The example given in the book is of a double-headed arrow. There are two groups of particles in the universe: particles with a spin of 1/2, and particles with a spin of 0, 1,. All of these particles follow pauli's exclusion principle. Pauli's exclusion principle says that particles cannot be in the same place or have the same speed. If pauli's exclusion principle did not exist, then everything in the universe would look the same, like a rougly uniform and dense "soup". File:Quark structure This is a proton. It is made up of three quarks.
A brief History Of Time summary
Quarks also have three "colors red, green, and blue. There are also anti-quarks, which are the opposite of the regular quarks. In total, there are 18 different types of regular quarks, and 18 different types of antiquarks. Quarks are known as the "building blocks of matter" because they ano are the smallest thing that make up all the matter in the universe. File:Arrow A particle of spin 1 needs to be turned around all the way to look stenographer the same again, like this arrow. All particles (for example, the quarks) have something called spin. The spin of a particle shows us what a particle looks like from different directions. For example, a particle of spin 0 looks the same from every direction. A particle of spin 1 looks different in every direction, unless the particle is spun completely around (spun 360 degrees). Stephen Hawking's example of a particle of spin 1 is an arrow. A particle of spin two needs to be turned around halfway (or 180 degrees) to look the same.
The highest point of a wave is the crest, and the lowest part of the wave is a trough. Sometimes more than one of these waves can interfere with each other - the crests and the troughs line. This is called light interference. When light waves interfere with each other, this can make many professional colors. An example of this is the colors in soap bubbles. Chapter 5 quarks and other elementary particles (very small things) are the topic of this chapter. Quarks are very small things that make up everything we see ( matter ). There are six different "flavors" of quarks: the up quark, down quark, strange quark, charmed quark, bottom quark, and top quark.
If a lower frequency light paper is used, the light can find the speed more accurately but the particle's position will be unknown. The uncertainty principle disproved the idea of a theory roles that was deterministic, or something that would predict everything in the future. File:Simple here is a picture of a light wave. How light behaves is also talked more about in this chapter. Some theories say that light acts like particles even though it really is made of waves; one theory that says this is Planck's quantum hypothesis. A different theory also says that light waves also act like particles; a theory that says this is heisenberg's uncertainty principle. Light waves have crests and troughs.
A scientist named Edwin Hubble found that many stars are red shifted and are moving away from. Stephen Hawking uses the doppler shift to explain that the universe is getting bigger. The beginning of the universe is thought to have happened through something called the big Bang. The big Bang was a very big explosion that created the universe. Chapter 4 This chapter is about the uncertainty principle. The uncertainty principle says that the speed and the position (or where something is) of a particle cannot be found at the same time. To find where a particle is, scientists shine light at the particle. If a high frequency light is used, the light can find the position more accurately but the particle's speed will be unknown (because the light will change the speed of the particle).
Brief History of Time, updated and
If one of the twins went to live on a high place (such as a mountain and another biography twin went to live at a lower place (such as near the sea the twin who went to live on the mountain would be a little bit. Chapter 3 File:cmb the big Bang is shown here. From the picture, we can tell the universe is getting bigger over time. In this chapter, Stephen Hawking talks about the expanding universe. This means he believes the universe is getting bigger over time.
One of the things he uses to explain his idea is the doppler shift. The doppler shift happens when something moves toward or away from another object. There are two types of things that happen in Doppler shift - red shifting and blue shifting. Red shifting happens when something is moving away from. This is down to the wavelength of the visible light word reaching us increasing, and the frequency decreasing, which shifts the visible light towards the red/infa-red end of the electromagnetic spectrum. Red-shift is linked to the belief that the universe is expanding as the wavelength of the light is increasing, almost as if stretched as planets and galaxies move away from us, which shares similarities to that of the doppler effect, involving sound waves. Blue shifting happens when something is moving toward us, the opposite process of red-shift, in which the wavelength decreases and frequency increases, shifting the light towards the blue end of the spectrum.
Einstein's idea was also the same as Henry poincare's idea. Einstein's idea is called the theory of relativity. Also in this chapter, Stephen Hawking talks about light. He says that events can be described by light cones. The top of the light cone tells where the light from the event will travel. The bottom tells where the light was in the past.
The center of the light cone is the event. Besides light cones, Stephen Hawking also talks about how light can bend. When light goes past a big thing, like a star, the light changes direction because the star has a lot of gravity. After talking about light, Stephen Hawking talks about time in Einstein's theory of relativity. One prediction that Einstein's theory makes is that time will go by slower when something is near big things, like the earth. However, when something is farther away from the big thing, time will go by faster. Stephen Hawking used the idea of two twins (two people who are the same-looking) living at different places to describe his idea.
History of Carrots, a brief summary and timeline
The idea of absolute rest did not work when objects move very presentation fast (at the speed of light, or light speed). The speed of light was found out in 1676 by the danish astronomer Ole Christensen roemer. The speed of light was found to be very fast, but at a finite speed. However, scientists found a problem when they tried to say that light always traveled at the same speed. The scientists created a new idea, called the ether, which tried to explain light's speed. File:thumbleft Einstein said that time was not absolute, or always the same. The idea of the ether paper was said to be not needed by another scientist, Albert Einstein. He said that the idea of the ether was not needed if another idea, the idea of absolute time (or time that is always the same) was dropped.
Issac Newton also wrote a book about gri gravity, which helped to prove copernicus's idea right. Hawking also talks a little about the other topics (things) in the book. Chapter 2 In this chapter, Stephen Hawking talks about space and time. He describes the motion of planets moving around the sun and how gravity works between the planets and the sun. He also talks about the ideas of absolute rest and absolute position. These ideas are about the thought that events stay in place over a period of time. This was found not to be true by newton's laws of gravity.
planetary model that described Aristole's thinking. Today, it is known that the opposite is true; the earth goes around the sun. The Arisotle/Ptolemy ideas about the locations of the stars and sun was disproved (or proved to not be true) in 1609. The person who first thought of the idea about the earth going around the sun was Nicholas Copernicus. Galileo galilei and Johannes Kepler, two other scientists, helped to prove that Copernicus's idea was right. They looked at how the moons of some planets moved in the sky, and they used this to prove copernicus right.
It was also updated because new information was found. A briefer History of Time is shorter legs than the first version and was also updated. This book is very popular and well-known. This book was on the. London Sunday times bestseller list for over 4 years. 1, summary, chapter 1, file:thumbleftA picture of what Ptolemy thought about the location of the planets, stars, and sun. In the first part of the book, hawking talks about the history of physics. He talks about the ideas of philosophers such as, aristotle and.
Brief History of of Palestine, israel and the Israeli
A Brief History of Time (1988) is a book written by the scientist and mathematician, stephen Hawking. This book is about physics, or the study of laws that predict how things work in reviews the universe. It is also about cosmology, or how we see the universe and how the universe exists. In this book, stephen Hawking talks about many theories (or ideas) in physics. Some of the things that he talks about are the history of physics, gravity, how light moves in the universe, space-time, elementary particles (very small objects that make up things in the universe black holes, the, big Bang (the theory that the universe started from. There are two other versions of this book: The. Illustrated a brief History of Time and, a briefer History of Time. The Illustrated a brief History of Time has pictures to help explain its ideas.