How the Universe got its Spots

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How the Universe got its Spots

• The Big Bang

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Goals

• Where did the Universe come from?
• Where is it going?
• How can we see the past?
• How can we learn about the future from seeing the
  past?

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Can you accept understandconcepts like these?

• Nuclear reactions and the weak interaction the
  rules that govern the universe are foreign by
  everyday standards, but there are still rules we
  can know them in detail, and use them to study
  other phenomena.
• Dark matter and dark energy the universe is
  controlled on large scales by entities unlike us
  there is no problem with this its exciting,
  and probably solvable.
• Big bang theory the universe is vast in space
  and time and evolves over time like our world
  does, but it is not beyond our ability to measure
  with precision!
• Origin and evolution of life we appear to be
  part of a cosmic system, organized and tweaked
  chemically on Earth in a way that could have
  happened elsewhere too.

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The Future from the Past

• Is the Universe
• Slowing down?
• Speeding up?
• Staying the same velocity?
• In the past, was the Universe
• Going faster?
• Going slower?
• Going the same velocity?
• The Universe is a time machine.

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Time line Cosmic Soup, Radiation Era, Matter
Dominated Era
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The Big Bang

• Big Bang the event from which the Universe began
  expanding.
• Into what did the Universe expand?
• Where was the Big Bang?
• Where is the center of the Universe?

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Consequences

• If everything is moving away from us and things
  farther are moving faster
• Then the Universe is expanding!

This doesnt mean what you are probably thinking
. . . .
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Expanding Universe

• Space itself is expanding, not matter flying
  apart within space.
• Examples
• dots
• rubber band
• raisin bread
• ants on a balloon

• It does not mean we are at the center of the
  Universe
• every part of the Universe sees everything moving
  away from it

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Looking Back in Time

• Remember it takes time for light to reach us
• travels at 300,000 km/s
• So we see things as they were some time ago
• The farther away, the further back in time we are
  looking
• 1 billion LY means looking 1 billion years back
  in time
• So the greater the redshift, the further back in
  time
• redshift of 0.1 is 1.4 billion lightyears which
  means we are looking 1.4 billion years into the
  past

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Big evidence for Big Bang

• 1992 COBE satellite Cosmic Background Explorer
  satellite Background radiation
• its the discovery of the century, if not for
  all time Stephen Hawking
• the handwriting of God Dr. George
  Smoot, astrophysicist, ? there was a
  definite beginning to the universe

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Galactic Redshifts

• Edwin Hubble (1889-1953) and colleagues
• measured the spectra (light) of many galaxies
• found nearly all galaxies are red-shifted
• Redshift (Z)
• (Doppler effect) Z v/c
• (for speeds approaching c, well need a
  relativistic version of this equation.)

Andromeda galaxy
Z (1 v/c)/(1 v/c)1/2 - 1
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Do you know what Red Shift is?
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Redshift
Quasars Cosmology
In relativity the space between the galaxies is
expanding.
Department of Physics, Applied Physics
Astronomy, RPI
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Hubbles Law

• Galaxies are moving away from us.
• The farther away the faster they go.
• V Ho x D

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Expanding Universe

• If galaxies are all moving away, then at some
  point they were all much closer.
• Hubbles Law implies the Universe is expanding.

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Look back Time

• We see everything as it once was.

Old
Young
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Age of the Universe

• Since all galaxies are moving away from us, how
  long has it been since all galaxies were
  together?
• time distance / velocity
• velocity Ho x distance
• time distance / (Ho x distance)
• time 1/Ho

An expanding universe does not preclude a
creator, but it does place limits on when he
might have carried out his job. -Steven Hawking,
A Brief History of Time
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But does it give us enough time?

• Agnostic biophysicist Dr. Harold Morowitz
  wondered
• Suppose you break all chemical bonds in the
  simplest organism (a bacteria) and put those
  atoms under ideal chemical conditions
• Question How long would it take for it to
  reassemble?

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Answer 10100,000,000,000 years!

• Written out completely, that would be
• 1,000,000,000,000,000,000,000,000,000,000,000,000,
  000,000,000,000,000,000,000,000,000,000,000,000,00
  0,000,000,000,000,000,000,000,000,000,000,000,000,
  000,000,000,000,000,000,000,000,000,000,000,000,00
  0,000,000,000,000,000,000,000,000,000,000,000,000,
  000,000,000,000,000,000, (on and on)
• ? a thousand sets of Encyclopedia Britannicas
  filled with zeros!!

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So, is it feasible?

• 10100,000,000,000 yrs is impossible because
• Hydrogen atoms would decay after 1033 years
  500,000,000,000,000,000,000,000,000,000,000 years
• Heat death of the universe will occur at
  80,000,000,000 years
• Big Bang restricts the age of the universe to be
  lt50,000,000,000 years
• ? We clearly dont have enough time for atoms
  to randomly combine together to form even a
  simple bacteria!

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Hubble Space Telescope

• Use HST to find Cepheids in other galaxies.

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Luminosity and Distance

• Brightness goes as 1/D2.
• Move light
• 2x farther away, one quarter as bright.
• 3x farther, one ninth as bright
• 10x farther, one hundredth as bright.
• If you know
• How bright it looks
• How bright it SHOULD be
• You know how far away it must be.
• Standard candles yield distances!

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Baby Boomer Universe
Farther away we look, further back in time we see!
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What We See
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Density of the Universe

• Add up all the mass we see and Wo 0.01
• But we know there is some dark matter in galaxies
  and clusters.
• How much?
• Think 10 x more dark matter than light matter.
• Cosmologists think Wo lt 0.3
• Result Open Universe ? Big Freeze!

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Are We Slowing Down?

• In our experience, things slow down over time.
• Is the Universe slowing down at all?
• Plot distance versus velocity.
• Use supernovae as standard candles.
• Distant supernovae (large lookback time).

Slowing
Accelerating
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Are We Slowing Down?

• Unseen mass making stars move fast
• Dark Matter
• Unseen energy accelerating galaxies
• Dark Energy

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We are not made of the same type of matter as
most of the Universe!
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The End of the Universe

• Will the universe expand forever?
• Depends on the density of the Universe.
• Too big Big Crunch
• Closed Universe
• Bound Universe
• Too small Big Freeze
• Open Universe
• Unbound Universe

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Concluding comments

• "Astronomy leads us to an unique event, a
  universe which was created out of nothing and
  delicately balanced to provide exactly the
  conditions required to support lifethe
  observations of modern science seem to suggest an
  underlying, one might say, supernatural plan
  Nobel Laureate Arno Penzias
• the origin of life appears to be almost a
  miracle, so many are the conditions which would
  have had to be satisfied to get it going
  Nobel Laureate Francis Crick

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Some references

• John D. Barrow and Frank J. Tipler, The Anthropic
  Cosmological Principle (New York Oxford
  University Press, 1996)
• J. P. Moreland (ed.), The Creation Hypothesis
  (Downers Grove, Illinois InterVarsity Press,
  1994)
• Charles B. Thaxton, Walter L. Bradley, and Roger
  L. Olsen, The Mystery of Lifes Origin
  Reassessing Current Theories (Dallas Lewis and
  Stanley, 1992)
• Robert Shapiro, Origins A skeptics guide to the
  creation of life on earth (New York Summit
  Books, 1986)
• www.origins.org - www.arn.org -
  www.leaderu.com