AGE OF THE
UNIVERSE
There are at least 3 ways that the
age of the Universe can be
estimated:
The age of the chemical elements.
The age of the ...
• The age of the Universe can also be
estimated from a cosmological model based on
the HUBBLE CONSTANT and the densities
o...
1650: James Ussher, Archbishop of Armagh and Primate of All
Ireland, correlates Holy Writ and Middle Eastern histories to
...
1831: Charles Lyell uses fossils of marine
mollusks to estimate age as 2.4x108 years
1760: Buffon uses cooling of Earth from its
molten state to estimate age as 7.5x104 years
• Current Jewish calendar would
“suggest” a date of creation about
Sep/Oct 3760 BCE
• 1905: Lord Rutherford uses
radioacti...
• . In 1915 Albert Einstein published the theory
of general relativity.[16] Based on Einstein's
theory, Mgr. Georges Lemaî...
The Age of the Universe
No gravity: v = Hor  to = r/v = Ho
-1
Newtonian gravity for a flat universe:
½ mv2 - GmM/r = 0  ...
• The first direct observational
evidence that the Universe has a finite
age came from the observations of
astronomer Edwi...
• The first reasonably accurate
measurement of the rate of expansion
of the Universe, a numerical value now
known as the H...
NASA's Wilkinson Microwave Anisotropy Probe
(WMAP)
 project's nine-year data release in 2012 estimated the
age of the uni...
• The discovery MICROWAVE COSMIC
BACKGROUND RADIATION announced in
1965 finally brought an effective end to the
remaining ...
This number represents the first accurate
"direct" measurement of the age of the
universe (other methods typically involv...
`
• In the early 1990's, one thing was
fairly certain about the expansion of the
Universe. It might have enough energy
densi...
• Then came 1998 and the Hubble Space
Telescope (HST) observations of very distant
supernovae that showed that, a long tim...
Eventually theorists came up with
three sorts of explanations. Maybe there is
something wrong with Einstein's theory of
gr...
More is unknown than is known.
We know how much dark energy
there is because we know how it
affects the Universe's expansi...
quantum theory of matter
• In this theory, "empty space" is actually full
of temporary ("virtual") particles that
continua...
• Another explanation for dark energy is
that it is a new kind of dynamical
energy fluid or field, something that
fills al...
• A last possibility is that Einstein's
theory of gravity is not correct. That
would not only affect the expansion of
the ...
• AND FINALLY; the last thing that
we needed to decide between
dark energy possibilities –is that a
property of space, a n...
astronomy age of the universe
astronomy age of the universe
astronomy age of the universe
astronomy age of the universe
astronomy age of the universe
astronomy age of the universe
astronomy age of the universe
astronomy age of the universe
astronomy age of the universe
astronomy age of the universe
astronomy age of the universe
astronomy age of the universe
astronomy age of the universe
astronomy age of the universe
astronomy age of the universe
astronomy age of the universe
astronomy age of the universe
astronomy age of the universe
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astronomy age of the universe

  1. 1. AGE OF THE UNIVERSE
  2. 2. There are at least 3 ways that the age of the Universe can be estimated: The age of the chemical elements. The age of the oldest star clusters. The age of the oldest white dwarf stars.
  3. 3. • The age of the Universe can also be estimated from a cosmological model based on the HUBBLE CONSTANT and the densities of matter and dark energy. This model- based age is currently 13.75 +/- 0.1 Gyr. But this Web page will only deal with actual age measurements, not estimates from cosmological models. The actual age measurements are consistent with the model-based age which increases our confidence in the Big Bang model.
  4. 4. 1650: James Ussher, Archbishop of Armagh and Primate of All Ireland, correlates Holy Writ and Middle Eastern histories to “correct” the date to October 23, 4004 BC
  5. 5. 1831: Charles Lyell uses fossils of marine mollusks to estimate age as 2.4x108 years
  6. 6. 1760: Buffon uses cooling of Earth from its molten state to estimate age as 7.5x104 years
  7. 7. • Current Jewish calendar would “suggest” a date of creation about Sep/Oct 3760 BCE • 1905: Lord Rutherford uses radioactive decay of rocks to estimate age as > 109 years (later refined to 4.3x109 years)
  8. 8. • . In 1915 Albert Einstein published the theory of general relativity.[16] Based on Einstein's theory, Mgr. Georges Lemaître's work showed that the Universe cannot be static and must be either expanding or contracting. Einstein himself did not believe this result and so he added what he called a Cosmological Constant to his equations in an unsuccessful attempt to produce a theory consistent with a Steady State Universe.
  9. 9. The Age of the Universe No gravity: v = Hor  to = r/v = Ho -1 Newtonian gravity for a flat universe: ½ mv2 - GmM/r = 0  v = dr/dt = (2GM/r)½ so we can integrate r½adr = (2GM)½dt to get to = 2/3 (r3/2GM)½ = 2/3 (r/v) = 2/3 Ho -1
  10. 10. • The first direct observational evidence that the Universe has a finite age came from the observations of astronomer Edwin Hubble published in 1929.Earlier in the 20th century, Hubble and others resolved individual stars within certain nebulae, thus determining that they were galaxies, similar to, but external to, our Milky Way Galaxy.
  11. 11. • The first reasonably accurate measurement of the rate of expansion of the Universe, a numerical value now known as the Hubble constant, was made in 1958 by astronomer Allan Sandage. His measured value for the Hubble constant yielded the first good estimate of the age of the Universe, coming very close to the value range generally accepted today.
  12. 12. NASA's Wilkinson Microwave Anisotropy Probe (WMAP)  project's nine-year data release in 2012 estimated the age of the universe to be 1.3772±0.0059×1010 years (13.772 billion years old, with an uncertainty of plus or minus 59 million years).  However, this age is based on the assumption that the project's underlying model is correct; other methods of estimating the age of the universe could give different ages. Assuming an extra background of relativistic particles, for example, can enlarge the error bars of the WMAP constraint by one order of magnitude.  BASED ON THE LIGHT TIME TRAVEL.
  13. 13. • The discovery MICROWAVE COSMIC BACKGROUND RADIATION announced in 1965 finally brought an effective end to the remaining scientific uncertainty over the expanding Universe. The space probe WMAP, launched in 2001, produced data that determines the Hubble Constant and the age of the Universe independent of galaxy distances, removing the largest source of error.
  14. 14. This number represents the first accurate "direct" measurement of the age of the universe (other methods typically involve HUBBLE’S LAW and age of the oldest stars in globular clusters, etc.). It is possible to use different methods for determining the same parameter (in this case – the age of the universe) and arrive at different answers with no overlap in the "errors".
  15. 15. `
  16. 16. • In the early 1990's, one thing was fairly certain about the expansion of the Universe. It might have enough energy density to stop its expansion and recollapse, it might have so little energy density that it would never stop expanding, but gravity was certain to slow the expansion as time went on. Granted, the slowing had not been observed, but, theoretically, the Universe had to slow.
  17. 17. • Then came 1998 and the Hubble Space Telescope (HST) observations of very distant supernovae that showed that, a long time ago, the Universe was actually expanding more slowly than it is today. So the expansion of the Universe has not been slowing due to gravity, as everyone thought, it has been accelerating. No one expected this, no one knew how to explain it. But something was causing it.
  18. 18. Eventually theorists came up with three sorts of explanations. Maybe there is something wrong with Einstein's theory of gravity and a new theory could include some kind of field that creates this cosmic acceleration. Theorists still don't know what the correct explanation is, but they have given the solution a name. It is called dark energy.
  19. 19. More is unknown than is known. We know how much dark energy there is because we know how it affects the Universe's expansion. Other than that, it is a complete mystery. But it is an important mystery. It turns out that roughly 70% of the Universe is dark energy.
  20. 20. quantum theory of matter • In this theory, "empty space" is actually full of temporary ("virtual") particles that continually form and then disappear. But when physicists tried to calculate How much energy this would give empty space, the answer came out wrong - wrong by a lot. • The number came out 10 times too big. That's a 1 with 120 zeros after it. It's hard to get an answer that bad. So the mystery continues.
  21. 21. • Another explanation for dark energy is that it is a new kind of dynamical energy fluid or field, something that fills all of space but something whose effect on the expansion of the Universe is the opposite of that of matter and normal energy.
  22. 22. • A last possibility is that Einstein's theory of gravity is not correct. That would not only affect the expansion of the Universe, but it would also affect the way that normal matter in galaxies and clusters of galaxies behaved. This fact would provide a way to decide if the solution to the dark energy problem is a new gravity theory or not: we could observe how galaxies come together in clusters.
  23. 23. • AND FINALLY; the last thing that we needed to decide between dark energy possibilities –is that a property of space, a new dynamic fluid, or a new theory of gravity - is more data, better data.

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