Science and Inquiry discussion

The group read selection for September 2012 is The Hidden Reality: Parallel Universes and the Deep Laws of the Cosmos by Brian Greene. You can use this thread to post questions, comments, or reviews, at any time.

Great. I'm going to read it! At the same time as the group. For once. I promise.

Oh, boo. I was actually happy when your PM said the Stephen Pinker book, because I've been waiting for an excuse to read the Pinker book..

The Pinker book is now, in August. So get cracking, girl!

I'm intending to join in on the Pinker book and this book, since I voted for both.

I'll move this up then! I've been wanting to read a physics book for some time now.

Ooh, Carlo and Traveller here. This is great!

Many thanks Aloha :)

Aloha wrote: "Ooh, Carlo and Traveller here. This is great!"

Oops, well, i've belonged to this group for ages and ages, but i've sadly not been very active on it. :p

Now that I've noticed you are here, Aloha, i'll have to start making time for it! Oh, and Carlo too, another friend of mine- and Jim!

Aloha wrote: "The Pinker book is now, in August. So get cracking, girl!"

Ack, i was going to say i thought it got in sometime... I'm going to start on it in a day or 2 as soon as RL allows, thanks for the reminder, Aloha!

Sure, Traveller. I hope you'll enjoy it.

I will join the group read in September for the hidden reality too.

This has been on my to read list since the day it came out. Now I have no excuse not to read it.

Cool...I'm on.

When do we meet for the discussion if there's one? Who's starting the google hangout?

Good idea, Yaser, but I don't think that many of our members subscribe to Google+ and since we're located all over the world, it might be hard to find a compatible time. I'm afraid we'll just have to settle for a discussion by post in this thread.

Does anyone have a sense of how much Brian Greene's books build upon each other?

I'm still working on The Elegant Universe: Superstrings, Hidden Dimensions, and the Quest for the Ultimate Theory, so, wondering if it is essential to have read both that and The Fabric of the Cosmos before diving into our September pick.

Lindsay, I think each of Brian Greene's books is pretty much "stand-alone". You don't need to have read any of his previous books to understand The Hidden Reality.

I haven't dropped by this group in ages (I've been caught up in novels - I know, lame) but I'm totally in for Hidden Reality! I've had it on my shelves giving me accusatory looks for like a year, since the wonderful Kirsten mailed it to me. I might be a week or so late, but I'll be here. Looking forward to it!

I have my copy. I wanted to start Greene with The Elegant Universe, but this will have to do. ;)

I liked Elegant Universe, Oscar. I've seen one or two metaphors reappear in Hidden Reality, but they do seem pretty different so far. I don't think you'd need Elegant Universe to understand Hidden Reality. Not that I understand either of them anyway, because when it comes to string theory here's how the explanation goes: Ten dimensions, Calabi-Yau, metaphors involving drinking straws, MATH. And the math part is so complicated that even the people doing the math don't really understand it, so we kinda have to take the whole thing on faith.

(Which is fine with me, because why would a bunch of scientists make up stuff about ten dimensions? Well, it would be a fairly funny joke.)

I'm about a third of the way in here. Anyone else?

I started it about a year ago, but got distracted with something else. I'm still back at How the Mind Works. Those neuroscientists just had to blow how I was going to review the darn book. Now, I don't know what to think of it. I'm taking a break with some fiction now.

i just finished the book and agree, alex.
much of this stuff must be taken on faith... you either buy in or not. it's complicated: as quantum mechanics is so counter intuitive it's not so easy to reject something simply because it doesn't make sense by standard human reference points. but, yeah, it's also fun to imagine a bunch of theoretical physicists yukking it up in a back room after playing a hell of a joke on the world! that said, even if most (if not all) of this stuff turns out to be untrue, it's still wildly fascinating to read/think about.

"Hey guys, if we make up the craziest story we can imagine - let's say, oh, the universe only makes sense if there are ten dimensions and then throw in something about black holes and then whenever anyone asks us how we came up with that, just start drawing complicated-looking math stuff on white boards until they get bored and go away - you think they'll just take our word for it?"
"No harm in trying!"

The world's scientists have pretty much just been playing video games for the last twenty years.

LOL! I've read so much of this stuff, they've become mundane.

Well, I would like to think that in at least one of those dimensions, I've gone mad with power! >:)

Lindsay, Hidden Reality references his previous books loosely. I read it without having read Greene's other books, and I had no problem with it.

I read this book a few months ago, and while it was interesting, Greene doesn't go that much into actual evidence for the existence of other universes. Most of it must be taken on faith and he goes into how this or that type of multiverse would work and how it's possible with our current understanding, but not into the evidence that would indicate that alternate universe are there. It's a lot of interesting speculation, but at the same time felt a little hollow to me.

Agreed to a point, Sheldon: Greene doesn't go into actual evidence, but then, a) there sortof isn't any and b) what little there is is, again, so much math that we can all forget about it.

So...I'm about 2/3 now. Do y'all think there's a point to reading this? String theory is so in-progress, and it's so impossible to update the layman on why we're where we're at with these crazy-sounding theories....why bother?

I think it's worth reading because...it makes fun dinner party conversation, and that's a pretty good reason. I may not get anything beyond, y'know, I guess the universes are like Swiss cheese? But like The Elegant Universe, it gives me enough to contribute to the occasional interesting conversation: physics comes up sometimes, and you'll have as much knowledge as anyone else at the table. If nothing else, it's funny because it's basically the conversation you had the first time you got stoned, plus MATH.

I think cognition makes better dinner conversation because you can point out to the person the quirks that we human beings have, maybe even do some mental tricks on them.

I'm only a little way in but finding it way more accessible than I expected. On the matter of evidence, so far at least it's not as if he's claiming there is evidence - he's pretty up front about both the lack of direct evidence and the difficulty (impossibility) of obtaining any. For me, it's added to the significance of the various experiements going on at the LHC in that success will add weight to the idea of string theory. It's added insight to my understanding of the scientific method too, which is cool.

I was about halfway through the book about a year and a half ago, when I got distracted with another book read. If I recall, the language was in a chatty tone for the general public interested in the topic.

I was watching a PBS series with Brian Greene based on his Elegant Universe book and, lol, he seems normal and down to earth, which surprised me because I thought all physicists were supposed to be weird. *puts down his Richard Feynman book*

;)

Oscar, everybody's weird, I've discovered. Some hide it better than others until you get to know them.

Not me, I am the definition of normal.

Until you get to know me. >:)

Lol!

No, but you get my point, no? Guys like Feynman and say Newton were really eccentric and they've helped create that stereotype that to be a genius one has to be crazy and see the world unlike the common person.

Hell, there's a similar stereotype with writers of literature that the crazier the more talented.

It really is a stereotype, and from the looks of it Greene might have his idiosyncrasies, but nothing tells me he's as eccentric as Feynman, but I might be wrong. ;)

Aloha wrote: "Oscar, everybody's weird, I've discovered. Some hide it better than others until you get to know them."

Wise words.

And yeah, I figure what makes Greene so successful is his normalness.

And good point Jenny: I agree that he's good at making sure we understand which parts we have some evidence for and which we don't, which is important to me.

I've read a couple of Hawking books too (The Grand Design and A Briefer History of Time) and I think Greene does a way better job of explaining tough concepts.

I'll have to pick up the book again. I think I reached a saturation point with speculative physics concepts.

I finished The Hidden Reality and felt a sense of relief and some discombobulation, glad to hear others were somewhat at sea in the arguments. After a career in another field, I am attempting to go back to my first academic love and update my knowledge. This book brought a flood of ideas, vocabulary, procedures, and grist for my mind -- in that it was wonderful. What helped me most was watching the author on U-Tube and reading information about him on line. I think an earlier book might be helpful as well.

Am just a couple of chapters in. I was hungry for an all encomassing theory and not a smorgasbord. When I took a qunatum physics course in college, the Many Worlds Theory was acknowledged to be mathematically plausible even then, but I could personally reject it on aestheic grounds as too absurd to be true. But Ockham's Razor doesn't work that way. Simpler doesn't have to be non-absurd. And somewhere I ran into current theorists making an Ockham's Razor argument for parallel universes based on attempts to integrate of string theory and gravitational theory. So I will be looking for some meat in this book.

If the theory wins out, it will be very upsetting to me and will likely have a big impact on the trajectory of art and literature. So far science fiction just uses the idea as an excuse to play with alternate histories. A recent read of Stepehnson's Anathem struck me as an important book for making the theory come alive, especially from the perspective of epistemology.

A bit of a personal reaction on finishing the book.

Greene makes it clear how the Everett Many-World's interpretation is simpler and more elegant than the Copenhagen interpretation that the probability wave for a particle mysteriously collapses when it is detected or interacted with. He explains very well how the latter effectively throws out Schroedinger’s equations out whenever a “measurement” is made and restricts their applicability only to very small objects. Despite Occam’s Razor favoring Everett’s hypothesis, the interpretation of possible alternative states as each being somehow each equally “real” has always been too absurd to be true to me. Thus, it’s a relief to me that there is still scientific, not just emotional, resistance to Everett/DeWitt's theory, particularly in its undermining of the meaning of probability. If the probability wave for an electron being at one location is ten times higher for one site over another, how is that reflected in the evolution into it being located at each location in separate realities? Greene notes: “I don't expect theoretical or experimental consensus to come in my lifetime concerning which version of reality-a single universe, a multiverse, something else entirely—quantum mechanics embodies.”

The other theories are fascinating and do not call for my alternative choices to have an existence in parallel universes. It was great to get a perspective on the excitement and challenges with string theory and its promise for helping unify the gravitational force with the other forces already in the fold of quantum field theory. The discovery that our universe is undergoing an acceleration in its expansion, and the need for some kind of anti-gravity force (“dark energy”) was a shock to me, so the recent successes of the theory of empty space having an “inflaton” field was satisfying to read about. Greene’s coverage of recent work on the meaning of entropy and information in physical systems was also a pleasure for me.

More details on my reactions are in the review: Hidden Reality review

I finished this over the weekend; totally dug it. Greene's a good pop science writer.

Met a buddy's new girlfriend on Saturday night; she's a mathematician, so just for the heck of it I said, "So, do you think we're all in a simulation?" And her eyes lit up (seriously, they actually lit up) and we geeked out about that possibility for the next half hour, while my buddy and my girlfriend periodically said things like "Hey, are you guys just about done geeking out over your weird nerd stuff?" "Er...no, sorry." So this book has already totally come in handy!

That simulation theory brings you to some very weird places, doesn't it? For example: if I believe it, then I sortof also believe in God: if we're living in a simulation, then someone set that simulation up, and has the power to change it, to rewrite the rules, even to elevate me into that person's own reality. For most intents and purposes, that person is God. Weird thought for a lifelong atheist.

Finished two days ago, and I've been avoiding this thread until I finished.

I guess I like that there's a book that basically acts as a survey of 'here are the various multiverses that anybody has envisioned.'

Where do you go from there, though? Most of the ones he discussed are not mutually exclusive. You could have infinite space, each piece of which, bounded by time/light horizons, is unavailable to other pieces, and each piece of which is in one of a finite number of quantum states, and you could have bubble universes popping up, and you could have simulated universes.

I had a problem with his arguments that our universe holding values for constants in places we expect is evidence that we're a typical, or at least not extremely atypical, universe, therefore it bolsters the case for a multiverse. You can't make tests on one piece of data. Statistics doesn't allow it, even for a 'kind of' hunch. It just doesn't. You can't look at one flipped coin that's already been flipped and use it to guide hypotheses about how coin flips turn out.

Other than that, I have no idea how any of this would ever be tested.

I'll say this: the "hologram worlds model" really intrigues me. Math for a ten-dimensional world, and a two dimensional surface, working out the same is astonishing. As much as I understand it, anyway.

My favorite thing in the book was really off his main thrust anyway - had little (if anything) to do with multiverses. I feel like I kind of intuitively get quantum physics a little bit! Probabilities are a great model for beings like us who could never gather nearly enough information. But if 'particles' really are tiny, tiny jingling strings (that with a lot of energy can get pretty long), maybe it is all deterministic; it's just thinking of things as particles that makes its position seem random. Am I way off base with that?

I guess that's my final feeling about the book - The Elegant Universe and Fabric of the Cosmos really expanded my understanding of physics beyond the Newtonian stuff I was taught in high school. This one left me feeling not much more informed.

Alex wrote: That simulation theory brings you to some very weird places, doesn't it? For example: if I believe it, then I sortof also believe in God: if we're living in a simulation, then someone set that simulation up, and has the power to change it, to rewrite the rules, even to elevate me into that person's own reality. For most intents and purposes, that person is God.

Right, but I don't buy into self-aware simulations. Things could be a Matrix-style universe, in my mind, where there is an entity that's plugged into the simulation, but the simulation parts themselves having self-awareness? I have no confidence computers will ever become self-aware.

Agreed, bup. The whole thing rests on the idea that we can develop AI, and I'm not convinced of that. The idea that at a certain level of complexity computers just sortof automatically develop intelligence...well, I'll be very happy to believe it when I see it, because that sounds neat.

Also agreed that it didn't teach me anything terribly important, but it's very fun stuff to know about anyway.

bup wrote: "...I had a problem with his arguments that our universe holding values for constants in places we expect is evidence that we're a typical, or at least not extremely atypical, universe, therefore it bolsters the case for a multiverse...."
I had trouble understanding the "anthropic" perspecitve from Wheeler. I feel he wasn't committed to the power of the argument for positive support but a sort of check for negative evidence. I.e. if your multiverse theory predicts constants which makes our accesible universe atypcial, it would undermine the multiverse theory.

Obviously Greene felt compelled to cover all the multiverse theories, but only one felt closer to the core of physics, the Inflationary Multiverse. Only with the weirdness of infinity do you get stuck in this and other various multiverse models postulating that somewhere out there an exact duplicate of our world must exist. Having another universe out there is not any harder to accommodate for me than an undetected galaxy. But I hate giving up the uniqueness of our world and one's individual experiences.

So did either of you feel relieved to have an out over Everett's Many Worlds Theory having problems that undercut its power to claim Occam's Razor points? Of course, in rejecting that theory, one still wants resolution of the weaknesses of Bohr's interpretation about instantaneous collapse of the probability wave and all the mysteries spawned about the role of the observer in effectively grounding reality (and, as in the Einstein quote, "does a mouse glancing sideways" for an electron's position count?).

I agree that the Simulated Universe doesn't resonate with me. The likelihood of a robot becoming conscious and self-aware like us doesn't sing for me. After reading the Pinker book last month, I was refeshed with his admission of bafflement over the sentience component of consiousness. I think that the mind-brain-wet computer analogy is missing how much the brain is connected to the body. That virtually every single cell in most tissues of the body are connected to the brain I feel is important for a sense of self. That emotions are essential for the meanings that imbue thought and that feelings are intimately aligned with bodily sensation and expression makes a big barrier for AI in my view. Still Matrix worlds and programmers as gods are fun conceptions.

My understanding about string loops do not change the Uncertainty Principle. The business about Planck distances as the level where quantum jitters dominate probably corresponds to the size ballpark of string loops.

Not having read Greene's other books, the excitement over the Hawking's documenting how blach holes don't violate the 2nd Law of Thermodynamics was new and pleasurable to me. The Hologram Universe to me was a highlight of the book, along with glints of understanding about Shannon's theory relating information to entropy and the conception of reality as an "information processor". Maybe problem of the shape of those hidden dimensions in string theory can be made to disappear with the discovery of a dictionary of equivalency to a 4 dimensional perspective. Not sure why string theory requires so many dimensions. If they can get mileage out of the variation involving membranes, maybe they can invent a version with only a couple of extra dimensions (lot of ignorance here for me).

Michael wrote: "So did either of you feel relieved to have an out over Everett's Many Worlds Theory having problems that undercut its power to claim Occam's Razor points?..."

I want to answer you, but I'm having trouble understanding the question. Is this the part where he used a model of Manhattan, and a point with a 50% probability of being at Strawberry Fields, and a 50% probability of being at Grant's Tomb?

That didn't make sense to me. Saying "having universes branch at this point to accommodate both outcomes would explain the uncertainty" didn't make me feel like it explained the uncertainty, and it came out of nowhere. "A is a way of thinking about B, therefore maybe A exists" is how I read it, and I wasn't impressed.

bup wrote: "Saying "having universes branch at this point to accommodate both outcomes would explain the uncertainty" didn't make me feel like it explained the uncertainty, and it came out of nowhere. ..."

"There is no denying quantum theory sounds a lot like snake oil." The Everett-deWitt theory is trading one snake oil for another, one that is elegant but absurd in its interpretation for one that is ugly but more psychologically acceptable.

A probabilty wave with two spikes suggests an electron could be in one of two places. "Everything we know attests that one device and one measurement will yield one reading; one reading and one mind will yield one mental impression." The solution that makes all possible outcomes be realized gets rid of the collapse of the probability wave and the presumption that measurement involves large objects not subject to the field theory. But in the process it undermines the meaning of probability: "How can we speak of some outcomes as being likely and others being unlikely when all take place?" For example, if probability wave spike for the electron being at Strawberry Fields was twice as high as for Grant's Tomb, the projected evolution of the wave by the Many-World's Hypothesis into two separate realities does not take into account the different initial relative probabilities. The reality for the Strawberry Fields detection isn't somehow twice as real as the proposed parallel reality with the electron in Grant's Tomb reality.

Greene says that "Should future research show the the equations of quantum mechanics, however reliable they've been so far, require small modifications to match more refined data, this type of multiverse could be ruled out. A modification of quantum theory that compromises the property of linearity would do just that." I hope so. The tiny, tiny amount of energy tied up with each unit of empty space was not very plausible either, yet it nicely complies with the dark energy required to account for the accelerating expansion of the universe.

I've got a question - a general question about string theory.

Greene says that one hypothesis for gravity's weakness is that it's a string that it manifests itself in the 'other' dimensions - the 8 dimensions besides the 3 we can observe.

But...isn't gravity directly proportional to mass? Those 'gravity strings' - aren't they part of particles with mass? Is a 'particle' in the classic sense - are they collections of strings? Do they get a prescribed number of gravity strings, proportional to the number of Higgs-Bosons in the proton/neutron/electron/etc?

I think particle is not a collection string but a string vibrate in a pattern.Different pattern made up different particle,like a electron will have a specific type of pattern that the string vibrate in,if you change the pattern you will get a different sub-atomic particle.
I might be wrong or misunderstand your question but I'm just trying to help
Thank you

Ok, I hate to put a wet blanket on exuberance for science, but I have to comment. Brian Greene, while being an entertaining writer that I have learned from, is a lackey of the STRING THEORY gestapo. String theorists have used the vast majority of funding for theoretical string theory for over 30 years, with NO RESULTS, or even testable theories. I recommend Lee Smolin's 'The Trouble with Physics' if you'd like to understand why physics has been at a standstill for decades.

I agree, Robbover, that The Trouble with Physics: The Rise of String Theory, the Fall of a Science and What Comes Next is an excellent book. I would second your recommendation.

Oh,So I guess I should atop reading "Hidden Reality" and get on with that book