Check out this site, it has simulations on how the sky looks like when you’re orbiting a black hole, or on what happens when our galaxy will collide with Andromeda, etc.
[quote]LIFTICVSMAXIMVS wrote:
Aragorn wrote:
I’m looking for material on Quantum Mechanics/Physics to read.
Totally interested in quantum (my uncle works at Brookhaven), but need more learning.
Try Sam Treiman’s The Odd Quantum for a non-rigorous look at the nature of quantum behavior.
If you think you can handle the math…which three semesters of Calc should give you I recommend the text by David J. Griffiths Introduction to Quantum Mechanics. His writing style is great and easy to follow–but his explanations are tricky if you don’t have a grasp of diff eq. or partial differentials but does an excellent job of describing Heisenberg Uncertainty matrix operator methods. I reference this book all the time–it never leaves my desk.[/quote]
Sweetness. Well, for some reason physics enables me to do and understand math. I suck at math itself, but physics is ok…to a point. This is probably why quantum for me is such a draw, and so impossibly unreachable. As a prev. poster said, physical intuition means not to much in QM.
I think it’s the way our math classes are taught. If I can dialogue with someone I’m usually ok.
Thanks!
boomerlu–
Wheeler is one of my favorite physicists, I was drawn to him particularly from what Kip S. Thorn wrote about him in Black Holes and Time Warps.
I don’t have the Feynman lectures (going to be getting them sometime…), but I do have Six Not-So-Easy Pieces. It’s good.
Thanks.
The crazy thing is, if I had nothing to work for, I’d be eating this stuff up day and night. Not just the physics, but the computer science and mathematics, philosophy, et al. Everything. I just don’t have time to get my head around everything I want to.
Now, someone mentioned the failing of string/superstring theory. What is this about? How so? Enlighten me.
[quote]LIFTICVSMAXIMVS wrote:
Awesome! Some good stuff. I have read a few of these ‘pop-science’ books and can say that, yes, they are in fact pretty good and also entertaining. Anything by Feynnman is good because I always laught at his writing. Brian Green is good, too. Also, Carl Sagan is great to read to inspire the mind.
My problem is that I am biased toward physics related material because that is my field so I need some non job realted reading.[/quote]
Try Mind Language and Society by Prof John Searle.
The guy is a freaking genius. He is at odds with Pinker and others in the area of the philosophy of the mind with regard to the nature of conciousness, but I find his arguments compelling, esp the Chinese Box, which finally lays to rest the idea that the human mind is a computer of sorts. He also offers the only logical explanation of conciousness I have ever read. Prof Searles genius is partly in the way he makes complex abstract ideas accesible to the casual reader. I once had the pleasure of hearing a tape of one of his lectures, wish I still had it.
Well…aside from the fact that it hasn’t been proven?
It’s a theory for which the specific experimental evidence has NOT been obtained.
However, ANY physics theory has to explain all relevant phenomena, so there should not be any gaps in string theory as far as that goes.
Essentially we have like 20 different theories which explain what we currently see, but have not been experimentally proven.
After LHC is active (unprecedented operating energy, 14 TeV!), there should be more evidence one way or another. I’m actually doing a small part to help find the Higgs boson. Cool eh?
Edit: I realized what I wrote was kind of vague about being proven.
Ok, since string theory is accepted as a good hypothesis which should be tested, that means it passes the test of explaining all CURRENTLY KNOWN physical phenomena. For it to be a good hypothesis, it also has to predict phenomena which has NOT YET been observed. This is what I mean by it hasn’t been proven. We haven’t observed phenomena which string theory predicts exclusively.
[quote]Aragorn wrote:
The crazy thing is, if I had nothing to work for, I’d be eating this stuff up day and night. Not just the physics, but the computer science and mathematics, philosophy, et al. Everything. I just don’t have time to get my head around everything I want to.
Now, someone mentioned the failing of string/superstring theory. What is this about? How so? Enlighten me.[/quote]
We actually have a whole major devoted to consciousness.
Computational and Neural Systems. One time I was just using a public computer and happened to pull up a set of CNS notes.
What stuck in my mind was “The Learning Algorithm”…
[quote]hankr wrote:
LIFTICVSMAXIMVS wrote:
Awesome! Some good stuff. I have read a few of these ‘pop-science’ books and can say that, yes, they are in fact pretty good and also entertaining. Anything by Feynnman is good because I always laught at his writing. Brian Green is good, too. Also, Carl Sagan is great to read to inspire the mind.
My problem is that I am biased toward physics related material because that is my field so I need some non job realted reading.
Try Mind Language and Society by Prof John Searle.
The guy is a freaking genius. He is at odds with Pinker and others in the area of the philosophy of the mind with regard to the nature of conciousness, but I find his arguments compelling, esp the Chinese Box, which finally lays to rest the idea that the human mind is a computer of sorts. He also offers the only logical explanation of conciousness I have ever read. Prof Searles genius is partly in the way he makes complex abstract ideas accesible to the casual reader. I once had the pleasure of hearing a tape of one of his lectures, wish I still had it.
[/quote]
Cool, Kip Thorne is a professor where I’m at, and we used Wheeler for our freshman level intro to Special Relativity.
The Feynman lectures are…interesting.
Feynman isn’t the most concise lecturers, but he offers valuable insights into the life of a research scientist, the value of mathematics, and puts a lot of things into perspective. Like that lecture series posted on this thread earlier, he mentions that “Mathematics is just a tricky way of doing things.”
I had never thought about it that way. It’s incredible, but true. Sure it’s oversimplifying, but it allows one get to the matter at hand, which is the PHYSICS of it.
Also in one of the first Feynman lectures, he talks about energy and conservation of energy.
He mentions that energy is an abstract concept. It’s just some quantity that when you calculate, remains the same. I never thought about it that way. Before, energy to me was something fundamentally physical, something you could touch and feel, something concrete. But then I thought about it, and yes indeed energy is just an abstract quantity.
[quote]Aragorn wrote:
boomerlu–
Wheeler is one of my favorite physicists, I was drawn to him particularly from what Kip S. Thorn wrote about him in Black Holes and Time Warps.
I don’t have the Feynman lectures (going to be getting them sometime…), but I do have Six Not-So-Easy Pieces. It’s good.
Thanks.[/quote]
I have to agree with whoever posted the cal tech lectures, computer science is the most interesting by far. Of course, I’m biased seeing as I have a degree in CS (soon to be starting an advanced degree hopefully). If you want something really fascinating yet at the same time incredibly dull, try Donald Knuth’s “The art of computer programming”.
If you’re looking for something more obscure, try some of Umberto Eco’s writings on semiotics (his fictional stuff is good too, especially his humorous essays).
One of my favorite pop-math pieces is the essay on large numbers over at http://home.earthlink.net/~mrob/pub/math/largenum.html It’s not the lightest reading out there, but there are some very interesting ideas that show up once you get into large finite numbers.
[quote]boomerlu wrote:
We actually have a whole major devoted to consciousness.
Computational and Neural Systems. One time I was just using a public computer and happened to pull up a set of CNS notes.
What stuck in my mind was “The Learning Algorithm”…
hankr wrote:
LIFTICVSMAXIMVS wrote:
Awesome! Some good stuff. I have read a few of these ‘pop-science’ books and can say that, yes, they are in fact pretty good and also entertaining. Anything by Feynnman is good because I always laught at his writing. Brian Green is good, too. Also, Carl Sagan is great to read to inspire the mind.
My problem is that I am biased toward physics related material because that is my field so I need some non job realted reading.
Try Mind Language and Society by Prof John Searle.
The guy is a freaking genius. He is at odds with Pinker and others in the area of the philosophy of the mind with regard to the nature of conciousness, but I find his arguments compelling, esp the Chinese Box, which finally lays to rest the idea that the human mind is a computer of sorts. He also offers the only logical explanation of conciousness I have ever read. Prof Searles genius is partly in the way he makes complex abstract ideas accesible to the casual reader. I once had the pleasure of hearing a tape of one of his lectures, wish I still had it.
[/quote]
Do you still have any of those notes/save them on your hard-drive?
boomerlu–
What surprised me was the post by TONEdef on the Peter Woit book. That made it sound like it was a fundamentally flawed hypothesis, not just lacking exclusive predictive power/evidence… Does anyone here have an idea of what Woit is talking about?
which Wheeler text is it that you use?
[quote]Aragorn wrote:
boomerlu–
What surprised me was the post by TONEdef on the Peter Woit book. That made it sound like it was a fundamentally flawed hypothesis, not just lacking exclusive predictive power/evidence… Does anyone here have an idea of what Woit is talking about?[/quote]
Check out the review of his book here
[quote]Aragorn wrote:
Do you still have any of those notes/save them on your hard-drive?[/quote]
No, sorry it was a public computer. I can’t find the exact set of notes since that was like 6 months ago, but if you just go to www.caltech.edu and search for CNS you’ll find the classes that I speak of.
Let me first say that I do not have the theoretical background to truly dismantle any claims that Woit makes. I read the review, and I’ll assume some of the things he says are true (I’ll outline them whenever it comes up).
Ok let me start with some background:
The search for a Grand Unified Theory is a MAJOR goal in physics. We as humans would like to believe that everything we see is the result of ONE simple idea, or a simple set of ideas.
For example, Electricity and Magnetism is unified via Special Relativity. If you analyze certain electrical phenomenon using the tools of special relativity, magnetism pops out. In other words, magnetism is just electricity, in theory. (of course in practice it is useful to treat them separately).
Ok back on topic:
Mathematics has evolved to describe very abstract systems, arbitrary numbers, arbitrary operators, and arbitrarily large dimensions (infinite dimensional systems for example).
If we simply make the hypothesis that the universe obeys the laws of logic, then string theory is strictly possible, as is any theory that bases itself on mathematics.
Let’s analyze Woit’s four main arguments
First, that String Theory can’t make predictions. I do not know if this is true or not, but it does seem like it since the higher the math, the harder it is to COMPUTE or envision a way to compute it(ie, make the predictions).
Second, that there’s never going to be something give evidence for it. Well, if the scale is truly as small as stated in the review, then yes it will be a long ways before we can do anything to confirm it. In fact, if string theory goes down to Planck lengths (as it seems so), then it may actually be IMPOSSIBLE to find experimental evidence. This coupled with the above argument that it is hard to make predictions to test is a pretty good argument.
The third argument is simply one made on human/social grounds, not theoretical ones, so I won’t examine it.
The fourth argument is pretty good as well. There has to be some kind of upper -limit on how much you can reduce things down. It may just be that physics is not MEANT to be unified, although that would be sad, as it is encouraging to believe in an Elegant universe.
Now, just because these arguments are GOOD does NOT mean that they are in fact TRUE. You’d have to ask somebody who’s actually studied string theory in depth.
Plus, the landscape of physics is constantly changing. We thought we had things figured out and then whoops, Quantum mechanics and Relativity popped out and totally changed the way we thought about things.
Between now and the time we’re able to measure down to the string scale, physics will have changed a lot.
Now some discussion of the role of GRAVITY in all this:
All known fundamental forces besides gravity are EXTREMELY strong on very SHORT length scales, and very weak on long length scales.
One of my professors remarked that Gravity seems to be “not all there” or off in some other place, hence why string theory uses higher dimensions. It does seem logical because gravitational force is so weak in comparison to the other forces.
Ahh well, hopefully LIGO will provide some explanation to all this.
PS - Spacetime Physics is the book we used.
[quote]Aragorn wrote:
boomerlu–
What surprised me was the post by TONEdef on the Peter Woit book. That made it sound like it was a fundamentally flawed hypothesis, not just lacking exclusive predictive power/evidence… Does anyone here have an idea of what Woit is talking about?[/quote]
bump
I thought this thread was too interesting to let die.