Download Thesis: The Big Bang theory is the most widely accepted scientific

Thesis: The Big Bang theory is the most widely accepted scientific explanation for the
origin of the universe. There is a substantial amount of observational evidence
supporting the theory, and more data continues to be collected as research progresses.
Summary: The Big Bang theory is the model most broadly accepted by the scientific
research establishment for the birth of the cosmos, or universe. After decades of
observation, verification, and testing, the amount of convincing scientific evidence
supporting the theory is overwhelming, and the predictions based on the theory about
the behavior of matter and energy in the universe have consistently been demonstrated
in reality. Physicists and cosmologists continue to elaborate upon the basic concepts of
the model using data from increasingly sophisticated equipment.
History of Cosmology
Researchers, philosophers, and poets alike have long grappled with questions about
how and when the cosmos began, where matter came from, and whether time and
space are finite or infinite. Humanity's understanding of cosmology has shifted many
times over the course of recorded history. People once believed that the heavens were
composed of divine celestial material, though it is now known that the planets and the
stars are comprised of large balls of gas and minerals. Scientists once thought that the
length of our Milky Way galaxy was no more than a few tens of thousands of light years
(one light year equals about 5.88 trillion miles); current figures for the size of the galaxy
hover around 100,000 light years across or more. The focus of scientific research has
shifted as well; controversies over the relative importance of Earth's position within the
universe have given way to larger debates about the origin and future of the universe
itself. To date, the theory of the Big Bang represents by far the most complete and
convincing scientific response to these questions.
The Big Bang Explained
The most basic version of the Big Bang theory proposes that all the matter that would
eventually make up the many galaxies of the universe was compressed together into a
single point marked by unimaginably high temperature and density. In its entirety, all of
the physical substance of the universe is thought to have fit into a tiny area
approximately the size of a fist, and perhaps even smaller than that. Then, about 14
billion years ago, according to the most current cosmological estimates, a sudden
change in the state of energy gave rise to a tremendous sudden expansion (sometimes
called "inflation"). This explosive event caused what had previously been densely
packed matter to be abruptly thrown out into space, where it began to rapidly move
apart, creating time and space as it went. Slowly, fundamental subatomic particles such
as electrons and positrons reacted and combined to form elements, which in turn
clumped together to shape planets and galaxies. The powerful cosmic explosion that
precipitated all this is known as the Big Bang. Ever since this astonishing occurrence,
physicists assert, the universe has continued to expand and cool down.
Twentieth-century Belgian astronomer Georges Lemaître first proposed the idea of an
initial cosmic explosion leading to an inflationary universe. At the time, the major
competing cosmological theory claimed that the universe is and always was in an
essentially static, unchanging state. Initially the scientific establishment as a whole was
more inclined to support an eternal steady state model, largely due to prevailing
scientific ideas about such things as the age of the universe and the stability of the
universe's overall density. However, the debate among cosmologists heated up when it
became clear that the Big Bang theory was consistent with various scientific
observations. For instance, it explained the curious fact that data from telescopic
observations of the sky showed faraway galaxies moving ever-faster away from Earth.
Given the speed and direction of this cosmic movement, the idea that all matter once
originated from a single tremendously dense spot began to seem less far-fetched.
Evidence of the Big Bang
It is important to recognize that science does not strive to establish absolute truth, as all
scientific statements are open to re-evaluation. A scientific hypothesis becomes an
accepted theory when it manages to explain most or all of the available observational
data about a given phenomenon, and when, based on that theory, specific, testable
predictions consistently match experimental results. Although scientists were initially
skeptical, decades of research and observation have transformed the hypothesis of the
Big Bang into a robust, well-established theory, backed by an abundance of supporting
evidence from different sources.
The Big Bang theory suggests certain things about the state of various physical
characteristics of the universe, and an examination of hard data shows that these ideas
do, in fact, match reality. For example, scientists calculated that the extremely high
temperatures present at the time of the Big Bang would result in a particular proportion
of hydrogen and helium in the universe; measurements of these elements subsequently
reflected precisely this proportion. Also, the theory predicts that the expansion and
cooling of hot gases after the Big Bang would leave behind a consistent level of leftover
radiation throughout the universe that is uniform in temperature, a phenomenon known
as cosmic microwave background radiation (CMB or CMBR). In 1965, two
communications engineers in New Jersey recorded signs of just such radiation in the
form of noise in their radio receiver. This historic discovery was the first tangible
evidence of the Big Bang, but not the last.
In the mid-1980s, a group of National Aeronautics and Space Administration (NASA)sponsored scientists sent a satellite into space, (COBE, or the Cosmic Background
Explorer) designed to study CMB and collect data that would support the veracity of the
Big Bang theory. In particular, the COBE team wanted to see if the current temperature
of the CMB matched a particular profile predicted by the theory's calculations and
known as a "blackbody spectrum" of radiation. According to measurements made by an
instrument designed by physicist John C. Mather, it did. In addition, his colleague
George F. Smoot analyzed the measurements made by a separate instrument on
COBE. This information allowed Smoot to produce a startlingly detailed picture of the
formation of the early universe. Again, these results closely matched earlier predictions,
and provided answers to some questions about how matter may have initially spread
throughout the universe. In 2006, Mather and Smoot were jointly awarded the Nobel
Prize in Physics for their work, which is considered the most compelling evidence
supporting the Big Bang theory.
Faith-Based Challenges to Science
In recent decades there has been an increasing tendency among conservative
Christians in the United States to challenge established scientific theories that they
believe to be in conflict with religious ideas about the age of the universe and the way
the world came into being. Creationist thinkers, who call their description of the divine
origin of the universe "intelligent design," frequently write about what they consider to be
holes in scientific explanations. Faith-based criticisms of the theory also often point out
that scientists do not understand all of the mechanisms that brought about the Big
Bang. They call into question every piece of the abundant evidence for the model.
The scientific indications that the Big Bang actually happened are extremely varied and
sound. While open questions still remain, the mere fact of their existence by no means
shows that the theory is weak. Research into the Big Bang progresses every day, and
work in the new frontiers of physics, such as quantum mechanics and string theory,
continue to add to our understanding of the model. Recently, for example, Penn State
University physicist Abhay Ashtekar and his colleagues developed a method of
mathematically describing the changes in the early universe, based on loop quantum
gravity. By positing the existence of another shrinking universe, their work suggests
answers to the burning question of what may have happened before the Big Bang. In
addition, as experimental equipment becomes more sophisticated, scientists are able to
acquire more and more finely-tuned data about the CMB using instruments such as the
Wilkinson Microwave Anisotropy Probe (WMAP).
Conclusion
As technological advances bring more data to the table, scientists are increasingly able
to substantiate predictions made by the theory of the Big Bang, and to add to the
model's sophistication. The Big Bang theory is a comprehensive, scientifically valid
explanation for the origin of the universe that is widely accepted by the scientific
community. The variations in the basic model and the differing scientific interpretations
of various aspects of the theory only point to its robustness.
Ponder This
1. Do you agree with the author that "while open questions remain...their existence by
no means shows that the theory is weak"? What questions could potentially undermine
the strength of the Big Bang theory? Explain.

2. Does the author provide enough scientific data to support the validity of the Big
Bang theory? Discuss.

3. Since there can be no absolute proof for a scientific theory, what does it mean
when an idea becomes established or well-accepted by scientists? Does the author
convincingly argue that the Big Bang is such a theory?

4. In your opinion, is it an increase in religiosity or a lack of scientific education that is
driving the current movement toward teaching "intelligent design" in American
schools? Explain.