogeneous of space

  • sadegh4137
  • · Replies 3 ·
Replies
3

Graduate The Fate of the Universe: Expansion, Matter Decay, and the Ultimate End

  • MathematicalPhysicist
  • · Replies 72 ·
3
Replies
72

Graduate At what speed are we moving through space?

  • jabbercookie
  • · Replies 19 ·
Replies
19

Graduate How is gravity considered as the weakest force?

  • B.M.Gray
  • · Replies 10 ·
Replies
10

Undergrad Unraveling the Mystery of the Universe's Center: Theories and Explanations

  • francium87
  • · Replies 18 ·
Replies
18

Graduate A good book for astrophysics&astronomy

  • plasmon
  • · Replies 3 ·
Replies
3

Graduate Is the Universe's Expansion Rate Truly Accelerating?

  • Deeviant
  • · Replies 17 ·
Replies
17

Undergrad Does Light Have Mass? Gravity Effects Explained

  • Safamm
  • · Replies 10 ·
Replies
10

Undergrad Basic Big-Bang ?'s For First Thread

  • B.M.Gray
  • · Replies 9 ·
Replies
9

Graduate Geocentricism, could you comment on a conversation I had about it?

  • jarrah-95
  • · Replies 6 ·
Replies
6

Graduate The Universe shouldn't look like it does if it is expanding

  • dedwarmo
  • · Replies 27 ·
Replies
27

Graduate Cherenkov radiation detection

  • stargazer3
  • · Replies 8 ·
Replies
8