The Formation of Matter as we know it

In the Beginning (as science thinks)  All matter existed in a very small space  Very dense  Temperatures were over Kelvin  Atoms, protons, neutrons, and electrons didn’t exist due to the high temperature and density  The universe was a “soup” of matter and energy  radiation

First Second after the Big Bang  Temperatures had fallen  100 Billion Kelvin (179,999,999,540.6 ºF)  Neutrons, protons, and electrons began to form  Too much energy at this time to form atoms  When they ran into each other they would bounce off each other  Neutrons  Were being created and destroyed as a result of interactions between protons and electrons  Due to the amount of energy lighter electrons and protons collide to form neutrons.  Some did decay back into a positive proton and a negative electron

Universe continues to expand  Temperature keep falling  Protons and electrons no longer had enough energy to collide to form neutrons  Number of neutrons and electrons stabilized  7:1, with protons outnumbering electrons

100 seconds after the big bang  One billion Kelvin  1,799,999,540.6 ºF  Neutrons and protons collide and stick together  Deuterium  First atomic nuclei  Neutron-proton pairs  Type of hydrogen with an extra neutron  Sometimes deuterium would collide to form helium nucleus  Rare occasion there would be enough collision between deuterium to form lithium

Universe – a few minutes old  95% Hydrogen  5% Helium  Trace amounts of lithium

10s of thousand of years old  Matter dominated over radiation  Temp. 10s of thousands of Kelvins

Next few 100 thousand years  Universe expanding (factor of 10)  Temp. few 1,000 kelvin  Electrons and nuclei combined to form neutral atoms  Epoch of decoupling  At temp. of 3000 K  Atoms, photons, and dark matter

The proton-proton chain  All atomic nuclei are positively charged  repel one another  closer they get the stronger the repulsion  Takes a lot of energy to get them to stick together  Speeds of few 100 km/s  Creates temp. of 10 million kelvin

The proton-proton chain Cont.  Proton + Proton Deuterium + Energy  Deuteron is the nuclei of a deuterium  Energy is released in the form of two new particles  Positron  Positively charged antiparticle of an electron  Same properties as an negatively charged electron  Neutrino  Charge less and virtually massless particle  Move close to the speed of light (possibly faster)  Don’t really interact with anything  Penetrate several light-years of lead without stopping  Particles and antiparticles meet they annihilate each other and produce pure energy in the form of gamma ray-photons  Diagram on board

200 million years after the big bang  Stars began to shine and the creation of new elements began.

Nuclear Fusion  Combining of light nuclei into heavier ones  Produces a lot of energy  Total mass decreases  E = mc 2  Energy = mass X speed of light  Law of conservation of mass and energy  Sum of mass and energy must always be constant  Hydrogen/helium diagram