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 Black Holes Explain the Mystery of Dark Matter in the Universe?

  • SD das
  • · Replies 2 ·
Replies
2

Undergrad Gravitic Field of Rotating Disk-Shaped Mass Along Ecliptic

  • havonasun
  • · Replies 3 ·
Replies
3

Stargazing How Can a Grain of Sand Create a Bright Meteor?

  • megacal
  • · Replies 80 ·
3
Replies
80

Undergrad Effort to get us all on the same page (balloon analogy)

  • marcus
  • · Replies 548 ·
19
Replies
548

High School Is dark matter self-interacting?

  • wolram
  • · Replies 20 ·
Replies
20

High School Significance of a planet's "surface gravity"

  • lifeonmercury
  • · Replies 1 ·
Replies
1

High School Move vehicle in space by rail structure systema

  • Juuso
  • · Replies 10 ·
Replies
10

High School Confused about traveling at the speed of light

  • lifeonmercury
  • · Replies 26 ·
Replies
26

High School Is the Earth in its original orbit?

  • scincemaniac
  • · Replies 11 ·
Replies
11

Undergrad What is the Role of Space in this Apparatus?

  • GrantSB
  • · Replies 1 ·
Replies
1

Undergrad Boltzmann Brains: Existence, Models & Opinion

  • durant35
  • · Replies 24 ·
Replies
24

Stargazing Nebulosity is a hard program for the aged?

  • sophiecentaur
  • · Replies 7 ·
Replies
7

High School B Calculating the age of the universe with the Hubble constant

  • anonymous24
  • · Replies 8 ·
Replies
8

Undergrad Cosmological electroweak phase transition

  • Carlos L. Janer
  • · Replies 22 ·
Replies
22

High School Black Holes & Time: How Do We Observe Movement?

  • Jacob Gable
  • · Replies 7 ·
Replies
7

Undergrad Galaxy Merger and Damped Oscillation?

  • FallenApple
  • · Replies 2 ·
Replies
2

High School What is your favorite planet of the solar system?

  • bellocchiocarmel
  • · Replies 16 ·
Replies
16

Undergrad Dumb Question: How do we know galaxies are in SSCM?

  • Csmith
  • · Replies 17 ·
Replies
17

High School If Earth moves at 500,000 mph then why don't satellites stay behind?

  • IsItSo
  • · Replies 18 ·
Replies
18

Undergrad Has anything in the universe ever reached 0 Kelvin?

  • Remon
  • · Replies 16 ·
Replies
16

Undergrad Is the fabric of space a "medium" for light?

  • GrantSB
  • · Replies 3 ·
Replies
3

Undergrad Is angular momentum conserved in a Supernova?

  • FallenApple
  • · Replies 2 ·
Replies
2

Undergrad How to solve for the volume of the universe / redshift

  • rano jojo
  • · Replies 11 ·
Replies
11

Undergrad Can 21 cm Emission Be Detected in a Laboratory?

  • amarante
  • · Replies 2 ·
Replies
2

High School Emergent Gravity and the Dark Universe

  • wolram
  • · Replies 4 ·
Replies
4

High School Where Has All the Energy Gone? The Mystery of Big Bang and Dark Energy

  • ChrisisC
  • · Replies 15 ·
Replies
15

High School What is the Relation Between Jeans Mass and Fundamental Mode in Acoustic Waves?

  • Discman
  • · Replies 12 ·
Replies
12

Graduate Why isn't the pull of gravity neutral on large scales?

  • rede96
  • · Replies 34 ·
2
Replies
34

High School Questions about the origin and evolution of dark energy.

  • K. Doc Holiday
  • · Replies 8 ·
Replies
8

High School How can a physical entity be infinite?

  • Chris Miller
  • · Replies 28 ·
Replies
28

High School What Do Scientists Think a Black Hole Is?

  • wolram
  • · Replies 23 ·
Replies
23

High School Is the Universe infinite or not?

  • Robertphysics
  • · Replies 38 ·
2
Replies
38

High School Does dark matter make black holes bigger?

  • adolphysics
  • · Replies 11 ·
Replies
11

Undergrad Measuring Time w/o Entropy: Can It Be Done?

  • windy miller
  • · Replies 22 ·
Replies
22

High School Are OH molecules in masers ionized?

  • TheCanadian
  • · Replies 2 ·
Replies
2

High School Is the Universe Infinitely Large Since the Big Bang?

  • kjamha
  • · Replies 1 ·
Replies
1

Undergrad Is Stellarium More Accurate Than VSOP87?

  • Tegalad
  • · Replies 2 ·
Replies
2

Undergrad What Does the h Subscript 70 to the Power of 3 Mean in Supernova Units?

  • resurgance2001
  • · Replies 4 ·
Replies
4

Undergrad How is the first multipole calculated from the Plank Study?

  • Jules Winnfield
  • · Replies 1 ·
Replies
1

High School Are asteroids found by the light they reflect?

  • Albertgauss
  • · Replies 9 ·
Replies
9

Undergrad Why do things fall into a black hole?

  • Singlau
  • · Replies 2 ·
Replies
2

Undergrad Why do planets follow the same curvature at both foci?

  • StandardsGuy
  • · Replies 12 ·
Replies
12

High School Determining the transition frequency

  • TheCanadian
  • · Replies 2 ·
Replies
2

Undergrad Is It Time to Rethink Our Models of Dark Energy and Dark Matter?

  • Sheldon Cooper
  • · Replies 2 ·
Replies
2

High School What would happen if 6 black holes surrounded a planet?

  • phillovix
  • · Replies 15 ·
Replies
15

High School Could a black hole be hiding inside a neutron star?

  • James Minwell
  • · Replies 3 ·
Replies
3

Undergrad Would quantum laws work in other hypothetical universes?

  • FallenApple
  • · Replies 3 ·
Replies
3

High School Theory that challenges Einstein's physics could soon be put to rest

  • wolram
  • · Replies 9 ·
Replies
9

Graduate Is the Cosmic Microwave Background Linked to Dark Energy?

  • RankAstronamateur
  • · Replies 6 ·
Replies
6

Undergrad How do mass and temperature change in black holes due to Hawking Radiation?

  • James Way
  • · Replies 3 ·
Replies
3

Undergrad Bullet clusters & CMB accoustic peaks dark matter

  • kodama
  • · Replies 9 ·
Replies
9

High School Answers to Beginner Questions about Black Hole Event Horizons

  • K. Doc Holiday
  • · Replies 2 ·
Replies
2

Graduate Understanding MASERs and their properties

  • TheCanadian
  • · Replies 1 ·
Replies
1

High School Can Orbiting Bodies Slow Down Over Time?

  • micropulsar
  • · Replies 11 ·
Replies
11

High School Black Holes & Time: A Closer Look

  • charles watson
  • · Replies 27 ·
Replies
27

Undergrad Does Free Space Permeability Change with Applied Magnetic Fields?

  • MarSuper
  • · Replies 12 ·
Replies
12

High School Can Hydrogen-Based Plastic Provide Better Radiation Protection than Lead?

  • entrance
  • · Replies 4 ·
Replies
4

High School Temperature in the space between planets of our solar system?

  • Albertgauss
  • · Replies 11 ·
Replies
11

High School Spiral Galaxies: Why Do Arms Bifurcate & What's Moving In/Out?

  • Sanborn Chase
  • · Replies 25 ·
Replies
25

High School Discussing Juno/JunoCam Mission and Jupiter Data

  • 1oldman2
  • · Replies 112 ·
4
Replies
112

High School Earth's Radio Bubble: Alien Civilization Unaware of Human Existence

  • lifeonmercury
  • · Replies 21 ·
Replies
21

High School Dark matter interacts with visible matter via gravity

  • Sanborn Chase
  • · Replies 5 ·
Replies
5

High School Is a Black Hole Really Just a Spherical Structure?

  • Simon Peach
  • · Replies 52 ·
2
Replies
52

Undergrad Where does a polytropic EoS come from?

  • Vrbic
  • · Replies 2 ·
Replies
2

Graduate Did the universe Absolutely begin?

  • JhonnyDx
  • · Replies 47 ·
2
Replies
47

Undergrad Black Holes: What They Are & What They're Made Of

  • Will K
  • · Replies 1 ·
Replies
1

Undergrad Black Hole Time Dilation: What Would an Astronaut See?

  • Will K
  • · Replies 4 ·
Replies
4

High School Infinite amount of matter in the universe?

  • lifeonmercury
  • · Replies 53 ·
2
Replies
53

High School Cosmic Rays: How Fast Do They Travel?

  • Dr Wu
  • · Replies 8 ·
Replies
8

High School Is There a Limit to the Expansion of the Universe?

  • Subrata Paul
  • · Replies 2 ·
Replies
2

Undergrad Planet Composition: Detecting Exoplanets via Spectroscopy

  • akashpandey
  • · Replies 6 ·
Replies
6

High School Living on Titan: A New World for Humans?

  • lifeonmercury
  • · Replies 1 ·
Replies
1

High School Action and reaction of a rocket in space.

  • Clara Chung
  • · Replies 3 ·
Replies
3

High School Is the effect of gravity limited by distance?

  • lifeonmercury
  • · Replies 29 ·
Replies
29

Undergrad Terraforming Mars: Possibility or Pipe Dream?

  • juanitosguitar
  • · Replies 14 ·
Replies
14

High School How does black hole merger cause loss of mass?

  • danihel
  • · Replies 8 ·
Replies
8

Stargazing How Can Both Jets from a Black Hole Appear to Move Faster Than Light?

  • K. Doc Holiday
  • · Replies 3 ·
Replies
3

High School Are all galaxies moving away from the Milky Way?

  • Pbody101
  • · Replies 16 ·
Replies
16

High School What is the true vacuum and does it exist in our expanding universe?

  • Delta2
  • · Replies 32 ·
2
Replies
32

High School Thickness & Distance of Milky Way at Sun's Location

  • lifeonmercury
  • · Replies 3 ·
Replies
3

High School Are black holes white or monochromatic?

  • newjerseyrunner
  • · Replies 3 ·
Replies
3

Graduate Philosophy of a Mathematical Multiverse

  • FallenApple
  • · Replies 1 ·
Replies
1

Undergrad How did scientists figure out the expansion is accelerating?

  • resurgance2001
  • · Replies 1 ·
Replies
1

Undergrad Is the Cosmic Void Between Galaxies Truly Empty?

  • Mohd Abdullah
  • · Replies 6 ·
Replies
6

High School How can we create a map of the universe?

  • Andrew Whalen
  • · Replies 19 ·
Replies
19

High School Height measurement on other planets

  • Gustav S
  • · Replies 1 ·
Replies
1

Graduate Density of White Dwarfs: Questions & Answers

  • K. Doc Holiday
  • · Replies 2 ·
Replies
2

Stargazing Researching AN Ursae Majoris B for Supernova Possibilities

  • K. Doc Holiday
  • · Replies 2 ·
Replies
2

High School Luminosity and neutrino questions

  • K. Doc Holiday
  • · Replies 8 ·
Replies
8

Stargazing What Is This Strange Light in the Night Sky?

  • jane ellis
  • · Replies 12 ·
Replies
12

High School Can we detect ancient EMR attenuation from before the recombination epoch?

  • stoomart
  • · Replies 10 ·
Replies
10

High School Re-evaluating Dark Matter and Kepler's Law in Spiral Galaxies

  • Trenton
  • · Replies 3 ·
Replies
3

Undergrad How can gravity hold galaxy groups togehter?

  • Tryggvas
  • · Replies 5 ·
Replies
5

High School Retrograde star orbits in the Milky Way

  • lifeonmercury
  • · Replies 15 ·
Replies
15

Stargazing Where Is the Hubble Telescope in Orbit?

  • lifeonmercury
  • · Replies 8 ·
Replies
8

High School Beyond the standard model through 'mini spirals'

  • wolram
  • · Replies 2 ·
Replies
2

High School Is Weak Gravitational Lensing Enough Evidence to Confirm Dark Matter?

  • wolram
  • · Replies 2 ·
Replies
2

Undergrad Nebulosity around Pleiades stars

  • virgil1612
  • · Replies 2 ·
Replies
2

High School What is the link between ordinary and dark matter?

  • Dee Flont
  • · Replies 5 ·
Replies
5

High School Gravity waves and density perturbations

  • Discman
  • · Replies 9 ·
Replies
9