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Resources for this Topic

  1. Imagine the Universe! "Origin and Destiny of the Universe"

  2. Universe: Cosmology 101 (

  3. Cosmology Tutorial (

  4. Cosmology Primer FAQ (

  5. Cosmos in a Computer (

Library of Past Questions and Answers

    Common Questions about Cosmology

  1. Where in the Universe did the Big Bang originate?

  2. What was before the Big Bang?

  3. If all the distant galaxies are flying away from us, does that mean that we're in the center of the Universe?

  4. What is the Universe expanding into?

  5. What is at the edge of the Universe?

  6. How can we see light that should have already passed us?

  7. Could the Big Bang have been a Black/White Hole?

  8. Is it possible that there are many Universes?

    The Big Bang and the Expansion of the Universe

  1. What does the evidence tell us about the origin of the Universe and what is the evidence that concludes this point?

  2. What was Friedman's theory on the expansion of the universe?

  3. What does the concept of relative time frames mean for the Universe's expansion?

  4. How much energy was released in the Big Bang?

  5. Where is the newest information on inflation theory?

  6. Doesn't faster than light inflation violate Relativity?

  7. Will the universe acceleration exceed the speed of light?

  8. Does time slow down in distant galaxies?

  9. Is the Universe rotating? With reference to what?

  10. What holds the Universe together? What holds us together?

  11. What is the longevity of light?

  12. How can galaxies merge in a expanding universe?

  13. Why dosen't the space in and between atoms also expand?

  14. If everything expands, how can we measure the expansion of the universe?

    The Age of the Universe and the Hubble Constant

  1. How do you determine the age of the Universe?

  2. What is the Hubble Constant?

  3. How has the new Hipparcos data affected the Hubble constant and thus the estimated age of the Universe?

  4. How does Polaris being a Cepheid variable in a binary help us understand the expansion of the universe?

  5. What is the Sunyaev-Zeldovich Effect and can it be used to calculate the Hubble Constant?

  6. Do you have information on the Loh and Spillar test that can be used to determine the Hubble Constant?

  7. Is the expansion of the Universe slowing down or speeding up?

  8. Is the existence of a Cosmological Constant being considered?

  9. The accelearted expansion of Space is not a constant.

  10. Is the Hubble Constant really a constant, if the Universe is expanding?

    The Size and the Mass of the Universe

  1. Does the Universe have a dimension or size?

  2. Is the observable Universe not all of the Universe?

  3. Did WMAP results prove an infinite universe?

  4. How do you measure the size of the Universe?

  5. Is my conclusion about the Cosmic Particle Horizon correct?

  6. Can two areas of the Universe be so far away from each other that the light from area A can not reach area B?

  7. How can one estimate the size of the Universe if any part of it past this critical distance is forever cut off from our measurement?

  8. How do astronomers measure the mass of the cosmos?

  9. How do we find the mass of the visible Universe by finding the number of galaxies in the Universe and the mass of an average galaxy?

    The Density and the Fate of the Universe

  1. What is the present accepted value of the density of the Universe?

  2. Can you tell me about the end of time?

  3. Is there enough matter in the Universe for a "Big Crunch"?

  4. Does the discovery of intergalactic hydrogen imply a Big Crunch?

  5. Will the Universe keep collapsing and re-expanding?

  6. Is a vacuum causing the acceleration of the universe edge?

    Matter and Anti-Matter in the Universe

  1. What is the known percentage of hydrogen in the Universe and where is it?

  2. If the Big Bang was pure energy, what made the matter?

  3. How serious is the hypothesis about anti-stars?

  4. Did the Big Bang also create anti-matter galaxies?

  5. If the Big Bang made equal amounts of matter and antimatter, where is all the antimatter?

    The Cosmic Microwave Background

  1. Can light be contained and how do we observe light from the Big Bang?

  2. Why is the CMB seen only in the microwave range?

  3. Does the CMB imply that the universe is not infinite?

  4. How did COBE measure the temperature of the Cosmic Background?

  5. What does it mean for the universe to become transparent?

  6. Can we map the Universe before inflation?

    Stars and Galaxies - their Formation and Clustering

  1. What is the structure of the Universe?

  2. Were there seeds for galaxy formation before atoms formed?

  3. What is the Great Attractor?

  4. Which formed first in the universe - galaxies or stars?

  5. Did bigger stars in the early universe make more black holes?

    Advanced Cosmology Questions

  1. Can you explain Olbers' Paradox?

  2. Will a closed universe violate the 2nd law of thermodynamics?

  3. Will entropy increase with time as the Universe evolves?

  4. Could we compare the early Universe to a black hole?

  5. Could the Laws of Physics be different in another Universe?

Imagine the Universe is a service of the High Energy Astrophysics Science Archive Research Center (HEASARC), Dr. Alan Smale (Director), within the Astrophysics Science Division (ASD) at NASA's Goddard Space Flight Center.

The Imagine Team
Acting Project Leader: Dr. Barbara Mattson
All material on this site has been created and updated between 1997-2012.

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