How Did Einstein's Theory Contribute To The Advent Of The Universe?

“We used to look up at the sky and wonder about our place in the stars, now we just look down and worry about our place in the dirt” (Interstellar). No one knows, or may ever know for certain, how the universe ever came into existence. Cosmologists have uncovered multiple viable theories that explain the advent of the universe, but we assume that there can only be one. In 1927, Georges Lemaître suggested that the universe began at a moment in time and from there everything expanded exponentially outward from that single point. Lemaître’s model was only one of many developed that genuinely offered an explanation to how the universe was created. Lemaître’s model was approached with skepticism because, at the time, a static universe was generally

accepted. A static universe meant that everything has always already existed and that there was no beginning of the universe. As Lemaître learned of new discoveries from several other important cosmologists, astronomers, and physicists, he was able to develop a theory that accurately described the creation of the universe, it was eventually called the Big Bang Theory.
The Big Bang Theory is the prevailing cosmological model for the earliest known periods of the universe. It states that the universe was in a very high-density state and then expanded. “If the known laws of physics are extrapolated beyond where they are valid there is a singularity” ("Big-bang model" Encyclopedia Britannica). Scientists have observed that modern measurements place this moment at approximately 13.8 billion years ago, which is thus considered the age of the universe. After the initial expansion, the universe cooled sufficiently to allow the formation of subatomic particles, and later, simple atoms. Giant clouds of these primordial elements later conjoined through gravity to form stars and galaxies. One cannot assume nor fathom what was before this point of expansion. There is no proof as to what could have existed therefore, nothing. “The Big Bang theory does not provide any explanation for the initial conditions of the Universe; rather, it describes and explains the general evolution of the Universe going forward from that point on” (Singh 2005).
All ideas concerning the very early universe are speculative. No experiments have yet probed energies of sufficient magnitude to provide any experimental insight into the behavior of matter similar to that of the energy levels occurring during this period. Each proposed scenario differs radically. The most common timeline of the universe takes place over several phases. The first phase of the earliest universe was so hot that initially no matter particles existed, or could exist, perhaps only fleetingly. “The Planck epoch is an era in traditional (non-inflationary) big bang cosmology where the temperature was so high that the four fundamental forces—electromagnetism, gravitation, weak nuclear interaction, and strong nuclear interaction—were one fundamental force” (Robbins). Little is understood about physics at this temperature; different hypotheses propose different scenarios. “Traditional big bang cosmology predicts a gravitational singularity before this time, but this theory relies on general relativity and is expected to break down due to quantum effects” (Hawking). Inflationary cosmology: times before the end of inflation (roughly 10−32 second after the Big Bang). When the universe was 10-35 seconds old, it had cooled by a factor of 10,000 to 1028 K (2x1028 °F). The universe was now cool enough for particles that are the building blocks of atoms to form. In name, this was the time of Baryogenesis, where baryonic matter formed, which includes quarks and all particles made of three quarks, such as protons and neutrons. The universe was still too hot for the quarks to combine into these heavier particles, so all that existed during this time were quarks” (Robbins). When the universe had aged to 10-6 seconds (the time it takes light to travel the length of three football fields), it had cooled to approximately 1013 K (2x1013 °F). Now, another major change occurred. The universe had cooled enough to form leptons (fundamental particles along side quarks; electrons and neutrinos are examples) and for quarks to form baryons (protons and neutrons are examples) and mesons (Robbins). It was still too hot for these to combine into the first atoms, but this is often called the Quark-Hadron Transition (McDonald).
When the universe had been in existence for 1 second, it had cooled to approximately 1010 K (2x1010 °F) (1000 times hotter than the core of the sun). Protons and neutrons were in thermal equilibrium, and the Boltzmann Equation gives the ratios. This works out to approximately 0.223, so for every 1000 protons, there were 223 neutrons. After this time, the universe was no longer hot nor dense enough to create neither protons nor neutrons, so the ratio is frozen. However, free neutrons undergo beta decay, which converts neutrons into protons with a half-life of approximately 617 seconds (McDonald). Since there is not yet an intact theory of quantum gravity, very little is understood about this time period in the universe's distant past.
Georges Lemaître was a Belgian Jesuit priest and physicist in the 20th century. “Father Lemaître's intellectual background was unique. His education was a synthesis of the classics, philosophy and theology along with engineering, mathematics and physics” (Laracy). “Lemaître described the beginning of the universe as a burst of fireworks, comparing galaxies to the burning embers spreading out in a growing sphere from the center of the burst. He believed this burst of fireworks was the beginning of time, taking place on ‘a day without yesterday’” (Midbon). Lemaître also discovered a solution to the variables of Einstein’s Theory of General Relativity, which was a turning point in the development of the Big Bang Theory because it aided in support for his theory. However, his examinations were interrupted when he served in World War 1, and his research facilities were destroyed. Lemaître was the missing piece to Einstein’s Theory of General Relativity, one of the biggest influencing factors in the development of the Big Bang Theory.
Albert Einstein is one of the most respected scientists in history for his revolutionary discovery and insight about space-time.

Einstein’s General Theory of Relativity explains the natural gravitational pull of all objects. He proposed that, “matter causes space to curve” (Illinois). To paint a picture, matter itself causes space to bend. Imagine a bowling bowl on a rubber sheet, “the large ball will cause a deformation in the sheet’s surface. A baseball dropped onto the sheet will roll toward the bowling ball… smaller masses travel toward larger masses… because the smaller objects travel through space that is warped by the larger object” (Illinois). Newtonian gravity and Einstein’s general relativity differ in a small difference that causes dramatic changes. “The key difference is that Newtonian gravity has extra absolute structures that General Relativity does not have…General Relativity describes gravity as space time curvature while Newtonian gravity describes it as something living on top of a static space with no curvature” (Brown). Newtonian gravity also states, “all objects attract each other with a force that is directly proportional to the product of their masses and inversely proportional to their distance of separation” (Newton's Law of Universal Gravitation). Newtonian gravity explains the motion of planets and moons, but was replaced by General Relativity. Thus also, the Big Bang Theory was a consequence of the creation of General

Relativity.
Among other cosmologists and physicists there is only one who has defied the odds of science himself, Stephen Hawking. Stephen Hawking is a world-renowned British theoretical physicist, known for his contributions to the fields of cosmology, general relativity and quantum gravity, especially in the context of black holes. In the 1960s and 1970s, he worked on groundbreaking theorems regarding singularities within the framework of general relativity, and made the theoretical prediction that black holes should emit radiation, known today as Hawking radiation. Hawking radiation is black body radiation that is predicted to be released by black holes, due to quantum effects near the event horizon (Hawking). Hawking predicted that black holes should have a finite, non-zero temperature and entropy.
Hawking is held at an even higher stature considering his defying odds since being diagnosed with ALS (amyotrophic lateral sclerosis), a type of motor neuron disease, which eventually cost him almost all neuromuscular control. Despite the set back of losing control of almost his entire being Hawking’s mind never gave an inch. In Hawking’s worldwide bestseller, A Brief History of Time, he theorizes that if the universe did not have a beginning, there would be an infinite period of time before any event, which he considered absurd. Hawking believed the concept of time had no meaning before the beginning of the universe.
Edwin Hubble was an American astronomer whose discoveries changed the direction of development of the Big Bang Theory. Hubble discovered that the universe is constantly expanding, in a process that is known as redshift. Hubble also discovered light, sound, and radiation waves emitting from every direction in the universe. Each of these discoveries was becoming redder and lengthier; this is also known as the Doppler effect. “Because of the inverse relationship between frequency and wavelength, we can describe the Doppler shift in terms of wavelength. Radiation is redshifted when its wavelength increases, and is blueshifted when its wavelength decreases” (Adrian).
Edwin Hubble’s cutting-edge discovery of redshift authenticated the belief that the universe began from a single point and was constantly expanding. Hubble quantified that; “galaxies outside our own Milky Whey were all moving away from us, each at a speed proportional to its distance from us. He quickly realized what this meant that there must have been an instant in time (now known to be about 14 billion years ago) when the entire Universe was contained in a single point in space” (NASA). This model of proportional expansion is known as the Hubble Constant. The constant is given by: H=v/d; “v” is the galaxy’s outward velocity, and “d” is galaxy’s distance from Earth. The variables in the equation deal with immensely large speeds and distances, therefore making the constant increasingly enormous. Furthermore, another hypothetical theory of the redshift: “Measurement of red shift magnitude relation for supernova indicate that the expansion of the universe has been accelerating since the universe was about half its present age. To explain this acceleration, general relativity requires ‘negative pressure’, called Dark energy” (Unsolved problems in the Big Bang model). Dark energy is still under immense logical research, and continues to perplex many scientists today.
The universe has four fundamental forces, the weak, strong, gravitational, and electromagnetic force. Many theories concerning these forces have already been verified, but there is one theory left unproved which states that at a previous point in time all four forces were unified. “Theories that postulate the unification of the strong, weak, and electromagnetic forces are called Grand Unification Theories. Theories that add gravity to the mix and try to unify all four fundamental forces into a single force are called Superunified Theories. The theory that describes the unified electromagnetic and weak interactions is called…the Standard Model” (The Fundamental Forces of Nature). The Grand Unification and Standard Model are the two theories that have already been proved by scientists combing forces, while scientists have yet to unite the fundamental forces that would prove the Superunified Theory. In relevance to the Big Bang Theory, it is believed that all four forces were combined, creating a single, colossal force. Following the Big Bang, the unified force broke apart, thus creating the four fundamental forces.
Planck time is the time it would take a photon travelling at the speed of light to across a distance equal to the Planck length. This is the 'quantum of time', the smallest measurement of time that has any meaning, and is equal to 10-43 seconds (Summons). “Originally proposed in 1899 by German physicist Max Planck, Planck units are physical units of measurement defined exclusively in terms of five universal physical constants. These are the Gravitational constant (G), the Reduced Planck constant (h), the speed of light in a vacuum (c), the Coulomb constant 1/4??0 (ke or k), and Boltzmann’s constant (kB, sometimes k)” (Williams). Planck time is the smallest unit of time, and is used to time the Big Bang.
“Some say the world will end in fire, some say in ice. From what I’ve tasted of desire I hold with those who favor fire. But if it had to perish twice, I think I know enough of hate to say that, for destruction, ice is also great and would suffice” (Robert Frost). Apart from Robert Frost’s convictions, the density of the Universe determines the fate of the Universe. The majority of evidence to date, based on measurements of the rate of expansion and the mass density, favors a universe that will continue to expand indefinitely, resulting in the "big freeze (NASA).
The Big Freeze is a scenario under which continued expansion results in a universe that “asymptotically” approaches absolute zero temperature. It could, in the absence of dark energy, occur only under a flat or hyperbolic geometry (Glanz 2156-2157). “With a positive cosmological constant, it could also occur in a closed universe. In this scenario, stars are expected to form normally for 1012 to 1014 (1-100 trillion) years, but eventually the supply of gas needed for star formation will be exhausted” (Laughlin 337). As existing stars run out of fuel and cease to shine, the Universe will slowly and unescapably grow darker. Eventually black holes will overshadow the Universe, which themselves will disappear over time as they emit Hawking radiation (Laughlin 339).
Another possible fate of the universe is a scenario in which the universe undergoes a heat death. Heat death states that the Universe verves into a “state of maximum entropy in which everything is evenly distributed, and there are no gradients — which are needed to sustain information processing, one form of which is life” (Yurov). The heat death scenario is compatible with any of the three spatial models, but requires that the Universe reach an eventual temperature minimum (Yurov). Furthermore, is it believed under specific quantum fluctuation it is possible to produce a secondary Big Bang (Carroll).
The Big Bang Theory is immensely important in the world today. Not only is it generally accepted, but also it’s scientifically proven and explains numerous aspects of the universe. The Big Bang has altered all sciences and theories over the last century. With the observations and progression of science, more unknown information of the universe can be obtained. However, observations are not conclusive, and alternative models are still possible (Princeton “Phoenix Universe”). In the wise words of Stephen Hawking: “The past, like the future, is indefinite and exists only as a spectrum of possibilities.”