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 without resorting to scalar fields

  • marcus
  • · Replies 1 ·
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1

Graduate Could a distant brown dwarf companion explain outer solar system anomalies?

  • Astrobuff
  • · Replies 7 ·
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7

Graduate Is Gravitational Radiation the Key to Unlocking Cosmology's Secrets?

  • wolram
  • · Replies 8 ·
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8

Graduate On the 'constantness' of Hubble's Constant

  • Brinx
  • · Replies 8 ·
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8

High School Liftoff for Ceres and Vesta (July 2007)

  • marcus
  • · Replies 7 ·
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7

Graduate Can MOND be ruled out at laboratory scale?

  • Jonathan Scott
  • · Replies 7 ·
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7

Graduate Lyman Page new idea for CMB observations

  • marcus
  • · Replies 5 ·
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5

Graduate Does a singularity violate the uncertainty principle?

  • SpitfireAce
  • · Replies 2 ·
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2

Undergrad Looking once around the universe

  • birulami
  • · Replies 7 ·
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7

Graduate MOND-related Formula in GR Calcs at Cosmological Scale

  • Jonathan Scott
  • · Replies 1 ·
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1

Undergrad What is the impact of the moon's mass on Earth's orbit around the sun?

  • ukmicky
  • · Replies 5 ·
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5

Graduate Ratio of radiaton energy to mass energy?

  • Nasher
  • · Replies 13 ·
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13

Graduate Are Parallel Universes Possible According to M-Theory?

  • Nasher
  • · Replies 3 ·
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3

Undergrad How does the Julian day number formula work?

  • lewis198
  • · Replies 4 ·
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4

Graduate The link between the cosmological constant and the higgs field

  • deneve
  • · Replies 6 ·
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6

Graduate Review of Dark Matter and Dark Energy by M. Kamionkowski

  • EL
  • · Replies 5 ·
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5

Graduate How do X-rays and gamma rays escape from black holes?

  • Pakbabydoll
  • · Replies 3 ·
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3

Graduate Does Hawking radiation prevent black hole formation?

  • George Jones
  • · Replies 10 ·
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10

Graduate What Is the Expansion Limit of Our Universe?

  • .ultimate
  • · Replies 65 ·
3
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65

High School What does wave aspect mean on telescope mirror kits?

  • Saladsamurai
  • · Replies 11 ·
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11

Graduate Nice thumbnail sketch of Earth's future by John Baez

  • marcus
  • · Replies 10 ·
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10

Graduate Is it theoretically possible to open a stable wormhole?

  • Dr.Calpol3
  • · Replies 12 ·
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12

Undergrad Could Extraterrestrial Life Exist in Unique Environments Like Titan?

  • jonegil
  • · Replies 31 ·
2
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31

Graduate X-ray background/peculiar velocities and the Big Bang

  • xratx
  • · Replies 2 ·
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2

Graduate Physical basis for dark energy-I think Bojo found it

  • marcus
  • · Replies 12 ·
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12

Undergrad Why does light not slow down when moving through air?

  • madphysics
  • · Replies 30 ·
2
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30

Undergrad What is a catastrophic nova?

  • 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 Black hole video for high school physics class

  • NDHurdler
  • · Replies 5 ·
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5

Graduate How can we see a black hole from 12.7 billion years ago?

  • bassplayer142
  • · Replies 16 ·
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16

Graduate Using the solar atmosphere as a laser amplifier to extract energy

  • 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 Can you calculate a star's radius from its mass, luminosity and temperature?

  • Magister
  • · Replies 7 ·
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7

High School What is dark matter and why does it have such strong gravity?

  • pixel01
  • · Replies 4 ·
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4

High School Did ancient people name Mars for its 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 First confirmed exoplanet discovery: 51 Pegasi or PSR B1257+12?

  • kop442000
  • · Replies 2 ·
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2

Undergrad Can Distance Alone Prove Gravitational Binding?

  • wolram
  • · Replies 3 ·
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3

Graduate Is Earth's orbital radius stable over geological timescales?

  • 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 Websites on lunar perturbations from differential gravity

  • lewis198
  • · Replies 9 ·
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9

Graduate Debunking claims that matter and energy are identical

  • 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 Can retrocausality explain why our universe favors life?

  • madness
  • · Replies 19 ·
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19

Graduate Why objects at lagrangian points 4 and 5 are stable?

  • magnetar
  • · Replies 4 ·
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4

Mysterious hole discovered on Mars

  • chief
  • · Replies 20 ·
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20

Graduate Does the universe's acceleration have magnitude and direction?

  • 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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1

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 Good books on inflation theory for beginners

  • 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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29

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 Bostrom's philosophy and Hardy's causaloids in defining the universe

  • Chronos
  • · Replies 59 ·
2
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59

Undergrad Why are distant galaxies bluer than nearby tan galaxies?

  • 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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1

High School What colors represent different stages of a star's life cycle?

  • vi3taznb0i
  • · Replies 2 ·
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2

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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0

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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2

Graduate Will the cosmic microwave background redshift beyond our horizon in trillions of years?

  • 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
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9

Graduate Can gravity limit how precisely we can measure pi?

  • Teresa
  • · Replies 11 ·
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11

Graduate Dark matter searches (a survey of-)

  • marcus
  • · Replies 1 ·
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1

Undergrad What will the SKA study and what are job prospects there?

  • Teresa
  • · Replies 1 ·
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1

Undergrad Why isn't the local group the center if everything else shows redshift?

  • OSalcido
  • · Replies 3 ·
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3

Undergrad Why can we see further back than the universe's age?

  • 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

Where can I find information about black holes and their gravity?

  • 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 Will a supernova 7000 light-years away outshine the sun?

  • Ronhrin
  • · Replies 15 ·
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15

Graduate Where does the repulsive force in an accelerating universe come from?

  • 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