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Time class copy 2
- 1. All About Time Time- a profound issue in modern physics
- 2. Why is Time a Mystery? Our life is embedded in the concept of Time How would you explain it? Our goal is to understand it from the perspective of physics…and then… Connect it to other aspects of science and to our everyday lives
- 3. The pace of life quickens… …but a full understanding of Time still eludes us
- 4. The pace of life some believe time exists outside man, exist objectively, and has measurable and linear characteristics. “ For some in primitive societies time is apprehended differently. For them it is a much looser concept, more open, elastic, subjectively. it is said the pace of life is fastest in Switzerland and Germany
- 5. Time works the way it does in our everyday lives because of the way the universe works An understanding of time cannot be found in everyday experience but in the creation of the universe itself
- 6. The importance of Time In every endeavor of mankind… In physics, biology, medicine, neuroscience, psychology, and all the human sciences (history, politics, economics If we can achieve an understanding from physics, then maybe we can better understand times connections elsewhere and in everyday living
- 7. time intervals • we are fundamentally aware of time intervals of only a few seconds • our Flicker Fusion Frequency: the shortest perceivable interval between events-for humans between 50 and 60 flashes per second-hearing seems to be more sensitive to time intervals • time seems to speed up as you age, because experiences are repeated and memories condensed, seeming to take up less time • psycho active drugs have a similar effect
- 8. the reverse can often be true: a stretch full of action and excitement seems to have taken a long time, while a tedious. A board of his condensed to a brief moment. A month of sickness may hardly yield more memories than a day a week of travel and sightseeing may seem more like three weeks in the memory
- 9. Physicists, artists and graph makers of all kinds routinely depict time as another dimension of space, creating a unified spacetime—shown here as a three-dimensional block in which a ball bounces off a wall. Relativity theory holds that spacetime can be sliced up in various ways. But not all are equally sensible.
- 12. IS TIME AN ILLUSION?
- 13. Sideways Clock Daniel Arsham, 2012
- 14. The flow of time.. is it an illusion? Does consciousness give us the impression of living moment-to-moment? There are differing views on this, but we will focus on the view that the “arrow of time” is real and time itself is different from the other dimensions of the “space- time continuum”
- 15. Views on Time The “eternal list” or “block universe” view …time is an illusion: the entire history of the universe simply is Time is real, and that the passage of time plays a generative role: it brings the future into existence. Additionally Lee Smolin in “Time Reborn” has suggested that the laws of physics themselves are evolving with time. Sean Carroll: Time is real-actually existing, not merely illusory-and yet it may turn out not be a fundamental measure of the universe
- 18. The Beginning of Time the cosmologist answers are different than that given by the creation myths of the civilizations around the world in the Judeo-Christian tradition time began with God's creation of the universe, and always moves forward in one direction: but many other cultures, both past and present, believe in cyclical time
- 19. Estimates of the age of the earth age, thousands of years date USSHER 6 1650 de Maillet 2,400,000 1738 Buffon 75 1774 Lyell 35 1831 Phillips 100,000 1860 Kelvin 20-40,000 1897 Current estimates 4,540,000 2000
- 21. Lightspeed 300,000 km/s, or 186,000 mi./s in one nano second, light travels about a foot, 30 cm or so one nano second is one billionth of a second (10-9 or 0.000000001 seconds)
- 22. A Summary Time: everyone knows what it is, no one knows what it is quantum mechanics suggests there is no difference between the past the present and the future relativity suggests there is no difference between the past the present and the future the details about the beginning of the universe-the Big Bang- are not understood. Was this the beginning of time or not?
- 26. The sun is about 5 billion years old. In another 5 billion years, it will swell into a red giant, after which it will form a spectacular planetary nebula like the Eskimo nebula, and for the Earth time will end. a galactic year is the time it takes the sun to orbit the Milky Way galaxy-about 230 million Earth years if the age of the earth were compared with a 24 hour clock, the first humans would appear only 40 seconds a four midnight. F
- 27. Mathematics and the Universe • Once you believe the creation is the work of a rational God, mathematics becomes the key to unlocking its secrets and to establishing a union with the creator. It is in the Pythagorean legacy that we find the idea that nature’s essence is mathematically symmetrical and thus perfect, a notion that is at the root of the unification dream. To decipher nature secret was to unveil the symmetries hidden in the deeper layers of reality, below the chaotic diversity of the world. From “A Tear at the Edge of Creation” by Marcelo Gleiser.
Editor's Notes
- Sean M. Carroll of the California Institute of Technology sets out to explain why time marches along unfailingly in one direction. Carroll argues for the necessity of marrying three seemingly disparate concepts: time, entropy and cosmology. Entropy, which, in rough terms, is the measure of a system’s disorder, creeps up over time, as dictated by the second law of thermodynamics. To illustrate entropy’s inexorable growth, Carroll takes us to the breakfast table—you can’t unscramble an egg, he points out, and you can’t unstir the milk out of your coffee. These systems invariably proceed to disordered, or high-entropy, arrangements. Each of these examples shows how the continual growth of entropy fills the world with irreversible processes that divide the past from the future: the making of an omelet and the mixing of milk into a cup of coffee are events that work in only one temporal direction. But why should entropy always increase? This is where Carroll turns to cosmology, which must explain what happened at the hot, dense big bang and, even before that, when the universe began. We spoke to the physicist about his book and the challenges of presenting cutting-edge physics to a wide audience. Carroll sees the present as a particularly exciting time to be a theoretical physicist. There is a flood of new data in cosmology, and new experiments are under way at particle accelerators and elsewhere. What’s so interesting about time? To a naive observer, it’s something that just passes by and that we can’t do anything with; it’s unchanging. There are two things that inspired me to write this book. One is that time is something we all are familiar with. We all use it— we have no problem reading a watch. But then, when you act like a good scientist or philosopher and try to make sense of it, this puzzle arises: the fundamental laws of physics treat the past and the future as being exactly the same, whereas the world does not. There’s a big difference— the past happened, and the future is still up for grabs. So it would be nice to know how to reconcile that . That’s the arrow of time problem as it’s been thought about for at least a couple of hundred years. I think this is an important and interesting problem, and it’s just as good to write about as anything else. But there is something that I think makes this problem a little bit special, which is that the answer to why the past is different from the future, whatever it is going to end up being, is not just about what happens here as you and I are talking, as time goes by in our daily lives. It is intimately connected with the whole universe—with what happened at the big bang, with the special condition in our universe when it started. A full understanding of what happens in our everyday lives needs to take into account what happened at the big bang. Not only is that intrinsically interesting and just kind of cool to think about, it’s also a mystery that is not given much attention by working scientists ; it’s a little bit underappreciated. We are so far from knowing what the final answer to this is that we sort of don’t think about it that much. So I wanted to draw attention to this connection between the arrow of time and cosmology, both to everyday readers and to my scientific friends. I think this is something that we really should keep in mind as one of the fundamental puzzles facing us in modern science. Scientific American Editors (2012-11-30). A Question of Time: The Ultimate Paradox (Kindle Locations 1359-1386).
- Einstein in 1955 wrote a letter to the family of a friend who had just passed away in which he put forward a scientists consolation: “This is not important. For us who are convinced physicists, the distinction between past, present, and future is only an illusion, however persistent.” the idea that time is an illusion is an old one, predating any Times Square ball drop or champagne celebrations. It reaches back to pre—Socratic thinkers who are staples of introductory philosophy courses. In other words the entire history of the universe simply is. This is the “eternal list” or “block universe” view-thinking of space and time together as a single four dimensional collection of events, rather than a three-dimensional world that evolves over time.
- According to conventional wisdom, the present moment has special significance. It is all that is real. As the clock ticks, the moment pass- es and another comes into existence—a process that we call the flow of time. The moon, for example, is located at only one position in its orbit around Earth. Over time it ceases to exist at that position and is instead found at a new position.
- Researchers who think about such things, however, generally argue that we cannot single out a present moment as special when every moment considers itself to be special. Objectively, past, present and future must be equally real. All of eternity is laid out in a four- dimensional block composed of time and the three spatial dimensions. (This diagram shows only two of these spatial dimensions.)
- Calvin was fond of making profound statements. Some of these were gloriously wrong. He said that X-rays were hoax, until he saw the evidence for himself. He said in a 1902 newspaper interview, “no balloon and no aero plane will ever be practically successful.” And he is widely reported to have said in 1900, “there is nothing new to be discovered in physics now. All that remains is more and more precise measurement.” He did not foresee that the new science of quantum mechanics and relativity would appear on the scene in five years. And f
- “In more sophisticated models, which include quantum effects, any pair of galaxies must have started off a certain minimum distance apart. These models open up the possibility of a pre-bang universe.” Excerpt From: Scientific American Editors. “Possibilities in Parallel.” iBooks. https://itun.es/us/QxjsM.l
- this diagram represents the entire history of the universe, and of time itself. The Big Bang started as a singularity-eight point-and a moment later the incredibly hot massive particles ballooned outwards in a period of rapid inflation. Within a few minutes this mass cool down to around 1,000,000,000 K, and the first atoms were formed. Stars followed, and the first galaxies appear after about 1 billion years. The universe is still expanding, apparently being pulled apart by dark energy.
- During the last 50 years or so there has been controversy among astronomers and cosmologists about what will happen to the universe. There seem to be three possibilities. Either it will go on expanding forever, or it will slowly come to a stop, or it will stop and then fall inward again, so that everything meets in a big crunch.
- … What we can see and measure determines our perspective on the world. Our imagination may leap forward and expand the possibilities of the real, but ideas will remain mere ideas unless they are confirmed. And since-in spite of our wonderful measuring tools-we will never have complete information about the world, our view of reality will always be limited. We will always be like a fish trapped in a fishbowl, even if our fishbowl grows all the time.