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Universe: from Beginning to End

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Presentation on theme: "Universe: from Beginning to End"— Presentation transcript:

1 Universe: from Beginning to End
Brief History of Universe form Birth to Death OR

2 What is matter? Experiments at Fermilab have helped defined the proton, a particle inside the atom’s nucleus, and proton’s substructure of quarks. Study the top quark may give clues to the scientific mystery of why matter has mass

3 Classification of Matter

4 Particles of the Standard Model

5 Neutron n  p + e- +ne Decay time t~ 16 minutes

6 Bineutron g+2D  2n + p+ or g+2D n + n + p+ m- + 2D  2n + nm
m- + 2D  n + n + nm

7 3n is trineutron a bound state of three neutron?

8 4n is tetraneutron a bound state of four neutron?

9 Final State: Nucleons in continuum spectrum
4He, 3He, 3H g, p, m Final State: Nucleons in continuum spectrum 2 ds/dW Transition operator

10 From Elementary Particles to Stars
We discussed the tiniest object in the universe – the neutron, and existence of the bineutron, trineutron and tetraneutron. Now we leap to the largest – stars especially, neutron stars

11 History of our Universe t=0 The Big Bang
Universe originated in the explosion of a primordial fireball 0<t<10-43 Seconds. General Relativity should not be valid and should be replaced by a new theory which incorporates the principles of quantum theory. We do not know anything about this epoch

12 10-43 <t<1 Seconds. During this period the universe expanded and the matter density dropped from about 1092 g/cm3 to ~ 106 g/cm3. Matter in the Universe consisted primarily of the very high energy elementary particles. Exotic elementary particles (m, p, W, S, K, L) decayed and at the end of this epoch we had “soup” of photons, neutrinos, electrons, positrons, protons, neutrons. The temperature of the matter cooled to about C. There were about five times as many protons as neutrons


14 1Second<t<1000 Seconds
Density of the ‘soup” dropped from about 106 g/cm3 to 0.5 g/cm3 Temperature dropped from ~ C to C. e-+e+  2g During this period was nucleosynthesis: protons and neutrons formed elements: 2D, 4He … p +p  2D + e+ + n p + 2D  3He +g 3He + 3He  4He + p + p Proton-proton cycle : 4p  4He + 2e+ + 2n + 2g 4He + 4He  8Be +g 4He + 8Be  12C +g

15 1000 Seconds<t< 100,000 Years
The Universe continued expanded rapidly and cool The important constituents of the soup were photons, protons, helium nuclei and free electrons. At the end of this epoch, the temperature of the “soup” dropped to ~ C and the electrons combined with the protons, helium nuclei to form neutral hydrogen and helium atoms. There were no longer any charged particles and electromagnetic radiation decoupled from matter

16 Atomic Structure Atomic Nucleus

17 100,000 Years<t<8 to 18 Billion Years (Present Era)
Universe continued to expand. Electromagnetic radiation fills the entire Universe. And the temperature dropped to ~ 3 0K. Small inhomogeneities in the mater distribution began to grow under their own self-gravitation attraction. The galaxies, star clusters and stars formation.

18 The process of stellar evolution from the birth to the death of the star depends on the mass of the star. If the star has mass less than about 1.4 solar masses the star collapses under the action of gravity and becomes a white dwarf If mass is greater than 1.4 solar mass the stars follow to quite different scenario. High-energy collisions breaking iron into helium nuclei, and eventually into protons and neutrons 56Fe 13 4He + 4n 4He  2p + 2n Then e- + p  n +n The star begins to contract rapidly toward forming an enormously dense neutron star The core of a neutron star contracts to the point at which all neutrons are as close together as they are in a nucleus.


20 Black Holes If the mass M of the star is compressed to such small size that the escape speed exceeds the speed of light, the mass M forms a BLACK HOLE

21 Big Crunch Universe stops expanding at some time in the future, will then contract again down to its initial, highly condensed state in a finite time …starts another expansion phase Or will it just go on contracting and then … … new Big Bang

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