It is impossible to know how the very first particles of space, time and matter first came into being. This causes much frustration among scientists. After all, if there was nothing there in the very beginning – Who or what designed the laws of nature? How did the universe know how to evolve as it did? Why did nature produce a universe suited to supporting life? These are very difficult questions, but nevertheless, scientists are beginning to try and at least partially answer them using increasingly bold ideas and experimental techniques.
In order to truly understand how the universe first began, it is essential that a much better theory is developed in terms of the relationship between space, time and matter. In the field of Physics, a theory cannot be merely a guess or hypothesis. Instead it is a precise mathematical model which is used to make informed predictions about how the word around us will behave. Let’s take Einstein’s famous theory of gravity as an example, it is able to accurately describe how matter responds to gravity in the world around us. In an additional example, quantum theory, which is the best theory we have in regards to sub-atomic particles, is able to make accurate predictions about the general behavior of samples of matter at tiny distances. However, neither theory is complete and are unable to predict with any accuracy, what was going on at the earliest stages of the universe when it was still a tiny, and dense thing.
With the various pieces of information which has become available to cosmologists, they have been able to chart a time line of the evolution of the cosmos which plots the major events in the life of the universe starting with the big bag 13.7 billion years ago.
The cosmic renaissance, which is also known as the dawn of light began around 13.3 billion years ago – around 400,000 years after the Big Bang. At this time, Hydrogen began to collapse into smaller particles, eventually de-constructing enough that gravity was strong enough to trigger the first nuclear fusion reactions which would result in the formation of the very first stars. These are sometimes called the ‘first generation stars’.
The astronomers of today are beginning to show a much greater interest in the cosmic renaissance and to date approximately one thousand different galaxies have been pinpointed which had light leave them when the universe was somewhere around one billion years old. At that particular point, stars would have been forming at a rate ten times greater than they are today. The earlier stars produced heavy elements like Carbon and Oxygen which then combined with the gas left by the Big Bang to produce future generations of stars.
In those days, the sky would have been filled with primeval star-burst galaxies filled with bright, hot stars a little bit like fireworks. The largest of the stars would have detonated as supernovas exploding and setting off chain reactions across the sky like giant firecrackers. New galaxies would have formed from hot bubbles from the explosions combined with stellar wind.
A great deal of emphasis has been focused on the beginnings of the universe. However, it is also very important to consider what the future holds for the universe. While it is unlikely to end in our lifetime, it is still useful to understand what is happening. Can the universe continue to expand indefinitely or does it have an expiration date?
Carnegie Observatories astronomer, Dr. Allan Sandage is credited with once having defined cosmology as ‘a search for two numbers’. These two numbers are :
- The Hubble Constant
- The Declaration Parameter
The first number (the Hubble Constant) tells us the rate at which the universe is actually expanding. When combined with the declaration parameter (which tells us the rate at which the universe is slowing) it can also be used to determine whether or not the universe will continue to expand forever.
The second number (the Declaration Parameter) tells us to what extent the universe has been warped due to the overall density of its contents. There are various possibilities. Firstly, a ery dense universe would have space curving around itself to create a sphere. This sort of universe would certainly stop growing and would eventually collapse in on itself and destroy space and time – crushing all of the stars and galaxies in the universe. Alternatively, we could have a low density universe which would curve almost like a saddle shape. This would be capable of expanding indefinitely. There is also a third model where there would be no curve at all. This is sort of a ‘Goldilocks’ universe where the density is ‘just right’. This is a flat universe which could in theory continue to expand forever, but the rate would slow over time until eventually it would grind to a stop. This is the model which is not only the simplest, but the one which has been confirmed by WMAP.
Article contributed by: Mike Thomas
Data collected in 2006 from the Wilkinson Microwave Anisotropy Probe, or WMAP, has given cosmologists their best evidence in support of a scenario referred to as ‘inflation’. The inflation scenario is where the universe would have rapidly grown to massive proportions within the first trillionth of a second of its existence. This particular set of evidence was collected over the course of three years by continuous observation of leftover afterglow light. This is background cosmic radiation which has hung around since the beginning of the universe almost 14 billion years ago.
NASA made an announcement in 2003, that WMAP had been able to take a very detailed image of the universe in it’s infancy by charting changes in the temperature of the afterglow. This allowed scientists to answer many unanswered queries they had about things such as the age of the universe, its composition and how it developed. Since that time the team operating the WMAP satellite has built upon that initial image and incorporated new results including the measurement of the glare from afterglow in order to learn further clues regarding the first few moments of the universe. This is where the initial seeds were sown which would lead to the creation of the stars 400 million years on.
How the Universe Came To Be
What is the origin of the universe? Providing an answer to this question has always being a challenge. Thanks to modern science and technology, scientists can now explain some things about the vast universe. This is an incredible achievement given the size of the whole universe. To understand how large the universe really is, did you know that the stars visible at night are only a tiny fraction about 3000 closest to the earth out of about 300 billion stars found in our galaxy only. Consider that there are about 100 billion more galaxies in the universe yet to explored and that ends up being a pretty big number.
The biggest questions human beings have about the universe are whether it has always existed or whether it just started all of a sudden. A significant discovery made at the beginning of the past century indicated that the whole universe is expanding. Scientists took this to mean that the universe began long ago very time and expanded to what it is today with time.
The discovery that the universe has not always existed but had a start combined with its large size and complexity led people to wonder what the origin of the universe was. After years of research and speculations, the Bing Bang theory is one of the most popular theories of the origin of the universe.
The Bing Bang Theory if the most widely accepted theory of the origin of the universe. Scientists are confident about this theory because of observational results showing that the universe originated from the big bang. Here are the three major evidences that the universe formed from the big bag explosion.
1. The Discovery That the Universe Is Expanding
The first evidence of the Big Bang happening is the observation that the universe is continuously expanding creating a bigger distance between the different galaxies in the universe. This realization indicates that everything in the universe was once close together until an explosion triggered the expansion.
When speculations began about the universe being in an expansive state, there was no evidence to support this. This changed when Vesto Slipher, an explorer, observed that more galaxies where moving away from ours rather than were approaching. By monitoring the spectrum of light produced by a galaxy, Slipher was able to know whether the galaxy was moving away or towards our galaxy.
Galaxies coming towards us have a spectrum of light with a shorter wavelength (blueshift). This is similar to how an approaching vehicle produces a higher pitch due to a shorter sound wavelength. On the other hand, galaxies moving away from our galaxy exhibit a spectrum of light characterized by a longer wavelength/ redshift similar to how a disappearing vehicle produces a lower pitch due to a longer sound wavelength. Slipher found out that most of the galaxies had a longer wavelength and were moving away.
What You Didn’t Know About Mars
Mars is one of the most interesting planets in the solar system. Being that it is Earth’s neighbor, the ancient civilizations were curious about this planet leading to a lot of speculations and explorations. Here are some of the interesting facts about and related to this planet.
Interesting Thing to Know About Mars- Early Beliefs and Discoveries
- In the past, scientists believed that most of Mars polar caps consisted of mainly carbon dioxide with a little water to form dry ice. Deeper explorations revealed that the composition is mainly frozen water and a little layer of carbon dioxide.
- In the history of Mars exploration, Galileo Galilee became the first person to make a telescopic study of mars in 1607.
- In the fiction book The War of the Worlds by H.G Wells written in 1898, Mars inhabitants are very intelligent and highly technologically advanced. They use their power to destroy humans in order to dominate the world. Although a work of fiction, this book raised tension in people.
- An Italian explorer noticed strange network lines on Mars in 1877. He named them Canali in Italian, which means channels but people understood this to mean canals. An American explorer speculated that the lines transported water from Mar ice caps to the dessert. This discovery aroused the curiosity of the public about Mars supporting life.
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One of the most common questions about the universe is how far and how big everything is. The stars in the night sky appear so close as if it is possible to reach out and touch them. However, the stars are very far away. This raises questions as to exactly how far away the stars are, what is above them and how large the universe is.
Without considering the distance, the sky appears to be like a bowl above our heads. Figuring out the distance the stars are from us is the first step to figuring out how the entire universe looks like and forming a three dimensional picture. This is the first step to getting answers to some of the questions bothering scientists for years. Such questions include, how old is the universe? How large is the universe? What is our place and role in the universe?
Over the years, different generations of scientists have explored the universe discovering new things about the vast expanse that is the universe. In the third century BC, Aristarchus of Samos estimated the distance to the moon using the shadow of the earth formed during a lunar eclipse. However, the large size of the universe means that this there is a long way to go and the discoveries made so far are the first steps of a long journey of discovery.
Our universe is believed to be approximately 14 billion years old. This figure is believed to be accurate to within 120 million years. The age is based on very accurate measurements of the universe’s oldest light. This date was announced in March 2006, although it is believed that additional data from WMAP in recent years has reduced the margin of error to within tens of millions of years.
It was around 380,000 years after the Big Bang that the temperature of the universe has reduced by enough to allow Hydrogen atoms to be formed from protons and electrons. This resulted in a burst of light which as time progressed (several billion years to be exact) became microwaves detectable as background radiation across the cosmos. There are a number of variations which can be observed in this radiation and NASA have been monitoring this since 2001 and the data collected all provides further evidence to support the idea of inflation. This rapid expansion would have occurred in the first trillionth of a trillionth of a second of the universe’s existence! The latest data provided by WMAP has allowed scientists to make a distinction between the various suggested inflation models. There is now very viable evidence to support the universe being filled with subatomic particles with virtually no mass called neutrinos. This presence of primordial neutrinos was predicted in the Big Bang theory.
It is very difficult for some to comprehend, but space is actually expanding. In particular the huge empty areas in between galaxies are growing. I say empty spaces, but if we take Albert Einstein’s view – he believed that space was not empty, but rather that it was a real and somewhat flexible thing that could be stretched. This is part of his predictions based on his theory of gravity which is at its base level a simple explanation of the relationships between space, time and matter.
It was towards the end of the 1920′s that astronomer Edwin Hubble (now famous for the Hubble telescope) first made the observation that far off galaxies were actually pulling away from ours. This of course supports the idea that the space that lies in between them is expanding as theorized by Einstein. Since this first observation, astronomers have continued to measure the ever growing distances between millions of other galaxies.
The galaxies themselves appear somewhat passive. They sit in space while it expands between them carrying them further and further away from each other. From time to time the gravity from any one particular galaxy – or even from several – can interfere with natural path of the galaxies as they are pushed further apart. This can result is them colliding with neighbouring galaxies. However, this is very rare and for the most part if you were to look at any two adjoining areas of space the galaxies in each would appear to move away from each other. The most confusing part of all is that space isn’t actually expanding into something else! When one region expands it does not have to push something else out of its way.