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 Can I Pursue an Astrophysics Masters/PhD in the USA with a Mathematics Degree?

  • buddhikapriya
  • · Replies 4 ·
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4

Graduate Inflation Theory: Matter-Antimatter Annihilation Concept

  • endverse
  • · Replies 5 ·
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5

Graduate Period-Luminosity Relationship of Type I Cepheids - Need Better Formula

  • Desmos
  • · Replies 2 ·
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2

Graduate Must a Hot Jupiter be relatively young?

  • jscroft
  • · Replies 2 ·
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2

Graduate Is dark energy actually zero-point energy?

  • jimjohnson
  • · Replies 4 ·
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4

Graduate Testing time dilation with a spinning object in space

  • jreelawg
  • · Replies 6 ·
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6

High School Does the earth translate around the sun?

  • nonequilibrium
  • · Replies 7 ·
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7

Graduate Why Do Disk Galaxies Appear to Spin Despite Irregular Redshift Patterns?

  • TrickyDicky
  • · Replies 8 ·
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8

Undergrad What Are the Competing Theories in Astrophysics: Dark Matter vs MOND?

  • Ironside
  • · Replies 1 ·
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1

Graduate Galaxy at redshift z=8.6 (the actual paper)

  • marcus
  • · Replies 1 ·
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1

Graduate How Is the Distance to the CMB Measured and How Does It Relate to Its Structure?

  • AutoToAlek
  • · Replies 2 ·
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2

Graduate Does the universe need an escape velocity?

  • jhe1984
  • · Replies 12 ·
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12

Graduate How Do Critical Density and CMB Irregularities Explain the Universe's Shape?

  • leatherneckpa
  • · Replies 2 ·
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2

CERN scientists eye parallel universe breakthrough

  • Gaius Baltar
  • · Replies 2 ·
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2

Stargazing Increasing the resolving power of a telescope

  • Idoubt
  • · Replies 1 ·
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1

High School Could Gliese 581 Be Our Next Habitable Planet?

  • AfRoMaNn
  • · Replies 2 ·
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2

Undergrad How is measuring Redshift possible?

  • timbreman
  • · Replies 8 ·
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8

High School Ideas for High School Astrophysics Course Syllabus

  • kungfuscious
  • · Replies 8 ·
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8

Undergrad Signal reception interval for starship traveling at 0.8c to Alpha Centauri

  • Aurealis
  • · Replies 7 ·
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7

Graduate What are the limits of interstellar travel?

  • skippy1729
  • · Replies 44 ·
2
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44

Undergrad *Quick moon question - (about orbit)

  • nukeman
  • · Replies 6 ·
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6

Undergrad Formation of Stars: How Gas Spins to Fuel Birth

  • Sniperman724
  • · Replies 2 ·
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2

Undergrad Is this angular size calculation correct?

  • nukeman
  • · Replies 1 ·
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1

Undergrad Universe Origin: How Could Galaxy be 13B Light Years Away?

  • Trimike
  • · Replies 1 ·
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1

Graduate Does gravitational time dilation affect stellar redshift measurements?

  • temoisio
  • · Replies 10 ·
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10

Graduate Superstring Cosmology: Compactifying 7 Dimensions

  • Kevin_Axion
  • · Replies 5 ·
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5

Undergrad How do I normalize the likelihood distribution?

  • aymer
  • · Replies 8 ·
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8

Undergrad Is the Big Bang Theory Debunked?

  • phoenixthoth
  • · Replies 55 ·
2
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55

Stargazing Pictures I took at a 2.5m telescope in the Canary Islands

  • kungfuscious
  • · Replies 1 ·
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1

Undergrad Do wormholes exist and can they be created?

  • 2rashmi1993
  • · Replies 6 ·
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6

Graduate Could Dark Energy be Caused by a Slow Shift in the Base State?

  • Upisoft
  • · Replies 3 ·
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3

Undergrad Calculating the Earth-Sun distance during perihelion

  • nukeman
  • · Replies 9 ·
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9

Graduate Inflation and initial conditions

  • skydivephil
  • · Replies 2 ·
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2

Graduate What happens when a medium elliptical galaxy collides with a dwarf elliptical?

  • TrickyDicky
  • · Replies 2 ·
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2

Stargazing What is the Best Catadioptric Telescope for Portability and Versatility?

  • procq
  • · Replies 4 ·
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4

Undergrad Greenwich Mean Timt, GMT and Universal Coodinated Time, UT

  • Philosophaie
  • · Replies 2 ·
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2

How do I protect an astronomy idea from being taken by others?

  • nukeman
  • · Replies 16 ·
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16

Undergrad Are the crossed objects in the Hubble Ultra Deep Field nearby stars or distant galaxies?

  • AdkinsJr
  • · Replies 3 ·
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3

Stargazing Heyy, i've had a telescope before and know how to use them.Has

  • nickthrop101
  • · Replies 3 ·
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3

High School Is Earth’s orbit far from circular?

  • nukeman
  • · Replies 1 ·
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1

Stargazing What Are the Best Telescope Models Within the £100-£250 Range?

  • nickthrop101
  • · Replies 1 ·
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1

Graduate Faster than Light Travel Side Effects

  • Ultrastar 1
  • · Replies 17 ·
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17

Undergrad Black holes giving birth to stars?

  • discord73
  • · Replies 1 ·
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1

Graduate How Do Stars Achieve Their Massive Sizes?

  • discord73
  • · Replies 1 ·
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1

Graduate What are the Current Main Research Topics in Astrophysics?

  • ahmadfadl92
  • · Replies 1 ·
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1

High School Shading moon phases as viewed from space above the North Pole

  • nukeman
  • · Replies 13 ·
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13

High School Is the Waning Crescent Visible Near the Horizon?

  • nukeman
  • · Replies 4 ·
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4

High School What would happen if you fell into a black hole?

  • wangdang
  • · Replies 5 ·
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5

Undergrad How would tides change if the moon were twice as far away?

  • kay89
  • · Replies 11 ·
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11

Stargazing Aug 21st, 2017, a total solar eclipse will cross the US

  • Ivan Seeking
  • · Replies 29 ·
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29

Graduate Dark matter and keplerian revolution

  • TrickyDicky
  • · Replies 19 ·
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19

High School The Grand Design - Stephen Hawking and Leonard Mlodinow

  • yarixen
  • · Replies 5 ·
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5

Graduate What Causes Hypervelocity Stars to Eject from Black Holes?

  • shnazzybox
  • · Replies 1 ·
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1

Graduate How do I find Earth's motion with gravity from both the Sun and Mars?

  • Sakriya
  • · Replies 12 ·
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12

Undergrad Calculating Gravities for Math to the Moon

  • nution
  • · Replies 2 ·
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2

Undergrad From physics how can we figure out how old the earth and the universe is?

  • dcderek24
  • · Replies 7 ·
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7

Graduate Can a "Dead Universe" be Revived?

  • geordief
  • · Replies 8 ·
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8

Undergrad Astrometry and Elliptical orbits

  • Mu naught
  • · Replies 4 ·
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4

Graduate How is the Final Velocity of Star Movements Calculated?

  • lenfromkits
  • · Replies 1 ·
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1

Undergrad Can We Reach the Moon with a Slow, Steady Launch?

  • nution
  • · Replies 9 ·
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9

Undergrad How Can We Determine the Size of a Black Hole?

  • fillipeano
  • · Replies 4 ·
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4

Undergrad Could Heat Exchange Be the Reason Behind Earth's Spin?

  • JamiePocock
  • · Replies 3 ·
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3

Undergrad Strange wikipedia entry about the sun's core

  • Fanaval
  • · Replies 3 ·
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3

Graduate The infinite possobilities presented by the infinite amount of probabilities

  • dr.probable
  • · Replies 14 ·
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14

High School Why are solar eclipses so short compared to lunar eclipses?

  • nukeman
  • · Replies 3 ·
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3

Graduate Negative pressure and dark energy

  • relativityfan
  • · Replies 10 ·
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10

Graduate Why smaller particles come together

  • A Dhingra
  • · Replies 6 ·
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6

Graduate Colliding Black Holes: Will the Smaller Get Pulled In?

  • Worzel
  • · Replies 4 ·
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4

Undergrad Define/explain this gravity calculation (picture)

  • nukeman
  • · Replies 4 ·
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4

John Huchra Dies at 61; Maps Altered Ideas on Universe

  • diogenesNY
  • · Replies 1 ·
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1

Graduate Can FLRW metric be taken to describe stretching in time rather than space?

  • themos
  • · Replies 2 ·
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2

Graduate Quasar Alignment to Cosmic Strings

  • Kevin_Axion
  • · Replies 5 ·
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5

Graduate Expanding present time formula for matter-dominated universe at Ω₀ = 1

  • knightq
  • · Replies 8 ·
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8

Graduate Can a QM/GR overlap provide a breakthrough in understanding gravity?

  • Ran out of sp
  • · Replies 3 ·
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3

Undergrad How can all galaxies see other galaxies if some started on the outer edge?

  • jimjohnson
  • · Replies 5 ·
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5

Graduate What caused the expansion of the universe for the 1st 7 billion years?

  • mysearch
  • · Replies 10 ·
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10

Graduate What is the relationship between mathematical structures and real existence?

  • PhanthomJay
  • · Replies 8 ·
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8

Graduate Is the Expansion of the Universe Driven by Mass?

  • wolram
  • · Replies 22 ·
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22

Graduate What is the energy of the galactic magnetic field? (E/c^2)

  • MTd2
  • · Replies 1 ·
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1

Graduate Plotting Intensity in Airy Pattern of Telescope - 1D

  • theneedtoknow
  • · Replies 1 ·
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1

Graduate Is the cosmological constant a ratio of dark energy to gravity?

  • Ikoro
  • · Replies 18 ·
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18

Graduate Testing Newtonian gravity with NGC 1851 and NGC 1904

  • inflector
  • · Replies 19 ·
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19

Graduate If Big Crunch = True, then Reincarnation = True?

  • SeventhSigma
  • · Replies 18 ·
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18

Graduate Subatomic particle and space curvature

  • richerrich
  • · Replies 10 ·
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10

Graduate Could dark energy come from before the Big Bang?

  • richerrich
  • · Replies 7 ·
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7

Graduate How many methods for dating a galaxy

  • lenfromkits
  • · Replies 1 ·
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1

Graduate Was the Universe Really Chaotic Right After the Big Bang?

  • Descartz2000
  • · Replies 15 ·
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15

High School Super black holes and stars orbiting them

  • littlebanger
  • · Replies 16 ·
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16

Graduate Super-black holes and the universe

  • gta-maloy]
  • · Replies 11 ·
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11

Graduate Why millimeters and not Planck length for extra dimensions

  • PhanthomJay
  • · Replies 11 ·
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11

Undergrad Was the Moon Ever Touching Earth Billions of Years Ago?

  • dcderek24
  • · Replies 10 ·
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10

Graduate State of matter before a black hole is formed.

  • conan
  • · Replies 16 ·
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16

Graduate Pressure in stars from photons vs. electron/positron pairs

  • PAllen
  • · Replies 5 ·
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5

Undergrad Degeneracy pressure and interactions

  • relativityfan
  • · Replies 7 ·
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7

High School What Are Some Math-Based Topics for an Astrophysics Project?

  • Fragment
  • · Replies 1 ·
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1

Graduate Dark Energy, Light, the Universe, and Black Holes

  • bredmond812
  • · Replies 4 ·
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4

Undergrad Angular size of Venus: Is my math correct?

  • nukeman
  • · Replies 9 ·
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9

Graduate Some questions about energy conservation

  • Upisoft
  • · Replies 2 ·
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2

High School *Quick question: When is VENUS visable in the sky in this period ?

  • nukeman
  • · Replies 14 ·
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14

Graduate Why Doesn't Light from the Big Bang Get Stretched Out?

  • leonstavros
  • · Replies 10 ·
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10