Beyond The Universe
The universe is an infinite expanse of space and time, containing everything that exists. The
universe can be described in many ways, but one of the most common is to say it has no boundaries.
The universe does not have a beginning or an end; it just keeps on expanding forever.
The Big Bang Theory
In 1929, Albert Einstein developed his theory of general relativity. His work led to the prediction
that light would be bent by gravity if viewed from a high-speed spaceship traveling near the sun
during an eclipse. This prediction was tested in 1965 when scientists sent a satellite into orbit
around Earth using solar sails as propulsion systems (“The Big Bang Theory”). After several years
in space, scientists found that the bending of light had occurred as predicted (“The Big Bang
Theory”). This discovery helped support Einstein’s theory of gravity and provided further evidence
for his work on curved spacetime (Barrow & Tipler 1986). In 1965, George Gamow proposed
another idea about how our universe came into being: the big bang theory (Barrow & Tipler 1986).
According to this theory, our universe began with a single point called ‘the big
Bang’. As the universe expanded, it cooled and formed the first atoms from which everything else
in our universe is made (“The Big Bang Theory”). The big bang theory was developed to explain
how our universe began, but it also helps explain other things about our universe. For example, it
explains why there are galaxies like the Milky Way that contain stars like those in our solar system
(Barrow & Tipler 1986).
Gamow proposed that at some point in time, all of the matter and energy in the universe were
contained within a single point called ‘the big bang’. This idea was based on his understanding of
quantum mechanics (Barrow & Tipler 1986). According to quantum mechanics, particles can be
both particles and waves at the same time. When light hits an object such as a mirror or glass
window pane, its wave nature shows through while its particle nature is hidden behind what
appears to be a solid object (Quantum Mechanics: A Beginner’s Guide). Gamow reasoned that if
all of space-time was once contained within a single point then this would cause gravity to become
infinite because nothing could escape from within ‘the big bang’ (Barrow & Tipler 1986). This
idea led him to propose another theory: inflationary cosmology. Inflationary cosmology proposes
that during ‘the big bang’ there were many smaller explosions called ‘inflations’ which created
bubbles of
matter and energy (Barrow & Tipler 1986). These inflations would cause the universe to expand
at an exponential rate. This idea was based on his understanding of quantum mechanics again,
because it predicted that the universe should be expanding at an exponential rate (Quantum
Mechanics: A Beginner’s Guide).
Gamow realized that if inflationary cosmology was true then there would be a period of time when
our universe was very small and dense. He called this time ‘the primeval atom’ (Barrow & Tipler
1986). This idea led him to propose another theory: big bang nucleosynthesis. In big bang
nucleosynthesis, Gamow reasoned that all of the hydrogen in our universe came from a single
explosion called ‘the big bang’ which created all of space-time (Barrow & Tipler 1986). The
explosion caused helium to fuse with boron into lithium, which fused with three other elements
into oxygen, neon, sodium and magnesium. After this point in time there were no more explosions
so these elements continued to build up into heavier and heavier elements until they reached iron
(Barrow & Tipler 1986). Gamow also proposed another theory: big bang nucleosynthesis because
it explained why there are only a few different types of atoms in our solar system while other stars
have many different types of atoms (Barrow & Tiopter 1986).