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Post by Satori on Feb 8, 2005 9:21:53 GMT -5
Parallel Worlds by Micho Kaku.
Explores the latest theories about the fundamental nature of the universe and its quantum strangeness.
Also touches on some philosophical areas. Kaku tells us that:
"Physicists have been forced to entertain two outrageous solutions [to the Schrodinger's Cat hypothesis]; either there is a cosmic consciousness that watches over us all, or else there are an infinite number of quantum universes."
..."Or is our universe the result of a collapsed quantum wave function with God Himself as the observer that collapses it?"
And ..
"Science cannot solve the ultimate mystery of nature because, in the last analysis, we ourselves are part of the mystery we are trying to solve."[Max Planck]
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Post by Electron on Feb 9, 2005 16:53:40 GMT -5
That's the cool thing about quantum mechanics - the theories developed at the turn of the previous century were bang-on (theories that have stood every test thrown at them for the last 100 years - despite the fact that many of the original predictions described apparently luicrous outcomes). However, despite giving rise to all manner of practical applications (transistors, lasers etc.) no single interpretation of what the theories actually describe has been agreed upon. This leaves a divide between those that say "never mind just shut up and get on with your calculations" and those that seek to explain what is really going on. Apart from the "Copenhagen interpretation" www.benbest.com/science/quantum.html that Neils Bohr was responsible for, there have been few others until very recently - in addition to the paralled universes there are a number of others. I also recommend the book "Schrodinger's Kittens" by John Gribben.
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Post by Satori on Feb 10, 2005 17:03:36 GMT -5
Well the ultimate goal of physics at the moment is the Theory Of Everthing and the two most promising solutions at the moment are superstring theory and what they call 'membrane theory'. Both throw away the standard four dimensional view of space-time and operate in up to 23 dimensions I believe. It sounds more like science fiction sometimes, but so did Einstein's 4D space-time at first.
I can understand Einstein's reluctance to submit to quantum uncertainty, but it does seem to be the best description of how things operate at a quantum level.
My maths simply isn't good enough to get too deep into quantum at the moment, but when I get the time I'll pick up some books on the maths behind it and try to get a better idea of the basics.
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Post by Electron on Feb 13, 2005 6:54:57 GMT -5
The string theorists themselves are still all over the place after decades of inquirery. All the more recent theories start with a superlative e.g superstrings, supersymetry etc. which indicates a concerted attempt to draw the various stands (no pun intended) together.
It's not that no progress is being made, it's more frustrating than that. Even the most bizzare predictions made by the quantum mechanics of the first half of the 20th century have by now been successfully demonstrated in experiments. This is an extraordinary achievement given the nature of those predictions.
A very recent experiment actually showed one of the standard (Copenhagen) interpretations principle tenets to be false: that an electron can be measured as either a particle or a wave - but not both at the same time! A very ingenious experiment has now shown it to be both simulataneously!
One half of Science is still grappling with the appropriate interpretation, while the other continues to verify the observations of this seemingly mysterious process. I have a hunch that we will crack this within the next hundred years and finally gasp at the implications.
I say this because all roads lead in the end to the 'two-slit' experiment. Quantum Electrodynamics is the jewel in the crown of science - providing a model capable of describing all the interactions between matter and energy. From atomic behaviour up exists a complete understanding of all the apparently diverse phenomena that arises from the Electro-weak forces at work. That gravity and the strong nuclear forces are still somewhat outside this picture does not hinder the application of QED to describe everything else. This is no small achievment.
Unfortunately the maths is horrible. It puts off many students as the calculations themselves are tedious rather than challenging. I can never get particularly enthusiastic about path integrals.
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Post by Satori on Feb 13, 2005 7:58:10 GMT -5
M-theory - 'membrane' theory - is the current successor to string theory and is the 'hot' topic in the scientific world. Whereas string theory visualises elementary particles as the 'notes' created from vibrations of superstrings (picture a violin), M-theory sees membranes creating the 'notes' (picture a drum head) rather than superstrings.
On another point, I think the picture of the universe taken from the WMAP satellite is astonishing. It's a picture of the universe when it was only 380,000 years old and shows the tiny fluctuations in the afterglow of creation that later went on to form galaxies and clusters.
One analogy I liked about how close we are to seeing the point of creation was: if you stand at the top of the Empire State Building looking down and imagine that distance (100+ floors) to represent the age of the universe. The tenth floor represents where the first galaxies where formed; the seventh floor represents where the first quasars were formed. The WMAP satellite now has a picture of things just half an inch above the ground!
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Post by Electron on Feb 13, 2005 11:56:28 GMT -5
That's what I find frustrating... M-theory represents yet another re-formulation in a different number of dimensions. No one seems to know just how many dimensions should be entertained.
And yes it is wonderful that Astronomy can play such an important role - particularly seeing as how it can answer questions arising at both ends of the scale.
Isn't it nice that we find ourselves somewhere in the middle of the scale - looking down and up we see things that are just as distant!
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