Can you explain the expanse of the universe; because I think that is what we are all looking for? We just wanna know how we got here and where we are going or are we going anywhere (I am referring to the human race when I say we FYI)! thanks!
The prevailing theory is that quantum fluctuations in the vacuum of space were pulled far apart during the Big Bang. Normally these fluctuations result in pairs of virtual particles that come into existence briefly and then annihilate each other. However, the rapid expansion of the universe during the Big Bang separated these particle pairs before they had time to couple thus making them 'real.' The particles created by quantum fluctuations have the ability to become either matter or energy.
American Scientist (peer reviewed journal)
http://www.americanscientist.org/template/AssetDetail/assetid/14770Matter and energy were interchangeable during the earliest moments after the Big Bang. Colliding photons formed particle-pairs, and matter/anti-matter annihilation created photons. The very instant these photons were created, they immediately converted into matter and vice versa. It wasn't until 10
-12 sec. after the Big Bang that quarks and electrons were able to exist separate from photons.
http://archive.ncsa.uiuc.edu/Cyberia/Cosmos/InTheBeginning.htmlhttp://www.astronomy.ohio-state.edu/~pogge/Ast162/Unit5/early.htmlAs space expanded, it began to cool down. The universe entered the nucleosynthesis epoch during which the first hydrogen atoms began to form. However, the distribution of hydrogen gas in the universe was not homogenous. Over time, regions of higher density collapsed and coalesced due to gravitational forces. These clouds of collapsing interstellar hydrogen were so massive that the gravitational forces at the center caused the atoms to ignite in a process called fusion. Thus the first stars in our universe were born.
The process of fusion produces many new elements. Stars fuse hydrogen to helium, and helium to heavier atoms. Heavier elements are formed in denser areas of the star. These elements were blasted out into space when the earliest stars underwent supernova.
There is evidence that heavy-element formation occurs in stars.
"observations in red giants of one kind of nucleus – 99technetium – provides direct evidence that heavy-element formation really does occur in stars today."
Wright Center for Science Education
http://www.tufts.edu/as/wright_center/cosmic_evolution/docs/text/text_stel_6.htmlThe newly formed elements that were casted into space existed in the form of rocks and gas clouds, which coalesced to form planets, moons, and other celestial bodies. It was only a matter of time before the elements released from stars gathered on one of the planets that is hospitable for life, such as Earth, and combined to form molecules that combined to form amino acids, which evolved into very simple cells, and thus life began.
It is believed the earliest signs of life appeared 600 million years after the earth formed. These life forms were possibly derived from self-reproducing RNA molecules. The replication of these organisms required resources which soon became limited, resulting in natural selection. DNA molecules then took over as the main replicators. They began to develop inside enclosed membranes which provided a stable environment for replication: proto-cells. 100 million years passed before cells resembling prokaryotes appeared. These organisms were chemoautotrophs. Another 900 million years passed before photosynthesizing cyanobacteria evolved which produced oxygen. The oxygen concentration in the atmosphere subsequently rose. Eventually, more complex cells began to appear: the eukaryotes. After 2 billion years, the first multicellular organisms evolved. Natural selection fueled the evolutionary radiation that occurred during the last 1 billion years. Homo sapiens (modern humans) didn't appear until approximately 200,000 years ago.
