Revolution in Cosmology Resolves Dispute over Universe's Age

It is easy to flip to the index of an astronomy textbook to discover that, say, the Sun lies 150 million kilometers away from Earth.  It is far more difficult (if not impossible), however, to picture this distance in the human mind.  In this exercise, we will learn to access the often unpalatable distances encountered in astronomy by simply scaling the huge distances to more recognizable, pedestrian numbers.  So long as every distance within the system of interest is scaled by the same factor, we retain the meaningful information about relative distances between objects.

When it comes to theories and law’s concerning the movement of stellar bodies and why the universe is moving the way it is and how it came to be, data is continuously being added and revised. It is through this constant revising of theories and establishing of laws that core ideas are proven, with modern day scientists expanding knowledge for the rest of us. One of the earliest pioneers of spatial theories was the Italian astronomer, Galileo Galilei, who used the theories of those who came before and he learned from to paint a better picture of the way the universe was set. True to form, he dealt with accusations of heresy and resistance to his ideas from others during his life, which today are held as being before his time.

Before the Shapley-Curtis Debate most people were under the impression that the sun was the center of the galaxy, and the universe. Most people couldn’t grasp the idea that there was a bigger world in space beyond our planet, the sun and our moon. While we saw stars in the night sky, the idea that our universe was as vast and complex as it is seemed unreasonable. In 1920, Harlow Shapley showed just how vast the Milky Way was. However Shapley did not believe that there was anything more to our universe than our galaxy. He believed that because it was so big that nothing else could possibly be out there. His opponent, Heber Curtis, argued that the Milky Way galaxy was not as big as Shapley said, but that he believed that there was more to the universe than just our galaxy.

In 1920, two astronomers named Harlow Shapley and Heber Curtis had a big public debate. They argued about a lot of things, but the main thing they were arguing about was the size of the Milky Way and whether or not there were other galaxies like ours in the universe. Shapley had figured out that the Milky Way was a lot bigger than people thought before, and he was right, but because of that he also believed that there couldn't be other galaxies like ours out there. Curtis, on the other hand, thought the Milky Way was smaller than it actually is, but argued that there might be other galaxies like ours out there.

One astronomer, named Harlow Shapley, believed that the Milky Way, which is the region of space in which our planet is located, was much larger than previously thought. However, he thought that because it was so big, there were no other regions of space similar to our Milky Way. Another astronomer, named Heber Curtis, believed that the Milky Way was much smaller, but that there were other regions of space similar to it. Shapley ended up being right that the Milky Way was much larger than previously estimated, however, he was wrong about it being the only region of space, also known as a galaxy. Curtis was correct that there were other regions of space, or galaxies, other than our Milky Way.

Discovery that the universe was bigger than just the milky way changed the scientific view of the universe

The law that Edwin Hubble created has ultimately supported the Big Bang Theory and our knowledge of galaxies. It states that Recessional Velocity is equivalent to Hubble's constant times distance, or V = Ho D. This basically says that the farther a galaxy is

Since velocity is a distance unit by a time unit, unit analysis yields that the inverse of the Hubble Constant is an estimation for the time the universe has been expanding, and if one assumes the universe expands linearly for its life, an estimate of the age of the universe, known as the Hubble Time [3]:

But it was not until the 1970’s that an American astronomer, Vera Rubin, measured the speed of stars in rotating galaxies accurately enough to convince the scientific community. She observed that stars in spinning galaxies were all rotating at roughly the same velocity, no matter their distance to the galactic centre. This is in contradiction with Kepler’s law that describes the rotation of planets around the Sun.

Astronomers believed if they count stars in the different directions it might reveal their shape and if it's longer in or in a particular direction, you see more stars. They learned the galaxy is actually an oval shape with the sun to be in the center. Though the counting method is great if does not account for the dust. The globular clusters revealed there was more going on in the galaxy. The spherical balls of stars orbited the galaxy outside the main body of the galaxy. There appears to be more globular clusters on one side than on the other, however they were evenly distributed into space, but we were actually the ones off center of the universe. Measurements put the sun 25,000 light years from the galaxy’s center which was in the direction of Sagittarius. It was in the same place in the

The Hubble’s constant is a measure of the current expansion rate of the universe (1). Researchers have deduced that the expansion rate of the universe is found by the current density and composition it holds (1). Hubble’s constant is represented by H0; the equation use is 1/H0 (1). According to Hubble’s constant, it is around 72 km/sec/Mega parsec (1). Thus, approximately equals to about 13.77 billion years; give or take about 50 million years (1). However, researchers discovered that the universe is currently expanding slower than previous years; affecting the rate of the universe (1).

Hubble law can be interpreted as universe is expanding in all direction with a constant speed. Furthermore, Hubble’s law also contains an equation which is “linear relation between velocity and distance, written as v = Hd in modern notation” (Osterbrock). This equation can relates to the Law of Red Shifts, which is the relation between velocity and distance, as velocity increases distance also increases. Researcher also know “cosmological principle … very simple postulate that, on the grand scale, the universe will appear much the same from whatever position it may be explored … there is no favor position in the universe, no center, no boundaries” (Hubble). Cosmological principle can be interpreted as that no matter where the observer is located, they will see than same universe expansion as the observer on earth. Hubble has collected few data on the velocity of the nebulae, “the nebulae are found to be drifting about in space at average speeds of the order of 150 miles per second. Such speeds, of course, are minute fractions of the velocity of light” (Hubble). This data shows how fast nebulae are traveling in the universe in all direction. Furthermore, recent research have discovered something called the dark energy, and the result of the discovery has shown that dark energy has an effect on

Edwin Hubble discovered that the further away galaxies were from the Earth, the faster they were moving, this discovery was one of the most significant. it meant that the universe between the galaxies were expanding. The theory that Hubble found was the Red shift also known by physicists as ‘Hubble’s Law’ . When hubble tried to measure the distance to the different galaxies he found that there was distorted light known as the doppler effect.

Throughout history astronomers have contributed knowledge to understand the holistic picture of our universe. During 140 AD Claudius Ptolemy used geography to determine the position of planets, stars, and the sun. He finally concluded that our sun orbited earth basing his evidence with Aristotle’s philosophy of the universe. This theory was used for one thousand years because it integrated with society’s standards, yet Nicolaus Copernicus disproved this concept and published his new idea in 1544. Times where difficult to shed light on important matters which contradicted the population’s idea, Copernicus was extremely vigilant as he did not want to stir a riot and be punished for sharing the truth, so as I mentioned he published his work a

In 1929, Edwin Hubble used observations of distant galaxies to show that such galaxies were moving away, suggesting the expansion of the universe. He also showed that there is a linear relationship between how far away a galaxy is and how fast it is moving away. This is known as Hubble’s Law. It suggests that the universe has been expanding at a constant rate since the Big Bang (Observatories of the Carnegie Institution for Science). Physicists generally assumed that gravity would slow the expansion of the universe as time went on. Since the Universe is full of matter, and gravity pulls all matter together, eventually gravity would overcome the expansion of the universe and cause it to decelerate. However, no one knew exactly how much the expansion