Physicists bid farewell to reality?

[nabraxas]

There's only one way to describe the experiment performed by physicist Anton Zeilinger and his colleagues: it's unreal, dude.

Measuring the quantum properties of pairs of light particles (photons) pumped out by a laser has convinced Zeilinger that "we have to give up the idea of realism to a far greater extent than most physicists believe today."

By realism, he means the idea that objects have specific features and properties —that a ball is red, that a book contains the works of Shakespeare, or that an electron has a particular spin.

For everyday objects, such realism isn't a problem. But for objects governed by the laws of quantum mechanics, like photons and electrons, it may make no sense to think of them as having well defined characteristics. Instead, what we see may depend on how we look.

This notion has been around ever since the advent of quantum mechanics in the early twentieth century. The theory seemed to show that, in the quantum world, objects are defined only fuzzily, so that all we can do is work out the probability that they have particular characteristics — such as being located in a specific place or having a specific energy.

Allied to this assault on reality was the apparent prediction of what Albert Einstein, one of the chief architects of quantum theory, called 'spooky action at a distance'. Quantum theory suggests that disturbing one particle can instantaneously determine the properties of a particle with which it is 'entangled', no matter how far away it is. This would violate the usual rule of locality: that local behaviour is governed by local events.

Einstein could not believe that the world was really so indeterminate. He supposed that a deeper level of reality had yet to be uncovered — so-called 'hidden variables' that specified an object's properties precisely and in strictly local terms.

Failed test

In the 1960s the Irish physicist John Bell showed how to put locality and realism to the test. He deduced that if both ideas applied to the quantum world, then two particular quantities calculated from measurements made on a pair of entangled photons would be equal to one another. If so, there would be nothing 'spooky' about entanglement after all.

Experiments were done to test his prediction in the ensuing two decades, and results showed that Bell's equality was violated. Thus, either realism or locality, or possibly both of these ideas, do not apply in the quantum world.

But which is it? That's what Zeilinger, based at the University of Vienna in Austria, and his colleagues tried to find out.

They came up with a similar test to Bell's, to see whether quantum mechanics obeys realism but not locality. Again the experiment involves comparing two quantities calculated from measurements on entangled photons, to see if they are equal. But whereas in Bell's test these quantities are derived from the so-called 'linear' polarization of the photons — crudely, whether their electromagnetic fields oscillate in one direction or the other — Zeilinger's experiment looks at a different sort of polarization, called elliptical polarization.

Like Bell's, Zeilinger's equality proved false. This doesn't rule out all possible non-local realistic models, but it does exclude an important subset of them. Specifically, it shows that if you have a group of photons that all have independent polarizations, then you can't ascribe specific polarizations to each. It's rather like saying that you know there are particular numbers of blue, white and silver cars in a car park — but it is meaningless even to imagine saying which ones are which.

Truly weird

If the quantum world is not realistic in this sense, then how does it behave? Zeilinger says that some of the alternative non-realist possibilities are truly weird. For example, it may make no sense to imagine what would happen if we had made a different measurement from the one we chose to make. "We do this all the time in daily life," says Zeilinger — for example, imagining what would have happened if you had tried to cross the road when a truck was coming. If the world around us behaved in the same way as a quantum system, then it would be meaningless even to imagine that alternative situation, because there would be no way of defining what you mean by the road, the truck, or even you.

Another possibility is that in a non-realistic quantum world present actions can affect the past, as though choosing to read a letter or not could determine what it says.

Zeilinger hopes that his work will stimulate others to test such possibilities. "Our paper is not the end of the road," he says. "But we have a little more evidence that the world is really strange."

http://www.nature.com/news/2007/070416/full/070416-9.html

[No_One]

That's exciting news, hopefully it'll lead to something.

Specifically, it shows that if you have a group of photons that all have independent polarizations, then you can't ascribe specific polarizations to each. It's rather like saying that you know there are particular numbers of blue, white and silver cars in a car park — but it is meaningless even to imagine saying which ones are which.

Don't really get this part, anyone wanna have a go at explaining it?

I'm thinking he means that by the time you measure something, define it and then express your findings as z, x has probably already has changed to y so saying something is x is meaningless when it is now something different?

I guess then it comes back to working out what tells a fractal, slice of DNA, etc. what it has to do.

[Ace]

I love this sort of stuff - Quantum Mechanics is just so bizarre

In an attempt to explain for Shiva, I think they are trying to show that if the photons (parlicles/waves/wavicles of light) have their own polarisation (some are north and some are south magnetic poles), then it is next to impossible to determine which is which. Hence the comparison to the colours of cars in a car park at any given time.

At least, thats what I am thinking it is meaning, but it is all very hard to explain I think...

[No_One]

So your saying it's like the analogy people use about fish knowing nothing of the water they live in, while your in it you can't know it sort of thing?

Until you abstract the observer from the experiment the results are meaningless.

I guess whats needed is for the observer to dissociate from the 3rd Dimension before we know anything of the 3rd Dimension?

This would be pretty hard since most of the principals we use to define reality today are rooted in the 3rd Dimension.

Edited April 20, 2007 by Shiva

[Jesus On Peyote]

Cool, kind of over my head but sounds like quantum mechanics is like religion, someone will keep on tweaking it till something new comes along.

[Fenris]

Ive said it once and Ill say it again "Physics is Kewl and you know it"

Ive just finished a book on quantum effects in the brain and non-local conscoiusness.

Can consciousness arise from matter or does matter arise as a consequence of consciousness?. Tied in very nicely with eastern philosophy.

This poem summs up quantum mechanics very nicely.

`Twas brillig, and the slithy toves

Did gyre and gimble in the wabe;

All mimsy were the borogoves,

And the mome raths outgrabe.

"Beware the Jabberwock, my son!

The jaws that bite, the claws that catch!

Beware the Jubjub bird, and shun

The frumious Bandersnatch!"

He took his vorpal sword in hand:

Long time the manxome foe he sought --

So rested he by the Tumtum tree,

And stood awhile in thought.

And, as in uffish thought he stood,

The Jabberwock, with eyes of flame,

Came whiffling through the tulgey wood,

And burbled as it came!

One, two! One, two! And through and through

The vorpal blade went snicker-snack!

He left it dead, and with its head

He went galumphing back.

"And, has thou slain the Jabberwock?

Come to my arms, my beamish boy!

O frabjous day! Callooh! Callay!'

He chortled in his joy.

`Twas brillig, and the slithy toves

Did gyre and gimble in the wabe;

All mimsy were the borogoves,

And the mome raths outgrabe.

Edited April 20, 2007 by Fenris

[Jesus On Peyote]

I dident get that poem Well i got it but not its connection to QM.

Maybe matter and consciousness are intertwined and neither can exist without the other? (If that dont make sense then that shows how much i know :/ )

Edited April 20, 2007 by Jesus On Peyote

[No_One]

Physics is Kewl

Damn Straight!

Did that book give any answers? Last I read they still haven't solved the Mind/Body problem.

I reckon the hypothetical gap between our mind and our body is where all the magic lies, figure that out and shit'll be sorted.

I like to imagine an egg cup holding an egg. Zoom in enough and you'll find space between the egg and the cup. This space is filled with air as is everything external to the egg and the cup. This air is the magic force. Obviously the cup is our body, the egg is our brain and the air is our mind. What do you reckon?

[botanika]

Yeah agreed this stuff is fascinating Nabraxas. I dont understand much of quantum physics either but I am interested in the theories of how quantum physics work, particularly on a macro scale and in relation to locality. For example is telepathy a similar process in the macro level as quantum particles exchanging information in the micro level? (particularly when it involves instantaneous exchange over vast, infinate or non local distances). Its all weird and I love it!

I reckon the hypothetical gap between our mind and our body is where all the magic lies, figure that out and shit'll be sorted.

'Seeing seperateness but feeling connectedness'

I like to imagine an egg cup holding an egg. Zoom in enough and you'll find space between the egg and the cup. This space is filled with air as is everything external to the egg and the cup. This air is the magic force. Obviously the cup is our body, the egg is our brain and the air is our mind. What do you reckon?

LOL, it would explain Humpty Dumpty and why I like scrambled eggs a lot!

Edited April 20, 2007 by botanika

[Ace]

I like to imagine an egg cup holding an egg. Zoom in enough and you'll find space between the egg and the cup. This space is filled with air as is everything external to the egg and the cup. This air is the magic force. Obviously the cup is our body, the egg is our brain and the air is our mind.

Awesome way to put it Shiva. I have always thought of the mind as being a sperate entity to the physical body, but never been able to explain it with such simplicity. Thanks for that post!

[No_One]

No dramas.

I'm tipping you can see how this is like stepping out of the the 3rd Dimension and looking at things from the 4th?

You can go on like that for as far as you want i.e. imagine looking at yourself watching yourself looking at the cup etc. etc. etc.

[Qhorakuna tantani]

I just think its funny that the man who changed physics in such a major way struggled to come up with a better name for a phenomenon than "Spooky action at a distance," which is what he actually called it btw.

The problem with quantum physics is that we can't actually physically observe anything, because once we do we change the outcome. So, as the article mentioned, we have to make predictions using probablilty about things as simple as where the particle is LOL For a science that is so heavy in maths, I find the idea of not being able to observe or know where a particle is with 100% certainty ironic.

[phloom]

I like what Albert Einstein said, something like "why does the universe go to all the trouble of existing at all?". This makes a hell of alot of sense to me, a layperson in QM....what catches me is this apparent diversion from symmetry...or is everything symetrical all the time? in 11d space.

the aliens said to me " you humans are really funny/stupid/sexy/cool/uncool/evil/holy/flawed because you need to keep explaining reality to yourself, and where does it get you_________maybe were're onto something, this reality thing____this finite trip______dodeeddeedooddoodeedooo....okay seriously though, their doing real reseach!!!! have some damn respect!!

Research papers aren't easy write after all okay!!!!

You humans....tsk tsk

[Jesus On Peyote]

Man, im glad i never tried learning QM.i would be lost

[phloom]

MMMMM

yeah Fenris, im diggin it cowperson;)

[Jesus On Peyote]

Fenris, am i missing something from that poem?

[nabraxas]

Fenris....excellent poem. it comes from the book Alice through the looking glass (the sequel to Alice in Wonderland)

i can't speak for fenris but what i get from that poem is that when you read it as a whole it makes a kind ov sense, but when you try & analyse the individual words it seems totally meaningless (& that seems to me analogous to QM).

reading both ov those books is a total trip. Lewis Carroll was a mathematician/logician & his love ov logical puzzles comes through in his writing.

`Then you should say what you mean,' the March Hare went on.

`I do,' Alice hastily replied; `at least--at least I mean what I say--that's the same thing, you know.'

`Not the same thing a bit!' said the Hatter. `You might just as well say that "I see what I eat" is the same thing as "I eat what I see"!'

`You might just as well say,' added the March Hare, `that "I like what I get" is the same thing as "I get what I like"!'

`You might just as well say,' added the Dormouse, who seemed to be talking in his sleep, `that "I breathe when I sleep" is the same thing as "I sleep when I breathe"!'

Edited April 21, 2007 by nabraxas

[No_One]

The poem to me follows the journey consciousness/life/humanity takes or has taken.

First it's all sort of swampy and reminiscent of the "primordial stew" that people speculate life came from.

Then it's like consciousness/life is sparked and it learns it has to watch out for predators if it's to survive.

Next he works out how to use tool in the form of the sword which also suggests he has learnt to contemplate and think, the reference to the flame suggests a questioning of reality and the search for a higher power i.e. fire, energy, GOD.

Then it suggests a slaying of old beliefs or concepts similar to The Matrix, Maya, etc. before he is "reborn" to have another go. This part of the poem has strong connotations to "We shall not cease from exploration And the end of all our exploring Will be to arrive where we started And know the place for the first time"...TS Elliot

Then it loops back to start all over again, it's top stuff.

[Jesus On Peyote]

hmm, I dont think im ready for QM yet lol.

Alice though the looking glass sounds pretty good, that qoute was cool

Might try find a copy, been thinking of something to read.

[Fenris]

In QM there are a lot of things that don't make sense when looked at in isolation, you pretty much have to accept that the maths and probability behind it describe something that seems like it couldn't or shouldn't work. In reality QM does work regardless of how esoteric the reasoning is. If you think you understand QM you have obviously missed something.

The poem uses a large number of made up words which have no literal meaning, looked at in isolation they don't describe anything tangible. In the larger picture the poem makes sense but you still take your own meaning from the poem as no two people will interpret the same meaning from the words.

Plus I like the poem

The Self Aware Universe http://astore.amazon.com/science-books-20/detail/0874777984

Personally I believe that spiritual & esoteric beliefs fit in nicely with physis

I like your take on it Shiva

Edited April 21, 2007 by Fenris

[teonanacatl]

cool, one thing though is that quantum mechanics arised because microscopic particles didnt follow the same rules as macroscopic particles. Concurrently because you dont know what polarisation a particle has doesnt mean you cant know what colour a car is. Granted both are relative to the perceiver.

[apothecary]

I am also interested in quantum physics to a degree.

For anyone who isn't familiar, I recommend Stephen Hawkings "A Brief History of Time" as an extremely good laymans guide to quantum physics. The information contained therein is still contemporary.

I recall discussing quantum physics with Mr E at the camp, and he described his perception of the event horizon. I had been reading the above mentioned book at the time and was kind of freaked out when he was describing one of these (from the book) without actually having seen one before...

[Ace]

I've got Stephen Hawkings "A Brief History of Time" and I can only recommend it. it is incredibly advanced, yet very easy to grasp (at least a few parts ). It goes into a lot of subjects that you simply dont even think of, nor ever would, but they seem very fundamental. I thought it was a great read, and would love to see a few others learning about QM and mathematical science.

I might re-read it soon, actually

[devance]

Loved the poem.

But heres my slight addition.

Hope any physicist can get their teeth into it as I find it very interesting and not part of strange occult teachings.

The photon quantum entaglement of simultaneous generated split photons is less mysterous if they still share the same location and time and space in the origination as well as the duality of not sharing, distance travel.

So both are happening.

A physicist would like to a particle or wavecle exchange between the two linked photons but its not observable and so the strange predestination of the Quantum particles.

-------------------------------------------

In macro quatum physics the observable is quite astonishing and as easy to do observe as newtonian physics.

For instance time variation as in 3 hours passing in 15 minutes or time repetition such as the burning bush in the bible.

It burned but didn't burn up.

According to God theres 12 universes that he views a simultaneous but for a human observer would be linear.