Is the Big Bang really 13.8 b old ?

Discussion in 'Astronomy, Exobiology, & Cosmology' started by arauca, Mar 7, 2013.

  1. arauca Banned Banned

    Messages:
    4,564
    "We have found that this is the oldest known star with a well-determined age," said Howard Bond of Pennsylvania State University in University Park, Pa., and the Space Telescope Science Institute in Baltimore, Md. The star could be as old as 14.5 billion years (plus or minus 0.8 billion years), which at first glance would make it older than the universe's calculated age of about 13.8 billion years, an obvious dilemma. But earlier estimates from observations dating back to 2000 placed the star as old as 16 billion years. And this age range presented a potential dilemma for cosmologists. "Maybe the cosmology is wrong, stellar physics is wrong, or the star's distance is wrong," Bond said. "So we set out to refine the distance." The new Hubble age estimates reduce the range of measurement uncertainty, so that the star's age overlaps with the universe's age—as independently determined by the rate of expansion of space, an analysis of the microwave background from the big bang, and measurements of radioactive decay.

    Read more at: http://phys.org/news/2013-03-hubble-birth-certificate-oldest-star.html#jCp
     
  2. Google AdSense Guest Advertisement



    to hide all adverts.
  3. Dr Mabuse Percipient Thaumaturgist Registered Senior Member

    Messages:
    714
    According to theory, yes it was approx that far back.

    In actual fact? We don't know.
     
  4. Google AdSense Guest Advertisement



    to hide all adverts.
  5. rpenner Fully Wired Valued Senior Member

    Messages:
    4,833
    Actually, if you want to read more, you have to read the paper on which the estimate of the star's age is made. Pre-print: http://arxiv.org/abs/1302.3180


    In short, the attempt to calculate how long after the Big Bang that this star formed is an operation that loses all significant digits.

    Assuming both calculations are correct, and independent, and the uncertainties quoted represent standard deviations, the most likely age of HD 140283 is \(13.684 { \tiny +0.067 \\ - 0.557 }\) billion years.
     
  6. Google AdSense Guest Advertisement



    to hide all adverts.
  7. arauca Banned Banned

    Messages:
    4,564
    How accurate are the measurements ? in view of



    Estimates of the distance to a nearby galaxy orbiting the Milky Way, a key parameter that astronomers use to gauge the scale of the universe, are now more accurate than ever—a feat that may help cosmologists in their search for dark matter. Previous studies calculating the distance to the Large Magellanic Cloud (close-up shown), a group of stars that together weigh about 1% of our galaxy, are accurate only to somewhere within 5% or 10%. Now, astronomers have used observations of eight pairs of binary stars in the distant cluster to develop a new figure. The orbits of these pairs are aligned such that one star passes in front of the other as seen from Earth, which allowed the researchers to approximate the size of each member from the durations of the eclipses. The spectra of these cool, mature stars allowed the team to determine their surface temperatures. Together, those bits of data enabled the astronomers to estimate the amount of energy emitted by the stars, and that, in conjunction with observations of their actual brightness as seen from Earth, allowed the researchers to estimate the distance to each pair. The average of the distances to those eight binary systems, which conveniently are all located near the center of the Large Magellanic Cloud, is a shade under 163,000 light-years—a figure that's accurate to about 2.2%, the team reports online today in Nature. The new, better estimate of distance to the Large Magellanic Cloud, in conjunction with observations of other stars in the cluster, will serve as a yardstick to better approximate a parameter called the Hubble constant, which helps cosmologists estimate how quickly the universe is expanding. A more accurate value for the Hubble constant could also aid researchers who are searching for dark energy and dark matter, the mysterious components of the universe that remain invisible to Earthbound instruments.
     
  8. mukesh Registered Member

    Messages:
    2
    there are certainly more theories on big bang timing than we know. It is because of its uncertain nature..it happened and imaging transfer of all elements in entire universe, arrival of life and then to human form(life reaching human form has taken millions of years)..hence it is very possible that bing bang happened that ago.
     
  9. river

    Messages:
    12,760
    It just keeps going on and on ad-hocs to make the BB work ?

    Whatever
     
  10. Rhaedas Valued Senior Member

    Messages:
    1,516
    Yes, things in science can change if enough facts present a reason to change.
     
  11. river

    Messages:
    12,760
    Cosmic plasmas would be a start
     

Share This Page