Astronomy and Astrophysics Forum

Post thread
Join in expert discussion on the topics of Astronomy and astrophysics. This may include discussion on celestial objects, space, and the physical universe as a whole. Mainstream science only.
Inverse square law resolves Olbers' paradox
  • · Replies 58 ·
2
Replies
58
Views
14K
Since the earth orbits in an ellipse, not a circle
  • · Replies 2 ·
Replies
2
Views
2K
Does Dark Energy Repel Light and Cause Damage?
  • · Replies 2 ·
Replies
2
Views
3K
Can Black Holes Bend Time?
  • · Replies 3 ·
Replies
3
Views
4K
Does time run fast near universe's edge?
  • · Replies 6 ·
Replies
6
Views
3K
Stargazing 60-80 mm refracting telescope for beginners
  • · Replies 5 ·
Replies
5
Views
2K
How does momentum dumping work on the Hubble Space Telescope?
  • · Replies 2 ·
Replies
2
Views
18K
Can a Spacecraft Achieve Light Speed Using Jupiter's Magnetic Field?
  • · Replies 4 ·
Replies
4
Views
4K
What is the Color of a Neutron Star?
  • · Replies 43 ·
2
Replies
43
Views
12K
Stargazing How do radio telescopes form images?
  • · Replies 18 ·
Replies
18
Views
6K
How to convert flux from counts to erg.
  • · Replies 3 ·
Replies
3
Views
7K
Stargazing World’s largest Cherenkov telescope opens
  • · Replies 6 ·
Replies
6
Views
5K
Urban Space Saving: Reducing Traffic with Raised Roadways and Shops
  • · Replies 1 ·
Replies
1
Views
3K
Can Amateur Telescopes Detect Exoplanets?
  • · Replies 11 ·
Replies
11
Views
4K
Planet Found Orbiting Alpha Centauri
  • · Replies 31 ·
2
Replies
31
Views
9K
Just how dark is Pluto from orbit? How about Saturn?
  • · Replies 9 ·
Replies
9
Views
7K
Position and angle of Earth/Moon/Sun and timing
  • · Replies 1 ·
Replies
1
Views
4K
Can I see stars through the moon?
  • · Replies 13 ·
Replies
13
Views
29K
Could Ice Form Inside the Sun?
  • · Replies 4 ·
Replies
4
Views
4K
What is the Scientific Understanding of Gravity?
  • · Replies 21 ·
Replies
21
Views
7K
Interesting simulation of a spiral galaxy evolution.
  • · Replies 5 ·
Replies
5
Views
3K
What Determines the Diameter of a Moon Halo?
  • · Replies 1 ·
Replies
1
Views
3K
Did Mars Once Have Flowing Water?
  • · Replies 14 ·
Replies
14
Views
5K
What is the distance needed for a rocket to reach a velocity of 0 on Planet X?
  • · Replies 6 ·
Replies
6
Views
3K
Can Shock Waves Initiate Protostar Formation?
  • · Replies 3 ·
Replies
3
Views
2K
Apparent size of comets in images from the SOHO satellite
  • · Replies 4 ·
Replies
4
Views
4K
Periodicity in the mass of planets?
  • · Replies 5 ·
Replies
5
Views
3K
Life in the Early Universe: Origins and Evolution
  • · Replies 38 ·
2
Replies
38
Views
11K
Is Retro-Rocket Still a Relevant Term for Slowing Down Satellites?
  • · Replies 14 ·
Replies
14
Views
7K
Can a person catch an object in space and stop it without being pulled along?
  • · Replies 1 ·
Replies
1
Views
2K
Does Light Exist Outside Time?
  • · Replies 8 ·
Replies
8
Views
8K
Can someone explain abberation of starlight?
  • · Replies 3 ·
Replies
3
Views
3K
Could the Formation of Great Voids be Explained by Ordinary Laws of Motion?
  • · Replies 4 ·
Replies
4
Views
3K
How Does the Moon Influence Earth's Rotation and Orbit?
  • · Replies 4 ·
Replies
4
Views
3K
Oceans vs Outer Space: Colonization & Resources
  • · Replies 14 ·
Replies
14
Views
4K
Vogt-Russell Theorem: Learn & Model Stellar Structures
  • · Replies 2 ·
Replies
2
Views
3K
Temperature of planets from their Luminosities at specific wavelengths.
  • · Replies 12 ·
Replies
12
Views
3K
Spacetime Crystal: Theory & Possibility
  • · Replies 4 ·
Replies
4
Views
2K
Is Dark Rift a Rotating Cloud or a Dust Belt Surrounding the Galactic Center?
  • · Replies 4 ·
Replies
4
Views
4K
Higgs Boson and Dark Matter / Dark Energy
  • · Replies 11 ·
Replies
11
Views
5K
Jupiter and Saturn - Back and Forth in the Early Solar System?
  • · Replies 3 ·
Replies
3
Views
5K
Solar Activity Trends: Historical Chart and Validation for Current Increase
  • · Replies 8 ·
Replies
8
Views
5K
How did gravity build astronomical objects that rotate?
  • · Replies 31 ·
2
Replies
31
Views
7K
Backwards Orbiting Moon: Impact and Visibility with Earth's Rotation
  • · Replies 17 ·
Replies
17
Views
7K
How would Earth mass loss theoretically affect its orbital mechanics?
  • · Replies 12 ·
Replies
12
Views
13K
Do You Know Why Stars Have Different Colors?
  • · Replies 13 ·
Replies
13
Views
5K
Is This Fomalhaut's Debris Disk?
  • · Replies 4 ·
Replies
4
Views
3K
How Are Fluid Solutions Used in Astrophysics and Cosmology?
  • · Replies 19 ·
Replies
19
Views
4K
How is mass distribution understood within the LCDM cosmological model?
  • · Replies 5 ·
Replies
5
Views
3K
Angular Velocity of a Nebula Accretion Disk
  • · Replies 1 ·
Replies
1
Views
3K
How much space mining would begin to affect earth
  • · Replies 8 ·
Replies
8
Views
5K
Creating artificial ultradense objects by ablation implosion?
  • · Replies 23 ·
Replies
23
Views
6K
The Kantian Wall - The Meaning of Space, Time, and Mass in Modern Physics
  • · Replies 1 ·
Replies
1
Views
6K
The First Law of Thermodynamics VS. The Universe Created from Nothing
  • · Replies 16 ·
Replies
16
Views
9K
How to Generate Accurate Initial Conditions for Simulating Galaxy Dynamics?
  • · Replies 2 ·
Replies
2
Views
3K
Do Solar Systems with Eccentric Planets Have More Stable Orbits?
  • · Replies 29 ·
Replies
29
Views
10K
Q about moon and sun tides, energy related to comet strikes and the mass water?
  • · Replies 1 ·
Replies
1
Views
2K
Source of magnetic field of Neutron stars.
  • · Replies 2 ·
Replies
2
Views
3K
Heat Interactions with Non-Normal Matter
  • · Replies 4 ·
Replies
4
Views
2K
How do you calculate declination and Right Ascension from Earth Coordinates?
  • · Replies 3 ·
Replies
3
Views
13K
Understanding Rotation Curves: A Study of Galactic Density and Derivatives
  • · Replies 1 ·
Replies
1
Views
2K
At what speed are we moving through space?
  • · Replies 19 ·
Replies
19
Views
5K
A good book for astrophysics&astronomy
  • · Replies 3 ·
Replies
3
Views
3K
Does Light Have Mass? Gravity Effects Explained
  • · Replies 10 ·
Replies
10
Views
4K
Geocentricism, could you comment on a conversation I had about it?
  • · Replies 6 ·
Replies
6
Views
4K
Cherenkov radiation detection
  • · Replies 8 ·
Replies
8
Views
4K
Can you have binary stars with the same radius but different masses?
  • · Replies 5 ·
Replies
5
Views
4K
Coarsely modeling impacts between bodies on a planetary scale
  • · Replies 3 ·
Replies
3
Views
2K
On the Origin of Solar and Stellar Magnetic Fields
  • · Replies 7 ·
Replies
7
Views
5K
Another theory of the universe based on red and blue shifts
  • · Replies 4 ·
Replies
4
Views
3K
Instruments and Imaging: How to prevent condensation inside a closed system?
  • · Replies 4 ·
Replies
4
Views
4K
What Is a Black Hole Firewall?
  • · Replies 2 ·
Replies
2
Views
2K
What are the objectives of the GAIA mission and satellite?
  • · Replies 2 ·
Replies
2
Views
3K
Questioning the Expansion theory
  • · Replies 2 ·
Replies
2
Views
3K
Space: Is It an Idea or Physical Reality?
  • · Replies 8 ·
Replies
8
Views
2K
Gravity and Acceleration on a 50,000 km Space Elevator
  • · Replies 5 ·
Replies
5
Views
3K
Simple Question about the Solar System/Planetary Systems
  • · Replies 14 ·
Replies
14
Views
5K
Can Slow Space Travel Overcome the Speed Barrier in Vacuum Flight?
  • · Replies 2 ·
Replies
2
Views
2K
Why a space before a punctuation mark?
  • · Replies 23 ·
Replies
23
Views
4K
How Are Elements Beyond Iron Created in Stars?
  • · Replies 1 ·
Replies
1
Views
2K
Duke University Astronomy 101 Online Course
  • · Replies 1 ·
Replies
1
Views
5K
Comparing Large Stars and Black Holes: Understanding Event Horizons
  • · Replies 20 ·
Replies
20
Views
5K
Available Astronomy Research Topics?
  • · Replies 1 ·
Replies
1
Views
5K
Stargazing Bought Orion AstroView 90mm, good?
  • · Replies 9 ·
Replies
9
Views
9K
Dark matter solution: not receiving all the light?
  • · Replies 13 ·
Replies
13
Views
3K
Quick Question about the Doppler Effect
  • · Replies 18 ·
Replies
18
Views
5K
Naive question regarding black holes.
  • · Replies 2 ·
Replies
2
Views
2K
Black hole has a partiuclar fixed volume
  • · Replies 3 ·
Replies
3
Views
2K
How Can I Estimate Local Sidereal Time in My Head?
  • · Replies 4 ·
Replies
4
Views
11K
Solar system space dust avg density[kg/m^3]
  • · Replies 4 ·
Replies
4
Views
3K
After watching the Stephen Hawking Series
  • · Replies 9 ·
Replies
9
Views
3K
Question Gravity: Explaining Planetary Motion & Hailey's Comet
  • · Replies 7 ·
Replies
7
Views
4K
What Is the Relationship Between Time and Space in the Universe?
  • · Replies 32 ·
2
Replies
32
Views
6K
A basic question on gravity from a novice
  • · Replies 15 ·
Replies
15
Views
4K
What Would Happen If Mars Had a Higher Density and Maintained Its Radius?
  • · Replies 13 ·
Replies
13
Views
5K
What is the Probability of Multiple Universes?
  • · Replies 2 ·
Replies
2
Views
3K
Do Tidal Forces in Black Holes Affect Matter at the Quantum Level?
  • · Replies 4 ·
Replies
4
Views
3K
Gravitational binding energy of some stuff
  • · Replies 2 ·
Replies
2
Views
3K
Is the only evidence for an expanding universe the doppler Red Shift?
  • · Replies 2 ·
Replies
2
Views
2K
Which Observational Project sounds funner/easier?
  • · Replies 6 ·
Replies
6
Views
3K