This is a new book (which I have not yet bought)...

Smolin apparently thinks there could be 10 or 11 dimensions. He also thinks humans have reached the limits of our understanding and technology which is why it is difficult for us to pin down 'string theory'.

Any views?

Is that what Smolin thinks or what you think?

I haven't read that one either but I heard him talk about it on the radio and it is rather more of a critique of the current trend in physics toward abstract theories like string theory that are not experimentally testable.

I enjoyed two of his other popular books, "Three Roads to Quantum GRavity" and "Life of the Cosmos". The former I would recommend if you want an non-mathematical overvew of string theory.

Hi Dave - from a review, in the Sunday Times, it appears to be what he thinks. I just wondered if anyone here has read the book as yet.

Personally, I feel there are many more dimensions but I have not gone as far as thinking exactly how many or working out what they could be.

It's certainly true that string theory is a theory of higher dimensions. There are many lay books about it including a couple by Brian Green and he did a Nova PBS series on it.

It's the statement that humans have reached the limits of either our understanding or technology that I doubt he would agree with. Why would someone be doing science if they thought the limits had been reached?

More likely, he is discussing how far beyond any conceivable technology is the energy scale where string theory is testable.

This is a new book (which I have not yet bought)...

Smolin apparently thinks there could be 10 or 11 dimensions. He also thinks humans have reached the limits of our understanding and technology which is why it is difficult for us to pin down 'string theory'.

Any views?

Buy the book, I guess. I put it on my Christmas list but didn't get it.

I too would be surprised if Smolin thought we'd reached the limits of our understanding and technology.

I've read it. It's more of an attack on string theory than anything. He feels that string theory has been given too much positive attention, so here he is making a point to talk about its limitations and flaws, as well as present alternative unified theories. He suspects that our misunderstanding probably lies in the concept of time.

It's more of an attack on string theory than anything. He feels that string theory has been given too much positive attention, so here he is making a point to talk about its limitations and flaws, as well as present alternative unified theories.

This has been Smolin's perspective for the past few years. His arguments do hold some merit, as string theory has been at the forefront of theoretical pphysics for 20 years or so.

euphrosene you should read this book, if you want a minority opinion of modern physics. I would also read one of Brian Greene's books to get the majority opinion, if you care for a balanced report. I would avoid reading "Three Roads" to get the other side, just because it is also by Smolin. That being said, I would encourage you to read "Three Roads" if you want an overview of the three ways people try to deal with gravity. Keep in mind that there are things that string theory is by far the more popular and well studied of the two theories. Smolin is bitter about this, and I am sure this comes through in his book.

If you have any questions, you can ask me (I have been studying string theory for four years, albeit a very small piece of the theory...) in a PM or in one of the string threads. I can tell you that I am probably more of an expert on this subject than anyone else here, and if I can't answer your questions, I am sure I can find the answers for you.

Thanks Ben. I only heard about the book this weekend so will no doubt get it/read it. And thanks, I would like to run some ideas past you later.

Many thanks, Euphrosene

I've read it. It's more of an attack on string theory than anything. He feels that string theory has been given too much positive attention, so here he is making a point to talk about its limitations and flaws, as well as present alternative unified theories. He suspects that our misunderstanding probably lies in the concept of time.

You don't say.

Euphrosene---

How's the read?

A famous string theorist Cliff Johnson has a blog called Asymptotia. He has made several very posts about this book, and another by Peter Woit. There is a bit of frustration in the field of string theory because these people, who are not active researchers in the field, and who have a vested interest in string theory being defunded, have written books very critical of the research program.

The articles you should read are called "Storm in a Tea Cup", with as much of the discussion as you can digest following. It is a good way to see how science (should) work---You can tell the real physicsts in the blog postings because they use their real names.

Anyway, if you are reading The Trouble with Physics, you should at least look at Clifford's postings to hear the other side of things.

http://asymptotia.com/2007/03/13/more-scenes-from-the-storm-in-a-teacup-vii/

Ben - my mother has been ill and I have been very busy 'working' ... in an office and also preparing a cartoon portfolio... so I have not even bought it yet. Hangs head in shame.

It is on the list but not immediately now because of all this other stuff I have to do.

btw I went to a film preview yesterday (Sunshine - http://www.sunshinethemovie.co.uk/) and a guy said I ought to get a copy of Pi. Have you heard of it?

http://en.wikipedia.org/wiki/Pi_(film)

Sorry again. There is another post I need to reply to here as well:o

This has been Smolin's perspective for the past few years. His arguments do hold some merit, as string theory has been at the forefront of theoretical pphysics for 20 years or so.

euphrosene you should read this book, if you want a minority opinion of modern physics. I would also read one of Brian Greene's books to get the majority opinion, if you care for a balanced report. I would avoid reading "Three Roads" to get the other side, just because it is also by Smolin. That being said, I would encourage you to read "Three Roads" if you want an overview of the three ways people try to deal with gravity. Keep in mind that there are things that string theory is by far the more popular and well studied of the two theories. Smolin is bitter about this, and I am sure this comes through in his book.

If you have any questions, you can ask me (I have been studying string theory for four years, albeit a very small piece of the theory...) in a PM or in one of the string threads. I can tell you that I am probably more of an expert on this subject than anyone else here, and if I can't answer your questions, I am sure I can find the answers for you.
Brian Greenes book is quite good. But there is something that has always bothered me about string theory. It is very nice and expains many things, but could it be that this is just math? I am an experimentalist myself, I dont see any experimental evidence for the 11 dimensions. Or at least I am not aware of these. Any news, its been a while since I was in the loop.

That's a good point, and other than this fact, and the fact that string theory explains many things in one nice and tidy package, there is no real motivation to think the universe is really made from strings.

But the thing is, as long as we've been coming up with theories to quantitatively describe nature, we've found that the best theories are the ones which are mathematically consistent. That is, mathematical consistency seems to be a prerequisite for describing nature. A beautiful example of this is general relativity. (Do not listen to the crackpots called Zanket and Singularity because they would throw GR to the curb despite a century's worth of experimental confirmation.) At it's heart, GR is a mathematical theory about Euclidean manifolds, and at one time, people thought "well it's just a bunch of math". Since then, of course, we've found that GR describes our universe in an extremely precise manner.

The point is this---String Theory describes things that we used to take for granted in particle physics. It also describes things that we once thought impossible to describe, namely the quantization of gravity. It also tells us why gravity should be so drastically different from the other forces we experience (both in magnitude and character). And it offers a powerful unifying principle for all of physics.

When Eisnstein was waiting for experimental confirmation of his theory in 1923(?), someone asked him "What if it's proven false". "Then I would feel sorry for God" he replied. The point is, Einstein couldn't imagine how something so wonderfully consistent and beautiful couldn't be true. Many string theorists are in this crowd today---this is one of the points that Smolin makes. String theorists are so jaded as to disregard the alternatives. String theorists would say "There are no alternatives" and Smolin would say "That's not the point", or "Read my papers on Loop Quantum Gravity" to which String Theorists would reply "We have and we're not impressed".

The whole debate goes in circles, it seems, with people like Peter Woit and Lee Smolin are content to write popular books and tour the world deriding string theory, as opposed to actually doing physics. (Peter Woit hasn't published a physics paper to my knowledge in several years.)

Anyway, hope this helps. bd

It is a shame that the US Govt decided to cancel the Superconducting SuperCollider in Texas back in 1990. I worked on the big detectors for a while and was disappointed when funding was cut off.
The energy levels there may have yielded experimental results which answer some of these questions about string theory.
[not sure, maybe CERN or FermiLab can match SSC outputs by now ?]

Then again, why is there such a need for immediate experimental confirmation ?
Human discovery of the natural world is not on a time schedule that I know of.
Maybe that is a good thing. We can learn more about other things while we are waiting.

bd,

I agree with you that a theory must be mathematically sound and consistent. But, if we think of physics as something which describes and explains nature, verification through experiment and observation is the only way we can accept a theory as "true". Theory may go the half the distance (or 99%), but we need nature to tell us this is so.

bsemak---

No arguments from this end. The problem is this---if the theory is very far ahead of the experiments, should we stop working on the theory? We have no new experimental results to explain, so in some sense you offer me two choices---leave physics or go work on experiments. The former is not an option, and the latter would probably lead to negative progress because of my clumsiness.

I am sure that once we have new stuff to work on (i.e. LHC data), we will spend many hours trying to explain that data with our theories. If it turns out string theory can't do it, then most people will leave and do something else. New theories will come and go, and physics will pick its way ahead as it always has.

I would also say that our intellect in this area has been developing faster than our technology to test it. But I agree that math is the universe's language.

Smolin has said that the reviewers who say that he thinks string theory has failed must not have read the book. If you go to his website you will find his reply to the reviewers that misquoted him.

I find he is very openminded, as all good scientists should be. He says string theory has some problems but not that it should be given up on.

I would give a link but I'm not yet allowed. Maybe I should post a bunch of meaningless post just to get to the required number.

FRODO LIVES!

Post the link with extra characters or spaces and it may get thru.

Well, the point that has been made on several physics blogs (like the one linked to above) is that there seems to be two Lee Smolins. One makes reasonable statements that no one can really disagree with, and one makes outrageous claims about string theory.

One of the central points of "The Trouble with Physics" is that independant thought is squelched in Academia. This is a problem across all Academia, and not just a problem with physics or science. But the title of the book is "The Trouble with Physics", not "The Trouble with Academia".

I just want to make sure that you don't get the wrong impression after reading this book.

This is a new book (which I have not yet bought)...

Smolin apparently thinks there could be 10 or 11 dimensions. He also thinks humans have reached the limits of our understanding and technology which is why it is difficult for us to pin down 'string theory'.

Any views?

What is Smolin Smokin?

Many people think there could be 11 dimensions TimeTraveler.

Why should we expect the universe to be 4 dimensional? There are no principles which predict 4 dimensions.

The single most exciting thing mentioned in the book, in my opinion, is Alain Connes approach to quantum gravity using deep ideas in noncommutative geometry (which I dont claim to understand at all).

"It could only be the invention of someone who does not just exploit mathematics but thinks strategically and creatively about the structure of mathematical knowledge and its future...One success of noncommutative geometry is that it leads directly to the standard model of particle physics. As Alain and his colleagues discovered, if you take Maxwell's theory of electromagnetism and write it on the simplest possible noncommutative geometry, out pops the Weinberg-Salam model unifying electromagnetism with the weak nuclear force."

It seems that it would be better if all physicists (this isn't to say Connes is a physicist; he's a mathematician) would take the time to understand the mathematics they use rather than simply exploit it, but perhaps working physicists dont have time to learn cutting edge physics AND math simultaneously...?

The single most exciting thing mentioned in the book, in my opinion, is Alain Connes approach to quantum gravity using deep ideas in noncommutative geometry (which I dont claim to understand at all).

Not everybody thinks that Connes work is so relevant. Check here:http://motls.blogspot.com/2006/10/alain-connes-et-al-predictions-for.html
The point that Lubos makes is that the types of correlations that Connes gets out of his noncommutative geometry depend on so many arbitrary parameters as to be pretty much worthless.

I should say, I do not know anything about Connes' work, and you should read everything and make up your own mind:)

It seems that it would be better if all physicists (this isn't to say Connes is a physicist; he's a mathematician) would take the time to understand the mathematics they use rather than simply exploit it, but perhaps working physicists dont have time to learn cutting edge physics AND math simultaneously...?

The two are generally the same---that is, the very cutting edge physicists today are really mathematicians. It's not that the math is not understood, it's that the math doesn't exist! Witten has said that string theory is about 10 years ahead of the math.

I think that people who are interested in this cutting edge research MAKE the time to know the math and the physics. Or invent the math, as the case may be.

Many people think there could be 11 dimensions TimeTraveler.

Why should we expect the universe to be 4 dimensional? There are no principles which predict 4 dimensions.


That's not what I'm arguing. I'm saying that dimensions depend on observers.

I'm saying observers exist in all dimensions and there is no limits. When our ability to observe increases, we can access new dimensions. Sorta like how everything came from the original quantum dimension, and now is 3d/4d, then we came up with quantum entanglement.

I think that we should wait and see where these discoveries lead, and where string theory leads before we claim these sorts of claims. I think it's too soon, and that his writing is speculation, and no better than any of our speculations on physics. One thing clear is that we don't know whats going on in the quantum.

Not everybody thinks that Connes work is so relevant. Check here:http://motls.blogspot.com/2006/10/alain-connes-et-al-predictions-for.html
The point that Lubos makes is that the types of correlations that Connes gets out of his noncommutative geometry depend on so many arbitrary parameters as to be pretty much worthless.

I should say, I do not know anything about Connes' work, and you should read everything and make up your own mind:)



The two are generally the same---that is, the very cutting edge physicists today are really mathematicians. It's not that the math is not understood, it's that the math doesn't exist! Witten has said that string theory is about 10 years ahead of the math.

I think that people who are interested in this cutting edge research MAKE the time to know the math and the physics. Or invent the math, as the case may be.


The only reason I support string theory is because string theory is the ONLY theory which can explain non-locality, and quantum entanglement. All the other theories are ridiculou, or can't make sense. Stuff like saying everything comes from nothing, that makes little ot no sense, but many people would rather believe that than believe string theory.

The only reason I support string theory is because string theory is the ONLY theory which can explain non-locality, and quantum entanglement.

Do you care to explain this?

Do you care to explain this?

The non-locality basically means, that at the quantum, everything is one thing, basically all atoms, all particles, all photons, are all connected in such a way that if you alter one you alter another, as if they are part of a larger whole or even as if they are the same atom, photon, or particle in two places at once.

If one thing can be in two places at once on the quantum level, what does this mean exactly? Only string theory has any explaination at all for what this might be. The math all works, the simulations all work, the theories are out there, and they will give you a paradigm shift if you pay close attention.

Some questions are just unanswerable without string theory.

If one thing can be in two places at once on the quantum level, what does this mean exactly? Only string theory has any explaination at all for what this might be. The math all works, the simulations all work, the theories are out there, and they will give you a paradigm shift if you pay close attention.

What is this explanation?