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 Does Fine Structure Constant Vary From Place to Place?

  • Dotini
  • · Replies 13 ·
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13

Graduate Gleise 581g; does it exist and could it harbor life?

  • vanvlizr
  • · Replies 12 ·
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12

Undergrad Does Energy Gravitate? Answers Here

  • wolram
  • · Replies 3 ·
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3

Graduate Particles (The Universe) Popping Up Into Existence

  • RobinSky
  • · Replies 7 ·
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7

Graduate Is Space Infinite While Matter is Finite?

  • shifty88
  • · Replies 14 ·
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14

Undergrad Which elements/compounds can be liquid on Venus?

  • Ontophile
  • · Replies 3 ·
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3

Graduate How Can I Identify Elements in Jupiter's Absorption Spectrum?

  • Jahne7
  • · Replies 1 ·
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1

Graduate Time Before Big Bang: Is Time Eternal?

  • revo74
  • · Replies 8 ·
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8

What Higher Dimensions Feel Like

  • Hirams_bro
  • · Replies 6 ·
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6

Graduate How gravitational potential effects mass?

  • new_r
  • · Replies 5 ·
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5

Undergrad Measurement of Galaxy Rotation: How Long Does it Take?

  • jayaramas
  • · Replies 4 ·
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4

High School Light year, explanation required?

  • optical mouse
  • · Replies 27 ·
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27

Graduate Missing Matter - Is anything really Missing

  • yogi
  • · Replies 15 ·
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15

Graduate Zero-energy_universe doesnt add up

  • granpa
  • · Replies 2 ·
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2

Graduate Running in Space: Can You Accelerate?

  • vityav
  • · Replies 8 ·
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8

Undergrad How feasible you think Nemesis theory is

  • Chewy0087
  • · Replies 5 ·
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5

Stargazing Quick and Easy Telescope Measurments?

  • Willis666
  • · Replies 4 ·
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4

Graduate Determining the dominant body in a basic planetary system simulation

  • TheHarvesteR
  • · Replies 7 ·
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7

Undergrad The Drake Equation: Is there really other Life in the Universe?

  • PhysicsPost
  • · Replies 32 ·
2
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32

Stargazing How can I safely view a solar eclipse?

  • PhysicsPost
  • · Replies 1 ·
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1

Solar system on my date of Birth

  • sabrina82
  • · Replies 11 ·
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11

Graduate Is the Universe Losing Mass Through Stellar Energy Conversion?

  • jayaramas
  • · Replies 1 ·
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1

Graduate Why do so many people claim cyclic models brake down due to entropy?

  • lukesfn
  • · Replies 2 ·
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2

Graduate The Raisin Bread Analogy Question

  • Julius Caesar
  • · Replies 36 ·
2
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36

What is the best book on cosmology for all levels of knowledge?

  • think
  • · Replies 4 ·
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4

Graduate Is the Center of the Milky Way Not What We Think?

  • kjensen
  • · Replies 11 ·
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11

Graduate Creation of space what exactly does this mean

  • matthias31415
  • · Replies 20 ·
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20

Graduate Black holes, dark matter, the expansion of the universe, and unifying theories.

  • robertfergus
  • · Replies 4 ·
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4

Graduate Is the Big Bang Misunderstood as an Explosion in Static Space?

  • Imax
  • · Replies 2 ·
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2

Graduate What is the ultimate fate of a massive star in space?

  • PhysicsPost
  • · Replies 1 ·
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1

Graduate The limit of the observable universe

  • mrspeedybob
  • · Replies 8 ·
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8

Undergrad Possible energy sources that a lunar base might have as an option

  • MonserrateM
  • · Replies 4 ·
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4

Graduate Calculating density from CMB data

  • skippy1729
  • · Replies 3 ·
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3

Undergrad Are orbital planes generally parallel on large scales?

  • mrspeedybob
  • · Replies 3 ·
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3

High School Why Only One Sun & Moon on Earth?

  • rijaalu
  • · Replies 4 ·
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4

Uncovering the Mystery: Has Something New Been Found?

  • Fusiontron
  • · Replies 1 ·
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1

Graduate How to Accurately Convert FK5 to Altitude and Azimuth?

  • Scott S
  • · Replies 1 ·
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1

High School What distance will a traveler cover if they walk in a southwesterly direction?

  • luiseduardo
  • · Replies 6 ·
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6

Graduate Can Mic Oscillations Replace Dark Energy in Cosmic Expansion Models?

  • wolram
  • · Replies 1 ·
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1

Graduate Questions Regarding The Expansion of The Universe

  • RobinSky
  • · Replies 17 ·
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17

Virgin Galactic - the first step?

  • narrator
  • · Replies 7 ·
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7

Graduate Is There a Hidden Cause Behind the Big Bang?

  • GarryS
  • · Replies 116 ·
4
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116

Undergrad The size of the universe, and what we can see.

  • TheSwamper
  • · Replies 4 ·
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4

Undergrad Why aren't stars in a star cluster attracted to each other?

  • texasblitzem
  • · Replies 25 ·
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25

Graduate Exponential expansion and Higgs mechanism

  • lark
  • · Replies 15 ·
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15

Graduate Elliptical Orbit's curvature the same at opposite ends of semi-major axis?

  • bahamagreen
  • · Replies 9 ·
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9

Graduate We Know Less About CDM Than We Did Before

  • Dotini
  • · Replies 6 ·
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6

Undergrad The sun moves through space, right?

  • phinds
  • · Replies 8 ·
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8

High School What Are the Potential Benefits of a Lunar Base?

  • MonserrateM
  • · Replies 44 ·
2
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44

Undergrad Will Pluto Crash into Neptune?

  • Philosophaie
  • · Replies 8 ·
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8

Graduate Question: Regarding Stellar Spectroscopy Equipment.

  • Jahne7
  • · Replies 1 ·
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1

Undergrad Gravitational Lenses & Light Frequency: Same or Different?

  • jayaramas
  • · Replies 1 ·
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1

Undergrad How to simulate planets orbit curce around the sun ?

  • kjensen
  • · Replies 36 ·
2
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36

High School Is Velocity Consistent in Planetary Orbits?

  • AakashPandita
  • · Replies 14 ·
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14

Stargazing Choosing a Telescope: Orion vs Celestron

  • Willis666
  • · Replies 2 ·
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2

Undergrad Why do scientists believe the expansion of the universe is accelerating?

  • sdemjanenko
  • · Replies 11 ·
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11

High School If Universe is Expanding at an Accelerated Rate Why

  • ronholton
  • · Replies 22 ·
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22

Undergrad Formation/Expansion of Red Giant

  • Guni22
  • · Replies 3 ·
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3

Graduate Dark Matter Clumping: Unanswered Questions

  • bigmig
  • · Replies 26 ·
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26

Graduate Can a spaceship land on a pulsar?

  • bostonnew
  • · Replies 7 ·
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7

High School Is Dark Matter Just Unseen Water Vapor?

  • nmk
  • · Replies 9 ·
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9

Undergrad Could the Universe's Expansion be Compared to Oil on Water?

  • pilgrum90
  • · Replies 3 ·
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3

Graduate How can we measure time before the Big Bang?

  • kings7
  • · Replies 26 ·
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26

Undergrad What is the estimated energy output of the Milky Way?

  • jayaramas
  • · Replies 1 ·
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1

Graduate A question based on Lawrence Krauss' explanation

  • TRB8985
  • · Replies 3 ·
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3

Graduate What if light speed wasn't the limit?

  • narrator
  • · Replies 10 ·
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10

Undergrad Why are galaxies shaped like spirals?

  • jayaramas
  • · Replies 1 ·
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1

Undergrad What are some applications of lasers in astrophysics research?

  • d3nat
  • · Replies 7 ·
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7

Graduate Gravity and galaxy rotation curves: G vs. dynamics modifications?

  • hkyriazi
  • · Replies 38 ·
2
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38

Graduate Quantum fluctuations and Spacetime

  • DonSmith
  • · Replies 3 ·
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3

High School Andromeda Galaxy colliding with the Milky Wa

  • zytyxx
  • · Replies 14 ·
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14

Undergrad Star to black hole same mass/gravity?

  • narrator
  • · Replies 4 ·
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4

Undergrad Questions about Galactic Rotation

  • LaurieAG
  • · Replies 11 ·
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11

Undergrad What is the Smallest Possible Size of a Black Hole?

  • jayaramas
  • · Replies 9 ·
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9

Undergrad Is Gliese 581d a Goldilocks planet?

  • narrator
  • · Replies 52 ·
2
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52

Graduate What would Fermi say now about his 'paradox'?

  • udtsith
  • · Replies 1 ·
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1

Graduate Why are planetary orbits so circular?

  • oldman
  • · Replies 34 ·
2
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34

Graduate Accelerating expansion of universe is an illusion

  • bohm2
  • · Replies 44 ·
2
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44

Graduate PhD Astronomy Prof: Paucity of evidence for the Big Bang

  • csmcmillion
  • · Replies 19 ·
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19

Graduate Time dilation & the first galaxies

  • PetTastic
  • · Replies 2 ·
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2

Graduate What is information in a black hole

  • Astro.padma
  • · Replies 12 ·
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12

Graduate How close to constraining DE to simply be Lambda?

  • marcus
  • · Replies 0 ·
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0

High School Why doesn't tidal force pull earth and moon together?

  • AlonsoMcLaren
  • · Replies 4 ·
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4

High School Neutron Stars vs Black Holes: What's the Difference?

  • jayaramas
  • · Replies 4 ·
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4

Graduate Theoretical scenario for star-forming with a calculation

  • jcarper
  • · Replies 21 ·
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21

Graduate Are cycles and entropy compatible?

  • bill alsept
  • · Replies 82 ·
3
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82

Graduate What is expansion ? A thought experiment

  • matthias31415
  • · Replies 22 ·
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22

Undergrad Why most of the galaxies are having two spiral arms only?

  • jayaramas
  • · Replies 5 ·
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5

Graduate Is New Space Being Created Between Galaxies?

  • skydivephil
  • · Replies 8 ·
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8

High School Explore Manhattanhenge – the Manhattan Solstice

  • Ironside
  • · Replies 3 ·
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3

Graduate What are the main challenges in developing space-based solar power systems?

  • shashankac655
  • · Replies 2 ·
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2

Graduate Time dilations and our perspective

  • bill alsept
  • · Replies 2 ·
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2

Graduate Light travel paradox? Please, help to figure it out

  • Alexroma
  • · Replies 18 ·
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18

Graduate Soft landiing an asteroid at the south pole

  • khoopes01
  • · Replies 24 ·
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24

Graduate Universe cyclic model and energy loss

  • mtanti
  • · Replies 6 ·
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6

Graduate Big Bang Theory and Shape of the Universe

  • Vorde
  • · Replies 6 ·
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6

Graduate State Space control dervatives of input in B matrix.

  • controlboy
  • · Replies 1 ·
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1

Graduate Ptolemy reduces to Kepler as Epicycles → ∞?

  • Geremia
  • · Replies 18 ·
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18

Graduate Age of the Universe - is it meaningful?

  • Saddlestone
  • · Replies 22 ·
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22

Graduate Loop bounce and geometric entropy (re: Bill A's question)

  • marcus
  • · Replies 6 ·
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6