Tuesday, November 17, 2009

Thoughts and Experiments

Thought BubbleThe other day I got in an argument over what constitutes a "scientific question," after I invoked thought experiments in an attempt to illuminate some features of a model. Is a question that cannot be tested even in principle a scientific question? And thus, if it isn't, should scientists think about it at all?

Forced to take a point of view, I want to offer the possibly only intelligent words the former German chancellor Helmut Kohl ever uttered "Entscheidend ist, was hinten rauskommt." - "What matters is what comes out in the end."

I don't care very much about somebody's personal philosophy or what -ism they classify themselves under, I care whether it's an approach promising to lead to progress. Discarding a question as unscientific when it concerns extreme, and potentially untestable, limits extends the requirement on a theory to be scientific to the method how to get to a good theory. And with that cuts off frequently used methods, not only thought experiments, but also demanding mathematical consistency in regimes we have not tested. I simply think limiting allowable questions to those practically testable constrains our imagination and thus our opportunity to find answers.

One can certainly take such though experiments and the questions they raise for more important than they are. Steve Giddings for example claims that our failure to solve the black hole information loss paradox is akin to the failure of classical electrodynamics to explain the stability of atoms (see this talk or this paper). Well, the only difference is that Bohr's very existence was evidence for the stability of atoms, whereas we have yet to see a single black hole evaporate. Nevertheless, the information loss problem indicates clearly a lack in our understanding of Nature, and, wanting to understand, physicists have turned it inside-out and upside-down for decades. However, whether that eventually leads to something besides loads of papers yet has to be decided.

A more fruitful though experiment was of course Einstein's chase after a photon. And then one should not neglect that thought experiments are not only inexpensive but also fun.
Brain Stretching

130 comments:

Christine said...

I simply think limiting allowable questions to those practically testable constrains our imagination and thus our opportunity to find answers.

*Questions* can be "whatever", unconstrained.

But when one gets to the point of having something formulated as a "theory", it must be (in principle) testable. Otherwise one should rename it to something else.

Andrew Thomas said...

I think Einstein made most of his significant progress through thought experiments. He seemed to stagnate in his later years when he became engrossed in the mathematics.

Christine said...

Thought experiments are a great tool. BTW, who "invented" them? I can only think of Einstein as using them first...

Plato said...

Bee:I don't care very much about somebody's personal philosophy or what -ism they classify themselves under, I care whether it's an approach promising to lead to progress.

For example: Solvay was an intellectual breeding ground, "for or against a particular idea," or, the transformation to non-euclidean geometry historically.

I believe by doing this you know the limits science has been taken too, and all those that engage know this as well. So, this provides a creative thinking board(white board/blackboard) about what becomes possible when you gather together.

Ummm....you present your papers?

Science Fiction, can become an interesting play here on the limits of where science has been taken. Why scientists are sometimes consulted as to how far the story had been taken and if it follows the tenets to a point of demarcation

Gedanken Experiments Involving Black Holes

Best,

Phil Warnell said...

Hi Bee,

”I simply think limiting allowable questions to those practically testable constrains our imagination and thus our opportunity to find answers.”

I certainly agree as for instance the whole concept of atoms has been with us since before the 6th century BC, with the ability of confirming their actual existence only coming in the last century. None the less by science taking their existence seriously beginning in the early nineteen hundreds there evolved a theory of matter and energy that continues to serve and confirmed as being a good explanation of nature and its process.

Best,

Phil

Phil Warnell said...

Hi Christine,

“Thought experiments are a great tool. BTW, who "invented" them? I can only think of Einstein as using them first...|


“Salviati. If then we take two bodies whose natural speeds are different, it is clear that on uniting the two, the more rapid one will be partly retarded by the slower, and the slower will be somewhat hastened by the swifter. Do you not agree with me in this opinion?

Simplicio. You are unquestionably right.

Salviati. But if this is true, and if a large stone moves with a speed of, say, eight while a smaller moves with a speed of four, then when they are united, the system will move with a speed less than eight; but the two stones when tied together make a stone larger than that which before moved with a speed of eight. Hence the heavier body moves with less speed than the lighter; an effect which is contrary to your supposition. Thus you see how, from your assumption that the heavier body moves more rapidly than ' the lighter one, I infer that the heavier body moves more slowly. "


- Galileo - Discorsi e dimostrazioni matematiche (1628)

This may not be the first thought experiment and yet it demonstrates how they served to be useful long before Einstein.

Best,

Phil

Bee said...

What if I took a boulder, rolled it over the edge of the cliff, and let it fall on the head of the mammoth?

Thought experiments are as old as mankind. Their documentation however isn't.

Phil Warnell said...

Hi Bee,

”What if I took a boulder, rolled it over the edge of the cliff, and let it fall on the head of the mammoth?”

Sounds like the kind of thinking required to eventually be able to create an LHC, that being a Large Hunger Collider :-)

Best,

Phil

Christine said...

Hi Bee and Phil,

Sure, but I was thinking on using it systematically, in modern science, so I guess Phil is right -- Galileo was not only the "father of modern science" but also the father of "thought experiments" in that sense.

Christine
PS- On a "general" sense, I think that even my own dog makes thought experiments sometimes. :) So its just a part of making some mental projection with conclusions on possible outcomes.

Christine said...

Wikipedia has an article on thought experiments with interesting facts.

Arun said...

I thought Archimede's Eureka moment was the result of a thought experiment. Maybe I'm wrong.

However, whether that eventually leads to something besides loads of papers yet has to be decided.

Sufficient papers will collapse into a black hole and then the evaporation of such can be observed. This black hole would not exist without sufficient theoretical speculation and publication :) Kind of an anthropic effect.

Bee said...

Not dense enough... ;-)

Uncle Al said...

Einstein's elevator Gedankenexperiment transformed SR into GR, Jahrbuch der Radioaktivität u. Electronik 4 411 (1907). It was undoable in 1907, trajectory and vacuum both.

The ZARM Bremen drop tower offers (with catapult) 9.3 sec of vacuum (75 millitorr) free fall. Reasenberg's SR-POEM promises 1000 seconds in hard vacuum... and there we are.

Bee said...

Yes, but it was doable in practice.

Kay zum Felde said...

Hi Bee,

I would like to talk about the Paper and talk you mentioned. Lee Smolin http://arxiv.org/abs/hep-th/0507235, f.e. believes, that quantum gravity needs to be background independent. Gibbings talks a lot about a background dependent theory, e.g. String theory. Shouldn't it be be possible to find a background independent theory for this case. I didn't get his point why not ?

Best Kay

Bee said...

Giddings, not Gibbings. Sorry, I didn't understand the question which "case" are you talking about?

Christine said...

I thought Archimede's Eureka moment was the result of a thought experiment.

Maybe. But he *had* observed the change in water level in his bath, and *then* realized the relation of that change with the immersed volume. That was an *insight*, I guess.

I mean, I suppose there is a difference between an insight and a thought experiment, but I'm not sure.

One can get an insight from a thought experiment, and one can elaborate a thought experiment from an insight, so...

It is interesting that Mach used the term in a more strict sense, namely, "to exclusively denote the imaginary conduct of a real experiment that would be subsequently performed as a real physical experiment by his students" (c.f. Wikipedia). Einstein considered instead a physical experiment that could be conducted "in principle".

Kay zum Felde said...

Hi Bee,

sorry for my misleading question and the misspelling. I am talking about Giddings, where he claims that states, which are not Planckian, but higher concerning energy, could be described by String theory, which is surely an option. Shouldn't it be possible to find a background independent theory ?

Best Kay

Bee said...

Hi Kay,

Sorry for being dumb, but I still don't get it. Yes, it should be possible to find a background independent theory, but I what is the connection of that question to the first part of your comment, about Giddings and the transplanckian modes? Is the question whether a background independent theory could provide a solution to the bh information loss problem? Well, sure, I don't see why not. Does a solution to the bh information loss problem necessarily have to be background independent? I doubt so because the black hole is a background itself. Best,

B.

Bee said...

Hi Christine,

I was especially referring to thought experiments that are not doable. Archimedes was imagining an experiment that was doable and was done. Chasing a photon is a more elusive goal. The question was whether investigating thought experiments that are not doable is fruitful or not?

Btw, I agree of course with what you said in your first comment. But here the requirement has been extended from the theory to the process of obtaining a theory, and there I think it is too strict a notion. Best,

B.

Jean-Paul Billon said...

Hi Bee,

It's right there that being a mathematician is more comfortable than being a physician. Mathematics has been based on thought experiments that were not testable in practice. Think of the notion of limit of a continuous function that has been the main subject of thought experiments from Archimedes, Zeno, etc, for thousands of years before being made into a proper axiomatization, the notion of infinitesimal quantities that leads to calculus, etc, etc, The calculus of PI..., etc,...

Kay zum Felde said...

Hi Bee,

thanks for the info. That's what I wanted to hear.

Best Kay

Low Math, Meekly Interacting said...

Whatever heuristics or other helpful tools one wishes to employ to arrive at a fruitful idea are totall fine, I think, so long as one has a sense of where brainstorming ends and the scientific enterprise begins. For instance, it might be helpful for people to toy with the idea of so-called "einselections of the Hilbert space" being "real". If it makes them feel all better inside about the problem of wavefunction collapse, gives them a refined intuitive sense of the maths or whatever, well, why not.

But when people start to take absolutely unobservable "branches of the wavefunction" or the like too seriously from an ontological perspective, it seems to me they inevitably run off the rails. Eventually, IMO, for something to be scientifically useful, it has to lead to observable consequences. If it cannot ever do so, even in principle, then at a certain point, that line of thinking must be abandoned. So, to use the sundry interpretations of QM as an example, the situation does appear to be quite hopeless if one takes the matter beyond aesthetics. Maybe the future will prove me wrong, but the track record, so far as I am aware, looks not at all promising. QM simply passes every test we can throw at it, stretching our observational and experimental technology to the absolute limit with absolutely zero indication that Nature will deviate in any way from it that is within our conceivable grasp.

I am not oblivious to the irony of a man of my intellect challenging the likes of Nobel Laureates on this, but here I let hubris get the better of me: QM works too well, and it's smarter than we are. Is it not our human sensibilities that may be too limited, then? And have we taken the first-principles approach of the likes of Einstein and Dirac a bit too much to heart at times? Is it really a good idea to be altogether unconcerned about experiments? Are beautiful thoughts always right? I have no faith in that notion, or in much of anything, for that matter. I have great confidence in precision and reproducibility. Divorced from that, science loses its meaning, in my mind.

Arun said...

Christine, you are right!

Bee, are there any good thought experiments in quantum gravity?

Tie O'Twerp said...

Susskind famously said that when everyone accuses you of doing things that are unverifiable, you can be pretty sure that you are on the right track. Funny and true.

One thing's for sure: all of the observational evidence shows that people who incessantly whine about unverifiability never do anything worthwhile themselves.

Gordon said...

Arun: Yes, they are called collectively-- String Theory.

Bee said...

Tie O'Twerp: One could say that people who constantly whine never get anything worthwhile done period, but you don't find many of them in research anyway. Best,

B.

Bee said...

Dear Arun,

Well, the black hole evaporation is a thought experiment in quantum gravity, which is why I've mentioned it. This then brings up the question whether we should be concerned about the information loss to begin with.

Another thought experiment in qg is Eppley and Hannah's experiment. Best,

B.

Phil Warnell said...

Hi Bee,

If we conceive of a being whose faculties are so sharpened that he can follow every molecule in its course, such a being, whose attributes are as essentially finite as our own, would be able to do what is impossible to us. For we have seen that molecules in a vessel full of air at uniform temperature are moving with velocities by no means uniform, though the mean velocity of any great number of them, arbitrarily selected, is almost exactly uniform. Now let us suppose that such a vessel is divided into two portions, A and B, by a division in which there is a small hole, and that a being, who can see the individual molecules, opens and closes this hole, so as to allow only the swifter molecules to pass from A to B, and only the slower molecules to pass from B to A. He will thus, without expenditure of work, raise the temperature of B and lower that of A, in contradiction to the second law of thermodynamics.

-James Clerk Maxwell (1867)
-
The quintessential pre-Einsteinian thought experiment is one that was proposed by James Clerk Maxwell known as Maxwell’s Demon, which exposed the statistical nature of the 2nd law of thermodynamics as to have us consider if it could ever be defeated. The interesting thing being is although it appears this law can never be defeated a limited version of Maxwell’s demon has been practically developed which can help to keep our houses and buildings warm known as Low E glass (with the E representing emissivity¬), more properly called spectrally specific glazings.

These have a (microscopic non visible) metallic coating(s) applied whose grid spacing is tuned to reflect EM of the infrared wave length, while permitting shorter wave lengths including the near infrared, visible and ultraviolet to pass through. This in combination with summer shade controlling overhangs on the south side of buildings can be used to save energy by maximizing the advantage of passive solar heating. So because of Maxwell first conceiving his demon has lead use to understand that although we can’t ultimately defeat the 2nd law, we can however by being able to incorporate his idea better use the natural energy sources we have more efficiently.

So Bee even though when first concieved thought experiments may not present as having any real world uliily often they do in time become of practical consequences, such as my above noted example . Therefore who can say that these current thought experiments involving black holes and quantum gravity will never serve to have us understand things better as to have them also be utilized one day beyond just the theoretical.

Best,

Phil

Steven Colyer said...

Getting back to your original questions:

"Is a question that cannot be tested even in principle a scientific question?" ... Bee

I'm haunted by what specific topic you and the other were discussing that this general question arose in the first place. We all have our prejudices, alas, and mine are if the specific question was for example Many-Worlds or the Anthropic Landscape, then the answer is no.

"Is there a God?" can if fact be tested, and everyone tests it upon death. But is it Scientific? I would say no, because again with personal prejudice, I believe true Science to be agnostic.

Then again, what is "Science?" I would answer to that more fundamental question that's it's a system of discovery that grew out of Philosophy, and its cornerstones are Observe, Hypothesize, Test, Conclude.

"...And thus, if it isn't, should scientists think about it at all?" ... Bee

Yes, because we'll know more tomorrow to quote Smolin. We may not have the answers in our lifetime because we haven't the technology in our lifetime, but even worse we probably don't even have the right questions. So if asking wrong questions today leads future researchers to reject dead ends in their time, we've helped them.

"What matters is what comes out in the end." ... H. Kohl

Niccolo Machiavelli, whose patron was the Medici family, wrote a novel called "The Prince." I'd venture Kohl read that.

Bee said...

Hi Steve,

The offensive question made use of a reference system at boost much higher than we can plausibly ever expect to reach (not so different to Einstein's photon-chasing now that I think about it.) In contrast to many worlds etc, I was referring to an experiment impossible in practice as opposed to impossible even in theory (see my FQXi essay for details). Best,

B.

Bee said...

Btw, the question whether there is a God is not the same question as whether there is "life after death" (in the colloquial meaning, since arguably death is the end of life, thus strictly speaking it's an oxymoron).

Christine said...

Hi Bee,

I was especially referring to thought experiments that are not doable.

Thanks for clarifying.

Concerning Archimede, I agree with you, as my response to Arun on this matter indicates.

the question whether there is a God is not the same question as whether there is "life after death"

Yes.

One may, however, raise the issue on "what has a physical existence" and "what does not" (although it arguable whether this makes any sense to begin with).

So one would argue that death may only mean the end of life (as the physical body) but not all the essence that makes an individual. This essence is that which some state as "life" (after death), ie., some essence that remains regardless of the end of the physical body.

Here comes a connection with God, as "something" not necessarily "phyisical", so there is a similarity between the two as relating to some transcendental realm.

All that I wrote above does not mean that I believe in that, but how many religious people seem to.

Georg said...

Niccolo Machiavelli, whose patron was the Medici family, wrote a novel called "The Prince." I'd venture Kohl read that.

Of course he did in some way.
First, Machiavellis theses belong
to the basics to learn in german grammar schools.
Second, Kohl studied history after
grammar, "because this was the
art where one could get a Dr. degree within the shortest time".
Aha!
Third, like Bee still does, his
intelligence was often underestimated,
especially by "friends" in his own party. Their political "tombstones" tell that Kohl
either had read "Il Principe" or
he did not need to read it :=)
Georg

Phil Warnell said...

Hi Bee, Steven & Christine,

In as us all having to admit as not having complete knowledge of nature, then what could be definitely considered as a question not even testable in principle? There are some that would say the limit of what‘s possible rests with potential and so I find the better question is to ask, can human imagination exceed its or by extension natures potential? As silly as it may sound I for one don’t believe it can, as we are a product of nature. Some might consider this as strictly belief, yet I would contend it has time and time again demonstrated as being self evident. This being also the extent to which you could call me a spiritual or religious person.

Best,

Phil

Arun said...

Thanks, Bee!

-----

"God is as real as a QM wave function". :)

Arun said...

Gordon,

I wouldn't classify string theory as any kind of thought experiment. It is a pursuit of physically-motivated mathematical formalism.

-Arun

Plato said...

Christine: I thought Archimede's Eureka moment was the result of a thought experiment.

Stefan writes:To measure means to count. We measure a length by counting marks on a ruler, and a time span by counting ticks of clock. We compare the quantity we want to measure to multiples of a standardized quantity, the unit of measurement, such as the metre, the inch, or the second......Counting Atoms in a Sphere

It was problematic that a solution be found and that a solution is necessary. The whole subject itself "is" indeed a thought bubble and what could come out of the pursuit.

* I have found it! or I have got it!
* What he exclaimed as he ran naked from his bath, realizing that by measuring the displacement of water an object produced, compared to its weight, he could measure its density (and thus determine the proportion of gold that was used in making a king's crown); as quoted by Vitruvius Pollio in De Architectura, ix.215;



So then, it's application. "The King's Crown."

So a new a way, to approach a problem, and today "spectrum analysis" has us identifying elements cosmologically, as well as, and according too, the table of elements.

Turning now to Archimedes’ reckoning, he proceeds to fill up the (then) known universe with sand by considering a succession of spheres, each 100 times the diameter of its predecessor in the succession. He uses a fact well known to Greek geometers: the ratio of the volumes of two spheres is the third power of the ratio of their diameters. The Sand Reckoner

Running a mining company on the moon you need the data in order to start the colonization and transformation for producing infrastructure.?:)So we collide rocket on the moon.

Lets say you want to change the economic infrastructure of society(oil and gas) currently so you might want to create a "sustainable charging system" for the automobile?

Thought bubble?:)

Best,

Christine said...

Plato wrote:

Christine: I thought Archimede's Eureka moment was the result of a thought experiment.

Jesus Christ, I never said that! It was someone else, to whom I responded. Please read carefully!

Christine said...

This is what I wrote concerning Archimedes:

But he *had* observed the change in water level in his bath, and *then* realized the relation of that change with the immersed volume. That was an *insight*, I guess.

[not a thought experiment].

joel rice said...

Einstein speculated that matter might appear as singularities. Might there be a thought experiment to explore that - or is it considered a hopeless approach ?

Plato said...

I mean, I suppose there is a difference between an insight and a thought experiment, but I'm not sure.

Calm yourself. Yes, I read that post. I am responding to that.

Best,

Plato said...

Joel:Einstein speculated that matter might appear as singularities. Might there be a thought experiment to explore that - or is it considered a hopeless approach ?

If in analogy one were to point out a phenomenological relation(let's say structured geometrically in sonoluminescence) to the "intensity of thought" on a particular subject, many minds, what is the intensity of this measure to say, that something will emerge as a thought bubble( energy release) in the quantum gravity search?

Best,

Plato said...

So people understand I know the history of sonoluminescence very well already, so one does not have to remind me of it's failure, but on this point, I like to focus your mind to the geometrodynamics of how collapse is initiated. The surface of the bubble.:)

Low Math, Meekly Interacting said...

It's not at all clear to me how calling people whiners specifically addresses their objections to elevating unobservables to the same ontological status as observables, and then carrying that misrepresentation further by stating that, say, mathematical results and experimental results should be seen as equivalent.

Bee said...

Hi Joel,

I think more generally Einstein had the very appealing idea that matter would fundamentally be described by space-time itself. I can't really recall the details but I think he liked Kaluza-Klein theory because it gave a taste of exactly that by help of extra dimensions. Just add a 5th dimension, give it a U(1) symmetry and get photons for free. And in addition, it gives you a quantization of charge if you chose the radius correctly. We know today that this approach, enchanting as it is, has severe problems when it comes to the description of chiral fermions in particular. On the other hand, all these thoughts were precursors of theories we have today. So I wouldn't call it a hopeless approach, but a very immature one. Another taste of the same thought has survived in the idea that black holes might leave behind stable "remnants." Best,

B.

Bee said...

Maybe Dawkins will finally collapse God?

Gordon said...

Arun: "Physically motivated mathematical formalism"---isn't that what special and general relativity are? And aren't strings themselves a thought experiment?

Giotis said...

The notion of God has been embedded in human nature and psychology through the historical evolution. You may believe or not to God but God is in you and flows through you. The attempts of certain individuals to extract the divine from our collective subconscious are ridiculous and hopeless. It's like trying to separate the water from the river. The fate of humans has been sealed in that respect. Rather we like it or not we are blessed or doomed to walk our path along with God.

Arrow said...

I have some problems with the whole idea that information is a fundamental or even particularly useful quantity in physics and especially with the idea of conservation of information.

Take radioactive decay for example - a nuclei decays and part's fly in two directions, if decay is indeed random and has no cause as QM claims information is certainly not conserved - it is being created out of nothing the moment the decay occurs, the fact that it happened, the energy of products, their directions all that is information, one can easily hook up a detector and act on it if needed.

Plato said...

Giotis:The attempts of certain individuals to extract the divine from our collective subconscious are ridiculous and hopeless

Where is the subconscious?

If we are all matter defined, then there cannot ever be any finer description of what God can be and yet, you say it flows through you?? From where, to where? :)


Low Math, Meekly,

....your points are well taken although I am not sure who is whining?

Analogies to bubbles and all(your spherical cow) and we see where the supernova in expression is wonderfully projected computationally?

Yes, I see what you mean.

QGP has to have some relation to the intensity of "a collapse" to have it projected in computational figures "outward" from the collapse? Qui/Non

Best,

Plato said...

Maybe Dawkins will have no choice but to collapse in on himself:)

Plato said...

Low Math, Meekly,

Here's some good visualization.

Because "you" can't see it, doesn't mean it doesn't exist?:)

Best,

Arun said...

Arun: "Physically motivated mathematical formalism"---isn't that what special and general relativity are? And aren't strings themselves a thought experiment?

Gordon,
No.

Special and general relativity (no matter how they started in Einstein's brain) are well-validated physical theories.

String theory is not an experiment - e.g., what is the experimental set-up?

Bee said...

Arrow: If you have a problem with the notion of information, then just talk about unitary or non-unitary evolution. This is a better and cleaner way to formulate the information loss problem, see also the above mentioned post. Best,

B.

Igor Khavkine said...

Archemedes' thought experiment: "Give me a place to stand on, and I will move the Earth."

Phil Warnell said...

It appears many people are disturbed by the possibility one might be actually able to learn or discover something by at first simply to dare imagining the seemingly impossible . However, I would contend more than anything else, this as being what separates the ordinary thinker from the creative one and it is here we might find the central reason to the objection that there’s a lack utility in such thinking. Simply put I feel to place any restriction on thinking other than what is mandated by logic itself is not only non-scientific yet worse counter creative.

Anonymous said...

Bee - no-hair theorem is a semiclassical derivation. Therefore it doesn't necessarily exclude measurement process, which, as you said does indeed include loss of information.

Therefore, you can't talk about unitarity of that process, since you don't have necessary assumptions fulfilled.

a

Plato said...

Arun:String theory is not an experiment - e.g., what is the experimental set-up?

Shall we believe then "the narrow band of physics and theoreticians applicability", through their specialization, has no opinion other then to the areas to which they work?

Why can it not be that such specialization in physics is "multilateral in its application" to believe that such specialization can work "in other areas?"

For example, economics?

One sees it applicability to the way to societies interacts to also see that the basis of a theoretical approach, houses all that had already been discovered.

Currently then, the new model of application, is of that same ole economic structure.

The "ole work horses in economics" will laugh at you too?:)

You are trying to push the bubbles envelope creatively to hope that such topological descriptions(hmmmm..Kleinsche Fläche) releases condescending features of gravitonic proportions of all that has been already discovered, plus, new items of material interest. So some of these geometric configurations are placed in the valleys for examination.

Again, one without a "finer recognition of the matter states" or, "thought for that matter" to which "all things can exist" then what said there are times "closer to seconds" then what had always been counted as minutes?

Do you believe Steven Weinberg would be happy with this assertion of "only minutes" as a man of science?

Best,

Plato said...

"The lockes or plaine feakes of haire called cow-lickes, are made turning upwards."

Can't ever get away from that Bovine thinking.:)And then too, to become superstitious about thinking in such abstract ways?

Best,

Gordon said...

The thought experiment is thinking of particles as vibrating strings and seeing what follows from that.

Arun said...

Gordon,

The thought experiment is thinking of particles as vibrating strings and seeing what follows from that.

That exploration is not an experiment.

Arrow said...

Bee: "Arrow: If you have a problem with the notion of information, then just talk about unitary or non-unitary evolution. This is a better and cleaner way to formulate the information loss problem, see also the above mentioned post."

I've read the post, it is very nice and explains everything very well but I don't think it covers what I have against conservation of information and I also don't think unitarity helps here.

For example is particle decay unitary? I don't think so, there is certainly no one-to-one correspondence between initial and final state since according to QM the process is random and has no cause, meaning the exact same initial state can decay in different ways.

For example we start with an unstable particle and follow it until it decays and products fly away then reverse the time and follow the products back till they reform the particle, now run it forward again - will it decay after the same amount of time and in the exact same way as before?

If yes then QM has to be incomplete and decay is not really random - there is something about the state of this particular particle (or the environment) which predetermines when and how it will decay - hidden variables.

If no then the process is not unitary - the same initial state produces two different outcomes.

So the problem is not really about black holes it is about QM lacking internal consistency - you can either have randomness or unitarity but not both. Now if you admit hidden variables then of course this is where the actual information resides and the reason for the paradox becomes clear - it's there because QM pretends to be a complete description of reality. This is how I think this issue will be resolved eventually.

(Before someone says hidden variables are ruled out by Bell I want to clarify that there are many possible variants which can pass this test: non local ones, those with contextual hidden variables which do not correspond to measurements, those admitting tachyons and those with superdeterminism are some examples)

Giotis said...

Plato,

My point is that the divine and the quest for the divine is part of what we are. It is one of the fundamental notions that define us and makes us unique as a species. If you remove it what is left is not human. The search of truth and the search of the divine coexist in our nature. Fanatics like Dawkins simply can't understand that. Naive "Rationalists" of this kind all are really trying to do is to dehumanise us.

Anonymous said...

Oh, no need to reply, bee.
a.

Gordon said...

Arun: Einstein's gedanken experiments were not experiments either in that sense. They are "what if" statements. What if the speed of light were constant in all reference frames? etc What if a free falling body and a gravitational field were equivalent? I think that you are taking the word, experiment, too literally.

Plato said...

Giotis:The attempts of certain individuals to extract the divine from our collective subconscious are ridiculous and hopeless

Hi Giotis,

It was that statement that has me confused. Now you go on to say.....My point is that the divine and the quest for the divine is part of what we are.

What part?

I wanted to draw your attention to something that Ramanujan said of his own discoveries and where one might consider this information "to come from."

I am not talking about some dissociative state, but of actually connecting to the deeper inquirer within self. Awareness.

Namagiri, the consort of the lion god Narasimha. Ramanujan believed that he existed to serve as Namagiri´s champion - Hindu Goddess of creativity. In real life Ramanujan told people that Namagiri visited him in his dreams and wrote equations on his tongue.

If one does not recognize what they are "part and parcel of," how can you cut away something by making the first statement?

That was my intention by question, by making you aware of "where things begin" and "where they end?"

So, some are not happy with this Jungian interpretation, or, Plato's view on what we can gain access too.

It does not lesson the ability of those who do "turn back on themself" to be introspective looking for answers as to what they are indeed made up of, or, how they can attach themself too, by opening up creatively to the inspiration one might feel from ideas that flood through.

The gates are opened by willingly participating. By asking the question inside.

See, if you did not recognize something within your own self that is "quite capable" and is in all of us, then it is "easy to say what flows," and cannot exist in others, is subconsciously concealed" as a part of something that you admit cannot ever be?"

You don't explain how these things are not part of, are, and have been thrown away by speaking too "a point of view" in the first statement.

It's seals the fate then, that God cannot exist? Exist where?

Liminocentric orientated does not mean "self centred," but a return to what began, and from all of what your life is, as an expression of that.

I do believe there is an opportunity for all of us to experience the "finer constitutions of our thinking," that by what we do on reflection, we can extend in reaching beyond the matter defined. We all do it, and we all take an accounting of what we have done.

Maybe Ramanujan's mother, always had wise words for him?:)

Best,

Bee said...

Hi Arrow:

Particle decay is a unitary process. What isn't unitary about it is the measurement. What my earlier post should have taught you is that in black hole evaporation you have a problem already with the evolution, without measurement, which should be unitary in quantum mechanics. It isn't unitary in the black hole background basically because you lose part of the wavefunction that ends in the singularity. That's the mismatch between both theories. Saying hidden variables are the solution isn't sufficient. You'll have to show how they do, and how they do so without being in conflict with other experiments. Best,

B.

Arrow said...

Bee:"Particle decay is a unitary process. What isn't unitary about it is the measurement."

Ok, so we arrive at everyone's favorite cat ;)

Personally I adhere to ensemble interpretation in which the above statement does not hold but "unreal interpretations" aren't really solving anything. Your answer implies that you think the particle actually decays in all possible ways and one is only chosen when we somehow measure the decay, right? This view is even more problematic for many reasons.

For one such answer doesn't really solve anything since QM cannot say what constitutes a measurement, why it differs from any other interaction where the randomness comes from and so on.

Second this answer can be applied just as well to the black hole paradox - the process of particle falling on the black hole is unitary but when it hits the singularity measurement occurs - problem solved.

Third it means QM is never unitary since no matter what process you deal with you cannot get away from measurement so why do you even consider the fact that black holes don't preserve information a problem when in fact not a single physically observable process does so?

Bee: "Saying hidden variables are the solution isn't sufficient. You'll have to show how they do, and how they do so without being in conflict with other experiments. Best,"

Well, I agree it's not a very satisfactory solution since it doesn't let us show how information is preserved but it is still a solution in that if one cannot show that a situation leads to contradiction (or in this case that information is lost) there is no paradox.

Bee said...

Hi Arrow:

" it is still a solution in that if one cannot show that a situation leads to contradiction (or in this case that information is lost) there is no paradox."

One could also say it's not even wrong.

"Your answer implies that you think the particle actually decays in all possible ways and one is only chosen when we somehow measure the decay, right? This view is even more problematic for many reasons."

My answer doesn't imply anything of that sort. I was merely pointing out that the evolution in quantum mechanics is unitary, it's the measurement process that is not. You can then go and ask, well, then is the so called black hole information loss problem "really" a problem in that "will we ever be able to measure it?" That is exactly the question this post was addressing and the reason why I mentioned the example of black hole evaporation: if we can't observe it anyway, should we bother? My reply to this question is this post. Best,

B.

Bee said...

Hi A:

I believe we talked about the option of adding quantum hair to the horizon in the earlier post already. It's a solution attempt that has been tried, but for all I know it's been unsuccessful. If you want to use quantum hair to conserve anything you'll need conserved quantum numbers which require additional symmetries, which require additional quantum fields, for which there's no evidence, and then you have to get rid of them etc. To me it seems to create more problems than it solves. Best,

B.

Arrow said...

Bee: "My answer doesn't imply anything of that sort. I was merely pointing out that the evolution in quantum mechanics is unitary, it's the measurement process that is not. You can then go and ask, well, then is the so called black hole information loss problem "really" a problem in that "will we ever be able to measure it?" That is exactly the question this post was addressing and the reason why I mentioned the example of black hole evaporation: if we can't observe it anyway, should we bother? My reply to this question is this post."

Ok, I was more interested in the actual decay as opposed to it's mathematical description in QM which I know is unitary until measurement.

If decay is truly random as QM claims then it cannot be unitary unless one thinks there really is a superposition of a decayed and not decayed particle which last until something measures it. And even this only temporarily preserves unitarity by sweeping any creation/destruction of information under the measurement rug.

Now if one does not believe that superposition is what really happens then as I pointed out earlier one cannot have both unitarity and randomness.

All in all I think it all comes down to measurement problem which is a much more serious and pervasive problem for those who would like to see unitarity preserved. It may be that many simply see it as hopeless and would rather work on black holes but I fail to see why it would even matter if someone found that black holes do preserve information when so much of it is constantly being lost due to measurement.

Bee: "One could also say it's not even wrong."
Imagine you have two apples in a basket - one red and one green, you leave the basket in the room with Alice and Bob and walk out, soon you see Alice walking out with a green apple and afterwords Bob with another green apple - paradox! But what if Alice told you there were also apples in the kitchen you didn't know about? Does it solve the paradox or is it now not even wrong ;)

Now maybe you were referring to theories with hidden variables as being not even wrong due to those variables remaining hidden, but they do not have to be hidden forever. It's quite possible, even likely imho, that they are only hidden due to our ignorance and once we discover the final theory they will come out of hiding ;)

Bee said...

Arrow:

"Imagine you have two apples in a basket - one red and one green, you leave the basket in the room with Alice and Bob and walk out, soon you see Alice walking out with a green apple and afterwords Bob with another green apple - paradox! But what if Alice told you there were also apples in the kitchen you didn't know about? Does it solve the paradox or is it now not even wrong ;)"

The mere existence of the paradox tells us that there has to be a solution (another green apple) somewhere. The question is not whether there is such a solution but what it is (where the apple is). Alice might come and say there's apples in the kitchen, but Carl might say, no, the apples are in the garden and Doug says they're from the market, etc. The task of science is to determine which is indeed the case. If you go and say the solution might be xyz (apple in the kitchen), that's not sufficient. You'll have to show it is THE solution and why. And in particular that it doesn't create any other problems along the way.

"Now maybe you were referring to theories with hidden variables as being not even wrong due to those variables remaining hidden, but "

No. I have no particular problem with hidden variable theories in general. I was specifically referring to your assertion that hidden variable theories "solve" the black hole problem without any operational explanation for how so. Best,

B.

Anonymous said...

"Is a question that cannot be tested even in principle a scientific question?"

In physics, at least, I think that the answer is no. By "physics", I mean that the eventual goal of the questioning is to understand how nature works. It is, of course, theoretically possible to ask questions that cannot be tested even in principle and end up with useful knowledge about nature, as some commenters have pointed out. But, if you believe in the scientific method as the most efficient and proven method of going about in understanding nature, then asking such questions is less likely to enhance our understanding than following the scientific method. Therefore, it becomes a personal choice to go after a proven method or something else.

Feynman explains the scientific method beautifully in just 1 minute. I would interpret his piece as excluding questions that cannot be tested at some point.

See http://www.youtube.com/watch?v=b240PGCMwV0

What if mankind's ability to test falls far short of the ability to imagine and theorize? This creates an interesting situation where there are opposing opinions. My own opinion is to use our abilities to connect our ideas to experiments than give up and theorize too far out without any way of verifying the theory one way or another.

Phil Warnell said...

Hi Anonymous,

The role thought experiments play primarily is in the part that Feynman calls the guessing. Although such things cannot be directly tested they often prove to have physical consequences for the theory, which can be tested. In the more modern context J.S. Bell referred to such things being “beables” as opposed to actual observables. It is in then by the confirmation of these implied consequences, by experiment, that find the theory to be worthwhile and not the testing of the initial concept. In short, thought experiments have proven to be a powerful method to first discover the guesses, which is often the hardest part. That is why Albert Einstein called his guesses as being “happy thoughts”.

Best,

Phil

I apologize to Bee and Stefan if I appear to be putting in my two cents worth too often today

Steven Colyer said...

The Reference Frame: Thought experiments are essential in modern physics

That doesn't link, does it? Dammit! How do I link, what is the exaxt html code?

Anyway, Lubos Motl has considerable thoughts on Thought Experimentation at his blog, The Reference Frame, linking to this very page. Lots of replies there as well.

Meanwhile, what else is going on in Physics? seems like a slow week ... looks around ... still looking, um ... oh, YES!

The LHC FInally train wrecked protons into each other! Woo-hoo! Less than half a TeV, fine, so no stau particles yet, but hey, that's something, huh?

Why no CNN or BBC stories about this? That's a pretty momentous thing, you think?

Bee said...

Hmm. Last time I looked there was a trackback here. I wonder where it went... Anyway, it's also in my Google-reader feed, see sidebar, or here. The tag for a link is just the standard one.

Best,
B.

Steven Colyer said...

On Thought Experimentation at The Reference Frame

Steven Colyer said...

Thanks Bee, that worked! eureka! i feel so empowered now. :-)

Schrodinger's Cat returns to destroy LHC; CERN Management Mum

Sorry, don't mind me I'm feeling silly today.

But thinking of thought experimentation ... I say we all do it every day in just about everything. For example, I have to work outside in the rain today, darn. So I'll pre-emptive strike so to speak against a cold I may get by drinking an additional glass of orange juice, and dress in layers. I've never actually done that before, but it's a thought, so I will experiment. And if I do that and STILL catch a cold, then the experiment failed and it's back to the drawing board.

Christine said...

@ Steven Colyer

Your example is not a thought experiment but a "trial and error" type of heuristics for the following problem -- how to not catch a cold from exposure in the rain.

Phil Warnell said...

Hi Christine,

”Your example is not a thought experiment but a "trial and error" type of heuristics for the following problem -- how to not catch a cold from exposure in the rain.”

True yet these also can prove useful as one could say evolution is essentially nature asking the question “how do I ensure the continuance of life in face of ever changing conditions without first knowing what the end result will be” :-)

Best,

Phil

Phil Warnell said...

Hi Christine,

A relevant thought experiment might be to imagine how small, quick and agile one must be to be able to run between the raindrops as to not get wet; well at least everywhere except your feet. :-)

Best.

Phil

Plato said...

Catching colds from rain is a fallacy. Don't you people watch Dr.Oz?:)

You catch colds from viruses.

So, so much for that trial and error, and/or thought experiment :)

I do like "happy thoughts" though. It shows the mind is continuing to work things out.

Dress warm in cold weather. Oui!

Best,

Plato said...

Bee: The tag for a link is just the standard one.

You know those "thought clouds:) I put above a link, I was wondering how one could replace that wording with images so that the pictures you might want to show, come up in that cloud?

Any ideas? Thought cloud works good for latex writing to see symbol arrangement.

Best,

Arun said...

Catching colds from rain is a fallacy. Don't you people watch Dr.Oz?:)

You catch colds from viruses.

So, so much for that trial and error, and/or thought experiment :)


When you get chilled in the rain, blood vessels constrict in membranes in your nose, throat, etc., and the virus has more favorable conditions to take hold.

Plato said...

Yes, that's right Arun.

You get colds from viruses.:)

Dress warm, think happy thoughts.

Best,

Bee said...

Plato: Blogger doesn't allow pictures in the comments.

Phil Warnell said...

‘Catching’ a cold I’ve always thought was a strange way to express it, as why would anyone want to catch something they don’t want to receive? It would make more sense to say you where ‘hit’ by a cold :-)

Plato said...

Matter of factually....ummmm... hit by that fact....yes I could see how the virus could "shock the system.:)"

It's an re-orientation of the reality as one has known it, to another location, or formalization.

Shifting perspective.

Best,:)

Phil Warnell said...

Hi Plato,

I’m glad you concur on this, so instead we should be asking how to dodge or be protected from a cold, rather than how not to catch one. So Stevens’s method serves to lessen the effect from being being hit, while washing ones hands prevents the strike, then again a vaccine sharpens your defences. Personally I’ve always agreed that the best defence was in having a good offense, so finding ways to improve our immune systems not only seem to be the more sure fire and practical way, as it leaves one less afraid as being more in control. This then serves to demonstrate that before we can find good answers we first need to form good questions :-)

Best

Ph

Plato said...

Hi Phil,

Phil:So Stevens’s method serves to lessen the effect from being hit

On the basis of facts, and while the intentions are to attempt to be pre-emptive, the thought about prevention cannot have these related below. These fallacies do not contribute to forming the right questions.

But in the same breathe it got me to this point. Hmm....

Steven:So I'll pre-emptive strike so to speak against a cold I may get by drinking an additional glass of orange juice, and dress in layers.

If the clothes can be used to prevent being hit with sputum then this would be preventive indeed. Additional layers do not in and of itself help to prevent, other then in the way I relay above.

Is orange juice in and of itself preventative? You are right again here as to the formalization of what constitutes prevention and helps immunity.

Being cold though, does not induce a cold virus.

As you note, washing hands, vaccines to improve our immunities, are indeed managing the spread of, as to be more in control.

What I face in my education as a layman in the physics community of professionals are governed by, and has the same afflictions, is a learning experience and opportunity that covers society in general, and scientists are part of that same society.

It is a human struggle of trying to dispel the myths, as I am learning by staying close to the frontiers of science..:)

So "information" is energy?

Best,

Steven Colyer said...

I never intended my comment to turn into a discussion of viruses, and I hope this doesn’t degrade into a discussion of the very controversial swine flu thing, so let me restate my point using the not bad yet horrible language that is English (horrible that is compared to that greatest language of them all: Mathematics, which itself needs a ton of work), and the use of said words, which is: Semantics.

I state the following:

We humans are notoriously blind to TWO things, at least:

First, we can’t see polarized light. Some other animals on the planet can. We can’t. Our eyes are simply not built that way. Fortunately, and thanks very much to Physics, we can build instruments that can.

Second, we are blind to the future. As a believer in Block Time, I know the future exists. I simply can’t see it, neither can anyone else. However, we have an out. By understanding the Past and correctly assessing the Present, we can “think,” i.e., “extrapolate,” i.e., “perturbate” (small changes) a “bit” into the future, to calculate by the odds what is “likely” to occur, with the odds getting worst the farther in time forward we think ahead.

When we do that, we are running, in our heads, an “experiment.”

That was all I meant to say. I’m sorry if that wasn’t clear, and I sincerely hope my explanation didn’t muddy the waters even more.

Robert L. Oldershaw said...

Hi Steve,

"Belief" in "block time" is not very scientific, since there is no known way to test the "block time" hypothesis.

One could just as easily assume that the future does not exist , but rather that the past is created in the present.

It is scientific to explore both possibilities and their implications, and all reasonable other possibilities, but it is pseudoscientific to "marry" one hypothesis without good empirical evidence.

Just say no to untestable pseudoscience,
RLO

Andrew Thomas said...

Hi Robert, I'm absolutely not going to get involved in a discussion about block time (I've just had a heated discussion on my own site, so this is my last word on this subject!), but it would appear that presentism or the "tensed theory" of time as you suggest is incompatible with special relativity (scroll down in this big image).

In the words of Einstein: "People like us, who believe in physics, know that the distinction between past, present, and future is only a stubbornly persistent illusion." To refer to Einstein's conclusions as "pseudoscience" is a bit off.

Robert L. Oldershaw said...

The idea that there is a global or universal "present" would seem to violate SR. I agree that this has been falsified.

I see no reason to doubt that the "present" is locally defined in the rest frame of the observer. In this approach there does not appear to be a violation of SR, but the future still does not exist for any observer.

Even if Einstein did believe in "block time", and one qualitative comment hardly constitutes good evidence for this, that does not mean we are obliged to agree with him. He would have been the first to deny "argument from authority".

An existing "future" that in principle canot be experimentally tested is pure speculation[read: pseudoscience] no matter if Einstein favors it or anyone else. For this idea to move from pseudoscience to science there must be some means of definitive prediction/testing whereby it can be verified/falsified.

Are we in agreement on these points?

RLO
you know where

Andrew Thomas said...

Hi Robert, you make good points. Your idea of the present being locally defined is what Bee suggested here. Yes, it's not possible to argue with that. That represents an alternative to the block universe model, if you suggest the future does not exist.

I'm not convinced, though, that it is necessarily correct to say that the future doesn't exist. I think it depends on how you define the future. If you say that the shooting of President Kennedy is in our past, but it is in the future for a resident of Alpha Centauri, then the future does exist. Similarly, if you say that an event for Alpha Centauri is real for them but is still in our future (i.e., not real for us). So if you define the future in that way (i.e., the generally-accepted orthodox way) then the future does exist and is real (for someone somewhere), and the block universe model is therefore not pseudoscience. It's not like the pseudoscience of parallel universes - the future is really out there on Alpha Centauri, and it'll be real for us too in just a matter of time. If parallel universes are out there, though, then they will never be real for us.

Einstein would never have advocated pseudoscience - he was far too down to earth. I've never heard of the block universe model being called pseudoscience. I don't believe it is.

Andrew Thomas said...

One more thing, Robert. If you are suggesting that "only the present exists" and you also suggest that things change with time, then you have to have a "moving now", yes? In which case you come up against the argument of D.C. Williams: How fast does time flow?, which I think is a pretty compelling argument in favour of the block universe. How fast does your time flow, Robert? One second per second?

Steven Colyer said...

@ Andrew Thomas - Thank you.

@ Robert L. Oldershaw - be careful who you pick fights with and what you call "pseudo-science." Shall we discuss your fractal/self-similarity theory? How accepted in the mainstream is that (a mainstream in which far more accept Block Time than not)? Oh, and far as I know you haven't gotten back to me/us regarding a question I previously asked, which is how do you explain that the relative homogeneity of Galactic filaments, nexi, and voids look nothing like a spiral galaxy or solar system?

Your attitude re "Time" reminds me a lot of Sean Carroll's. Is that so? If so, Sean is coming out with a new book on same next month, and he has a thread up about it not very far down on the Cosmic Variance site. Always willing to help.

Andrew Thomas said...

To be fair, Robert made a good point. I just think calling it "pseudoscience" is a bit strong. After all, the alternative is definitely unorthodox.

(I wouldn't pick a fight with anyone!)

Robert L. Oldershaw said...

Steve,

The large-scale distribution of matter into a froth of filaments and voids is hardly what I would call "homogeneous". Take a look at the distribution of Atomic Scale matter in the Crab Nebula for the correct analogue.

Both are plasma-like distributions with a very strong fractal structure.

Galactic Scale phenomena, especially the plasma-like distributions seen in the filament/void structure, is explained in the "Galactic Scale Self-Similarity" page of my website, which I am, apparently, not allowed to draw attention to.

If you actualy studied the discrete self-similar cosmological paradigm, your opinion of it might change radically.

No definitive predictions - no science,
RLO
you know where

Plato said...

Hi Steven,

Yes semantics, and as subtle as the mathematical description in the partial image of a geometry, it is always hidden in the sociological discussion:)

So causal diagrams lead one to this point of thought and experiment?

You had to get rid of the basis of thought one can hold and examine the basis of your argument to see that it was not built on a good foundation.

So toward the substance of the thought experiment it left me with something that would contradict what I had seen of scientists who work toward a point of moving on toward clarification of the next step.

Was never intended to reach such denominational efforts in the discussion but were further points on the subject of.

By education, the divine essence of man may be unfolded, brought out, lifted into consciousness by Friedrich Fröbel

On a global effort?

The idea that such manifestation could reach such cosmological proportions seems to be only part of a much larger picture. That such a design could be specific to you is an amazing idea when you examine "your own example" that could arise from where?

So people like Garret like to work on them as an example of the universe, just as Tegmark might have.:)

But yes too, we have WMAP.

Best,

Steven Colyer said...

No, I don't know where, but I seriously suspect the UK home of crackpot magnet David Icke who lives on the crackpot island The Isle of Wight, which would bode poorly for you if Andrew Thomas of Swansea Wales didn't exist to "bring balance to the force" so to speak and save the UK from being Crackpot Central, along with many other fine Englishmen. If you're American, substitute "California" for "Isle of Wight" (outside of Cal Tech, JPL, Berkeley,(though not completely) amd UCSB (though not completely there either)). That's OUR Isle of Wight. Frigging crackpots.

Well thank you for directing me to the page on your site, Robert, I look forward to exploring it next week.

Putting aside our differences for the moment, one thing we have in common is our common love of fractals and hopefully cellular automata and nonlinear dynamics a.k.a. Chaos Theory, all of which are subsumed under the more general "Complexity Theory", the youngest of all the possible fields in Mathematical Physics which would not be possible whatsoever without Computer Science, the youngest science of them all.

Click here for the HIGHLY Interactive Complexity Science Map, and enjoy if you haven't seen it already.

I firmly believe in the nascent field of Complexity, our deepest questions will be answered. Someday.

Plato said...

"...underwriting the form languages of ever more domains of mathematics is a set of deep patterns which not only offer access to a kind of ideality that Plato claimed to see the universe as created with in the Timaeus; more than this, the realm of Platonic forms is itself subsumed in this new set of design elements-- and their most general instances are not the regular solids, but crystallographic reflection groups. You know, those things the non-professionals call . . . kaleidoscopes! * (In the next exciting episode, we'll see how Derrida claims mathematics is the key to freeing us from 'logocentrism'-- then ask him why, then, he jettisoned the deepest structures of mathematical patterning just to make his name...)

* H. S. M. Coxeter, Regular Polytopes (New York: Dover, 1973) is the great classic text by a great creative force in this beautiful area of geometry (A polytope is an n-dimensional analog of a polygon or polyhedron. Chapter V of this book is entitled 'The Kaleidoscope'....)"

Steven Colyer said...

Hi Plato,

My post above was meant for Robert Oldershaw, not you.

As far as your post goes, I must be stupid because I don't know what the hell you're saying half the time. You're either way ahead of me or the recyclable bin in your home holds more than one empty bottle of Warsteiner (best beer ever! ... Go Germany!)

Btw, I like your blog/website very much, Plato. I'd love to dig on it very much, but too many of the links on your very first post (from 2004, yes?) lead to "Operation Timed Out." Could you update that please (try Wiki links they'll never die)and inform us, yes?

I'll read from the beginning then, thanks. I like where your head is at on those occasions when I have a strong clue. I'm cool with it.

Plato said...

Nice picture?:)

Steven Colyer said...

Hi Robert,

I just re-read by post to you two posts above and realized I forgot to add comma after "UK" which gives the sentence a whole new (negative) meaning! I didn't mean to imply you were a crackpot, just that crackpot magnet Icke lives in the UK. my Apologies.

Steve

Plato said...

Hi Steven,

yes it does not ignite right away sometimes until the connection is made. So until then it seems..crACKPOTTY too or as if I have been drinking to much.:)

G -> H -> ... -> SU(3) x SU(2) x U(1) -> SU(3) x U(1).

I mean sure we are looking for the underlying mechanism?

So people like Feynman or Dirac like to see these things in different ways( a condensive view of?), while leading us to see a geometrical affect in a "time translation(i)" to see an effect of anti-matter spewing from some jet?

I'm grasping here to further show dynamical movement locally within the cosmos.

Best,

Best,

Steven Colyer said...

Yes, nice pic, Plato. I like Lisi very much. Not sure he's right (and to his credit, neither is he). Rooting for him to be right, though. I'm studying E8 Lie algebras to figure his stuff out and have actual "shop talk" comments about it. Too bad about the many particles (low energy ones, yes?) that it predicts that are not seen. Can't renormalization help, with all due respect to Chris Oakley
?

(The toilet is dirty, but it flushes, dammit.)

Robert L. Oldershaw said...

Hi Steve,

No offense taken.

And if being a "crackpot" means someone willing to seriously consider radically new ideas about physics and nature, as well as differentiating one from John Baez, then I say I'm a "crackpot" all the way. And proud of it!

But, no testable predictions - no science,
RLO

Robert L. Oldershaw said...

Hi Andrew,

Given the distance to Alpha Centauri, they already know that Kennedy was assasinated (if they are watching C-SPAN).

When EM signals reach Alpha Centauri they say: "What a shame; Kennedy was assasinated in 1963." They do not say: "It happened in our future". They say: "It happened long ago, but we did not know it until now".

If we just stick to the local Earth reference frame, do you envision our future "out there" somewhere, but inaccessible to us?

For example, either we will survive the population bomb or we won't. Has this already been decided, but we must wait to find out the answer? Could anyone know before us?!? It happens before it happens??? What a bizarre way of thinking!

"Time" "flows" at the speed of causality.

Feel free to quote me on that.

Just say no to pseudoscience,
RLO

Andrew Thomas said...

Hi Robert. You said: "When EM signals reach Alpha Centauri they say: "What a shame; Kennedy was assasinated in 1963." They do not say: "It happened in our future". They say: "It happened long ago, but we did not know it until now".

Special relativity tells us that the only concept of events happening "now" are events along our own simultaneity hyperplane. This applies to events happening 10 feet away from us (if someone falls over just 10 feet away from us, we still require the light to reach us), or an event on Alpha Centauri. If we look up in the sky and see the moon explode, we don't say "Oh look, the moon exploded 30 seconds ago", we say "The moon just exploded now".

It's very tempting to imagine we could carve up spacetime into layers (foliation), and consider each layer as now using some form of cosmic time, but there is now scientific justification for doing that (thanks to Einstein). This is considered extremely well on pages 115-121 of Michael Lockwood's "The Labyrinth of Time" which I can definitely recommend to you if you don't have it. There's many ways to imagine dividing spacetime up into foliations (or "existence planes"), but none is mathematically preferred. That's the problem with that theory.

Robert said: "For example, either we will survive the population bomb or we won't. Has this already been decided, but we must wait to find out the answer? Could anyone know before us?!? It happens before it happens??? What a bizarre way of thinking!"

If you do physics with an attitude of "if it sounds weird, it's probably wrong" then you're not going to get far. That is probably what they were thinking in 1890. It sounds weird that time moves slower for a moving object. The double slit experiment sounds weird. Nature is weird. I'm sorry to have to break the bad news to you, but it's not my fault.

Robert said: "Time "flows" at the speed of causality." How fast is that, Robert? You don't say. I'll assume 5mph.

Robert said: "Just say no to pseudoscience". Indeed, on this point I couldn't agree more. So with that thought in mind I'll just end with what Lockwood says about your theory: "We can, if we wish, postulate the existence of a unique privileged foliation, or 'slicing-up', of spacetime into simultaneity hyperplanes, the contents of which are successively actualized by way of an objective passage of time. It has to be said, though, that, in the absence of any scientific reason for doing so, this would strike many people as comparable to embracing an article of religious faith".

Robert L. Oldershaw said...

There are subjects about which it is very difficult to have a meaningful rational discussion that moves to a mutually agreeable endpoint(s).

Some examples are "time", which is nothing more than a relational ordering device, "information" which has no physical existence outside of a sentient brain, and "love" which has more definitions than a porcupine has quills.

I will read your last post carefully, but I think my time is better spent thinking about actual physical objects undergoing actual kinematics and actual dynamics.

Just say no to pseudoscience
and semantics,
RLO

Andrew Thomas said...

Hi Robert, I think we might have had a bit of a misunderstanding here as I've just seen your signature appears to be "Just say no to pseudoscience"! I never realised. It might be an idea to get a different signature! That was what got me worked-up.

Phil Warnell said...

All I can say is I wished someone had told me before that the future doesn’t exist, for I could have saved a little money in not having to buy all those calendars :-)

Robert L. Oldershaw said...

If we predict that 2010 calenders will appear in stores, then their appearance will prove that the future exists. Hard evidence!

Hey, its better than what string theory or multiverse theory has had to offer.

How many adjustable parameters does the Substandard Model have - 32 and counting?

The mediocrity can't last forever,
RLO

Phil Warnell said...

Can we all not agree that the future is at the very least what has us able to differentiate between nows that we can’t recall :-) It could also be said to be the end product of potential which if considered also as not having existence would totally eliminate all action born of either a kinetic or dynamic origin.

Phil Warnell said...

How about a quantum mechanical perspective born out of the realization that entangled particles, although they may never again share a common space, will none less be mandated to share a common destiny. The question to ask, is how could the future not exist if this be the truth , especially in light of the fact that the future is at the same time completely unknowable for certain?

Steven Colyer said...

Robert Oldershaw, would you back off a little bit please, because your comments are beginning to get a bit embarrassing, and me saying "a bit" is me being nice.

"SUBstandard Model"?! Are you kidding me?! Is THAT what you call "pseudoscience"? The Standard Model of Particle Physics? Really?

If so, allow me to introduce you to Terry Witt author of Null Physics, who thinks a neutron is just a proton and an electron (neutrinos be damned!).

Or Dr. Randall Mills and Hydrinos, which are hydrogen atoms where the electrons exist in a closer than ground state around the proton.

Or Dr. Lewis Little and the Theory of Elementary Waves, where the universe only consists of two things: waves and particles, where Maxwell was wrong about Magnetic Fields and Special Relativity is half-wrong because lengths do not contract and something is something and nothing is nothing and A=A and Ayn Rand is God.

Or Gene Ray and Time Cube Theory and ... OK, I'll stop there, that's going too far.

And semantics are unavoidable unless you're a hermit (are you?) so I don't know where you get off asking us to say NO to them.

Robert L. Oldershaw said...

Andrew,

I asked 3 questions that beg straight forward answers. Instead of answering them, you went with the comments on "weirdness". How about making a stab at candid answers?

Robert said: "For example, either we will survive the population bomb or we won't. Has this already been decided, but we must wait to find out the answer? Could anyone know before us?!? It happens before it happens???..."

weird. Nature is weird. I'm sorry to have to break the bad news to you, but it's not my fault.

I honestly want to understand how you perceive nature to work.

RLO

Robert L. Oldershaw said...

Ahh ... Steven,

It is very upsetting when one's fundamental paradigms are criticized. Our worldview comes under threat and we don't like that at all. It makes us feel insecure.

Your responses are completely predictable, especially the increasingly ad hominem nature of the remarks.

There are semantics-based arguments and evidence-based arguments.

I like evidence-based science. You?

Just say no to mediocrity,
RLO

Bee said...

Guys: Could you please stick to the topic? We were talking about thought experiments, remember?

Robert L. Oldershaw said...

Could you please let Andrew answer the 3 questions before you pull the plug on this little comedy?

If this is not possble, would Andrew please answer direct by email.

Thanks,
RLO

Phil Warnell said...
This comment has been removed by the author.
Phil Warnell said...

As a thought experiment it’s interesting to think of time as symmetrical where now forms the boundary between past and future, such that the past while knowable can never be reached again, while with the future unknowable is where one is headed, yet it to is never reached as to remain constantly in front of you. In this respect we exist our whole lives at this boundary, never actually able to go anywhere in regards to time as if consciousness itself forms to be our own event horizon.

Anonymous said...

Phil,

Not bad at all.

That's why Buddha-types urge us to "Live in the present". Well, where else can we live!

Om Mani Padme Hum,
RLO
www.amherst.edu/~rloldershaw

Phil Warnell said...

Hi Robert,

I’m happy to hear you liked my little thought experiment and strange you should mention it might be Buddha inspired. If it were the mantra you’ve chosen wouldn’t be the correct one as rather it should be “Nam Myōhō Renge Kyō “, being the one of Nichiren Daishōnin as central to the Japanese school of thought. Although never a serious devotee, yet in my late teens I did explore the philosophy for a while. One thing I did discover during this brief period is that my true passion as being physics contains and addresses many of the same questions and mysteries, with besides from the math much of the logic and hunger to know being the same. You could say I found it to be the thought experiments without the math as the extension.

Best,

Phil

Anonymous said...

Yes, I am familiar with the mantra you mentioned and once tried to use it for assistance on a physics test. Results only too predictable.

I much prefer the Tibetan mantra I give below.

The Wikipedia page for "Om mani padme hum" gives a link to monks chanting the mantra for 25 minutes. I love it, and have learned the "melody" so I can do it too.

I also do some yoga and Qi gong excercises each day.

I don't believe any of the mysticism that goes along with all this stuff, but the repetition of simple phrases and movements is quite pleasurable and refreshing.

Om mani padme hum,
RLO

Thomas Dent said...

Is is a coincidence that the picture next to Kohl's quotation about 'was hinten rauskommt' looks like a cloud of gas?

Robert L. Oldershaw said...

Speaking of "Thought Experiments", consider the following.

A new submission to hep-th at arxiv.org presents an interesting challenge: Sort of a 'Where's Waldo?' except that instead of 'Waldo' we are hunting for
a Definitive Scientific Prediction.

The paper deals with cosmology, dark matter, the putative Higgs boson and the Fermi satellite.

Paper: http://arxiv.org/PS_cache/arxiv/pdf/0912/0912.0004v1.pdf

We remember that a Definitive Prediction is:

1. feasible
2. made prior to the tests
3. quantitative [an exact number or very restricted range of numbers]
4. non-adjustable [fudging and excessive hedging not allowed]
5. unique to the theory being tested

We also remember that the mass of the putative Higgs particle is highly uncertain, except for a reasonable lower limit already set by previous testing. There is
no definitive upper limit that cannot be circumvented, to my knowledge. Lattice theories can generate very heavy putative Higgs particles. So it would appear that
the predicted putative Higgs masses might vary by factors of 3 or more.

Given the above, can anybody identify a truly Definitive
Scientific Prediction by which we might define this paper as science, as opposed to effectively untestable pseudoscience?


Yours in traditional science and its time-honored methods,

RLO

Steven Colyer said...

What about "Eureka!" moments? Thought experiments are nice, but what about those advances in Physics and Mathematics and other Sciences (the ones without central thematas ... but they're trying)?

I'm thinking of the fellow who came up with the idea of how benzene was organized. Was it the German chemist August Kekulé?

Well, whoever it was, he got the idea in a burst of a moment while traveling on a commuter bus. Just ... a moment. All the neurons coming together in a serendipitous bliss that created great insight and moved Humanity forward, thereby. What of that?