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the direction of time

Chapter 6: The Direction of Time

The laws of physics do not distinguish between the past and the future. This chapter begins by discussing CPT. C means changing particles of antimatter. P means taking the mirror image so left and right are swapped for each other, and T means reversing the direction of motion of all particles-in effect running the motion backwards. The laws of physics that govern the behavior of matter under all normal situations are unchanged under the operations CP on their own. This means that life would be the same for inhabitants if another planet who were our mirror images and who were made of antimatter. This chapter then shifts into the arrows of time. The arrow of time is something that gives a direction to time and distinguishes the past from the future. There are three different kinds of arrows of time; Thermodynamic arrow, Psychological arrow, and cosmological arrow. 

  


  I started off by watching a video by minute physics. He explains that the past and future are different. But what is unknown is the connection between past and future in physics. Every difference between the past and the future is that the universe was orderly in the past and is getting more and more disordered. Entropy increases with time.  This video didn’t really help me too much. It was really fun to watch because I now understand a lot of concepts which he talks about but I wasn’t that informative.

I then started watching another video on the arrow of time. This one says that the arrow of time is the fact that the past is different than the future. The direction of time looking into the past is known, while the direction of arrow looking into the future is unknown. The Arrow of time is the directiveness from past to future.  Some simple systems such as the earth going around the sun does not have an arrow of time. The equations of the arrows of time are reversible. We understand the equations behind the arrow of time, nut we do not understand why they were put in at the Big Bang.  There is an arrow because we are in the very influential vicinity of the Big Bang.


http://preposterousuniverse.com/eternitytohere/faq.html


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The origin and fate of the universe

Chapter 5: The Origin and Fate of the Universe

This chapter discards the idea of Black Holes and goes back to what I thought was interesting, The Universe. This chapter begins by explaining the Big Bang Theory. For more information, look at my page labeled "Big Bang Theory for Dummies". The chapter then transitions into alternative ideas of the universe such as the Inflationary model. The inflationary model is similar to the big bang theory. The theory suggests that the early universe had a very rapid or exponential expansion. This expansion accelerated as time went on until gravity began to slow it down. The chapter then talks about laws which we require in order to find out more information about our universe. These laws must require quantum physics however are currently unknown.

In order to succeed in understanding this chapter I needed to research three main parts. I needed to understand; the difference between the Big Bang theory and the Inflationary model, Cosmology and Quantum physics.
 

I started off by going onto http://www.felderbooks.com/papers/inflation.html , I began by reading the introduction. The introduction helped me learn that the big bang theory and the inflation theory go side by side. When the big bang theory was originally created, Einstein learned that the universe was not static; it must be either expanding or contracting. There were however many problems with the big bang theory. These problems were not able to be solved. This is when a modified theory which is formulated from the big bang theory comes into play. It is very similar but is different in the first few seconds of the Big Bang. This is a phenomenal site; I wish I had found it earlier. It uses a very appropriate language and explains with detail.
 

The second research topic which I wanted to tackle had been Cosmology. I started my research with a paper I found online. It is called “Introduction to Cosmology” by Barbara Ryden, Department of Astronomy, and The Ohio State University. It was a very long paper so I decided to read the introduction.  Cosmology is the study of the universe or cosmos, regarded as a whole. It is a science which regards entire galaxies as small objects. It is an attempt to answer questions such as “where do we come from”, “what are we” “where are we going” etc… Cosmology deals with distances that are very large, objects that are very big and timescales that are very long.
I then regoogled Cosmology in order to get a non textbook answer of what it is. I found that it is “the branch of astronomy involving the origin and evolution of the universe, from the Big Bang to today and on into the future. http://www.space.com/16042-cosmology.html


I started off researching Quantum physics by searching it up on space.com. I was not able to find anything. So I gave up from that site. I then decided to google “Quantum physics for Dummies” I thought this would be an ideal was to find what Quantum physics is in simple terms. I found many websites but the only one who gave me a real answer of what quantum physics is the most unreliable source, Wikipedia. I thought the definition did give me a starting base however. “Quantum mechanics is the science of the very small; the body of a scientific principles that explains the behavior of matter and its interactions with energy on the scale of atoms and subatomic particles.” I left this site right after because I did not want to waste anytime with an unreliable source. 
http://en.wikipedia.org/wiki/Introduction_to_quantum_mechanics

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chapter 4

Black Holes Ain't So Black


The title of this chapter refers to the fact that black holes are not black. When observed using the correct technology, they are in fact similar to bodies. This chapter discusses black holes and their emission of particles. Contrary to previous beliefs, black holes do release particles and radiation at the event horizon, the very tip of the black hole's gravitational pull. The particles present in that location are particles and antiparticles. The first law of thermodynamics, the energy cannot be created nor destroyed; therefore the partitives both have positive and negative energy. The antiparticle must find its its particle partner in order to follow the law. This emission would be in the form of x-rays and/or gamma rays. The smaller the black hole, the greater the amount of radiation there would be. 

An interesting fact which I learned through this read was that, if an astronaut was to fall in the black hole, the mass of the black hole would increase. Eventually, the equivalent to the mass of the black hole would be let out through radiation



.
This would be one of the most difficult and discouraging chapters I have ever read. It would happen to be either due to my lack of knowledge on black holes in the field of quantum physics, or simply because I do not even know what quantum physics is. First, it took me very long to read this chapter as I spent a lot of time analyzing it and trying to understand it. Then after that I spent very long watching YouTube videos and read up on articles for many aspects of this chapter. When I tried putting it all together... I still was unable to. This chapter really set me off pace on my project. It took me an additional week to do, and when it was all ready to be published, Google crashed and I lost all my research that I worked on for so long- with urls.
The chapter constantly speaks of the second law of thermodynamics, I further did research on what it was and found that it is  "the entropy of an isolated system never decreases in the course of every natural change." Despite being aware of the definition of entropy, I was not able to use it for the concepts which Hawking talks of. For example; "just throw some matter with a lot of entropy" I do not understand what entropy means here.
Black hole radiation was probably the easiest thing in this chapter as it was easier to research. Through the novel and chapters I discovered that in 1974 Hawking predicted that energy fluctuations from the vacuum causes the generation of particle-antiparticle pairs of virtual particles near the event horizon of the black hole. One of the particles falls into the black hole while the other escapes before they have an opportunity to annihilate each other. The result is radiation. I also thought it was really cool how the smaller the black hole is, the more radiation it emits off!

This chapter made me really stressed out. It constantly spoke of the uncertainty principle. I could not understand what it was. I researched and found that it is " any of a variety of mathematical inequalities asserting a fundamental limit to the precision with which certain pairs of physical..." I did not understand any of that. I read further did research and got that it is "succinct statement of the "uncertain relation" between the poistion and the momentum (VxM) of a subatomic particle.It was an easier definition but still quiet hard. I finally kind of got what it was after the follwoing YouTube video.
I tried researching Quantum physics but after 30 minutes I stopped. I didn't understand anything. Anything connected to quantum physics in this chapter was an absolute blank.


http://www.theguardian.com/science/2013/dec/01/what-is-the-second-law-of-thermodynamics
http://physics.about.com/od/astronomy/f/hawkrad.htm
\http://www.theguardian.com/science/2013/nov/10/what-is-heisenbergs-uncertainty-principle
http://www.aip.org/history/heisenberg/p08.htm
http://news.nationalgeographic.com/news/2014/01/140127-black-hole-stephen-hawking-firewall-space-astronomy/




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chapter three

Third Lecture: Black Holes
'
This Chapter of Stephen Hawking's book talks all about how Black Holes were discovered, who made the significant discoveries and when. In 1783, John Michell, pointed out that a star that was massive and compact would have such a strong gravitational field that light could not escape it. Any light emitted by the star would get dragged back by the stars gravitational force. The chapter then highlights the life cycle of a star in where it it explains the formation and the resistance of black holes. It then speaks of Chandrasekhar and his limit along with many other ideas implemented by scientists.

This chapter would be the first chapter upon which I actually had great difficulty reading. The terminology used in this chapter was not only fresh, but also hard to decipher and piece together. I had to initially research what is a black hole, despite it being given in advanced terms in the book. I discovered that   "A black hole is a place in space where gravity pulls so much that even light can not get out. The gravity is so strong because matter has been squeezed into a tiny space. This can happen when a star is dying." After this information, I was able to further learn and expand my knowledge with the insight and a little bit of background on the subject.






After knowing what a black hole was, I noticed that another aspect which the chapter constantly speaks of is Albert Einstein's General Relativity. I began doing a lot of research and was able to break it down to the idea that space is 4D and consists of a fabric called space time. The greater the mass of an object the more it bends space-time. The bends of space time make us feel gravity. Through my research and reading, I was able to discover that a blackhole is an object of zero size but finite mass. Blackholes cause warps space time however, there is nothing there.
Theory of General Relativity
I did not limit my research to just two background information pieces, I researched many other things such as spacetime, singularity, naked singularity , worm holes, light cones supernova, white dwarfs. All of these ideas were commonly used in this chapter and contributed to my research and discovery of blackholes. 



http://www.nasa.gov/audience/forstudents/k-4/stories/what-is-a-black-hole-k4.html#.U407IoFdVYA
https://www.youtube.com/watch?v=0rocNtnD-yI
http://hubblesite.org/reference_desk/faq/answer.php.id=62&cat=exotic
http://curious.astro.cornell.edu/question.php?number=694
https://www.youtube.com/watch?v=ev9zrt__lec
http://www.space.com/17661-theory-general-relativity.html
http://casswww.ucsd.edu/archive/public/tutorial/GR.html

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Chapter two

The Expanding Universe

The second lecture in The Theory of Everything is regarding the expansion of the universe. This chapter begins by discussing our galaxy and some galaxies around us. Only in 1924 did American astronomer Edwin Hubble demonstrate that our universe was not the only galaxy. One of the first historic debates the chapter talks about is static vs expanding universe debates. The novel then continues on by discussing two main topics, beginning with the Friedmann Models. It states Friedmann's two assumptions: The universe looks identical in whichever direction we look, this also would be true if we were observing the universe from anywhere. This helped prove that our universe cannot be static. The chapter continues by talking about pieces of evidence which proved Hubble and Friedmann's beliefs and theories, such as Pennzias and Wilson along with Dicke and Peebles' discoveries. After this the book begins to discuss another very key topic, the Big Bang theory.  The book does not define nor explain what the Big Bang theory is, it simply tells us the beliefs before, during and after the implantation of the theory.







To rate the level of difficulty of this lecture, I would give it a 6/10. The vocabulary had been to my grade level, however the content was slightly more advanced than my capability of understanding. Initially the chapter starts by discussing the thoughts on the universe, and I came across some difficulty understanding the difference between static and non static- expanding universe. In order to figure out the differences between the two, I began by defining them. A static universe, also known as  " Einstein's universe"  it is an infinite and stationary universe. It is neither expanding nor contracting. To begin with, I did not understand the difference between an infinite and an expanding universe. In reality, I am still in darkness of what the differences are. Through a Youtube video (below), I began to understand a little. A static universe would mean that all galaxies are not moving, and all stars would be visible to us here on earth, however the galaxies are moving and the farther the galaxy, the faster it is moving.  What I need to yet research is from what central point are galaxies moving faster away from as you go further? Is there a center to the universe?




The Friedmann models did not create much confusion, what they did create were questions. His assumptions led to one major question. If the universe looks identical in whichever direction we look and that is true for everywhere else does that make our location in the universe special. I was unable to obtain a definite answer but from a certain article (attached below paragraph), I learned that our Earth is not in the center of the universe.  In Friedmann's models, all galaxies are moving directly away from each other. What the universe reminds me of is a inflating balloon which has spots on it (galaxies)- as the balloon expands, the distance between two spots increases. There is no spot that can be said to be the center of the expansion. What I found interesting were the 3 models of the universe which obey Friedmann's assumptions; 
  1.   The universe is expanding so slowly that the gravitational attraction between the different galaxies causes the expansion to slow down and eventually stop. 
    • The galaxies then would start to move towards eachother and the universe would contract 
    • The distance would begin at 0 reach maximum then go back to zero


     2.   The universe is expanding so rapidly that the gravitational attraction can never stop it, however with time it will slow down a little. 
    • The distance will begin at 0 then reach maximum, then go to a constant speed
     3.  The universe is expanding just fast enough to avoid recollapse
    • The disrance begins at  0 but will increase forever, the speed will get smaller and smaller but will never touch 0 again. 

http://www.spacedaily.com/reports/Theory_of_Earths_special_place_in_the_universe_proven_unfounded_999.html 

The Big Bang theory had to have been the greatest challenge yet. I did not know what the Big Bang had been, who created the theory nor any other information on it. After a lot of research I was able to discover what it was. I enjoyed my discovery so much that I created another page just for others to enjoy my learning in a grade level language! Other challenges I faced had been terminology. The book talk about the Doppler Effect, and I had to research that. Along with many other words. All I researched is on the next page (look at menu bar at top of page) (page labelled The Big Bang Theory of Dummies). 


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Chapter One

Ideas About the Universe



The book The Illustrated Theory of Everything begins by explaining the different theories and ideas that physicists and philosophers have had in the past. The book initially explains the first published and popular theory by Aristotle in 340 B.C. Aristotle had been the first person to publish content on the fact that the earth is not flat, but rather a sphere.  This chapter discusses many other discoveries, however the most significant one discussed had been Newtons in 1687. That year, Newton published the Principia Mathemalica Naturalis Causae. This document is believed to be the single most important documentation of all time. Not only did he put forward theories of how bodies moved in space and time, but also developed mathematics needed to analyze these motions. After discussing all of these theories before the 20th century, Stephen Hawking shifts his attention to post 20th century theories. In this section of the chapter, Hawking discusses how Newton's theory had been modified to state that large bodies repelled at large distances. But we learn that if stars came close, they would attract not repel, and that if stars began to move farther, the repulsive forces would dominate and stars would move farther. In this section we also learn that before the 20th century, they had believed that the universe had existed forever and was not expanding but stationary. However Edin Hubble tells us that the universe is always expanding, the stars are always moving away from us. I discovered in this section that 10-20 million years ago, all stars were together and this had been a result of the Big Bang. The Big Bang had been when the universe was "small" and indefinitely dense. The Big Bang had been the beginning of our time, anything before the Big Bang is not required to be known as it does not effect what has happened, what will happen or what is happening.

As I came from having absolute no background of physics or the universe, all this material had taken me quite a while to grasp.  The initial reading had led no absolute no intake of any of the theories and information provided, however after the second and third read of this chapter I began to understand what Hawking was attempting to put forward. The fact that I borrowed the Illustrated version of Stephen Hawking's book greatly assisted me. The text of this novel is identical, however it is the footnotes, the images and the attractiveness of the book which assisted me in keeping my interest and helping a "rookie" physicist in learning about the origin and fate of the universe. In order to learn the information provided, I had to do a lot of outside of text research which included discussing my text with peers, using websites and youtube videos.

                                        

My adventure into learning about our universe all began by getting down the basics of what I would need to know. The first question that rose in my head had been "What is the universe?" , " what does it consist of" ? I goggled this question and found the famous Minute Physics. This video set a great foundation for me. I learned that the universe is everything. There are two definitions and types of the universe; Observable universe and the whole Universe. The observable universe is everything we know and can see. The whole universe is literally everything. It is the past, the present and the future. As far as we know, the universe is approximately 13.8 billion years old, and had a beginning. We do not know much on the universe, we know three things; space time, particles and how space time and particles interact to make everything. The next step for me had been to research some information on the Big Bang theory.  After watching numerous videos, reading numerous webpages, I was able to learn some things however not much had been learned. The level of detail exceeds my understanding. I learned that it all began with electrons. Free electrons would cause photons light to scatter. Overtime, the electrons met a nuclei and created neutral atoms which after 380 000 years turned into light. One thing which blew my ming had been that the Big Bang theory was not an explosion but just an expansion. 



This chapter has had to been one of my favourite chapters ever read. It is not often that a book is able to interest a teenager so much that instead of talking about his weekend he talks to his friends about what ideas were presented in his book. My favourite lines of this chapter had had to be; "... that brings us to the question of what could have caused the stars to have turned on in the first place". (8) After telling us that light from distant stars would be dimmed by absorption by intervening matter, and eventually the dimmed matter would begin to shine- which they do not. The only answer to this would be that the stars turned on at a finite point in time. What turned them on though? This thought has questioned me ever since I read it. 

Secondary information found:
http://csep10.phys.utk.edu/astr161/lect/history/newtongrav.html

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