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

Stargazing Expert Astrophotography Tips & Discussions | Share Your Photos!

  • Phobos
  • · Replies 315 ·
11
Replies
315

Stargazing What's Happening in the Night Sky? Upcoming Astronomy Events to Look Out For!

  • Phobos
  • · Replies 284 ·
10
Replies
284

Graduate Light-cone cosmological simulations

  • sketos
  • · Replies 11 ·
Replies
11

Graduate Travelling to the edge of the Universe, 4th Dimensional Time Travel

  • GetBent
  • · Replies 10 ·
Replies
10

Graduate MOND : Help with fitting procedure

  • devd
  • · Replies 9 ·
Replies
9

How Fast Does Beta Pictoris b Spin?

  • CygnusX-1
  • · Replies 2 ·
Replies
2

Graduate Can dark energy reveal absolute motion?

  • Ookke
  • · Replies 5 ·
Replies
5

High School Question: Expansion of the universe

  • IMLearningEng
  • · Replies 3 ·
Replies
3

Undergrad Could a planet get heavier without needing to grow in size?

  • Toldox
  • · Replies 3 ·
Replies
3

Undergrad Why can we see the CMB in every direction we look?

  • cosmictide
  • · Replies 3 ·
Replies
3

Undergrad How Is the Angular Diameter of Jupiter Measured and What Equipment Is Used?

  • aldool
  • · Replies 2 ·
Replies
2

Graduate Cosmic inflation and singularity

  • sshai45
  • · Replies 3 ·
Replies
3

High School Radiation on Mars: Does it Lack a Magnetosphere?

  • thomshere
  • · Replies 3 ·
Replies
3

Undergrad Why does gravity increase when a star dies?

  • HenryKhais
  • · Replies 3 ·
Replies
3

Graduate Questions about the multiverse theory

  • e_john96
  • · Replies 4 ·
Replies
4

Graduate Can we ask such a question about expansion of universe?

  • aleemudasir
  • · Replies 24 ·
Replies
24

High School How Often Do Blue Moons Really Occur?

  • caters
  • · Replies 17 ·
Replies
17

Graduate Our attempts at certainty (measurements) actually increase uncertainty

  • jgreavu
  • · Replies 14 ·
Replies
14

Earth-sized exoplanet spotted in star’s habitable zone

  • reenmachine
  • · Replies 44 ·
2
Replies
44

Undergrad Collision Sparks Star Birth at Our Galaxy's Edge

  • CygnusX-1
  • · Replies 1 ·
Replies
1

Graduate Can Pulsar Timing Arrays Detect Gravitational Wave Bursts with Memory?

  • wolram
  • · Replies 9 ·
Replies
9

Undergrad Is it really possible to see down to mag 8?

  • logic10
  • · Replies 4 ·
Replies
4

Graduate Sterile Neutrino Dark Matter: Case Advanced

  • Chronos
  • · Replies 2 ·
Replies
2

Graduate Information on large scale structure?

  • sketos
  • · Replies 4 ·
Replies
4

Undergrad Can NMEA (GPS) Data Tracker Help Improve Signal Reception?

  • camerart
  • · Replies 4 ·
Replies
4

Are green <5mW laser pointers legal to use in New York City?

  • jenny_shoars
  • · Replies 7 ·
Replies
7

Graduate Why do we observe only microwaves in the background radiation?

  • genefalk
  • · Replies 5 ·
Replies
5

Graduate Angular momentum of galaxies in galactic clusters

  • Theactualbman
  • · Replies 1 ·
Replies
1

High School Which Variable Star Has the Longest Period?

  • mishima
  • · Replies 5 ·
Replies
5

Graduate Bullet Cluster: Controversial & Puzzling Evidence for Alternative Models

  • Chronos
  • · Replies 3 ·
Replies
3

Graduate When we look at cosmic web images, what do we see?

  • awcrowe
  • · Replies 1 ·
Replies
1

High School Can WorldWide Telescope Help View Gas Clouds, Star Systems, and Galaxies Online?

  • leroyjenkens
  • · Replies 8 ·
Replies
8

Undergrad Time travel into the past a possibility now?

  • alteredmind
  • · Replies 7 ·
Replies
7

M42 and the Running Man nebula with Takahashi 150mm

  • Astronomus
  • · Replies 3 ·
Replies
3

Graduate Matter production during inflation

  • nomadreid
  • · Replies 12 ·
Replies
12

Graduate Is 4th Quantisation the Key to Understanding Multiverse Interactions?

  • Quantizer
  • · Replies 3 ·
Replies
3

Graduate BransDicke Cosmology and Accelerated Exlansion

  • Quantizer
  • · Replies 3 ·
Replies
3

Graduate What Gets 2nd Quantised in the WDW Equation: Geometry, Matter, or Gravity?

  • Quantizer
  • · Replies 1 ·
Replies
1

Undergrad Light & Black Hole: Absorbing Light w/o Mass

  • harshit
  • · Replies 14 ·
Replies
14

Graduate SVT Decomposition: Definition and Purpose

  • the_pulp
  • · Replies 3 ·
Replies
3

Graduate Formation of 1st Solar System: Timeline Since Big Bang

  • jing2178
  • · Replies 1 ·
Replies
1

Graduate Superluminal Gravitational Acceleration

  • Terdbergler
  • · Replies 10 ·
Replies
10

Undergrad Iapetus equatorial ridge fell from the skies

  • PhysicoRaj
  • · Replies 8 ·
Replies
8

High School Doubt in a scene from the movie Gravity

  • k.udhay
  • · Replies 22 ·
Replies
22

Graduate Quick question on CMB anisotropy in Earth frame

  • WannabeNewton
  • · Replies 3 ·
Replies
3

Undergrad Is circumnavigation possible on Phobos or Deimos?

  • megamind
  • · Replies 2 ·
Replies
2

Undergrad The Sun's Next Phase: Can We Avoid Extinction?

  • megamind
  • · Replies 3 ·
Replies
3

Graduate Eternal inflation disfavored by Planck and BICEP2?

  • Chronos
  • · Replies 2 ·
Replies
2

Undergrad Why terrestrial planets in inner solar system & gas giants in outer?

  • curious_ocean
  • · Replies 9 ·
Replies
9

Graduate Found: The First Double Star That BRIGHTENS During Eclipse

  • CygnusX-1
  • · Replies 2 ·
Replies
2

Graduate Age of the Universe: Intuitive Understanding

  • Ichimaru
  • · Replies 2 ·
Replies
2

Graduate Is the Big Bang Caused by a Four-Dimensional Explosion?

  • Mar
  • · Replies 4 ·
Replies
4

Undergrad Why is angular momentum not conserved in 2 similar mass planet system?

  • td21
  • · Replies 1 ·
Replies
1

Undergrad How accurate is our image (depiction) of the Milky Way?

  • Glenstr
  • · Replies 5 ·
Replies
5

Graduate Understanding the Luminosity of Radiative Stars

  • Ken G
  • · Replies 75 ·
3
Replies
75

Stargazing How big would a neutrino telescope have to be?

  • CosmicVoyager
  • · Replies 4 ·
Replies
4

Blood moon Total Eclipse tonight

  • Evo
  • · Replies 26 ·
Replies
26

Graduate Big Rip Cosmology and Many-Worlds Quantum Mechanics

  • caspiansea3
  • · Replies 3 ·
Replies
3

Undergrad Why did Earth lose its first atmosphere but keep its second?

  • curious_ocean
  • · Replies 9 ·
Replies
9

High School How did Copernicus get the idea of the heliocentric model?

  • Yashbhatt
  • · Replies 13 ·
Replies
13

Graduate Is the universe a causal system?

  • HamzahA
  • · Replies 16 ·
Replies
16

Graduate Reconsidering the Speed of Light: A Crazy Idea on Dark Matter and the Big Bang

  • genphis
  • · Replies 1 ·
Replies
1

Graduate What would happen if the moon's orbital radius were increased?

  • diffusegrey
  • · Replies 1 ·
Replies
1

Graduate How Does Space-Time Function at the Big Bang?

  • tlnarasimham
  • · Replies 11 ·
Replies
11

Graduate Neil deGrasse Tyson's Observable Universe

  • fishtail
  • · Replies 17 ·
Replies
17

Graduate Ideal gas laws in cosmology usage

  • Mordred
  • · Replies 23 ·
Replies
23

I captured a celestial event, could someone explain what it is?

  • yatharth
  • · Replies 6 ·
Replies
6

Graduate Why Are Saturn's Rings and Planetary Orbits Aligned Despite Cosmic Disturbances?

  • anorlunda
  • · Replies 5 ·
Replies
5

Undergrad What are the mysterious properties of Dark Matter?

  • kirred
  • · Replies 37 ·
2
Replies
37

Graduate What does it mean when cosmologists say the universe is flat?

  • mannygonzales1
  • · Replies 15 ·
Replies
15

High School Although the wrong theories contributed to scientific evolution

  • pomo
  • · Replies 3 ·
Replies
3

High School Gravitational Constant: Earth vs Other Planets

  • Emz19
  • · Replies 3 ·
Replies
3

The Mystery of the Pre-Big Bang Universe

  • thomshere
  • · Replies 2 ·
Replies
2

Undergrad How do they calculate how fast celestial objects are moving?

  • Glenstr
  • · Replies 8 ·
Replies
8

Graduate Was matter created during the big bang?

  • curious_ocean
  • · Replies 13 ·
Replies
13

Graduate What is the problem with the Big Bang Theory and seeing the early universe?

  • RyanXXVI
  • · Replies 29 ·
Replies
29

High School Why is the universe considered as cold?

  • ninja
  • · Replies 6 ·
Replies
6

Graduate Cosmological Redshift: Electron Energy Loss in Expanding Universe?

  • Matterwave
  • · Replies 8 ·
Replies
8

High School Which Telescope Offers the Best Value for Under $150?

  • DHF
  • · Replies 4 ·
Replies
4

Undergrad Unusual light rising from Martian surface

  • Dotini
  • · Replies 1 ·
Replies
1

Graduate Could the collapse of a black hole lead to the creation of a new Big Bang?

  • BenZaleschuk
  • · Replies 1 ·
Replies
1

Graduate Does BICEP2 kill Conformal Cyclic Cosmology?

  • twistor
  • · Replies 2 ·
Replies
2

Graduate What Are the Dynamics and Time Scales of Dark Matter Halos?

  • oldGhost1
  • · Replies 6 ·
Replies
6

Graduate How can we predict a Big Crunch?

  • Yashbhatt
  • · Replies 13 ·
Replies
13

Graduate Why do stars show absorption lines?

  • zincshow
  • · Replies 5 ·
Replies
5

Undergrad Gravitational Redshift and Hubble.

  • piareround
  • · Replies 17 ·
Replies
17

Graduate Describe & explain the significance of the 3K CMB

  • cakeislife
  • · Replies 9 ·
Replies
9

Undergrad Is the Mass-Luminosity Relationship for Main-Sequence Stars Linear?

  • Agasthiyaraj L
  • · Replies 4 ·
Replies
4

Graduate Black Hole Formation and Iron Distribution

  • nehorlavazapal
  • · Replies 5 ·
Replies
5

Graduate What sets the fusion rate in a main-sequence star?

  • Ken G
  • · Replies 5 ·
Replies
5

Graduate Calculating critical density of mass, from Hubble time, for exercise

  • marcus
  • · Replies 1 ·
Replies
1

Graduate Does Dark Matter Surround Us Unseen?

  • Quotidian
  • · Replies 20 ·
Replies
20

Undergrad The Sun's End: Predicting the Inevitable

  • flyinhigh
  • · Replies 5 ·
Replies
5

Graduate How many particles could be crammed into the universe?

  • Atomised
  • · Replies 1 ·
Replies
1

Graduate Quantum perspectives in basic astrophysics?

  • aim1732
  • · Replies 4 ·
Replies
4

Time magazine spreads the horse manure

  • phinds
  • · Replies 43 ·
2
Replies
43

Graduate Understanding Photon Thermalization and Its Impact on CMB Anisotropies

  • guest1234
  • · Replies 8 ·
Replies
8

Graduate Orbit change due to hypothetical mass change

  • meteor84
  • · Replies 8 ·
Replies
8

Undergrad Help building an n-body simulation incorporating the speed of gravity

  • nearc
  • · Replies 12 ·
Replies
12

Graduate Are Modifications Needed for Escape Velocity in Elliptical Orbits?

  • vikasagartha
  • · Replies 6 ·
Replies
6