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

High School Why does light travel at light speed?

  • jackpot337
  • · Replies 62 ·
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62

Graduate Is the nature of space and time still a mystery?

  • Curious6
  • · Replies 10 ·
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10

Graduate Scientific Logic for God's existence

  • Dr. Raj Baldev
  • · Replies 47 ·
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47

Graduate Unexplained Gravitational Phenomena in a Donut-Shaped Universe

  • rob_we
  • · Replies 2 ·
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2

Graduate Is Our Three-Dimensional Reality Just a Holographic Illusion?

  • PFanalog57
  • · Replies 5 ·
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5

Graduate Is the Universe Infinite or Finite: What Theories Suggest?

  • calculii
  • · Replies 29 ·
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29

Stargazing Build Custom Telescope Mount: Tips & Advice

  • Physicsisfun2005
  • · Replies 2 ·
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2

Stargazing What was the first object you saw through a telescope?

  • whydoyouwanttoknow
  • · Replies 17 ·
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17

Graduate Is the Universe Closed, Flat or Open?

  • Curious6
  • · Replies 18 ·
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18

High School City-Sized Asteroid to Pass Earth This Fall

  • Evo
  • · Replies 3 ·
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3

Able to catch the meteor shower this morning

  • check
  • · Replies 16 ·
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16

Graduate Parallel universes almost certainly do not exist

  • Sven Tingblad
  • · Replies 12 ·
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12

High School The Colors of Stars: Why Are Some Red and Others White or Blue?

  • Tree Penguin
  • · Replies 4 ·
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4

Graduate Is Space Merely a Manifestation of Matter and Energy?

  • mee
  • · Replies 40 ·
2
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40

Why the universe want to know itself?

  • Will_C
  • · Replies 15 ·
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15

Graduate Dear Nereid and Phobos (seat belt on) can we talk about redshifts?

  • rob_we
  • · Replies 4 ·
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4

Graduate Furthest Point on Earth from the Center: Mt Chimburazo, Ecuador

  • mee
  • · Replies 8 ·
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8

High School Is Research on Gravity Lifts a Step Towards Defying Gravity?

  • Pythagorean
  • · Replies 6 ·
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6

Undergrad How do we detect x-rays from the center of our galaxy?

  • turin
  • · Replies 14 ·
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14

Graduate Expanding Universe - weakening gravity?

  • Scott Sieger
  • · Replies 7 ·
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7

High School Hubble hit by instrument failure

  • Ivan Seeking
  • · Replies 8 ·
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8

Graduate Dark Matter & Gravitational Effects on Galaxies

  • Moose352
  • · Replies 4 ·
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4

Undergrad Is Isaac Asimov's Moon-Planet Theory Valid?

  • Starfleet2222
  • · Replies 8 ·
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8

Undergrad Is Bush's Vision for Space Exploration Grounded by Budget Cuts?

  • Ivan Seeking
  • · Replies 16 ·
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16

Graduate Stretched space far from our own

  • woodysooner
  • · Replies 49 ·
2
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49

High School Why Are We Orbiting Earth Instead of Landing on the Moon Again?

  • bozo the clown
  • · Replies 176 ·
6
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176

Graduate How was time and space created at the Big Bang?

  • niranjan
  • · Replies 20 ·
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20

Graduate Final project - fate of the universe - need ideas

  • brum
  • · Replies 4 ·
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4

Graduate What caused the planets to aggregate as they did?

  • Rader
  • · Replies 16 ·
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16

Graduate Why the Moon Looks Big at the Horizon and Smaller When Higher Up.

  • Rader
  • · Replies 2 ·
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2

Graduate Calculating viewing times of satellite from groundstation

  • Ed
  • · Replies 16 ·
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16

Undergrad Black holes do not collapse to singularity>

  • think
  • · Replies 18 ·
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18

Have you witnessed a dazzling Iridium flare in the night sky?

  • Artman
  • · Replies 32 ·
2
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32

Stargazing Best telescope for a young astronomer under $750?

  • nautica
  • · Replies 9 ·
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9

Graduate Gamma Ray Bursters: Cause of Short-Lived Flashes of Light

  • kurious
  • · Replies 16 ·
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16

Graduate The Hawking Effect: Unruh-Schutzhold Paper

  • Olias
  • · Replies 1 ·
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1

Graduate Could Superluminal Light Speeds Impact Theories on the Universe's Cold Death?

  • multifaciatus
  • · Replies 2 ·
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2

Graduate Could Our Universe Have Originated from Another Universe's Black Hole?

  • woodysooner
  • · Replies 19 ·
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19

Undergrad Favoured theory for planetary formation

  • wolram
  • · Replies 7 ·
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7

Graduate Why Do Some Stars Explode?

  • Antonio Lao
  • · Replies 8 ·
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8

Graduate What was the Maximum Energy Density at the Onset of the Big Bang Expansion?

  • marcus
  • · Replies 24 ·
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24

Graduate Supernova Ignition: Does Blackhole Mass Influence Star Formation?

  • Olias
  • · Replies 5 ·
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5

Graduate Explaining B-Field of N-Star: How Neutron Stars Have Magnetic Fields

  • turin
  • · Replies 2 ·
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Graduate Vacuum energy in gravitational fields

  • turbo
  • · Replies 6 ·
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6

Graduate What would the universe be like

  • wonderer
  • · Replies 88 ·
3
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88

Undergrad Probability of Intelligent Life in Our Galaxy

  • bozo the clown
  • · Replies 51 ·
2
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51

Graduate Hawking Radiation: What it is and How it Relates to the Schwarzschild Radius

  • woodysooner
  • · Replies 4 ·
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4

Graduate Fine structure constant changes over time

  • kurious
  • · Replies 22 ·
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22

Undergrad Space as a vacuum and earth's atmosphere

  • Leonidas
  • · Replies 9 ·
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9

Undergrad Cosmological Red Shift: What Is It & How Does It Relate to Gravity?

  • lvlastermind
  • · Replies 5 ·
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5

Graduate Is a larger initial size for the universe possible?

  • kurious
  • · Replies 13 ·
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13

Graduate The most significant, immediate relic of primordial quantum mechanics?

  • Loren Booda
  • · Replies 13 ·
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13

The Universe Is Alive And Thinking

  • RAD4921
  • · Replies 16 ·
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16

What came first CYBERSPACE or OUTERSPACE?

  • Blair
  • · Replies 21 ·
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21

Could Other Universes Exist Beyond Our Own?

  • HIGHLYTOXIC
  • · Replies 8 ·
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8

Graduate Understanding Type II Supernovae: N-Star vs. BH Supernova Explained

  • turin
  • · Replies 4 ·
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4

Graduate Is the existence of Hawking Radiation compatible with the Big Bang theory?

  • Ian
  • · Replies 7 ·
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7

Undergrad Explaining 4D Space-Time in Simple Terms

  • Omid
  • · Replies 7 ·
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7

High School Determining a Planet's Age Based on Mountain Ranges

  • Mattius_
  • · Replies 2 ·
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2

Undergrad Why do neutron stars have magnetic fields

  • Rodney
  • · Replies 4 ·
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4

Graduate What Is the Substance of Space and Its Role in Our Perception?

  • omin
  • · Replies 5 ·
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5

Undergrad What mass is lost after a hypernovae?

  • taylordnz
  • · Replies 10 ·
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10

Graduate Dark energy + missing antimatter

  • kurious
  • · Replies 7 ·
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7

High School Explaining Singularity: A Beginner's Guide

  • woz
  • · Replies 7 ·
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7

Undergrad Determining orbits from R.A., Dec, & time

  • bohr
  • · Replies 12 ·
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12

Graduate Steven Hawking / MKaku. Who's right about Black Holes?

  • Sean Gonzalez
  • · Replies 8 ·
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8

Graduate Black Holes: Comparing Hawking & Kaku Theories

  • Sean Gonzalez
  • · Replies 1 ·
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1

Graduate Observational Difference Between Neutron Star & Black Hole

  • turin
  • · Replies 3 ·
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3

Graduate Do Black Holes Truly Have Zero-Point Volume Singularities?

  • taylordnz
  • · Replies 4 ·
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4

UFO Sighting: Is It Real or Imaginary?

  • Grizzlycomet
  • · Replies 2 ·
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2

Graduate Has Stephen Hawking Solved the Black Hole Information Paradox?

  • Mentat
  • · Replies 8 ·
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8

Undergrad Black holes and dark matter holding galaxies together?

  • Themuffinman
  • · Replies 9 ·
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9

Graduate How Do Black Holes Create Dark Energy and Influence Universal Expansion?

  • kurious
  • · Replies 19 ·
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19

Graduate CalTech BH answer contradicts Hawking's

  • marcus
  • · Replies 4 ·
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4

Undergrad Are There Non-Rotating Objects in Space?

  • e(ho0n3
  • · Replies 2 ·
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2

Discover the Ultimate Guide: Gravitation by Misner, Thorne, and Wheeler

  • hemmul
  • · Replies 7 ·
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7

Graduate Is Dark Matter Made of Ordinary Matter or Something Exotic?

  • force5
  • · Replies 15 ·
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15

Graduate How Much Gravity Does a Black Hole Need to Contain Light?

  • terrabyte
  • · Replies 7 ·
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7

Graduate Time Travel: No spaceships, no wormholes

  • kokain
  • · Replies 27 ·
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27

Graduate Which force drives the expansion of the universe?

  • Pietro
  • · Replies 12 ·
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12

Undergrad Gigantic Black Hole Collision: Andromeda & Milky Way

  • pnjabiloafer
  • · Replies 19 ·
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19

Graduate Are There Stars with Highly Eccentric Orbits Around the Center of Their Galaxy?

  • alpha_wolf
  • · Replies 1 ·
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1

Graduate Did Hawking's Dublin Talk Redefine Quantum Gravity Observables?

  • marcus
  • · Replies 8 ·
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8

Undergrad Cause of Billiard Ball Spin: Celestial Connection?

  • IMMSHARMA
  • · Replies 1 ·
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1

Graduate Are White Holes the Key to Understanding Black Holes and Quasars?

  • kernelpenguin
  • · Replies 6 ·
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6

High School Planet formation DOES happen in slow motion

  • pnjabiloafer
  • · Replies 8 ·
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8

Undergrad Why Does the Moon Cause Tides despite Sun’s Greater Force?

  • Parth Dave
  • · Replies 13 ·
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13

Graduate Can a small black hole exist inside a larger black hole?

  • kurious
  • · Replies 3 ·
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3

High School Odds of Earth Impact vs Winning Powerball

  • bozo the clown
  • · Replies 16 ·
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16

Graduate Is there a limit to the validity of laws as the universe expands?

  • kurious
  • · Replies 13 ·
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13

Graduate Do Black Holes Generate Dark Energy?

  • kurious
  • · Replies 4 ·
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4

Undergrad Can Objects Enter a Black Hole from an Angle?

  • Echo 6 Sierra
  • · Replies 8 ·
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8

Undergrad Shock Wave in Space: Vacuum or Medium?

  • wolram
  • · Replies 4 ·
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4

Graduate Is the Sun Distorting Earth's Space-Time?

  • oscar
  • · Replies 30 ·
2
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30

Graduate What Does XMM-Newton Reveal About Dark Energy in the X-ray Universe?

  • wolram
  • · Replies 167 ·
6
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167

Graduate Can black holes ever truly disappear?

  • s4syth
  • · Replies 14 ·
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14

Graduate Do Black Holes Emit Higgs Particles in Hawking Radiation?

  • kurious
  • · Replies 1 ·
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1

Graduate What Would Happen if a White Hole Collided with a Black Hole?

  • Tim
  • · Replies 17 ·
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17

Graduate Can the Booda Cosmic Isotropy Duality Hypothesis Be Proven?

  • Loren Booda
  • · Replies 2 ·
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2

High School Astronomy Club: A Student's Adventure in Learning

  • Gale
  • · Replies 10 ·
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10