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 Can you have binary stars with the same radius but different masses?

  • AussieDave
  • · Replies 5 ·
Replies
5

Graduate Coarsely modeling impacts between bodies on a planetary scale

  • SkyMarshal
  • · Replies 3 ·
Replies
3

Graduate Latest z >1 Type1a supernova results?

  • johne1618
  • · Replies 2 ·
Replies
2

Graduate On the Origin of Solar and Stellar Magnetic Fields

  • betzalel
  • · Replies 7 ·
Replies
7

Graduate Another theory of the universe based on red and blue shifts

  • warriorjoe007
  • · Replies 4 ·
Replies
4

Undergrad Instruments and Imaging: How to prevent condensation inside a closed system?

  • Astrid
  • · Replies 4 ·
Replies
4

Graduate What is the Latest Measurement of the Hubble Constant Using Infrared Light?

  • Faradave
  • · Replies 4 ·
Replies
4

Graduate Could a universal Oort cloud structure cause expansive acceleration?

  • superdave
  • · Replies 15 ·
Replies
15

Graduate What Is a Black Hole Firewall?

  • Vorde
  • · Replies 2 ·
Replies
2

Graduate Could dark energy and expansion of space be just a topological effect?

  • Artifex 28
  • · Replies 2 ·
Replies
2

Graduate When talking cosmology what exactly is a manifold, is there any

  • wolram
  • · Replies 5 ·
Replies
5

Graduate Cosmic Distance Ladder: Advancing Physics of Cosmic Distances

  • Chronos
  • · Replies 2 ·
Replies
2

Graduate What are the objectives of the GAIA mission and satellite?

  • Astronuc
  • · Replies 2 ·
Replies
2

Graduate Philosophical: Is the universe a type of Turing machine?

  • algorithmDesi
  • · Replies 6 ·
Replies
6
Replies
3

Graduate Questioning the Expansion theory

  • ekeeley
  • · Replies 2 ·
Replies
2

Undergrad Space: Is It an Idea or Physical Reality?

  • Obani
  • · Replies 8 ·
Replies
8

Graduate Expansion of the universe and the speed of light

  • DHF
  • · Replies 15 ·
Replies
15

Graduate Gravity and Acceleration on a 50,000 km Space Elevator

  • jack5000
  • · Replies 5 ·
Replies
5

High School Simple Question about the Solar System/Planetary Systems

  • Magnawolf
  • · Replies 14 ·
Replies
14

Undergrad Can Slow Space Travel Overcome the Speed Barrier in Vacuum Flight?

  • spacecadet11
  • · Replies 2 ·
Replies
2

Why a space before a punctuation mark?

  • jtbell
  • · Replies 23 ·
Replies
23

Graduate How Are Elements Beyond Iron Created in Stars?

  • solarblast
  • · Replies 1 ·
Replies
1

High School Duke University Astronomy 101 Online Course

  • Greg Bernhardt
  • · Replies 1 ·
Replies
1

Undergrad Simple Beginner Dark Matter Question

  • iMatt
  • · Replies 4 ·
Replies
4

Graduate Comparing Large Stars and Black Holes: Understanding Event Horizons

  • jldibble
  • · Replies 20 ·
Replies
20

Undergrad Available Astronomy Research Topics?

  • bleist88
  • · Replies 1 ·
Replies
1

Graduate Why cannot the universe have net angular momentum?

  • chill_factor
  • · Replies 9 ·
Replies
9

Stargazing Bought Orion AstroView 90mm, good?

  • CowedbyWisdom
  • · Replies 9 ·
Replies
9

Graduate Dark matter solution: not receiving all the light?

  • euquila
  • · Replies 13 ·
Replies
13

Undergrad Quick Question about the Doppler Effect

  • Bridgeboy
  • · Replies 18 ·
Replies
18

Graduate Naive question regarding black holes.

  • rbj
  • · Replies 2 ·
Replies
2

Graduate Black hole has a partiuclar fixed volume

  • shivakumar06
  • · Replies 3 ·
Replies
3

Undergrad How Can I Estimate Local Sidereal Time in My Head?

  • bossman27
  • · Replies 4 ·
Replies
4

Undergrad Solar system space dust avg density[kg/m^3]

  • R.L.Jacobsen
  • · Replies 4 ·
Replies
4

Graduate After watching the Stephen Hawking Series

  • u84six
  • · Replies 9 ·
Replies
9

Undergrad Question Gravity: Explaining Planetary Motion & Hailey's Comet

  • mugenshiyo
  • · Replies 7 ·
Replies
7

Graduate What Is the Relationship Between Time and Space in the Universe?

  • mdl
  • · Replies 32 ·
2
Replies
32

Undergrad A basic question on gravity from a novice

  • flinky
  • · Replies 15 ·
Replies
15

High School Radio communication from the galaxy's far side?

  • modus
  • · Replies 10 ·
Replies
10

Undergrad What Would Happen If Mars Had a Higher Density and Maintained Its Radius?

  • willstaruss22
  • · Replies 13 ·
Replies
13

Graduate What is the Probability of Multiple Universes?

  • applebob
  • · Replies 2 ·
Replies
2

Graduate Light from MACS 1149-JD implausible

  • applebob
  • · Replies 4 ·
Replies
4

Graduate Omega being less than one in a flat Universe?

  • TheTraceur
  • · Replies 1 ·
Replies
1

Graduate Do Tidal Forces in Black Holes Affect Matter at the Quantum Level?

  • tanzanos
  • · Replies 4 ·
Replies
4

Graduate Gravitational binding energy of some stuff

  • jetwaterluffy
  • · Replies 2 ·
Replies
2

Undergrad Is Everything Shrinking Instead of Space Expanding in the Big Bang Theory?

  • Jeremy87
  • · Replies 14 ·
Replies
14

Graduate Is the CMBR a relic from the big bang or an image from background galaxies?

  • Lino
  • · Replies 6 ·
Replies
6

Graduate Number of Voids in the (observable) Universe

  • voidx
  • · Replies 16 ·
Replies
16

Undergrad Is the only evidence for an expanding universe the doppler Red Shift?

  • Chas Tennis
  • · Replies 2 ·
Replies
2

Undergrad Which Observational Project sounds funner/easier?

  • RockenNS42
  • · Replies 6 ·
Replies
6

High School Is Jupiter Brighter When Far from Venus?

  • PhanthomJay
  • · Replies 27 ·
Replies
27

Undergrad The importance of atmospheres for the planetary temperature

  • RobinSky
  • · Replies 5 ·
Replies
5

Graduate 3-dimensional implications of a black hole

  • wetwonder
  • · Replies 27 ·
Replies
27

Undergrad Figuring Out Mysterious Meteorite: Speed, Trajectory & More

  • H2Bro
  • · Replies 1 ·
Replies
1

Can Light Be Slowed or Even Stopped?

  • Tim13
  • · Replies 8 ·
Replies
8

Undergrad Perpendicular velocity of planets

  • KasperHdL
  • · Replies 4 ·
Replies
4

Graduate What Is the Universe Expanding Into?

  • hmetkaya
  • · Replies 37 ·
2
Replies
37

High School Gravitational Pull: Sun vs. Earth's on Moon

  • acvessey
  • · Replies 4 ·
Replies
4

Feynman checkerboard as a model of discrete space-time

  • wellingboy
  • · Replies 1 ·
Replies
1

Graduate Would Cosmic Expansion Break a Tether Between Galaxies?

  • Chiclayo guy
  • · Replies 10 ·
Replies
10

Graduate Gravitational Lensing and Redshift

  • SHISHKABOB
  • · Replies 5 ·
Replies
5

Graduate Does the holographic principle remove the need for dark matter

  • Lino
  • · Replies 2 ·
Replies
2

Graduate How inflation solves the horizon problem

  • Soph_the_Oaf
  • · Replies 10 ·
Replies
10

Graduate Is Dark Matter Uniformly Distributed Locally and in Distant Galaxies?

  • notaclue
  • · Replies 9 ·
Replies
9

Graduate Minimum Satellite Period problem

  • Eric M. Jones
  • · Replies 12 ·
Replies
12

Graduate Would motion explain the missing 'dark matter'?

  • oracle1965
  • · Replies 7 ·
Replies
7

Graduate Effect of gravitational tides on the moon

  • altergnostic
  • · Replies 27 ·
Replies
27

Undergrad Understanding Elliptical Orbits: Foci, Center, Barycenter, and Mass Relationship

  • mhuang
  • · Replies 1 ·
Replies
1

Graduate Dark Matter: Understanding Its Nature & Impact on Stars, Planets

  • swemy
  • · Replies 26 ·
Replies
26

Graduate Why is the age of the Universe the reciprocal of the Hubble constant?

  • johne1618
  • · Replies 33 ·
2
Replies
33

Undergrad Is the Sun Really Older Due to Relativity?

  • CuriousQ
  • · Replies 8 ·
Replies
8

Undergrad Could Dark Energy be Dark Matter cooling?

  • Reverend2010
  • · Replies 44 ·
2
Replies
44

Graduate Could a cosmo tabulator give hands-on experience with cosmic Event Horizon?

  • marcus
  • · Replies 10 ·
Replies
10

Graduate Can We Pull a Metal Ball Out of a Black Hole With a Steel Cable?

  • Algren
  • · Replies 17 ·
Replies
17

Undergrad Stellar Nebulae and angular momentum

  • mateomy
  • · Replies 3 ·
Replies
3

Graduate Is the Decaying Vacuum Model a Complete Description of Cosmic Expansion?

  • wolram
  • · Replies 1 ·
Replies
1

High School Black holes and gravity basic questions

  • danman21
  • · Replies 7 ·
Replies
7

Graduate Unraveling the Mystery of Black Holes: The Paradox of Singularity and Infinity

  • Crazymechanic
  • · Replies 6 ·
Replies
6

Graduate Can Super Mercurys Support Life and Sustainable Plate Tectonics?

  • KTevolved
  • · Replies 3 ·
Replies
3

Undergrad Can we give an analogy for nucleus to sun and electrons to planets

  • dexterdev
  • · Replies 5 ·
Replies
5

Graduate Space Smoothness: Virtual Particle Effects on Photon Paths

  • neginf
  • · Replies 1 ·
Replies
1

High School Magellanic Clouds — two irregular dwarf galaxies in the Milky Way

  • Philosophaie
  • · Replies 8 ·
Replies
8

Undergrad Horizontal + Celestial Coordinates to Geographic Coordinates

  • Weskhan
  • · Replies 8 ·
Replies
8

Is the sun visible if you're standing on the moon?

  • buzzdiamond
  • · Replies 36 ·
2
Replies
36

Graduate Gravity and the expanding universe

  • xaviat
  • · Replies 1 ·
Replies
1

Undergrad Why does the cosmic microwave background make a noise

  • g.lemaitre
  • · Replies 2 ·
Replies
2

Undergrad How to get longitude from Two Line Element (TLE)

  • hamzaaaa
  • · Replies 1 ·
Replies
1

Graduate AIPS: flagging bad data, calibration, etc

  • Aziza
  • · Replies 1 ·
Replies
1

Graduate Brian Powell's latest paper: Scalar runnings

  • Chronos
  • · Replies 3 ·
Replies
3

Undergrad .Understanding Stress on Space Elevator

  • RohitRmB
  • · Replies 16 ·
Replies
16

Undergrad What the minimum mass for a habitable exoplanet or moon?

  • cosmicrock
  • · Replies 5 ·
Replies
5

Graduate Does CMBR Cooling Mirror Black Body Radiation Processes?

  • nonspace
  • · Replies 3 ·
Replies
3

Undergrad A few questions about black holes

  • bmcphysics
  • · Replies 25 ·
Replies
25

Undergrad What would happen if someone was sucked into a black hole?

  • Kutt
  • · Replies 36 ·
2
Replies
36

Undergrad Hubble's law and the age of the universe

  • Orcinus
  • · Replies 6 ·
Replies
6

Undergrad Where do the heaviest elements come from?

  • aaricia
  • · Replies 7 ·
Replies
7

Undergrad How can the universe be moving faster?

  • cosmicrock
  • · Replies 2 ·
Replies
2

Graduate Fundamental Existence Of Matter/Energy

  • abhiroop_k
  • · Replies 16 ·
Replies
16

Undergrad Cosmological models and begining and ending of universe

  • Mahira414
  • · Replies 2 ·
Replies
2