Thebigbang-backbencher-150322102858-conversion-gate01.pdf

Group Name: Back Bencher Group Members S M Manna (14203083) Sumon Kumar Ghosh (14203098) Imam Uddin (14203071) MD. Sayham Khan (14203123) MD. Yousuf Hassan (14203100)

Presentation Day: 12 March 2015 The Big Bang

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Contents • • • • • • • •

The Big Bang Theory The Big Bang Phase Expanding Universe Testing Big Bang Model Dark matter & Dark energy Evidence of dark matter After time period of Big Bang Life cycle of star

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The Big Bang • The universe begins ~13.7 Billion years ago • The universe begins as the size of a single atom • The universe began as a violent expansion – All matter and space were created from a single point of pure energy in an instant.

Image 1: Beginning of Big Bang The Big Bang

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The Big Bang: Phase Phase 1 At the beginning of time, from Complete nothingness, a cosmic Explosion ignites.

Image 2: Phase 1

Phase 2 The thrust from the explosion sends Billions of tons of energy through space And the elements begin to cool. Image 3: Phase 2

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The Big Bang: Phase Phase 3 Galaxies begin to take shape while Still moving away from the initial Point of ignition.

Image 4: Phase 3

Phase 4 The universe continues to expand to This very day. Image 5: Phase 4

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Ever Expanding Universe

According to the Big Bang model, the universe expande d from an extremely dense and hot state and continues to expand today. Image 6: Ever Expanding Universe The Big Bang

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Testing the Big Bang model • Prediction: If the universe was denser, hotter, in past, we should see evidence of left-over heat from early universe. • Observation: Left-over heat from the early universe. (Penzias and Wilson, 1965)

Image 7: Left over heat from early universe The Big Bang

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Testing the Big Bang model • Prediction: A hot, dense expanding universe, should be predominantly hydrogen, helium. • Observation: Universe is ~75% hydrogen, ~25% helium by mass

Image 8: The Sun: 74.5% H, 24% He by mass The Big Bang

Image 9: Cecilia Payne 9

Testing the Big Bang model

• Observation: 90% of matter is an unknown form: Dark Matter. • Refine: A new and unknown form of matter exists. But its gravity • works the same way, and its presence is needed to explain how the universe looks.

Image 10: Testing Big Bang

Image 11: Vera Rubin The Big Bang

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Expansion is accelerating A recent discovery and of unknown origin, the concept of Dark Energy is actually an integral part of Einstein’s theory of gravity.

Image 12: Science Magazine The Big Bang

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Normal Matter 4%

Dark Energy 73%

Dark Matter 23%

Figure 1: Materials of Universe

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Evidence for Dark Energy supernovae as distance indicators - step 1

Image 12: A dying star becomes a white dwarf. The Big Bang

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Evidence for Dark Energy supernovae as distance indicators - step 2

Image 13: The white dwarf strips gas from its stellar companion…. The Big Bang

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Evidence for Dark Energy supernovae as distance indicators - step 3

Image 14: ….and uses it to become a hydrogen bomb. Bang! The Big Bang

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Evidence for Dark Energy supernovae as distance indicators - step 4

Image 15: The explosion is as bright as an entire galaxy of stars….

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Evidence for Dark Energy supernovae as distance indicators - step 5

Image 16: and can be seen in galaxies across the universe. The Big Bang

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How Everything Began ~ Several hundred thousand years after Big Bang

Figure 2: Atom Formation.

• ATOMS form (specifically Hydrogen and its isotopes with a small amount of Helium.) • The early Universe was about 75% Hydrogen and 25% Helium. It is still almost the same today. The Big Bang

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~200 to 400 million years after Big Bang • 1st stars and galaxies form

Image 17: ~200 to 400 million years after Big Bang The Big Bang

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~ 4.6 billion years ago • Our Solar system forms

Image 18: Our Solar system forms

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Misconceptions about the Big Bang • there was no explosion; there was (and continues to be) an expansion – Rather than imagining a balloon popping and releasing its contents, imagine a balloon expanding: an infinitesimally small balloon expanding to the size of our current universe • we tend to image the singularity as a little fireball appearing somewhere in space – space began inside of the singularity. Prior to the singularity, nothing existed, not space, time, matter, or energy - nothing. The Big Bang

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Figure 3: Life cycle of a star The Big Bang

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Big Bang evidence 1) 2) 3) 4) 5) 6)

Universal expansion and Hubble’s Law 3 degree background radiation Quasars Radioactive decay Stellar formation and evolution Speed of light and stellar distances

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Conclusions – Till Now • Big Bang model describes our current understanding of the universe. • New discoveries, such as dark matter and accelerating expansion (Dark Energy), lead us to refine our model, but there is no crisis in our understanding (yet). • Science is an ongoing process - forcing us to test our model through prediction and observation. • The more tests it passes, the greater is our confidence in it.

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The Future of Cosmology: Beyond Einstein

• What powered the Big Bang? • What Is Dark Energy? • How did the Universe begin?

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LASTLY – we are pretty sure everything has a beginning, right?

Image 20: Funny picture about Big Bang The Big Bang

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Thanks

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