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Archive for the ‘philosophy’ Category

The Creation of the World – According to Science

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Ram Brustein, Judy Kupferman
How was the world created? People have asked this ever since they could ask anything, and answers have come from all sides: from religion, tradition, philosophy, mysticism… and science.
While this does not seem like a problem amenable to scientific measurement, it has led scientists to come up with fascinating ideas and observations: the Big Bang, the concept of inflation, the fact that most of the world is made up of dark matter and dark energy which we can not perceive, and more.
Of course scientists cannot claim to know the definitive truth. But we can approach the question from a scientific viewpoint and see what we find out.
How do we do that? First, we look to the data.
Thanks to modern technology, we have much more information than did people of previous ages who asked the same question. Then we can use scientific methods and techniques to analyze the data, organize them in a coherent way and try and extract an answer.
This process and its main findings will be described in the article…..
Read more: http://arxiv.org/pdf

Written by physicsgg

February 6, 2012 at 9:21 pm

Posted in COSMOLOGY, philosophy

The Fabric of the Cosmos: The Illusion of Time

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Time. We waste it, save it, kill it, make it. The world runs on it. Yet ask physicists what time actually is, and the answer might shock you: They have no idea. Even more surprising, the deep sense we have of time passing from present to past may be nothing more than an illusion. How can our understanding of something so familiar be so wrong? In search of answers, Brian Greene takes us on the ultimate time-traveling adventure, hurtling 50 years into the future before stepping into a wormhole to travel back to the past. Along the way, he will reveal a new way of thinking about time in which moments past, present, and future—from the reign of T. rex to the birth of your great-great-grandchildren—exist all at once. This journey will bring us all the way back to the Big Bang, where physicists think the ultimate secrets of time may be hidden. You’ll never look at your wristwatch the same way again


http://youtu.be/Rp3_cPRQSh0

Written by physicsgg

November 14, 2011 at 1:43 pm

Posted in COSMOLOGY, philosophy

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Anthropic decision theory

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Stuart Armstrong

The Adam and Eve problem: what are the odds of descendants?

This paper sets out to solve the Sleeping Beauty problem and various related anthropic problems, not through the calculation of anthropic probabilities, but through finding the correct decision to make.

Given certain simple assumptions, it turns out to be possible to do so without knowing the underlying anthropic probabilities.

Most common anthropic problems are underspecified from the decision perspective, and this can explain some of the differing intuitions in the subject: selfless and selfish agents, total and average utilitarians, will all reach different decisions in the same problem.

These results are formalised into an anthropic decision theory, that is them used to solve many anthropic problems and paradoxes, such as the Presumptuous Philosopher, Adam and Eve, and Doomsday problems…….
Read more: arxiv.org

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November 1, 2011 at 7:09 pm

How Quantum Theory Helps us Explain

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Richard Healey
I offer an account of how the quantum theory we have helps us explain so much. The account depends on a pragmatist interpretation of the theory: This takes a quantum state to serve solely as a source of sound advice to physically situated agents on the content and appropriate degree of belief about matters concerning which they are currently inevitably ignorant. The general account of how to use quantum states and probabilities to explain otherwise puzzling regularities is then illustrated by showing how we can explain single particle interference phenomena, the stability of matter, and interference of Bose-Einstein condensates. Finally I note some open problems and relate this account to alternative approaches to explanation that emphasize the importance of causation, of unification, and of structure……

Read morearxiv.org

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November 1, 2011 at 1:29 am

Conceptual Problems in Cosmology

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F. J. Amaral Vieira

The Universe before and after in ation. The gridlines represent the commoving coordinate system, and the circle the Hubble volume 1/H, which has shrunk with respect to the commoving coordinates after in ation

In this essay a critical review of present conceptual problems in current cosmology is provided from a more philosophical point of view.
In essence, a digression on how could philosophy help cosmologists in what is strictly their fundamental endeavor is presented. We start by recalling some examples of enduring confrontations among philosophers and physicists on what could be contributed by the formers to the day-time striving of the second ones.
Then, a short review of the standard model Friedmann-Lemaitre-Robertson-Walter (FLRW) of cosmology is given.
It seems apparent that cosmology is living a golden age with the advent of observations of high precision. Nonetheless, a critical revisiting of the direction in which it should go on appears also needed, for misconcepts like “quantum backgrounds for cosmological classical settings” and “quantum gravity unification” have not been properly constructed up-to-date.
Thus, knowledge-building in cosmology, more than in any other field, should begin with visions of the reality, then taking technical form whenever concepts and relations inbetween are translated into a mathematical structure.
It is mandatory, therefore, that the meaning of such concepts be the same for all cosmologists, and that any relationship among all them be tested both logically as well as mathematically. In other words, the notorius feature of improbability of our universe, as is well-known, assures to cosmologists a priviledged degree of freedom for formulating interpretations and theories.
However, at the same time, it demands for their formulations and conclusions to be considered in the light of data taken from astrophysical observations…..
Read more: arxiv.org

Written by physicsgg

October 27, 2011 at 8:10 am

Posted in COSMOLOGY, philosophy

KNOCKING ON HEAVEN’S DOOR

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Knocking on Heaven’s Door: From Lisa Randall (Theoretical Physics/Harvard Univ.; Warped Passages: Unraveling the Universe’s Hidden Dimensions, 2006), a whip-smart inquiry into the scientific work being conducted in particle physics.

The author examines some fairly recondite material—the philosophical and methodological underpinnings of the study of elementary particles (with a brief foray into cosmology)—and renders it comprehensible for general readers. She brings a thrumming enthusiasm to the topic, but she is unhurried and wryly humorous. She explains how physicists conduct their theoretical studies, the logic involved and the confidence that comes only in what’s verified or deduced through experimentation. That knowledge must always be open to change, surrounded as it is by an amorphous boundary of uncertainties, where research is conducted in a state of indeterminacy, testing and questioning to ascertain veracity and implications (which includes investigating the likes of string theory, which doesn’t yield experimental consequences but may provide new ways of thinking). Randall brings great clarity to the application of theory. Not only will readers come to feel comfortably familiar with scaling—why, for instance, Newton’s laws work on one scale but not another—or how the Large Hadron Collider will provide access to fundamental particles, but appreciate how one “sees” a subatomic particle when visible light’s wavelength is too big to resolve it. While much of the book concerns the behavior of quarks, leptons and gauge bosons, the author ranges freely into the advantages and disadvantages of aesthetic criteria in science, the importance of symmetry and the creation and nature of black holes, black energy and black matter: “Why should all matter interact with light? If the history of science has taught us anything, it should be the shortsightedness of believing that what we see is all there is.”

A tour of subatomic physics that dazzles like the stars.
The 27-minute interview with Charlie Rose recorded last Friday is available now, too: click at the link in this sentence and then on Lisa’s picture

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September 20, 2011 at 4:40 pm

Posted in COSMOLOGY, philosophy

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Neuroscience vs philosophy: Taking aim at free will

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Scientists think they can prove that free will is an illusion. Philosophers are urging them to think again.

Read more: http://www.nature.com/news/2011/110831/full/477023a.html

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September 1, 2011 at 10:35 am

Why Philosophers Should Care About Computational Complexity

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Scott Aaronson
One might think that, once we know something is computable, how efficiently it can be computed is a practical question with little further philosophical importance. In this essay, I offer a detailed case that one would be wrong. In particular, I argue that computational complexity theory—the field that studies the resources (such as time, space, and randomness) needed to solve computational problems—leads to new perspectives on the nature of mathematical knowledge, the strong AI debate, computationalism, the problem of logical omniscience, Hume’s problem of induction and Goodman’s grue riddle, the foundations of quantum mechanics, economic rationality, closed timelike curves, and several other topics of philosophical interest. I end by discussing aspects of complexity theory itself that could benefit from philosophical analysis.
Read more: http://arxiv.org/PS_cache/arxiv/pdf/1108/1108.1791v1.pdf

Written by physicsgg

August 9, 2011 at 7:15 am