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

Graduate Questions about the balloon analogy

  • Rob Haskell
  • · Replies 11 ·
Replies
11

Stargazing Astrophotography -- Best Telescopes?

  • Kelson Adams
  • · Replies 12 ·
Replies
12

Undergrad How fast to shoot a bullet for it to hit the moon?

  • Treva31
  • · Replies 20 ·
Replies
20

High School Rapid Formation of the Moon: Insights from Theia Impact

  • Nobbstradamus
  • · Replies 5 ·
Replies
5

Graduate Does mass slow the expansion of space?

  • AndyFin
  • · Replies 5 ·
Replies
5

Graduate How to stop a black hole forming?

  • Graynell
  • · Replies 3 ·
Replies
3

Graduate Can Higgs be the inflaton - can LHC produce an inflaton 750

  • kodama
  • · Replies 2 ·
Replies
2

Graduate Is There Direct Evidence of Cosmic Re-acceleration?

  • wolram
  • · Replies 1 ·
Replies
1

Graduate Jumbled up spectra of stars/glaxies

  • terahertz
  • · Replies 3 ·
Replies
3

Graduate An article stating Cosmology is in crisis. Is it in crisis?

  • Tanelorn
  • · Replies 3 ·
Replies
3

Graduate Are Dual Supermassive Black Holes in Galaxies Rare and Insignificant?

  • Astronuc
  • · Replies 4 ·
Replies
4

Is Global Warming Responsible for My Amazing Astrophotography?

  • Andy Resnick
  • · Replies 7 ·
Replies
7

Insights The Balloon Analogy .... the Good, the Bad, and the Ugly - Comments

  • phinds
  • · Replies 58 ·
2
Replies
58

Graduate Quark Overproduction in the Big Rip Theory

  • Ryan Reed
  • · Replies 1 ·
Replies
1

Graduate Gravity wave cancellation cause space expansion?

  • udtsith
  • · Replies 1 ·
Replies
1

Graduate What happens when a star and a black hole collide?

  • EinsteinFan
  • · Replies 4 ·
Replies
4

Graduate How do we know that the universe is three dimensional?

  • Fiziqs
  • · Replies 5 ·
Replies
5

Graduate Large amount of mercury in space

  • Dhanush Shenoy
  • · Replies 25 ·
Replies
25

Graduate The Big Bang & What's Not: 2016 Edge Essays

  • Keith_McClary
  • · Replies 2 ·
Replies
2

Graduate Maximum velocity of a falling object at the event horizon?

  • Bernie G
  • · Replies 4 ·
Replies
4

High School Light & Blackhole: Can Light Escape?

  • Salman Rayeen
  • · Replies 4 ·
Replies
4

Undergrad Why do pulsars emit electromagnetic waves from their poles?

  • 24forChromium
  • · Replies 2 ·
Replies
2

Graduate Why does dark matter pool in the CMB plasma?

  • Dr. Strange
  • · Replies 11 ·
Replies
11

Graduate Conservation of energy and space expansion

  • Lopes1801
  • · Replies 4 ·
Replies
4

Graduate Question reguarding the expanding universe

  • Daniel K
  • · Replies 42 ·
2
Replies
42

Graduate Why is there no continuity on the temperature of the CMB?

  • sandrogiongo
  • · Replies 6 ·
Replies
6

The Science Behind Children's Love for Cinnamon Toast Crunch

  • Garth
  • · Replies 2 ·
Replies
2

Graduate Time Dilation Definition: What is Time Dilation?

  • Greg Bernhardt
  • · Replies 4 ·
Replies
4

High School What would happen if two stars collided?

  • ThomasLLS
  • · Replies 3 ·
Replies
3

Undergrad How can I generate an elliptical orbit using only position and velocity data?

  • 450AHX
  • · Replies 4 ·
Replies
4

High School Space X falcon 9. Why return to the launch site?

  • DTM
  • · Replies 17 ·
Replies
17

Graduate Gravity around small black holes

  • Paul Katan
  • · Replies 2 ·
Replies
2

Undergrad Hubble Finds Origin of Huge Cloud Crashing into our Galaxy

  • CygnusX-1
  • · Replies 2 ·
Replies
2

Undergrad How E Folds relates to our universe

  • wolram
  • · Replies 3 ·
Replies
3

Undergrad What is the energy in a cubic km of empty space?

  • Dr. Strange
  • · Replies 5 ·
Replies
5

Graduate Searching for Dark Matter in 3.5 Kev Line Mystery

  • Chronos
  • · Replies 2 ·
Replies
2

Undergrad How Does Supernova Light Dimness Indicate Universal Acceleration?

  • cosmos1111
  • · Replies 9 ·
Replies
9

Graduate Another age problem in the early universe?

  • Garth
  • · Replies 2 ·
Replies
2

Graduate Is Dark Matter Consumption by Black Holes Equal in a Galaxy?

  • jgreene
  • · Replies 9 ·
Replies
9

Graduate Accelerating Expansion and Mediocrity Priniciple

  • DaveC426913
  • · Replies 8 ·
Replies
8

High School Birth of the Earth: Big Bang, Dark Matter & More

  • Yashas CS
  • · Replies 4 ·
Replies
4

Undergrad Concerning SOHO's orbit, and its corrections.

  • Tasem
  • · Replies 4 ·
Replies
4

Undergrad Why can we not see auroras at lower latitudes?

  • MozAngeles
  • · Replies 1 ·
Replies
1

Undergrad What are the negligible forces in the solar system besides gravity?

  • whatisreality
  • · Replies 8 ·
Replies
8

Graduate How could the infant universe have existed as a singularity?

  • R. E. Nettleton
  • · Replies 6 ·
Replies
6

Graduate Stars in the early universe and stellar processes

  • Teichii492
  • · Replies 51 ·
2
Replies
51

Anyone in Honolulu interested in astronomy, etc.?

  • marinamiddleton
  • · Replies 1 ·
Replies
1

Graduate Relationship between energy, information and dark energy

  • Greta
  • · Replies 8 ·
Replies
8

Graduate How can a black hole be infinitely small?

  • Aaron380
  • · Replies 5 ·
Replies
5

Undergrad Spectra of Stars: Reliable Data & Quantitative Analysis

  • NihalRi
  • · Replies 10 ·
Replies
10

Help My Extraterrestrial Friend Arrive to Madrid's New Year's Eve Party

  • DrSirius
  • · Replies 4 ·
Replies
4

High School Into what is our universe expanding ?

  • Salman Ranjha
  • · Replies 1 ·
Replies
1

Graduate Distinction between observable and unobservable universe

  • Chiclayo guy
  • · Replies 11 ·
Replies
11

Graduate What are the key challenges facing aerospace tech for a manned Mars mission?

  • Jay K.
  • · Replies 1 ·
Replies
1

Undergrad Geocentric model: how long was it taught in universities?

  • Aidyan
  • · Replies 7 ·
Replies
7

Graduate Could accretion on a neutron star’s poles cause the jets?

  • Bernie G
  • · Replies 46 ·
2
Replies
46

Undergrad Universe Expansion: Is it Possible Beyond Light Speed?

  • 8143902066
  • · Replies 1 ·
Replies
1

Graduate How is time incorporated into the robertson walker metric?

  • NihalRi
  • · Replies 6 ·
Replies
6

Graduate Expansion of the Universe and Thermodynamics

  • g_mogni
  • · Replies 18 ·
Replies
18

Graduate Measuring space expansion without redshift

  • Netspirit
  • · Replies 9 ·
Replies
9

Graduate How can an inflaton field maintain its energy while expanding without diluting?

  • _PJ_
  • · Replies 8 ·
Replies
8

Undergrad Information on Dark Matter and Dark Energy

  • Tony Stark
  • · Replies 4 ·
Replies
4

Undergrad Can the Universe Expand Faster Than Light?

  • Jakecp
  • · Replies 51 ·
2
Replies
51

Graduate Might Dark Energy have anything to do with Inflation?

  • Gerinski
  • · Replies 6 ·
Replies
6

Graduate Proper distance integral limits seem wrong

  • deneve
  • · Replies 2 ·
Replies
2

Undergrad Another math in another universe?

  • Saif Almazrouei
  • · Replies 4 ·
Replies
4

Graduate Gravitational force of a neutron star

  • JohnnyGui
  • · Replies 31 ·
2
Replies
31

Graduate Space Expanding Proportional to Distance

  • Daniel K
  • · Replies 11 ·
Replies
11

Graduate Why does the universe have no net charge?

  • Buzz Bloom
  • · Replies 20 ·
Replies
20

Graduate New valuation of ΛCDM Cosmology by 41 authors....

  • grauitate
  • · Replies 6 ·
Replies
6

Graduate Size of Universe: Evidence of Finite Limits?

  • rjbeery
  • · Replies 8 ·
Replies
8

Graduate How cosmologists determine universe flatness

  • Buzz Bloom
  • · Replies 4 ·
Replies
4

Undergrad Can gravitational waves cancel out?

  • udtsith
  • · Replies 1 ·
Replies
1

Graduate Shape of quark matter bubble in a magnetized neutron star

  • Bernie G
  • · Replies 21 ·
Replies
21

Graduate Proper distance problem/interpretation

  • deneve
  • · Replies 4 ·
Replies
4

Graduate Could Dark Energy lead to a big bang?

  • newjerseyrunner
  • · Replies 3 ·
Replies
3

Graduate Explaining the Luminosity-Temperature Relationship for Stars on the Henyey Track

  • snorkack
  • · Replies 27 ·
Replies
27

Graduate Does accretion reduce the magnetic field of a neutron star?

  • Bernie G
  • · Replies 11 ·
Replies
11

New Closest Earth-like Planet (20/12/15)

  • RooksAndBooks
  • · Replies 5 ·
Replies
5

Graduate Why is it that scientists think that dark matter annihilates

  • rmoh13
  • · Replies 4 ·
Replies
4

Graduate Galaxy centre and rotation curve

  • Shailesh Pincha
  • · Replies 2 ·
Replies
2

Graduate What does expand: Space or Spacetime?

  • Smattering
  • · Replies 37 ·
2
Replies
37

Graduate Cosmic Mystery: Was There Baryonic Matter During Radiation Domination?

  • wolram
  • · Replies 6 ·
Replies
6

Graduate How are the effects of antimatter on gravity different?

  • rmoh13
  • · Replies 3 ·
Replies
3

High School Why does space appear differently to different astronauts?

  • Ian J.
  • · Replies 5 ·
Replies
5

Undergrad Black hole smaller than a neutron star?

  • Slyster
  • · Replies 7 ·
Replies
7

Undergrad Why Do Pluto and Charon Share the Same Diffraction Spike Orientation?

  • Imager
  • · Replies 1 ·
Replies
1

Graduate Neutron Stars from White Dwarf Mergers: Under 1.4 SM?

  • AdamAutism1998
  • · Replies 2 ·
Replies
2

Undergrad What if there was a black hole in the middle of a nebula?

  • Matthew Knowles
  • · Replies 4 ·
Replies
4

Graduate Can We Engineer Our Own Stars to Prevent the Heat Death of the Universe?

  • edwardauron
  • · Replies 2 ·
Replies
2

Undergrad Extraterrestrial Archaeological Expeditions?

  • Fuinne
  • · Replies 7 ·
Replies
7

Undergrad Spectroscopy and the doppler effect

  • The Subject
  • · Replies 4 ·
Replies
4

Undergrad Trying to calculate Orbit figures with C# and 3D space

  • Ajes
  • · Replies 8 ·
Replies
8

Undergrad Quick question on orbital eccentricity and mechanical energy

  • Contadoren11
  • · Replies 3 ·
Replies
3

Graduate The unification of quantum theory and relativity theory

  • BPL3
  • · Replies 1 ·
Replies
1

Undergrad Energy production of star given mass?

  • Lagraaaange
  • · Replies 12 ·
Replies
12

Graduate Hawking radiation from not-a-black-hole?

  • nikkkom
  • · Replies 1 ·
Replies
1

Graduate What's the most massive white dwarf in the MW?

  • AdamAutism1998
  • · Replies 11 ·
Replies
11

Graduate R136a defies Laws of Stellar Evolution

  • AdamAutism1998
  • · Replies 22 ·
Replies
22

Graduate Ptolemy's Theory of the Empty Focus of an Elliptical Orbit

  • greswd
  • · Replies 4 ·
Replies
4