When.com Web Search

Search results

  1. Results From The WOW.Com Content Network
  2. What is a light-year and how is it used?? - NASA

    starchild.gsfc.nasa.gov/docs/StarChild/questions/question19.html

    The light-year we have already defined. The parsec is equal to 3.3 light-years. Using the light-year, we can say that : The Crab supernova remnant is about 4,000 light-years away. The Milky Way Galaxy is about 150,000 light-years across. The Andromeda Galaxy is 2.3 million light-years away.

  3. How do I calculate light years to years? - Physics Forums

    www.physicsforums.com/threads/how-do-i-calculate-light-years-to-years.364768

    To calculate light years to years, you need to divide the distance in light years by the speed of light, which is approximately 9.46 trillion kilometers per year. This will give you the equivalent distance in years. 3. Can light years be converted to regular years? Yes, light years can be converted to regular years by dividing the distance in ...

  4. Just How Big is this Place? - NASA

    starchild.gsfc.nasa.gov/docs/StarChild/teachers/how_big.html

    4.21 light years If we hopped aboard our jet, how long would it take us to get to Alpha Centauri C? 40,000,000,000 hours How many years would that take? 4,566,210.0 years Are you packed yet? As an extra challenge, calculate the time it would take to reach Betelgeuse, a red giant located 600 light years away. First convert light years into ...

  5. Calculating Energy and Time for a Proton Crossing the Milky Way...

    www.physicsforums.com/threads/calculating-energy-and-time-for-a-proton...

    To calculate the energy of a proton crossing the Milky Way Galaxy, the equation E=mc² is used, where E is the energy, m is the mass of the proton, and c is the speed of light. The mass of the proton is known, and the speed of light is a constant value. Therefore, the energy can be easily calculated. 2.

  6. Calculating how long ago light was emitted from a star? - Physics...

    www.physicsforums.com/threads/calculating-how-long-ago-light-was-emitted-from...

    150 mile/50 mph =3 hrs. With your problem, light-years is the distance and years is the time. The speed is measured in light-years per year. Light travels at a speed of 1 light-year per year. So you would say that. 8.6 light-years/ 1 Light-year per year = 8.6 years. May 29, 2012.

  7. Redshift and Hubble's Law - NASA

    starchild.gsfc.nasa.gov/docs/StarChild/questions/redshift.html

    Redshift and Hubble's Law. For very far objects (beyond about 1 billion light-years) none of the above methods work. Scientists must move from direct observation to using observations in conjunction with a theory. The theory used to determine these very great distances in the universe is based on the discovery by Edwin Hubble that the universe ...

  8. Parallax - NASA

    starchild.gsfc.nasa.gov/docs/StarChild/questions/parallax.html

    From the image above, you can see that by knowing the size of Earth's orbit and measuring the angles of the light from the star at two points in the orbit, the distance to the star can be derived. The farther the star is, the smaller the angles. For stars more than about 100 light-years from Earth, we cannot measure any shift and the method fails.

  9. What do they mean when they say something is so many light years...

    www.physicsforums.com/threads/what-do-they-mean-when-they-say-something-is-so...

    Light Light years Mean Years. In summary: So, in summary, when we say an object is a certain number of light years away, we are referring to the distance the light from that object has traveled to reach us. This light may have been emitted many years ago and the object may have changed or moved since then. We use different methods to measure ...

  10. What is Light years: Definition and 53 Discussions

    www.physicsforums.com/tags/light-years

    How do I calculate the strength of gravity between two objects say that 2 years ago were 2 light years apart, during which they became 0.5 light years closer, if during those two light years, the stars lost 50% mass due to fusion and light, based on their mass "now", or based on how much...

  11. How far apart are two stars resolved by a 68-cm telescope? -...

    www.physicsforums.com/threads/how-far-apart-are-two-stars-resolved-by-a-68-cm...

    The distance between two stars is measured using a unit called a parsec, which is equal to 3.26 light years. This unit is based on the parallax effect, which is the apparent shift in position of a star when viewed from different locations on Earth. Scientists use telescopes to measure the parallax angle of a star and calculate its distance. 2.