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 Why do people think red shift is caused by big bang?

  • n_kelthuzad
  • · Replies 20 ·
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20

Graduate Viewing a far away galaxy through a wormhole

  • NWH
  • · Replies 2 ·
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2

Graduate Is there any gravitationally unbound' galactic clusters in observable universe

  • hitchiker
  • · Replies 4 ·
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4

High School Solar Flare & CME: August 9, 2011 X6.9 Flare

  • Astronuc
  • · Replies 26 ·
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26

Graduate Update to the BALLOON ANALOGY web page

  • phinds
  • · Replies 2 ·
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2

High School Need Big Bang Theory Evidence for a school debate.

  • SchoolDebate
  • · Replies 11 ·
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11

Graduate How Can We Measure Earth's Speed Relative to the Big Bang?

  • Borzol
  • · Replies 11 ·
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11

Undergrad Is a Multiverse Considered a Universe or Multiple Universes?

  • Flustered
  • · Replies 4 ·
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4

High School What conditions must be met before star becomes a black hole?

  • Stu21
  • · Replies 6 ·
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6

Graduate Gravity speed (I know it's been beat to death, apologies in advance)

  • DNMock
  • · Replies 4 ·
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4

Graduate Dark Matter Galaxy Collision Galactic Double Slit Test

  • FesterCluck
  • · Replies 4 ·
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4

Graduate Density fluctuations that result after inflation

  • robertjford80
  • · Replies 10 ·
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10

Stargazing What is a good aperture for a telescope collecting ISO far-infrared radiation?

  • Quagz
  • · Replies 9 ·
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9

Graduate Define Red-Shift: Explaining BH Event Horizon

  • Aurora-Sky
  • · Replies 3 ·
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3

Graduate Could Quantum Mechanics Explain a Super Heavy Universe?

  • mitcho
  • · Replies 1 ·
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1

Graduate How do physicists use redshift to determine the expansion of the universe?

  • hitchiker
  • · Replies 33 ·
2
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33

Graduate How the shape of the universe affects density

  • robertjford80
  • · Replies 7 ·
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7

Graduate The phase transition of the universe during inflation

  • robertjford80
  • · Replies 4 ·
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4

High School What do the stars look like from space?

  • Albertgauss
  • · Replies 12 ·
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12

High School Are there other periodic phenomena's other than the comet Hally?

  • Karimspencer
  • · Replies 4 ·
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4

Graduate Matter at the core of a neutron star.

  • CarlosLara
  • · Replies 8 ·
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8

Graduate Is matter not expanding together with the rest of the universe?

  • TVI_1405
  • · Replies 8 ·
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8

Undergrad Type 2 Supernova: Energy Source & Type 1 Comparison

  • goldsax
  • · Replies 2 ·
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2

Graduate Frame Dragging Explained: Dimensions, Schwarzschild Radius, Metrics & Angles

  • eggman100
  • · Replies 4 ·
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4

Graduate Black holes and the event horizon

  • thedude36
  • · Replies 3 ·
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3

Graduate Position and velocity vector of point referred to equinox

  • solarblast
  • · Replies 7 ·
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7

Graduate Why Does 'a' Being Smaller Than 'a0' Eliminate μ in MOND?

  • mesa
  • · Replies 31 ·
2
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31

Graduate Cosmological expansion of earth orbit

  • Naty1
  • · Replies 14 ·
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14

Graduate Questions about (potential) variations in the Fine Structure Constant

  • Lino
  • · Replies 7 ·
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7

Graduate Practical Interstellar Mission to Alpha Centauri?

  • chill_factor
  • · Replies 23 ·
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23

Graduate Is the Universe Really Expanding or Are We Just Moving Faster?

  • Tyah
  • · Replies 3 ·
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3

Graduate Did the universe have a beginning?

  • Mononoke
  • · Replies 15 ·
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15

Graduate All things aside, how big could a black hole actually get?

  • Lunar-Scooter
  • · Replies 27 ·
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27

Graduate Looking for advice on solar system integrator

  • Deadstar
  • · Replies 3 ·
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3

Graduate How all matter antimatter particles annihilated after bigbang

  • hitchiker
  • · Replies 28 ·
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28

Graduate Another nail in the MOND coffin?

  • Chronos
  • · Replies 1 ·
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1

Undergrad Universe expansion is slowing down

  • Myslius
  • · Replies 36 ·
2
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36

Undergrad A question regarding the B-V measurements of stars

  • Rumor
  • · Replies 1 ·
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1

Does Matter's Mass Determine Space's Curvature?

  • quantum12345
  • · Replies 11 ·
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11

Undergrad Source of Hydrogen: Where Does Our Sun Get Its Fuel?

  • Zman
  • · Replies 5 ·
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5

High School What Would Happen if Earth Had Two Moons?

  • SCKnight14
  • · Replies 22 ·
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22

Undergrad What is the Event Horizon of a Black Hole?

  • AbsoluteZer0
  • · Replies 3 ·
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3

Graduate Are Charged Black Holes Just a Myth?

  • trini
  • · Replies 7 ·
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7

Graduate A flat-torus as the geometry of space-time

  • zhermes
  • · Replies 6 ·
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6

Graduate Is Infinite Inflation Possible After the Big Bang?

  • PantherModern
  • · Replies 25 ·
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25

Graduate Using the CMB to verify the universe is flat

  • robertjford80
  • · Replies 2 ·
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2

Undergrad Understanding Stellar Lifespans: Comparing Luminosity & Mass

  • tommyboo
  • · Replies 5 ·
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5

Undergrad Againwhat is a vaccum made of?

  • Desraj
  • · Replies 17 ·
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17

Graduate Why is the moon's gravity differential field pointing away from the

  • vin300
  • · Replies 1 ·
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1

White Dwarf, 12 Billion Years Old, Found Only 100LY Away

  • Dotini
  • · Replies 18 ·
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18

Graduate Gravitational Perturbation - How does it work?

  • Bjarne
  • · Replies 2 ·
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2

Can Ordinary Telescopes Detect Moon Bases?

  • WhiteHawk
  • · Replies 1 ·
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1

Graduate Accretion disk around galaxy NGC 4261

  • JeffOCA
  • · Replies 3 ·
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3

Undergrad Could SF6, Photosynthetic Bacteria, Hydrogen, and Ozone Make Mars Habitable?

  • Frogeyedpeas
  • · Replies 15 ·
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15

Could Life Adapt to the Solar Flares of Red Dwarf Stars?

  • phyzguy
  • · Replies 3 ·
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3

Undergrad Layman question about distance and speed of light

  • Gaddasconi
  • · Replies 4 ·
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4

Graduate FRW Derivation History: Acker's Questions Answered

  • Acker
  • · Replies 3 ·
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3

Graduate Index of Refraction of Outer/Interplanetary Space

  • Jolb
  • · Replies 2 ·
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2

Graduate What is the significance of a universe emerging from nothing?

  • Chalnoth
  • · Replies 24 ·
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24

Graduate Is this possible? (regarding observable and actual size of universe)

  • Kaldanis
  • · Replies 5 ·
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5

Graduate Re: CMB Redshift Question (Visible Wavelengths)

  • JArnold
  • · Replies 5 ·
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5

High School Asteroid hits moon → moon hits Earth possible?

  • Blue_Jaunte
  • · Replies 68 ·
3
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68

High School Asteroid, Meteorite, Meteoroid, or Meteor?

  • jenny_shoars
  • · Replies 11 ·
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11

Graduate Dark Matter on Trial: Serious Blow to Theories?

  • Mononoke
  • · Replies 25 ·
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25

Graduate Pauli Exclusion Principle in Black Holes.

  • CarlosLara
  • · Replies 11 ·
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11

Graduate Proportion of energy compared to mass in universe

  • auntio
  • · Replies 2 ·
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2

Graduate What does a more massive neutron star constitute?

  • tomjennings
  • · Replies 6 ·
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6

Graduate How Can Space Exist Without Time?

  • peacerenity
  • · Replies 2 ·
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2

Graduate Gravitational waves in elsewhere of light cone

  • PhysicoRaj
  • · Replies 13 ·
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13

Undergrad Solar elements and their placement

  • Riptide
  • · Replies 4 ·
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4

Stargazing How do i make a telescope computerized?

  • Patridor
  • · Replies 2 ·
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2

Graduate What is Jean's Creation in Relation to Interstellar Mediums?

  • Mabs
  • · Replies 2 ·
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2

Undergrad Why Isn't the Moon's Shadow Line Perpendicular to the Sun-Moon Line?

  • johann1301
  • · Replies 8 ·
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8

Graduate Can Jupiter Become a Stable Star?

  • Bavid
  • · Replies 3 ·
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3

High School Science Fair Project Ideas for Astronomy

  • Masonn
  • · Replies 3 ·
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3

Undergrad Are there any fields of astrophysics with no general relativity?

  • chill_factor
  • · Replies 12 ·
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12

Undergrad How Does Visible Light from Quasars Reach Us?

  • seandarcher
  • · Replies 6 ·
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6

Is Nothing Still Considered Something?

  • Lensman
  • · Replies 35 ·
2
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35

Graduate What Happens to Sound Waves Near Black Holes?

  • freddy123
  • · Replies 18 ·
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18

Undergrad What is the photon sphere and where is the singularity in a black hole?

  • AbsoluteZer0
  • · Replies 2 ·
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2

Graduate How do we infer a closed universe from FLRW metric?

  • pellman
  • · Replies 3 ·
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3

Graduate Is the Dark Matter Hypothesis Dead?

  • LouisB
  • · Replies 7 ·
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7

Graduate How to find scale factor at recombination?

  • eherrtelle59
  • · Replies 11 ·
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11

Graduate How Long Does the Bipolar Outflow Stage Last in Proto/T Tauri Stars?

  • skydivephil
  • · Replies 1 ·
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1

What makes a great astrophysicist

  • cre8flow
  • · Replies 9 ·
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9

High School What If the Big Bang Was Caused by Another Universe?

  • KevinT
  • · Replies 10 ·
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10

High School Effects on earth from a heavier moon

  • Tomp115
  • · Replies 2 ·
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2

Undergrad Is the Universe Flat or Curved?

  • kaushik_s
  • · Replies 38 ·
2
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38

Graduate Chromosphere population inversion?

  • jabowery
  • · Replies 2 ·
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2

High School Do all stars have same revolving speed?

  • Ravi Mandavi
  • · Replies 8 ·
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8

High School What Makes Black Holes So Mysterious: Do They Really Absorb Light?

  • Marshallaw4
  • · Replies 6 ·
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6

Graduate Linear model uniquely implies a boundary to our Universe?

  • johne1618
  • · Replies 5 ·
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5

High School How do we move around the sun?

  • spark802
  • · Replies 16 ·
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16

Graduate What will Juice tell us about Europa?

  • skydivephil
  • · Replies 8 ·
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8

Undergrad Density of Venus' atmosphere - historical

  • PhilDSP
  • · Replies 2 ·
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2

High School How does and object get its color?

  • Marshallaw4
  • · Replies 6 ·
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6

Undergrad What Makes Gamma Ray Bursts a Fascinating Field of Study?

  • SHISHKABOB
  • · Replies 5 ·
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5

Graduate Where Does Gravity Originate From and Why Is It So Weak?

  • Snowgooned
  • · Replies 13 ·
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13

Undergrad How can I calculate planet trajectory for a 2d solar system simulation?

  • avpx
  • · Replies 11 ·
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11

High School History of the Earth's Axial Tilt

  • TheAzn
  • · Replies 2 ·
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2