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 LightCone Calculator Improvements

  • Jorrie
  • · Replies 100 ·
4
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100

Undergrad Identification of matter and dark matter proportions

  • Ranku
  • · Replies 23 ·
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23

Undergrad Interpreting solar event flux units

  • SteveA001
  • · Replies 8 ·
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8

High School Time Dimensions: Astronomy & Beyond

  • DaveC426913
  • · Replies 13 ·
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13

Graduate Cosmic Tidal Force: Measuring CTF With Strain Gauge

  • Jorrie
  • · Replies 61 ·
3
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61

High School So what's your go-to method to locate M31 (Andromeda Galaxy)?

  • swampwiz
  • · Replies 13 ·
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13

High School Nodal Precession: Satellites Orbiting Earth Explained

  • Sphere
  • · Replies 22 ·
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22

Stargazing Fixing declination runaway on a Meade LX200 telescope

  • collinsmark
  • · Replies 6 ·
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6

Graduate Multiverse and observational evidence?

  • apostolosdt
  • · Replies 10 ·
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10

Insights Intro to Big Bang and Infinity Concepts - Comments

  • Arman777
  • · Replies 62 ·
3
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62

High School Spatial Expansion -- Coincidence?

  • stuart100
  • · Replies 6 ·
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6

High School What would the planets look like in real life?

  • Nathi ORea
  • · Replies 17 ·
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17

Undergrad Mining the Universe's expansion?

  • Suekdccia
  • · Replies 25 ·
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25

Graduate On the origin and the evolution of information in the Universe

  • Rene Kail
  • · Replies 1 ·
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1

Undergrad Receding movement of a stopped object in an accelerating universe?

  • Suekdccia
  • · Replies 23 ·
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23

Undergrad Lectures on the Varying fine structure constant

  • Conn_coord
  • · Replies 7 ·
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7

Undergrad Cosmic strings increasing internal energy?

  • Suekdccia
  • · Replies 1 ·
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1

Undergrad How accurate is the distance to M4 and its stars according to different sources?

  • snorkack
  • · Replies 2 ·
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2

High School Amazing Rings: Intersecting Stars Create Spectacular Gas Rings

  • Hornbein
  • · Replies 6 ·
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6

Graduate Is the FLRW Metric a Valid Approximation for Our Universe on Large Scales?

  • Tanujhm
  • · Replies 7 ·
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7

High School The value of the standard acceleration due to Earth's gravity

  • Sphere
  • · Replies 10 ·
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10

Graduate Non-minimally coupled inflation — expansion

  • svenz706
  • · Replies 1 ·
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1

Undergrad What is the temperature dependence of the NIRCam sensor's responsivity?

  • Devin-M
  • · Replies 70 ·
3
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70

Graduate A pair of interesting papers: have counterarguments been published?

  • PeterDonis
  • · Replies 10 ·
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10

High School Understanding the Expansion of Space: Galaxies Moving Away and Proving Expansion

  • Richard lanning
  • · Replies 78 ·
3
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78

Undergrad How Does Space Expansion Affect the Velocity of Galaxies?

  • Martyn Arthur
  • · Replies 65 ·
3
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65

High School Could a black hole just be a planet?

  • JLemp
  • · Replies 6 ·
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6

Undergrad Distant Galaxy study, dark matter and the CMBR

  • pinball1970
  • · Replies 1 ·
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1

High School Celestial mechanics: Why is my planet orbiting faster and faster?

  • S Holtom
  • · Replies 22 ·
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22

Undergrad What Equation Determines the Cosmic Event Horizon Distance?

  • Jay B
  • · Replies 7 ·
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7

High School Could the source of dark energy be our parent black hole feeding?

  • Bob Walance
  • · Replies 6 ·
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6

Undergrad Upper limit of relativistic spin?

  • BWV
  • · Replies 7 ·
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7

Undergrad Can we see light pollution from space?

  • LightningInAJar
  • · Replies 7 ·
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7

Undergrad Does all infrared get detected as heat?

  • LightningInAJar
  • · Replies 22 ·
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22

High School What does relativity say about wormholes?

  • Gear300
  • · Replies 11 ·
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11

Undergrad Gas Density of Lunar Crater Rims: Comet vs. Asteroid Impacts

  • snorkack
  • · Replies 3 ·
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3

Undergrad Question about the William Herschel Telescope's new "Weave" device

  • phinds
  • · Replies 3 ·
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3

Undergrad What is the significance of slow-roll inflation in cosmology?

  • AHSAN MUJTABA
  • · Replies 1 ·
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1

Undergrad JWST breaks another Redshift record

  • Oldman too
  • · Replies 2 ·
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2

High School Could a Galaxy Older than 13.8 Billion Years Redefine Cosmology?

  • Jupiter60
  • · Replies 4 ·
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4

Graduate Is the Universe Finite, or Is It Infinite?

  • Greg Bernhardt
  • · Replies 27 ·
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27

Undergrad Is the Bullet Cluster Evidence for or Against Dark Matter?

  • accdd
  • · Replies 7 ·
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7

Undergrad Help me on the timeline of star formation in the early Universe

  • BWV
  • · Replies 2 ·
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2

Stargazing How can we see the ISS at 200 miles away with the naked eye?

  • TruthSeeker777
  • · Replies 80 ·
3
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80

Undergrad Voyager I and Voyager II informative video

  • Tom.G
  • · Replies 0 ·
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0

Undergrad Starlink and gaining energy from orbiting

  • planck999
  • · Replies 4 ·
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4

Undergrad Could a bubble shield at L1 combat global warming?

  • swampwiz
  • · Replies 18 ·
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18

High School Effect of JWST mirror damage on final images

  • GhostLoveScore
  • · Replies 1 ·
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1

Undergrad What do high-mass X-ray binaries, or HMXBs, tell us?

  • Astronuc
  • · Replies 1 ·
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1

Undergrad How to calculate an unknown planet's orbital period?

  • NODARman
  • · Replies 1 ·
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1

Undergrad A glitch in Jorrie’s Cosmo-Calculator?

  • JimJCW
  • · Replies 152 ·
6
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152

Undergrad Paradox: How can we look back at the Big Bang?

  • GreenWombat
  • · Replies 31 ·
2
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31

High School What Is the Information That Cannot Escape a Black Hole?

  • brendanxx
  • · Replies 3 ·
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3

Undergrad Solar system simulation errors

  • madsmh
  • · Replies 19 ·
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19

Undergrad Help with Sunrise & Sunset formulas please

  • Tomfmal
  • · Replies 6 ·
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6

Undergrad Amount of black hole entropy inside the Universe?

  • bbbl67
  • · Replies 5 ·
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5

High School Question about deep space pictures

  • gleen41
  • · Replies 3 ·
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3

Undergrad Question re flat infinite universe with a preferred direction

  • Buzz Bloom
  • · Replies 5 ·
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5

Undergrad What is the density of the Carina Nebula?

  • ozipin
  • · Replies 5 ·
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5

Undergrad Why is the observed local region of space flat?

  • PainterGuy
  • · Replies 25 ·
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25

Undergrad A new solution to Olbers' Paradox?

  • John_RB
  • · Replies 20 ·
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20

Undergrad Is the eccentricity of the lunar orbit constant?

  • Orthoceras
  • · Replies 2 ·
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2

Undergrad Confused by this armillary sphere in Australia

  • swampwiz
  • · Replies 4 ·
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4

High School Temporal differences across a galaxy?

  • narrator
  • · Replies 6 ·
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6

Undergrad Mass distribution in a celestial system

  • Ranku
  • · Replies 6 ·
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6

Undergrad Earth's orbit not perfect ellipse

  • Delta2
  • · Replies 19 ·
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19

Undergrad SpaceX says 5G expansion would make Starlink 'unusable' for most Americans

  • berkeman
  • · Replies 4 ·
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4

Undergrad Reheating and the horizon problem - chicken and egg?

  • GeorgeDishman
  • · Replies 6 ·
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6

Graduate From polar coordinates to heliocentric ecliptic coordinates

  • Shukie
  • · Replies 1 ·
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1

Graduate Can the Universe's Expansion Allow Us to Escape Its Event Horizon?

  • daveb
  • · Replies 1 ·
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1

High School Big Bang Question -- How was the first matter formed?

  • MagneticMagic
  • · Replies 69 ·
3
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69

Graduate How are time and distance measured in cosmology?

  • Greg Bernhardt
  • · Replies 1 ·
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1

Graduate What is the total mass-energy of the universe?

  • Greg Bernhardt
  • · Replies 1 ·
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1

Undergrad The curvature of space and curvature of spacetime

  • PainterGuy
  • · Replies 21 ·
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21

High School Can nuclear bomb(s) change trajectory of small black hole?

  • eggchess
  • · Replies 19 ·
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19

Undergrad Bubble universes and physical constants

  • JuneSpring25
  • · Replies 8 ·
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8

High School SOFIA IR Observatory in the Southern Sky

  • Baluncore
  • · Replies 8 ·
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8

Undergrad Why are Saturn's rings in its equatorial plane?

  • KurtLudwig
  • · Replies 3 ·
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3

High School Mars Probe gets Windows 98 Update, after 19 years

  • Tom.G
  • · Replies 6 ·
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6

Undergrad Some questions about Cosmic Microwave Background radiation

  • PainterGuy
  • · Replies 13 ·
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13

High School Where can I find information about Population III stars?

  • Cerenkov
  • · Replies 2 ·
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2

Undergrad I have an error in integrating to calculate the age of the Universe

  • Buzz Bloom
  • · Replies 40 ·
2
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40

High School Is it possible for a giant star to have a black hole inside it?

  • Thadriel
  • · Replies 11 ·
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11

Undergrad The gravitational center of the Earth

  • qnt200
  • · Replies 3 ·
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3

Undergrad How to find RAAN and argument of perigee for a satellite?

  • yzma
  • · Replies 1 ·
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1

High School How often do you re-acquire dark and bias frames?

  • Andy Resnick
  • · Replies 1 ·
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1

Undergrad How does the symbol Λ cosmological constant relate to Ω_Λ or ρ_Λ?

  • Buzz Bloom
  • · Replies 3 ·
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3

High School Is Stellina the Ultimate Telescope for Amateur Astronomers?

  • swampwiz
  • · Replies 8 ·
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8

Undergrad Voyager Spacecraft beginning to Power Down

  • Tom.G
  • · Replies 2 ·
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2

Undergrad Some questions about Cosmic Inflation

  • PainterGuy
  • · Replies 4 ·
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4

High School Where Can I Find Accurate Planetary Event Data for an Astronomy Course?

  • brainpushups
  • · Replies 5 ·
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5

Undergrad Are there types of spacetime where no symmetries are valid?

  • Suekdccia
  • · Replies 15 ·
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15

High School Has there been no update to Allen's Astrophysical Quantities since 1999?

  • Jenab2
  • · Replies 1 ·
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1

Undergrad Seeking understanding regarding Ω_b, Ω_c, and Ω_m

  • Buzz Bloom
  • · Replies 14 ·
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14

High School Evolution of planetary system around a white dwarf

  • Astronuc
  • · Replies 0 ·
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0

Undergrad What is a typical mass density for inter-galactic gas in a cluster?

  • timjdoom
  • · Replies 2 ·
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2

High School How much energy does our Universe have?

  • vasiladp
  • · Replies 12 ·
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12

Undergrad Postulating a minimum gravitational field strength

  • kodama
  • · Replies 11 ·
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11

Graduate What is a Bern model in planetary population synthesis?

  • Fabioonier
  • · Replies 9 ·
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9

Undergrad Questions about Negative Pressure and Vacuum Energy

  • darkdark10
  • · Replies 5 ·
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5