the big bang
this is the theory that the universe began from a singularity and this began to expand
rapidly
as it expanded, it cooled causing matter to appear and this lead to clouds of hydrogen
the hydrogen clouds were pulled together by gravity
the pressure increased, temperature rose creating a massive fusion reaction creating a
star
gravity pushes inwards while the energy released from nuclear fusion pushes outwards so
the star is in equilibrium and stable
eventually the hydrogen runs out and gravity continues to push inwards and it causes more
nuclear fusion to form heavier elements
in smaller stars, they cool and fade but bigger stars explode into a supernova
planets are formed when gas and dust particles form clumps and eventually a planet is
formed
this theory was developed by stephen hawking
this theory also says the expansion will slow down and eventually stop before collapsing in
on itself into a singularity again
origins of humanity
one theory is that life began in the water that covered earth
according to this theory, complex chemicals needed for living things to develop were
produced naturally
simple organic compounds (for example ammonia, methane and hydrogen) are believed to
have been present in the waters
, lightning or some other force passed through the water creating complex chemicals (such
as amino acids – which make up proteins)
this eventually lead to the creation of single celled organisms
environmental changes then meant there was more oxygen in the water and single celled
organisms developed into multicellular organisms
further environmental changes lead to more complex life that eventually came out of the
water and inhabited the land
life on earth continued to develop and change in response to their environment (known as
evolution)
evolution
charles darwin presented the theory of evolution
this theory says that animals who are better suited to their environment have an
advantage and so survive and produce offspring with the same characteristics while the
others die off
he called this the survival of the fittest (best fit to their environment)
the world and responsibility for the environment
they believe religious explanations of the world are unreliable
there are no good reasons to believe in a god and there is plenty evidence to say the world
formed itself
evolution also provides a good explanation to how species are related
this doesn't mean humanists don't value the planet, but they do for different reasons:
unique
remarkable and numerous conditions that had to be perfect for earth for sustain life
supports human life