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#38652 - 05/29/11 05:20 AM Re: Light From Distant Galaxies. [Re: Bill S.]
Orac Offline
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Bill S ... in my words I think what they are saying is that because of uncertainty principle that the quark binding forces can zip in out of being without an energy cost (ie perpetual motion)

That in itself I find both weird and interesting .. I really need to talk through this with some physicists.

I can view it one of two ways

1) The 2nd law doesn't apply to things in the QM uncertainty realm. I would really like to go read and look at what happens with entangled particles because this woudl imply you could use them for lossless transmission across vast distances a fact I find both weird and facinating.

2) That spacetime fabric has "resistance" (sorry best word I could use .. my english is very limited) so like in a electrical circuit transferring energy costs some of the energy. Also a very interesting concept.

Anyone got another view on that?
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#38656 - 05/29/11 03:37 PM Re: Light From Distant Galaxies. [Re: Bill S.]
Bill Offline
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Ok Bill S. I think this will be my last comment on your book about gravity. And I'm not going to look at any one part of it, just a few general comments.

I think your biggest problem is that you see gravity as a large source of energy and you don't know where that energy is coming from. Well, all I can say is that it is a part of the total energy of the universe. You kind of allude to that in your last paragraph. And you are having a problem with how it can keep up doing things like controlling the motion of all the masses, without losing energy in the process. Well, actually any individual mass will lose some energy. For example the Moon orbiting the Earth will radiate gravitational energy in the form of gravitational waves. The problem with this energy release is that we can't detect it. Gravity is far and away the weakest force in the universe, so detecting gravitational waves requires some extremely sophisticated systems. They are hoping to detect gravitational waves from sources such as neutron star mergers, or black holes in orbit. Here is an article on ScienceDaily Magazine. So then the energy of gravity is used up, or at least transferred from one object to another.

And of course the question of where the energy came from in the first place is still one that is wide open. It is still the question of "why". We just have no idea why the universe exists.

Bill Gill
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#38657 - 05/29/11 04:59 PM Re: Light From Distant Galaxies. [Re: Bill]
Bill S. Offline
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Orac, I knew you could do it! I get it now! When you have talked it through with some physicists, I hope you will share your findings.

You keep saying how limited your English is , then proving how wrong that is. Give yourself credit, you're good.
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#38658 - 05/29/11 05:08 PM Re: Light From Distant Galaxies. [Re: Bill S.]
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Thanks for an interesting link, Bill; and thanks to everyone for your contributions to this thread. I've been trying to find the time to tie all the ends together, but now its a must.

I hope I can tempt someone into "The Divided Universe" thread; even if only to say "rubbish", as long as they say why its rubbish. smile
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#38660 - 05/29/11 05:37 PM Re: Light From Distant Galaxies. [Re: Orac]
Bill Offline
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Originally Posted By: Orac
1) The 2nd law doesn't apply to things in the QM uncertainty realm. I would really like to go read and look at what happens with entangled particles because this woudl imply you could use them for lossless transmission across vast distances a fact I find both weird and facinating.

Physicists who work with quantum entanglement tend to dismiss the possibility of faster than light (FTL) communication using entanglement, but then Einstein tried to dismiss quantum entanglement completely. I have an interesting book about entanglement, but don't have access to it right now. My daughter has it. I will probably get it back in a couple of weeks, when I go see her. The book is "The Dance of the Photons" by Anton Zeilinger. In it Zeilinger clearly shows why it won't work, assuming that he is right. I figure he is probably right, but then I don't like to lock myself into a position when it comes to advanced scientific ideas. People keep coming up with new ways to bypass the built in limitation.

Bill Gill
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C is not the speed of light in a vacuum.
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#38662 - 05/30/11 04:08 AM Re: Light From Distant Galaxies. [Re: Bill]
Orac Offline
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Arg ... just when you think you understand stuff someone throws a rock in.

Speaking to some people they pointed this out.

Two views on same work.

http://www.technologyreview.com/blog/arxiv/24759/
http://www.smartplanet.com/blog/smart-ta...s-possible/3967

And that really does defy the second law

It sort of also implies QM isn'g just a wave function or add in to any fundemental theory of everything ... well unless you can explain how you can transfer energy via a probability wave function rather than information as we usually view it.



Edited by Orac (05/30/11 04:08 AM)
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#38664 - 05/30/11 02:27 PM Re: Light From Distant Galaxies. [Re: Orac]
Bill Offline
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Yep, it just keeps getting weirder and weirder. Entanglement has already been pushing the envelope in Special Relativity. After all Einstein really didn't like it since it seems to imply some kind of communication at speeds greater than C. But it is real. Now they are pushing the envelope even harder. There is definitely something we do not understand going on in the universe, since there are so many things that one well developed and tested theory says can't happen, and another well developed and tested theory says must happen. There is obviously a lot going on there that is hidden from us right now. I just hope that somebody has their 'aha' moment before long and shows us how to put it all together.

Bill Gil
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#38665 - 05/30/11 02:47 PM Re: Light From Distant Galaxies. [Re: Bill]
Bill S. Offline
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Could we be moving towards the concepts of the "Zero Point Field"?
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#38675 - 05/31/11 06:26 AM Re: Light From Distant Galaxies. [Re: Bill S.]
Orac Offline
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Yeah Bill.S we would be heading into those sort of theories if that energy transportation holds up and we probably need time for work to be confirmed. There are obviously quite a few theories this sort of result would favour QCD, variants of string theory (think they allow just about anything to happen ^_^) for example.

It's such a big shift from viewing QM as teleporting information in a classic sense to teleporting energy and able to get involved in energy processes.

Remember we also started out from another fundemental energy/binding force on quarks from the reference from redewener which I hate him for now cause my physics world just blew up :-)

I was backing the higgs boson to be found in a $10 bet ... It's not looking good for me at the moment :-)

I have alot of reading to do around QM but I am guessing theories based more around particles where they tag in QM when symmetry breaks like susy, LQG, spin foam etc with supersymmetry quantum mechanics may be in alot of trouble with this.
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#38692 - 06/02/11 02:03 AM Re: Light From Distant Galaxies. [Re: Orac]
Orac Offline
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This just in yesterday which is sort of heading the same way

http://www.newscientist.com/blogs/shortsharpscience/2011/06/tevatrons-mystery-signal-grows.html

They are saying it's definitely not a higgs boson so those in the QCD like theories are looking stronger.

I love the ending of punzi's presentation
http://blois.in2p3.fr/2011/transparencies/punzi.pdf

Quote:

We live in the Higgs era
• Coming to terms with EW symmetry breaking.
• We know quite a lot already about the Higgs
– The SM Higgs mass is very constrained
– No model with a rate >> SM is viable.
– Coexistence of a SM-like Higgs and a 4-th quark generation is very
nearly excluded
• The next step is finding out whether SM is right or wrong.
Should not take long. Surprises might come up.
• A new era will follow - we don’t know its name.
• We should enjoy this special time we are so lucky to live in.


And for Bill.S the stand-up physicist has put a spin on it for you (Don't get hung up on the maths) just follow the story.

http://www.science20.com/standup_physicist/why_quantum_mechanics_weird-79513


Not sure I like where this all goes I sort of like my old solid world interpretation but I am guessing the jury will be in sooner rather than later at the rate this is going.


Edited by Orac (06/02/11 03:01 AM)
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#38728 - 06/07/11 03:26 AM Re: Light From Distant Galaxies. [Re: Orac]
Orac Offline
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I think we must be close to calling some TOE theories dead now.

http://www.physorg.com/news/2011-06-researchers-create-light-from-almost.html
http://physicsworld.com/cws/article/news/46193
http://www.physorg.com/news/2011-06-quantum-physics-photons-two-slit-interferometer.html

QM is throwing up way to many weird things for them to survive unless they can explain them.

I made http://images.iop.org/objects/phw/news/15/6/4/double1.jpg my new background thats an image that is going to haunt alot of physicists for a long time. You really wonder what Einstein would have said a particle going through both slits.



Edited by Orac (06/07/11 03:35 AM)
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#38735 - 06/07/11 04:54 PM Re: Light From Distant Galaxies. [Re: Orac]
Bill Offline
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There are a lot of unanswered questions in both QM and GR. The major thing about both of them is that they work. They are really strange and trying to figure them out is impossible for most of us. But I'm not going to give up, after all, they do describe the world as we see it. It is just that we don't really 'see' it the way they describe it.

And of course Einstein really didn't like a lot of things about QM, even though he did a lot of the work that led up to it.

Bill Gill
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C is not the speed of light in a vacuum.
C is the universal speed limit.

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#38740 - 06/08/11 05:51 AM Re: Light From Distant Galaxies. [Re: Bill]
Orac Offline
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For me alot of the answers are there I just don't like them they play with my sensibilities.

I quite liked the idea of light as a probability wave that when I measured solidified to a particle .. see I know waves can go thru 2 slits at once but particles should only go through one.

The idea a single particle can somehow split and pass through both slits but when I measure it's only one particle not two plays with my sensibility.

So I have to accept that everything I perceive is an illusion and now how deep does the hole go ... don't expect me to like this :-)
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#38749 - 06/10/11 01:37 AM Re: Light From Distant Galaxies. [Re: Orac]
Bill 6 Offline
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Originally Posted By: Orac
I quite liked the idea of light as a probability wave that when I measured solidified to a particle .. see I know waves can go thru 2 slits at once but particles should only go through one.

Individual photons generate their own electrical and magnetic fields that travel along with the photon.

When the photon passes through one of the slits some of the accompanying em radiation passes through the other slit and when it emerges from that slit it interferes with the photon causing it to change direction.

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#38751 - 06/10/11 02:40 AM Re: Light From Distant Galaxies. [Re: Bill 6]
Orac Offline
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They are measuring the actual spin of the particle via a weak measurement (http://physicsworld.com/cws/article/news/46193) and EM wave simply would not give the results they produce.

The particle has to be there and as the work shows its in both slits at the same time (see the graphs) there is no denying what it is seeing.

That's why this is going to haunt lots of theories like yours above it's dead in the water.

This result is a profound as the original double slit experiment.

I can't explain it, I don't like it but I have to accept it.
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#38775 - 06/13/11 06:54 AM Re: Light From Distant Galaxies. [Re: Orac]
Bill 6 Offline
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Originally Posted By: Orac
They are measuring the actual spin of the particle via a weak measurement (http://physicsworld.com/cws/article/news/46193) and EM wave simply would not give the results they produce.

That information is either misrepresented or misinterpreted.

The diagram does not present a picture of what actually takes place (i.e. as would a camera) but is a computer generated picture of what is thought to be happening however on the assumption that the diagram depicts what is assumed to take place between the slit card and the target card it shows photons appearing at the back of the slit card at locations where the slits do not exist.

Text books show that a single photon arrives at the target card location as a single pinpoint of light that is located at some position along the curve shown in that diagram but not as an entire curve.

They also show that a series of single photons aimed at the target card will eventually add up to and produce that curve and I believe that this is what that diagram depicts.

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#38782 - 06/14/11 03:55 AM Re: Light From Distant Galaxies. [Re: Bill 6]
Orac Offline
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No you can not take a picture because you are only allowed to take weak measurements.

What they are doing is reconstructing the trajectories (they know a position and time but not together) and from that they put the partcile in both slits similtaneous, admittedly based on probability.

And thats the point the text books which use Bohr interpretation are wrong.

Edit: The original article has a better image of the single photon tracks emitted by the quantum dot generator
http://www.aip.org.au/Congress2010/Abstr...rajectories.pdf

Edit: I found a more layman breakdown of the experiment which may help

http://arstechnica.com/science/news/2011/06/an-experiment-that-just-keeps-on-giving.ars

I loved the comment.

Quote:

The current experiment can be described as a physicist hearing that the photon went through both slits, agreeing, but then saying, "No, seriously, which slit did the photon go through?" Yes, there remains a visceral and fundamental discomfort with the realities of quantum mechanics. Nevertheless, this discomfort has led to a very clever experiment that comes as close as is possible to answering this question.



At every point along the trajectory including going through both slits there was a particle it was never just a wave.

So what we are probably looking at is something like a more modern explaination, I think the doug sweetser (the standup physicist) does a pretty good job here (http://www.science20.com/standup_physicist/why_quantum_mechanics_weird-79513)


At no point do we have light as solely a wave it is always a particle and yes it can go through two slits simultaneous. The wave like behaviour comes from its fundemental quantum nature.

This is a bit like the problem of time in relativity observers can disagree on time because of there frame of reference what doug is showing and mathematically is the reverse of that, observers can disagree on 3d space positions and that is what the experiment shows.

It's not a massive shift you just need to accept that there is always a particle and it can be at two places at once rather than a wave which collapses back to a particle.

When you think about entagled partciles it really is no different and that looks to be where we are heading.

Superposition looks to be a norm for photons and given we can do it to "soild" things is it really that surprising.

There are more and more experiments showing the same thing I am seeing them daily

http://francisworldinsideout.wordpress.c...-the-same-time/

Coming at it from the other way you also do a controlled entanglement of a photon

http://www.physorg.com/news197900557.html
http://www.physorg.com/news/2011-06-chinese-team-entangles-photons.html

There are groups setting up to attempt double slit with entangled photons which should really show us some things.

I should also add this actually may ease the explaination of of the H2 and other particle experiments with double slits

http://www-als.lbl.gov/index.php/science...ysics-meet.html
http://www.physorg.com/news113822439.html

and more recent matter experiments

http://www.physorg.com/news/2011-04-scientists-quantum-breakthrough.html

Light and matter seem to be converging in QM.

Can we definitively say all this to be true at the moment ... no ... but in the same way almost all the old classic "stories" in the text books have shown to be wrong.



Edited by Orac (06/14/11 05:23 AM)
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#38785 - 06/14/11 07:23 AM Re: Light From Distant Galaxies. [Re: Orac]
Bill 6 Offline
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I fail to see how any of the material you provide negates the idea that when a single photon passes through one of the slits that its trajectory is then determined by em radiation emerging from the other slit.

The diagram in the first link shows 'Trajectories of a Single Photon' and depicts perhaps 100 separate routes but I believe that it should be headed 'Trajectories of Single Photons' on the basis that a single photon can have only one trajectory not hundreds.

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#38786 - 06/14/11 08:04 AM Re: Light From Distant Galaxies. [Re: Bill 6]
Orac Offline
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And thats the point its a single photon from a quantum dot (there was a pile of anti-bunching testing done to check it was only one photon) so the photon should have only 1 path not hundreds. Remember those paths are going to be the "light" spot of an interference pattern against itself and it is a partcile on trajectory on each and every path which are meters apart. You can backtrack the trajectory to which slot it came through.

We can't proove to you that it is the same parcticle everywhere beyond that because of QM.

The reality old interpretations are going to have to contrive ways to explain the results like that the particle chooses a different path randomly each time and thats why we see partciles on each of trajectories or its only a wave as it goes through the slit they couldnt get the trajectory up any closer to the slit. But that begs the question why does it change at the slit and how would it even know there was a slit.

I saw a really neat analagy.

Quote:

Assume that you want to measure the weight of a sheet of paper. But the problem is that your measurement apparatus (weighing scale) is not precise enough to measure the weight of such a light object such as a sheet of paper. In this sense, the measurement of a single sheet of paper is - weak.

Now you do a trick. Instead of weighing one sheet of paper, you weigh a thousand of them, which is heavy enough to see the result of weighing. Then you divide this result by 1000, and get a number which you call - weak value. Clearly, this "weak value" is nothing but the average weight of your set of thousand sheets of papers.

But still, you want to know the weight of a SINGLE sheet of paper. So does that average value helps? Well, it depends:

1) If all sheets of papers have the same weight, then the average weight is equal to weight of the single sheet, in which case you have also measured the true weight of the sheet.

2) If the sheets have only approximately equal weights, then you can say that you have at least approximately measured the weight of a single sheet.

3) But if the weights of different sheets are not even approximately equal, then you have not done anything - you still don't have a clue what is the weight of a single sheet.

But what if you don't even know whether 1), 2) or 3) is true? Then you have different interpretations of your weak measurement. And that is precisely the case with quantum mechanics: We don't know whether particles have even approximately equal velocities at the same position (with the same wave function), so we have different interpretations. Bohmian interpretation says they have exactly equal velocities, which corresponds to the case 1), while Copenhagen interpretation corresponds to the case 3).


No one is ever going to be able hard proove to you beyond this if you believe one of the other options they are equally valid beacuse I will never be able to disproove them QM stops me.

However you are also ignoring alot of the other weirdness thrown up by QM because we have done this with electrons, neutrons, whole atoms, and entire conglomerates of atoms and they all do the same thing but we had the reverse problem we were struggling with where the wave like behaviour came from.

I don't buy either Bohmian or Copenhagen views I am a number 2 man and that means a different yet to be defined interpretation.


Edited by Orac (06/14/11 08:31 AM)
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#38793 - 06/15/11 05:27 AM Re: Light From Distant Galaxies. [Re: Orac]
Bill 6 Offline
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Originally Posted By: Orac
And thats the point its a single photon from a quantum dot so the photon should have only 1 path not hundreds.

That's what I SAID!

A single photon can have only one trajectory at a given instant not hundreds of trajectories.

If a single photon is directed towards one such slit you cannot then have hundreds of identical photons emerging from both slits.

Originally Posted By: Orac
...the particle chooses a different path randomly each time...

That's what I SAID! The diagrams to which I referred show a number of trajectories applicable to a NUMBER of particles NOT to a SINGLE particle i.e. as you wrote, above - "...the photon should have only 1 path not hundreds."

Originally Posted By: Orac
...and thats why we see partciles on each of trajectories...

That's correct - that's what I'VE been saying! We 'see' individual particles on each of the trajectories. We don't see the same photon on each of the trajectories!

Your analogy of weighing a thousand sheets of paper confirms my argument that the experiment to which you refer shows the assumed trajectories of 'hundreds' of photons NOT of a single photon!

Originally Posted By: Orac
No one is ever going to be able hard proove to you beyond this if you believe one of the other options they are equally valid beacuse I will never be able to disproove them QM stops me.

You gave the impression that the experiments to which you referred 'proved' that my posting regarding the effect on a particle's trajectory by em radiation passing through the other slit was erroneous - they do NOT!

Originally Posted By: Orac
However you are also ignoring alot of the other weirdness thrown up by QM...

I object to your unwarranted, belittling criticism. I am NOT ignoring same but am not referring to same on the basis that they have no application to the subject on hand i.e. an explanation for the deflection of photons in the twin slit experiment.

I anticipate no response to this request but perhaps you might suggest which of the other weirdnesses arising from QM provide a solution to the claimed particle/wave duality.

You cannot prove that it is "...the same particle everywhere..." because it is NOT the same particle everywhere and your comments, above, show that you are aware of this fact.

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