Astronomy, Astrophysics, Cosmology Forum

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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.
Graduate Can we see the Earth in the past
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Graduate How did the cosmos form w/o observers around?
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Graduate Looking for online solar astronomy book/course
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Could a Billion-Year Technology Gap Exist?
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Undergrad Stars: Fixed or Moving? | RA, Dec & Julian Date
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Graduate Perhaps we live in a black hole?
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Undergrad Where does the energy of gravity come from?
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Undergrad Could an ExoEarth with 70% Land and 30% Water Host Unique Life Forms?
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Graduate Can Antimatter Catalysed Engines Propel Us Across the Galaxy?
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Undergrad Reference book about astrophysics please
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High School Astronomy and astrophysics, are they the same?
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Graduate Is the Universe Both Flat and Accelerating?
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Undergrad Reccomend a stellar database for my software program?
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Undergrad The densest areas in the universe
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Undergrad Why Doesn't Earth Fall Into the Sun?
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High School Can We Overcome the Challenges of Space Travel Beyond Our Solar System?
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High School Catastrophic event stopped growth of galaxy{ON News}
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Graduate Why Were Early Universe Stars More Massive Than Today's Stars?
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High School Explaining Black Holes to 5th Graders
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Undergrad What are Black Holes and How Do They Differ from Dense Balls of Matter?
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Graduate Does expansion exist on the micro level as well as the galactic level?
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Graduate Heat Applied to Black Hole: What Happens?
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Graduate Speed of the Sun: Facts & Measurements
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Graduate What ideas does the discrepancy of CMB photons affect?
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Graduate Virtual particule and event horizon
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Undergrad Why are people saying that the radius of the observable universe is 46.5 ly
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Graduate Pair-Instability Supernovae & No Black Hole Remnant
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Graduate How Many Photons Reach the Hubble Telescope from a Distant Star in a Day?
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Graduate Paradox of the Universe - Physics or Voodoo Philosophy?
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Graduate Understanding Entropy: Speculations on the Properties of Our Universe and Beyond
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Graduate Changeover from deceleration to acceleration
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Graduate How Do Black Holes Affect Photons and What Mysteries Remain?
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Graduate How Does the Solar System's Angular Velocity Change Over Time?
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Graduate Effects of moon on prehistoric earth
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Graduate Cosmic background radiation - redshift, blueshift, anisotropies
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Graduate Question about black holes and graviational singularities.
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Graduate What is the role of gravity in the cosmological redshift?
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Graduate Could advanced technology artificially accelerate the evolution of our sun?
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Graduate Dark energy as an entropic force?
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Graduate How can all the matter in the universe start out as one point?
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Graduate What are the Quantum Mechanics Situations Allowing Light to Escape Black Holes?
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Graduate No Boundry Proposal: Hartle & Hawking's Theory Explained
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Graduate Is Gravity Weakening as the Universe Expands?
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Undergrad Changing Earth's Orbit: How Has the Speed Around the Sun Evolved?
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Graduate Can Quantum Tunneling Enable Faster-Than-Light Communication?
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What is the single most important thing for life to exist in the universe?
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Question on Binary Neutron Star Importance?
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Stargazing Celestron Astromaster 114EQ Reflecting Telescope: A Beginner's Guide
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Graduate There is no such thing as empty space in an atom. True?
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Black Hole Density: Facts & Info
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Managing Telescope Aiming: a Sky-Watcher Challenge
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Graduate Copernican Principle and Metric Expansion
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Graduate The Big Bang.. just one little question
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High School How do we know what the sun is made of?
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Graduate The formation of Galaxy Clusters from density fluctuations in the early Universe
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Undergrad Universe expansion, then deceleration, then acceleration?
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Graduate Absolute color - magnitude diagram
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What are your views on the future of Space Exploration
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Undergrad Visualizing daily life through broader EM spectrum
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Graduate Confusion with conversion for the Hubble Constant
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Graduate Blackholes In The Early Universe
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Undergrad Need Controversial Topic for an Eng102 Class
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Graduate Effective universe cutoff at z=1.73, is this circular logic?
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Graduate Dark matter: galaxy vs. super-cluster evidence
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Graduate What changes the rate of inflation
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Graduate Could Expansion Explain Gravity Mathematically?
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Graduate Unraveling the Mystery of the Universe's Dimension: Is it a Membrane?
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Undergrad Calculate the final velocity of an object accelerating towards a mass
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Graduate So what happen to a shuttle that enters a black hole?
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Undergrad Exploring Kinetic Energy & Recessional Velocity
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Undergrad Build Space Dirigibles: Alternative Freighter Idea
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Graduate Bolometric Magnitude and H-R diagram
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Undergrad *quantitative* fun with the cosmos (easy)
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Player Pays $330k (US) for Space Station in Project Entropia Universe
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Undergrad Variation of gravity along latitude
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Graduate How do I calculate the phase integral for the Bond albedo in astrophysics?
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Graduate Is Relative Motion Evidence of a Static Aether in Orbital Physics?
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What is the difference between astrology and astronomy?
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Graduate Finite Big Bang, Infinite universe?
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Undergrad Critical Expansion Rate: The Key to Understanding the Evolution of the Universe
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How to crack weird space cases: by Jim Oberg
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Graduate Big Bang - galaxies not mapping onto a point
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Undergrad Will we go the the past if we could go faster than speed of light?
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Questionable article in Scientific American?
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Graduate Dark Matter Particles: Not Atoms? Strings? Bubbles?
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Undergrad A small finite universe and some wierd thoughts from it
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Graduate Current eff. universe limited to redshift 1.73
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Graduate Constants and multiverse possibilities
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Graduate Can we see the earth in the past ?
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Graduate Formula of anti-gravitational force
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Graduate Finite Universe: Why Postulate an Infinite Universe?
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Graduate Center of the Universe (thought experiment)
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Graduate Can We Truly Conceptualize Quantum Particles and Four-Dimensional Space-Time?
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High School Big Bang: Is this statement true?
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Undergrad Hawking Radiation: Rate of Decay & Mass
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Undergrad Is Anything Else Expanding Like the Universe?
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Undergrad Expansion Algorithm: Acceleration Over Time
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Graduate Nagging Doubts just won't go away(song)
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Graduate How exactly can CMBR tell us universe age
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Undergrad An asteroid is orbiting around the sun at a distance of 4.2
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