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 Could Extraterrestrial Life Exist in Unique Environments Like Titan?

  • jonegil
  • · Replies 31 ·
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Graduate X-ray background/peculiar velocities and the Big Bang

  • xratx
  • · Replies 2 ·
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Graduate Physical basis for dark energy-I think Bojo found it

  • marcus
  • · Replies 12 ·
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12

Undergrad Unveiling the Mystery of Light: How Does it Move?

  • madphysics
  • · Replies 30 ·
2
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30

Undergrad Catastrophic Nova: Definition & Explanation

  • ameriti$h
  • · Replies 3 ·
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3

Graduate Condition for inflation presented by Liddle

  • Magister
  • · Replies 3 ·
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3

High School Video Recommendations for Black Holes & other space-related phenomena

  • NDHurdler
  • · Replies 5 ·
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5

Graduate Oldest Black Hole - Age of the Universe Explained

  • bassplayer142
  • · Replies 16 ·
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16

Graduate Giant Solar Laser: Harnessing Energy from the Sun

  • Ruslan_Sharipov
  • · Replies 3 ·
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3

Undergrad Star Collapse: Why Not in Early Stages?

  • bassplayer142
  • · Replies 2 ·
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2

Undergrad Calculate Star Radii: Mass, Luminosity & Temp

  • Magister
  • · Replies 7 ·
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7

High School Uncovering the Mystery of Dark Matter: A Beginner's Guide

  • pixel01
  • · Replies 4 ·
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4

High School Does the Name of Mars Reflect its Ancient Oceans?

  • baywax
  • · Replies 9 ·
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9

Graduate Hellfire's introduction to quantum cosmology

  • marcus
  • · Replies 15 ·
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15

Graduate Does Time Reversal Symmetry Apply to All Interactions?

  • FizX
  • · Replies 2 ·
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2

Xena officially named Eris (as of 13 Sept)

  • marcus
  • · Replies 9 ·
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9

Graduate Do Penrose and Carroll Agree on the Specialness of Conditions for Inflation?

  • George Jones
  • · Replies 10 ·
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10

High School Which exoplanet was the first comfirmed discovery?

  • kop442000
  • · Replies 2 ·
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2

Undergrad Can Distance Alone Prove Gravitational Binding?

  • wolram
  • · Replies 3 ·
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3

Graduate Earth-Sun Distance Over Time: Stability & Changes Explained

  • BillJx
  • · Replies 7 ·
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7

Undergrad Publications on the evolution of stars?

  • Prairie
  • · Replies 1 ·
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1

Stargazing About Parabolic Telescope Mirrors

  • Saladsamurai
  • · Replies 7 ·
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7

Graduate Homogeneous and Isotropic Stress-Energy Tensor in Cosmology

  • nrqed
  • · Replies 15 ·
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15

Undergrad What are Some Important Effects or Phenomena in Astrophysics?

  • soumyashant
  • · Replies 1 ·
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1

Undergrad Most Distant Black Hole Discovered: 13 Billion Light-Years Away!

  • Astronuc
  • · Replies 14 ·
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14

Graduate Moon Perturbations: Learn Differential Gravitational Forces

  • lewis198
  • · Replies 9 ·
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9

Graduate Is Matter and Energy the Same Thing? Debunking Claims About Physics

  • saderlius
  • · Replies 11 ·
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11

Graduate Permeability of free space question

  • captpaul101@hotmail.com
  • · Replies 3 ·
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3

Graduate Can Thermal Fluctuations in Loop Cosmology Solve the Horizon Problem?

  • marcus
  • · Replies 3 ·
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3

Graduate Is Retro Causality the Key to Understanding the Evolution of Universes?

  • madness
  • · Replies 19 ·
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Graduate Why objects at lagrangian points 4 and 5 are stable?

  • magnetar
  • · Replies 4 ·
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4

Anyway, Mysterious Hole on Mars Found

  • chief
  • · Replies 20 ·
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20

Graduate Accelerating Universe: Understanding Deceleration Parameter & Implications

  • blumfeld0
  • · Replies 7 ·
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7

Graduate How Do Black Holes Escape Their Own Event Horizon?

  • OSalcido
  • · Replies 27 ·
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27

Graduate Is Our Observable Universe Limited by the Cosmic Horizon?

  • Ricky2357
  • · Replies 8 ·
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8

Graduate HII Region Temperature Structure

  • Poppop
  • · Replies 4 ·
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4

Graduate What theories appose a multiverse?

  • Harmony
  • · Replies 1 ·
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Graduate Question regarding the arrow of time

  • Nasher
  • · Replies 6 ·
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6

Graduate Black hole gravity response question

  • Voltage
  • · Replies 1 ·
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1

Graduate About Hubble Radius (Radius of the Hubble sphere)

  • Ricky2357
  • · Replies 8 ·
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8

Graduate Do anti-stars emit or absorb photons?

  • Nasher
  • · Replies 6 ·
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6

Graduate Discover the Best Book on Inflation Theory for Your Studies

  • fresnelspot
  • · Replies 3 ·
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3

High School Seeing the Galilean Moons with Celestron 7x50 Binoculars

  • cepheid
  • · Replies 3 ·
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3

Graduate Does the Friedmann Model Suggest an Unbounded Universe?

  • da_willem
  • · Replies 29 ·
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Undergrad A Query on Sun and Moon Coordinate data

  • lewis198
  • · Replies 2 ·
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2

Graduate Are we rewriting the birth of the solar system?

  • Andre
  • · Replies 1 ·
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1

Graduate Understanding Omega: Baryons, Leptons, Photons and More

  • blumfeld0
  • · Replies 5 ·
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5

Undergrad What would a black hole look like?

  • MonstersFromTheId
  • · Replies 6 ·
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6

Graduate What Defines the Universe: Bostrom's Philosophy vs. Hardy's Causaloids?

  • Chronos
  • · Replies 59 ·
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Undergrad Astronomy POD: Tan & Blue Galaxies - Why the Color Difference?

  • Jimmy Snyder
  • · Replies 16 ·
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16

Graduate What kind of energy is released when matter and antimatter collide?

  • ensabah6
  • · Replies 4 ·
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4

Graduate What percent of baryonic matter is antimatter?

  • ensabah6
  • · Replies 1 ·
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High School What colors represent different stages of a star's life cycle?

  • vi3taznb0i
  • · Replies 2 ·
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Graduate Could Dark Energy and Dark Matter be .?

  • acitizenofearth
  • · Replies 9 ·
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9

Graduate Is Gliese 581d a Habitable Super-Earth?

  • marcus
  • · Replies 0 ·
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Undergrad Measuring the Distances to Stars and Galaxies

  • McHeathen
  • · Replies 4 ·
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4

Graduate If two black holes combind together-

  • magnetar
  • · Replies 16 ·
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16

Graduate Is Dark Matter More Significant Than Black Holes in the Universe's Mass?

  • FrigginGenius
  • · Replies 2 ·
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Graduate Cosmic Humility: Trillions of Years into the Future

  • blumfeld0
  • · Replies 9 ·
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9

Graduate Why Should The Atom's Form Exist At All?

  • justwondering
  • · Replies 3 ·
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3

Stargazing Is the James Webb Space Telescope Ready to Replace Hubble?

  • meteor
  • · Replies 14 ·
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14

High School What Can I See with My Telescope in Boston?

  • Saladsamurai
  • · Replies 11 ·
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11

Who said: however the Earth still rotates

  • haiha
  • · Replies 9 ·
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9

Graduate Does gravity affect the measurement of pi in non-euclidean geometries?

  • Teresa
  • · Replies 11 ·
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11

Graduate Dark matter searches (a survey of-)

  • marcus
  • · Replies 1 ·
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1

Undergrad SKA: What's Being Planned & Job Prospects?

  • Teresa
  • · Replies 1 ·
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1

Undergrad Understanding the Doppler Effect: The Red Shift and Our Place in the Universe

  • OSalcido
  • · Replies 3 ·
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3

Undergrad Age of Universe: Seeing More than 13.5 Billion Yrs

  • BoomBoom
  • · Replies 54 ·
2
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54

Graduate The Ashtekar density (you've heard of the Chandrasekhar mass, now here's )

  • marcus
  • · Replies 19 ·
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19

Undergrad Interstellar Medium: Est. Mean Mass of Particle

  • popffabrik1
  • · Replies 1 ·
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1

What Makes Black Holes So Mysterious and Dangerous?

  • andrewking
  • · Replies 20 ·
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20

High School Could Dead Stars Lead to Abandoned Solar Systems?

  • Frozenoak
  • · Replies 12 ·
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12

Undergrad Supernova 7000 ly Away: Impact on Earth and Light Visibility

  • Ronhrin
  • · Replies 15 ·
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15

Graduate Accelerating Universe: How Is It Possible?

  • da_willem
  • · Replies 19 ·
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19

Graduate Does 1a supernova release the same amount of neutrino as type2 supernova?

  • magnetar
  • · Replies 1 ·
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1

Graduate Gravitational Waves from Mergers

  • RJ Emery
  • · Replies 3 ·
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3

Graduate Why Do Stars at the Edge of Galaxies Feel an Inward Pull from Dark Matter?

  • Aschere
  • · Replies 2 ·
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2

Graduate Solar Cycle & Explanation for Recent Changes?

  • William Astley
  • · Replies 13 ·
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13

Graduate Simulating the Future: Great Attractor 100 Billion Years Ahead

  • HarryWert
  • · Replies 3 ·
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3

High School Gravitational Lensing: Learn More about Einstein Rings

  • Sourabh N
  • · Replies 3 ·
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3

Undergrad Learning Physics: How Do Neutron Stars Form?

  • madphysics
  • · Replies 6 ·
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6

Graduate Is the Universe in a State of Universal Motion?

  • wilgory
  • · Replies 6 ·
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6

Undergrad Is NASA's New Evidence the Most Direct Detection of Dark Matter?

  • ZapperZ
  • · Replies 24 ·
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24

Graduate How Do Accretion Discs and Black Holes Emit High-Velocity Charged Particles?

  • verdigris
  • · Replies 6 ·
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6

Amazing Saturn Photo: Cassini's Awe-Inspiring Image

  • setAI
  • · Replies 3 ·
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3

LCDM and Cosmology and Cosmologists

  • Wallace
  • · Replies 2 ·
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2

Undergrad Apparent Magnitude: Meaning & 3 Star System

  • Magister
  • · Replies 3 ·
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3

Graduate A hyperbolicshape of the universe, despite measurements

  • Hymne
  • · Replies 3 ·
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3

Graduate Einstein Cross vs. Ring: Understanding the Alignment of Quasar G2237+030

  • Jorrie
  • · Replies 3 ·
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3

Undergrad Gravity and the Rotation of Galaxies

  • sweet-stuff
  • · Replies 1 ·
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1

Undergrad Density of Gliese 581 d: What's the Real Number?

  • DaveC426913
  • · Replies 1 ·
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1

Could we(entire universe) be almost nothing?

  • u83rn00b
  • · Replies 9 ·
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9

Graduate Calculating Mass/Density for a 4x Larger Earth

  • surfaceGravity
  • · Replies 5 ·
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5

High School Maximum number of orbiting planets

  • Rothiemurchus
  • · Replies 3 ·
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3

Undergrad Why Do Comets Have Elliptical Orbits While Planets Are Circular?

  • madphysics
  • · Replies 9 ·
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9

Graduate Is Too Much Physics Bad For Astronomy?

  • ZapperZ
  • · Replies 5 ·
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5

Graduate Details on the galaxy crash in our future

  • marcus
  • · Replies 1 ·
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1

Undergrad Is Pluto's Axis of Rotation Almost Perpendicular to Its Orbit?

  • DaveC426913
  • · Replies 3 ·
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3

High School Signal Transmission from Mars to Earth

  • NeoScience
  • · Replies 4 ·
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4

Stargazing Refracting vs Reflecting Telescopes: Which is Easier to Build?

  • holliee
  • · Replies 2 ·
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2