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 Entropy and the big bang on to the big crunch and back

  • misnderstudge
  • · Replies 1 ·
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1

High School Lifetime of Earth: Planet vs Sun

  • mersecske
  • · Replies 3 ·
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3

Graduate How this equality exist between time and distance and the velocity

  • karawan
  • · Replies 6 ·
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6

Undergrad Universe Today: What Does It Look Like?

  • binbots
  • · Replies 2 ·
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2

High School Binary universe theory with black holes and white holes

  • spacegeek101
  • · Replies 3 ·
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3

Interactive panoramic of space

  • jhae2.718
  • · Replies 1 ·
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1

Graduate Gamma photon distribution in the galaxy and absorption processes

  • mersecske
  • · Replies 1 ·
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1

Graduate Where is the center of mass of the universe?

  • Quinzio
  • · Replies 14 ·
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14

Graduate Black holes and higher dimensional universe

  • pibb
  • · Replies 4 ·
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4

High School What is meant by floating, flying and moving freely in space?

  • karawan
  • · Replies 7 ·
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7

High School French claim first habitable planet found

  • aychamo
  • · Replies 4 ·
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4

Graduate H-alpha line in galaxies/ hubble redshift

  • SUDOnym
  • · Replies 1 ·
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1

Undergrad How Does Gravity Cause Acceleration Towards a Massive Object in Space?

  • automan
  • · Replies 4 ·
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4

Graduate Puzzled by new confirmation of dark energy

  • phinds
  • · Replies 3 ·
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3

Undergrad The mesure of distances using the redshift

  • houhou.trad
  • · Replies 3 ·
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3

Graduate What Could Have Possibly Triggered the Big Bang?

  • abhiroop_k
  • · Replies 3 ·
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3

Undergrad Relationship between mass and surface temperature of a star

  • jewfro420
  • · Replies 7 ·
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7

Graduate Dark energy observations in young and evolving universe

  • Naty1
  • · Replies 1 ·
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1

Graduate Why Do Some Stars Grow So Massive?

  • mjacobsca
  • · Replies 3 ·
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3

Undergrad How Powerful Is a Supernova in Megatons?

  • FishmanGeertz
  • · Replies 36 ·
2
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36

Undergrad Why does the nebular disk flatten during solar system formation?

  • Trinitiet
  • · Replies 6 ·
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6

High School When did we realize the Sun is a star like those in the night sky?

  • dotancohen
  • · Replies 18 ·
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18

Graduate Could undiscovered sister stars be hiding in our Oort cloud?

  • cph
  • · Replies 2 ·
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2

Graduate Tabeshband solar shading design at 36°N latitude

  • trina1990
  • · Replies 2 ·
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2

Undergrad Estimating the radius of planets

  • trina1990
  • · Replies 4 ·
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4

Undergrad How can Jupiter's gravity eject asteroids from the solar system?

  • ExNihilo
  • · Replies 3 ·
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3

Graduate Is Dark Energy Propelling the Accelerating Expansion of the Universe?

  • ibysaiyan
  • · Replies 7 ·
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7

Undergrad Can rogue planets explain dark matter?

  • Tanelorn
  • · Replies 6 ·
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6

Undergrad Server to query for sun/planets elevation at a given datetime?

  • dotancohen
  • · Replies 4 ·
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4

Graduate Dark Matter Distribution in the Milky Way

  • mersecske
  • · Replies 6 ·
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6

High School How does imaginary time work in cosmology?

  • nomisrosen
  • · Replies 8 ·
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8

Undergrad How do I calculate the direction from one geographic point to another?

  • RAHIL008
  • · Replies 1 ·
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1

Graduate Inflation timeline and scale: conflicting numbers in literature

  • phinds
  • · Replies 4 ·
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4

Undergrad How Does Time Connect to Space in Our Universe?

  • Cbray
  • · Replies 8 ·
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8

What is the Best Book for Learning About Astronomy?

  • phyzzy_physh
  • · Replies 7 ·
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7

Undergrad Could Rogue Planets be an Alternative to Dark Matter?

  • lalbatros
  • · Replies 3 ·
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3

Graduate Why does time move slower in stronger gravitational fields?

  • Blingles
  • · Replies 3 ·
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3

Graduate How does inflation create density perturbations without destroying them?

  • cp05
  • · Replies 14 ·
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14

Graduate News Article + Paper on Dark Energy

  • cepheid
  • · Replies 1 ·
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1

Graduate Understanding curvature and dimensions

  • TrickyDicky
  • · Replies 12 ·
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12

Undergrad Outer planets always gas planets?

  • JV
  • · Replies 12 ·
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12

Graduate What happens to time inside a black hole?

  • Wazkick3n
  • · Replies 29 ·
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29

Graduate Are cosmological redshifts evidence for accelerating expansion or just past inflation?

  • krrazypassion
  • · Replies 5 ·
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5

Red shape with jets in Google Sky map

  • Willis666
  • · Replies 19 ·
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19

Undergrad What is an equal-sun-elevation day called?

  • dotancohen
  • · Replies 15 ·
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15

Graduate Einstein's Gravity: Challenging the Traditional Concept of Forces

  • ender_88
  • · Replies 4 ·
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4

Graduate What are quantum fluctuations and how could they have led to human life?

  • narrator
  • · Replies 20 ·
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20

Graduate Why don't distant galaxies appear less densely packed from their perspective?

  • keepit
  • · Replies 7 ·
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7

Graduate Can a single wormhole have more than two mouths?

  • Godspanther
  • · Replies 21 ·
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21

Graduate Can We Travel at Light Speed and Return to Earth?

  • narrator
  • · Replies 13 ·
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13

Graduate What are the physical differences between matter and antimatter?

  • Cosmo Novice
  • · Replies 2 ·
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2

What is next for the US space program?

  • khemist
  • · Replies 3 ·
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3

Undergrad What is the difference between the left and right pictures of a Quasar Core?

  • Drakkith
  • · Replies 4 ·
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4

High School Has a Star Collision Ever Been Observed in Our Universe?

  • |Orion's Thought|
  • · Replies 16 ·
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16

Graduate Why do galaxies drift apart in the expanding universe?

  • Hexorg
  • · Replies 4 ·
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4

Graduate Are Black Holes sufficiently characterized?

  • cph
  • · Replies 3 ·
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3

Graduate How do I develop physical intuition for the tidal force?

  • Simfish
  • · Replies 1 ·
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1

Graduate Is There a Maximum Rotational Velocity for Pulsars?

  • Plaster
  • · Replies 9 ·
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9

Graduate What are the informations deducible from hubble diagram of supernova 1a?

  • humanist rho
  • · Replies 1 ·
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1

Graduate What is space and what is time?

  • Tanelorn
  • · Replies 36 ·
2
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36

Graduate Big Crunch. What happens at the moment the universe changes direction?

  • dabayman
  • · Replies 7 ·
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7

Undergrad Asteroid Impact Crater Size: Function of Diameter

  • mersecske
  • · Replies 3 ·
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3

Graduate What existed before the bigbang?

  • mdmaaz
  • · Replies 8 ·
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8

Graduate Information about stars indeterminate?

  • Helicobacter
  • · Replies 7 ·
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7

Undergrad How Did Ancient Civilizations Accurately Predict Astronomical Events?

  • BrockLee
  • · Replies 4 ·
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4

What do you think of the void theory vs acceleration article?

  • TalonD
  • · Replies 34 ·
2
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34

Graduate How Can Quasar Beams Emerge from Black Holes Despite the Event Horizon?

  • lnsanity
  • · Replies 7 ·
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7

Undergrad Measuring time in the 17th century.

  • Spinnor
  • · Replies 24 ·
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24

Undergrad What's the opposite of a blackhole?

  • mdmaaz
  • · Replies 6 ·
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6

Graduate Dark matter exerting a gravitational effect on earth?

  • albroun
  • · Replies 7 ·
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7

Undergrad Calculating the size of planets from length of days.

  • conrad141
  • · Replies 4 ·
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4

Graduate Is the Expanding Universe Slowing Down According to Age?

  • meatym
  • · Replies 4 ·
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4

Undergrad Is Faster-Than-Light Space Travel Possible with New Technology?

  • Astro.padma
  • · Replies 18 ·
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18

Graduate What came before the Big Bang?

  • McHeathen
  • · Replies 32 ·
2
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32

Graduate Draw Confidence Contours to Hubble's 1929 Data

  • humanist rho
  • · Replies 45 ·
2
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45

Undergrad Are Asteroids Outside Our Solar System and the Moon Affected by Impact Tsunamis?

  • mersecske
  • · Replies 6 ·
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6

Graduate Light approaching the event horizon

  • permapoop
  • · Replies 5 ·
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5

High School Do Galaxies Move? Rotation Around Something?

  • mdmaaz
  • · Replies 5 ·
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5

Graduate A Closed Universe and the Horizon Problem

  • jfy4
  • · Replies 9 ·
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9

Undergrad What are the consequences of pole reversals on Earth

  • Tokage
  • · Replies 9 ·
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9

Graduate Can tidal forces change a satellite's orientation while maintaining Earth lock?

  • firavia
  • · Replies 4 ·
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4

Undergrad Do we see the universe the way it is?

  • mdmaaz
  • · Replies 38 ·
2
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38

Undergrad Would Earth and moon accelerate toward each other at the same rate as Earth and sun?

  • Restructure
  • · Replies 35 ·
2
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35

Graduate Baby Universes? - Leonard Susskind's Hyperspace Theory

  • kcajrenreb
  • · Replies 1 ·
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1

Graduate Does This Cosmological Model Re-Collapse?

  • ajclarke
  • · Replies 8 ·
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8

High School Expansion of the Universe and Time

  • agreen
  • · Replies 5 ·
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5

Undergrad What methods are used to CONFIRM the compisition of a star from spectral lines?

  • Tokage
  • · Replies 1 ·
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1

Undergrad Why the plane of the rings is vertical to the rotation axis of Saturn?

  • Chris2MIT
  • · Replies 11 ·
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11

Undergrad Do photons travel between every pair of atoms in the universe?

  • Darken-Sol
  • · Replies 17 ·
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17

Graduate Why don't objects approaching a black hole's event horizon appear to slow down?

  • moejoe15
  • · Replies 20 ·
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20

Graduate Can a collapsing star only form a black hole if it has a companion?

  • TheBlackNinja
  • · Replies 7 ·
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7

Graduate What exists outside the expanding universe?

  • redthinker
  • · Replies 9 ·
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9

Graduate Would overcharging an extremal black hole tear it apart?

  • kcajrenreb
  • · Replies 5 ·
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5

High School Do two objects moving in parallel with the same velocity experience different times?

  • karawan
  • · Replies 2 ·
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2

Undergrad Physics of a satellite orbiting the sun

  • Polama
  • · Replies 10 ·
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10

Undergrad Elliptic orbit of earth round the sun

  • Apache
  • · Replies 1 ·
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1

Graduate So, what is the function for the redshift z as a function of distance r?

  • jfy4
  • · Replies 13 ·
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13

Graduate Need VERY recent paper in observational astronomy for journal club presentation

  • omoplata
  • · Replies 1 ·
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1

Graduate Why tidal forces near a black hole depend on its size

  • nukeman
  • · Replies 16 ·
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16

Graduate Was the Big Bang a Low Entropy State in the Universe?

  • johne1618
  • · Replies 4 ·
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4