Is this the time travel breakthrough?

Originally posted by Neon Haze

Originally posted by Tom Bedlam
The stress-energy tensor in GR says that they do. Not because they have mass, but because they have energy.

As far as warping space-time, since photons have energy, even one is enough, by the stress-energy tensor in GR. This is the substance of Einstein's paper, and Carlip's, among several others which I cited above.

This is where I believe you have it all wrong, and I'm not alone.

Does Light Produce a Gravitational Field?

So, just to be clear, you refute GR's stress-energy tensor, in that it describes light as possessing a gravitational field due to its energy?

Originally posted by Tom Bedlam
So, just to be clear, you refute GR's stress-energy tensor, in that it describes light as possessing a gravitational field due to its energy?

I don't refute GR's stress energy tensor at all. I simply state you cannot relate density and flux of energy and momentum to light.

In Loop Quantum gravity as I stated earlier a photon is not exactly considered a particle, light is propagated by braided space-time vibrations. There is no braid to describe a photon.

The only time I ever use the term photon is in attempting to relate concepts into GR and SR.

Originally posted by Abandon777
Photons must increase and decrease in energy or our understanding of space/time is all sorts of screwed up since the RedShift of photons is what is used as the measurement of universal expansion. (Not to say our understanding of spacetime isn't all sorts of screwed up....heh just that huge chunks of SM are based on it).

I hear what you are saying and if we are talking about reality in a classical sense then let's not get confused between light waves and a single photon.

In classical quantum physics the concepts of "intensity" and "amplitude" do not apply to an individual photon.

In addition, my original comment was meant to relate to the fact that there is an upper energy limit an individual quanta of light can have.

It is outrageous that Tom is suggesting that light would somehow gain more and more energy as it bounced around a mirror box indefinitely. I will re-state my earlier argument... No MATHS can add up to create a singularity based on photonic energy alone.

The photon in a mirror box would bounce around will split into many photons in correlation to quantum theory... but the energy carried by the photons would equal exactly the same as the original. There can never be an increase in energy output of a system without some change in the input…. It’s a principle law of thermodynamics.

This is such simple physics it's really frustrating to hear that people often get bogged down in theory when the answer is truly just a single step away.

Here is a paper that is attempting to marry observations in classical science to validate Loop Quantum Gravity.

Loop quantum gravity and light propagation

I do hope you can understand where I am coming from.

As I mentioned earlier by the time our students have reached us we hope all of this historical classical learning has been absorbed and questioned.

The nature of our classes has always been on pushing back the boundaries and looking not only at conjecture for new and interesting idea's but also in allowing our students some freedom to reach out and prove or disprove so called established laws.

Tom is obviously studying a subject that is not open for discussion in this way and as such I understand his inability to open his mind to concepts outside of what a text book states.

And I might also add that if there are subs out there with nuke missiles in them I would want a man like Tom in sonar.

Thanks for listening.

All the best,

NeoN HaZe.

[edit on 14-3-2007 by Neon Haze]

NeoN,

I can say from reading many of Tom's posts that he does not get all of his opinions or answers from textbooks. Just by entertaining that possibilities exist outside the confines of "acceptable science" proves an open minded approach.

Since you are inferring to think beyond the textbook yourself, do you believe the concept of time travel is feasible? If so, do you see a direction to start looking for answers?

I would like to state that I do respect the opinions of both gentlemen.

Originally posted by Neon Haze

I don't refute GR's stress energy tensor at all. I simply state you cannot relate density and flux of energy and momentum to light.

This is in direct opposition to many other physicists, whom I have quoted in published papers above. So here we'll have to agree to disagree...I'm going to stick with the standard interpretation.

In Loop Quantum gravity as I stated earlier a photon is not exactly considered a particle, light is propagated by braided space-time vibrations. There is no braid to describe a photon.

The only time I ever use the term photon is in attempting to relate concepts into GR and SR.

There's a heaping pile of easily repeatable evidence that a photon is in fact a particle. Your new model's got a lot of 'splainin to do.

I hear what you are saying and if we are talking about reality in a classical sense then let's not get confused between light waves and a single photon.

In classical quantum physics the concepts of "intensity" and "amplitude" do not apply to an individual photon.

This is correct, however, your first comment was "a photon cannot increase in energy"; this has nothing whatsoever to do with amplitude or intensity, as you should know. The energy of a photon is, as I said at least twice earlier, h nu. This has diddly to do with the amplitude or intensity, which is a measure of photon flux, and can't be applied to a single photon.

One of several odd comments and omissions, I might add.

It is outrageous that Tom is suggesting that light would somehow gain more and more energy as it bounced around a mirror box indefinitely. I will re-state my earlier argument... No MATHS can add up to create a singularity based on photonic energy alone.

The photon in a mirror box would bounce around will split into many photons in correlation to quantum theory... but the energy carried by the photons would equal exactly the same as the original. There can never be an increase in energy output of a system without some change in the input…. It’s a principle law of thermodynamics.

Yet, I never said that at all. Let's review:

me, quoting Dumse: "..If you put two photons in a mirror box, its mass would increase (a tiny, but non-zero, amount). Fill
the mirrored box with many photons, and externally, you can't tell the
difference between the box with photons in it and the box with an
equivalent mass." (Note to other ATSers- this is one of Einstein's classic gedanken experiments published in 1906 in Annalen der Physik. It's called "Einstein's Box". You learn this in Modern Physics as a Bachelor. No one refutes it except NeonHaze.)

you: "I'm sorry but I am in total disagreement with your analysis. "


Next:

you: "I question your motives as you appear to be stating that a light bulb in a box of mirrors will eventually create a black hole....."

NB - Neon has just stated that the box contains a constant source of photons, the light bulb. So, yes, by adding photons to the box constantly over time, you are effectively adding mass to the box over time, since the box is a bound system. See Carlip, Einstein.

me: fired off a pile of scholarly journal quotes proving my point, that light has a gravitational field associated with its stress-energy tensor. From NeonHaze's own source.

Next:

you: Tom are you trying to say that photons in a box of mirrors will eventually warp space-time and create a black hole or worm hole where you can travel through time ????

me: As far as warping space-time, since photons have energy, even one is enough, by the stress-energy tensor in GR. This is the substance of Einstein's paper, and Carlip's, among several others which I cited above.

As far as photons being able to cause a singularity, Wheeler certainly thought so, but only at hell's own energy density. This is the center of his geon work.

My comment: even a single photon causes a warping of space-time. That doesn't mean "black hole", nor did I say that. I said even a single photon has a gravitational field. Then I said that Wheeler's work included a way to cause a singularity using a geon, which can be a very small torus of extremely high energy photons. Thus addressing his two points.

next:

This is such simple physics it's really frustrating to hear that people often get bogged down in theory when the answer is truly just a single step away.

Here is a paper that is attempting to marry observations in classical science to validate Loop Quantum Gravity.

As I mentioned earlier by the time our students have reached us we hope all of this historical classical learning has been absorbed and questioned.

The nature of our classes has always been on pushing back the boundaries and looking not only at conjecture for new and interesting idea's but also in allowing our students some freedom to reach out and prove or disprove so called established laws.

Tom is obviously studying a subject that is not open for discussion in this way and as such I understand his inability to open his mind to concepts outside of what a text book states.

And I might also add that if there are subs out there with nuke missiles in them I would want a man like Tom in sonar.

Ah, yes, another ad hominem, to go with your arguments from authority.

My take on it:

NeonHaze initially stated:

"Simply put, light has no mass and so regardless of how much of it there may be it will never be able to deform space-time. "

There are any number of papers by reputable scientists that say he is wrong, some of which I have cited. Not only theoretical work, but also experimental work - it can be demonstrated that parallel beams of light do not interfere with each other and anti-parallel beams do, in ways that match the predictions based on the stress-tensor of GR. To say that they can't deform space-time is to ignore the evidence - to say bluntly that they are unable to deform space-time may have been an uninformed statement. Maybe he didn't know.

NeonHaze never referred to stress-tensors until I did. Then he said that the photon didn't have a stress-tensor: an error.

NeonHaze didn't seem to recognize the Einstein's Box problem when I threw it at him. Then he said it was incorrect. Personally, I'm going with Einstein and company on this one also.

NeonHaze quotes from random guys on the net and calls them "papers", there's a distinct difference between posts on a forum and a scholarly paper; his use of the term there was quite surprising.

Neon even cited some guy as authoritative that is, frankly, a crank. THAT was an eye-opener. You'll note that he hasn't been able to cite a paper that proves his point. I can't imagine any of my profs quoting TimeCube man, for example.

And that comment about a photon being a unit of measurement and saying they can't gain energy, conflating energy with intensity...really, for someone that quibbles over the term relativistic mass, to mistake photon energy for intensity is quite surprising. Not to mention that apparently the LQG guys are frantically trying to account for the bosons in their theory, rather than discarding them.

Quite frankly, it's one thing to question classical theory, I often doubt that the field theory we're taught is either correct or complete. But to fling GR and SM out the door (or worse, pieces of them?) and claim that I'm being closed-minded because I don't embrace LQG, a theory that frankly isn't yet accepted, well, ok. I guess I'm reactionary.



[edit on 14-3-2007 by Tom Bedlam]

Originally posted by jbondo
Since you are inferring to think beyond the textbook yourself, do you believe the concept of time travel is feasible? If so, do you see a direction to start looking for answers?

I am afraid Time travel will never be possible and I think this for one simple reason.

For an object to travel backwards through time, you would have to have the ability to revert the entire universe back to its former state.

In other words you would have to manipulate everything down to the Planck scale to re-create what existed previously.

Even if you somehow had the godlike power to do that... it still would not be time travel, you would simply be forming a replica of what once was.

You could however create the illusion of moving forwards through time, using established time dilation effects, slowing down the rate of entropy... though this is a one way ticket and not actually time travel in the true sense it is meant.

Time travel is in my mind the largest proverbial white elephant in physics than there ever has been.

Take a look over at my braids thread to gain a better understanding of where I am coming from.

Finally an answer to EVERYTHING - Quantum Field Gravity - BRAIDS >>

All the best,

NeoN HaZe.

P.S Tom after your last post I’m going to mark you down as a foe.

I welcome argument from anyone so long as it is not an attempt to discredit or create negativity.

I find your posts closed minded and you appear to have an inability to think beyond your established views.

I notice tom that you haven't authored any threads?? I wonder why that is?

[edit on 14-3-2007 by Neon Haze]

Originally posted by fullbrain
Sorry to break it to you, but Back To The Future was only a movie!

No, sorry to break it to YOU...

It was a cartoon also.

en.wikipedia.org...:_The_Animated_Series

Here's an interesting study:

An article on the work titled "Paradox in Wave-Particle Duality" recently published in Foundations of Physics, a prestigious, refereed academic journal, supports Albert Einstein’s long-debated belief that quantum physics is incomplete. For eight decades the scientific community generally had supported Niels Bohr’s ideas commonly known as the Copenhagen Interpretation of Quantum Mechanics. In 1927, in his “Principle of Complementarity,” he asserted that in any experiment light shows only one aspect at a time, either it behaves as a wave or as a particle. Einstein was deeply troubled by that principle, since he could not accept that any external measurement would prevent light to reveal its full dual nature, according to Afshar. The fundamental problem, however, seemed to be that one has to destroy the photon in order to measure either aspects of it. Then, once destroyed, there is no light left to measure the other aspect.

www.physorg.com...

Oh, come on, Neon. I think given your flair for the dramatic, it works better like THIS:




When LQG starts generating predictions that match up with test data better than SR or GR, let me know. Until then, it's another super-symmetry or Kaluza-Klein. Promising, but ultimately flawed. Maybe LQG won't be.

Oh, by the way, here's a bit of email I thought you'd like:

Dr Carlip:



Following a recent publication in smithsonian.com by

Dr Mallett (www.smithsonianmagazine.com...),

we’ve been having a small tiff on a forum about something

which I thought was relatively straightforward and non-conjectural.



Oddly enough, the argument isn’t about Dr Mallett’s theory per se,

but whether or not a photon has any gravitational effects at all, much

less that they can cause Cauchy horizons, closed time-like curves or

singularities.



I say that it’s been pretty much accepted since Einstein’s paper in 1906

that photons cause gravitational fields by their energy, through the stress-energy

tensor in GR. I’ve quoted Wheeler, geons, Podolsky, you, Einstein’s box, Baez et al,

posted links to refereed papers and what not, and still there are some that say

that since a photon has no rest mass, there is no associated gravitational field.



I’m standing alone, one poor EE working on a masters in Physics, vs a proclaimed

PhD in quantum physics.



In a nutshell, could you give me a quote I can drop in, whether it supports my

position or no? If you say I’m wrong, then I’ll post that too.



Thanks,
Tom

His response:


There are a number of different levels on which this can be addressed:

1. Theory: it is clearly and unambiguously true that in the general
theory of relativity, light gravitates. The source of gravity in general
relativity is not just rest mass, but the stress-energy tensor, and the
stress-energy tensor for light is not zero. There are exact solutions
of the Einstein field equations for electromagnetic plane waves -- these
date back to 1926 (Baldwin and Jeffery, Proc. Roy. Soc. A 111 (1926) 95).
In his 1934 book _Relativity, Thermodynamics, and Cosmology_, Tolman
has an extensive discussion of approximate solutions of the field equations
with light as the source -- see sections 109 through115. (Section 110,
for example, is entitled "The gravitational mass of disordered radiation.")
Bonnor has a nice derivation and discussion of exact solutions in Commun.
Math. Phys. 13 (1969) 163.

2. Experiment: we know observationally that electrostatic binding energy
gravitates, with an effective gravitational mass of E/c^2 to within a few
parts in 10^10. The limits come from precision tests of the equivalence
principle; there is a good discussion of this in section 2.4 of Will's book
_Theory and experiment in gravitational physics_. Thus at least some
forms of electromagnetic energy definitely gravitate, just as predicted by
general relativity.

3. Experiment + theory: we do not yet have a direct experimental test of
whether free electromagnetic radiation gravitates. We do know, however,
that free radiation responds to a gravitational field (deflection of light),
in precisely the manner predicted by general relativity. If light responded
to gravity but did not itself gravitate, we would have a violation of
Newton's third law, with extraordinary (and extraordinarily unlikely)
consequences -- momentum nonconservation, free energy, etc.

4. Cosmology: in standard big bang cosmology, electromagnetic radiation
gravitates, and for much of the early universe (the "radiation-dominated
era") it was the main source of gravity. If one were to assume that radiation
did not gravitate, it would have drastic effects, almost certainly destroying
the good fits of current models to observation -- for instance, primordial
nucleosynthesis. (On the other hand, this would also require throwing out
general relativity, so it's hard to say what the effect would be -- we would
no longer be able to do quantitative cosmology.)

Steve Carlip

I should note here, just for the sake of completeness, that Carlip is a professor of physics at UC Davis, is well known and published, and is a specialist in GR.

Tout fini.

Originally posted by Neon Haze

I notice tom that you haven't authored any threads?? I wonder why that is?

Whoops, missed that part.

Well, to be truthful, in my job as a government plant (VIGIL), I'm not allowed to sucker you into a conversation by starting a thread. I'm constrained to finding out who the next forum based threat to civilization is, then stopping them from exposing the real truth by sending MIBs to their houses to convince them, or if that's not enough, to make them disappear.

Hopefully, if my Big Pharma plant contract comes through, I'll be able to crush competing natural medicine with more impunity.

Pfft.

I generally find that there's more than enough topics on any forum. I do occasionally start a thread (not here) but I don't proliferate threads just to do so.

[edit on 14-3-2007 by Tom Bedlam]

Nice Tom very nice... I especially liked the part about the LQG ray....

I think it's a shame that you feel that you need not author on ATS. I can tell you that I have found ATS to be an excellent place for bouncing idea's around.

I will end this conversation with you now with a couple of quotes from Albert. Einstein.

First up we have this.

"Physics constitutes a logical system of thought which is in a state of evolution, whose basis (principles) cannot be distilled, as it were, from experience by an inductive method, but can only be arrived at by free invention.

The justification (truth content) of the system rests in the verification of the derived propositions (a priori/logical truths) by sense experiences (a posteriori/empirical truths). Evolution is proceeding in the direction of increasing simplicity of the logical basis (principles).

We must always be ready to change these notions - that is to say, the axiomatic basis of physics - in order to do justice to perceived facts in the most perfect way logically."

(Albert Einstein, Physics and Reality, 1936)

Secondly and lastly we have this....

"All these fifty years of conscious brooding have brought me no nearer to the answer to the question, 'What are light quanta?' Nowadays every Tom, Dick and Harry thinks he knows it, but he is mistaken.

I consider it quite possible that physics cannot be based on the field concept, i.e., on continuous structures. In that case, nothing remains of my entire castle in the air, gravitation theory included, [and of] the rest of modern physics."

(Albert Einstein, 1954)

Tom my best advice meant with the best of intentions, would be not to be blinded by the brilliance of the great thinkers of history... If you do then you run the risk of loosing your own luminosity....

All the best,

NeoN HaZe

[edit on 14-3-2007 by Neon Haze]

Originally posted by Neon Haze

Simply put, light has no mass and so regardless of how much of it there may be it will never be able to deform space-time. In fact we physicists often use the exact opposite when calculating the location of objects in space.

Just because light has no mass doesn't mean it has no gravitation.
Why would you assume that only mass gravitates?

I guess in particle physics, you would include stress energy tensors for all
physically real fields, including strong & weak and whatever.

Electromagnetic fields have an energy density---classically you
know it as (E^2 + B^2) in proper units.

Crack open Landau + Lif#z _Classical Theory of Fields_. Look
at equations (94.8) and (94.9). The first is the S-E tensor for
the electromagnetic fields, and the second is for masses (classically).
You add the two of them to get the stress-energy tensor for classical
E&M fields and masses. Read the further discussion on starting with the
Einstein equations 95.7 and through the next page.


Quantitatively the gravitatonal effect of electromagnetic fields is
extremely small in most practical situations that it is negligble and
neglected in most computations (except early universe cosmology
where energy density was titanic) but it is clearly in there.

It's damn small though and hence most people don't think
about it or care about it.

Take a radioactive particle in a completely reflective
box which decays with a photon. Before and after the decay the
active gravitational mass of the system is the same. As there
is conservation of energy (binding energy) goes into
exciting modes of the electromagnetic field, which classically is
E^2 + B^2, that energy density also gravitates.

General Relativity really is weird and is it is astonishing that Einstein could figure this all out with hardly a shred of prior experimental evidence.

Not directly related to the topic of the thread but somewhat appropriate since it came up in the discussion.

Box

Originally posted by Neon Haze
Nice Tom very nice... I especially liked the part about the LQG ray....

I find it difficult to sustain a net argument for long without getting silly eventually. The 'foe' thing somehow made Syndrome pop into my head, that and watching Incredibles for the 28th time with my kids I guess.

Tom my best advice meant with the best of intentions, would be not to be blinded by the brilliance of the great thinkers of history... If you do then you run the risk of loosing your own luminosity....

That I can buy, sir. In summary, I guess my point was, I do think that what experimental evidence there is DOES point towards light causing what looks like gravitation, in circumstances and to a degree that fits GR, which predicts that it should happen.

Whether GR is a sufficiently good model, that's another question. Or whether it's really gravitation that light is exhibiting, or just something that LOOKS like it is another issue. I'm sure that one day, we'll find that GR/SR and the standard particle model are wrong, or incomplete, and a new model will come along. That said, any new model has to fit observation as well or better, or there's no point chucking the thing.

As someone around here once said, "The current EM field theory may be bollocks, but I find it works well enough to design really neat gear that works just as predicted"

I haven't seen such an argument associated with time travel since Titor!

Talk about Battle of the Nerds... (and I mean that in the most admirable sense)

For the record, I do lean heavily in the direction that time travel is not possible but it certainly is an interesting subject.

Tom and Neon, I thank you.....that is unless you want to keep this slugfest going?

It would keep wracking up points for me and I am only a couple hundred thousand from qualifying for a brand new car....What? I...I can't get a car? Well then a plasma T...No, no prizes for points? So then you're say...Yea, OK...

Well then, that just sucks!

I agree jbondo.

This has been one of the best exchanges I have read on ATS in quite some time. I don't understand all of it, but the professionalism, respect, and intellect make it a winner.

Is this guy a nut?

The Seattle scientist who wants to test a controversial prediction from quantum theory that says light particles can go backward in time is, himself, running out of time.

With the new rules I don't want to post too much of the EX. See the rest here:

seattlepi.nwsource.com...

Hi,

I read trough the all the thread and I think that is an interesting subject. I respect any opinion, including that ones that are contrary to my ones. Was a petty that 2 members went into personal harass but I will not interfere and I think that both showed their arguments and was a good discussion (before went personal) with different points of view, that I respect.

About time Travel many information is already in this thread, including good physics resources and papers, but one (I don’t this that this one was already mentioned) that look at this from Quantum Theory point of view is Quantum Theory Looks at Time Travel from Karl Svozil, his conclusions are:

Karl’s paper conclusions (part)

(this information was originally posted in the thread www.abovetopsecret.com... , post “Time travel”, including some information on VSL-Variable Speed of Light theory)

From Wikipedia we have also is a good clarification in a simple language about Loop Quantum Gravity.

Hope this will bring some useful information for this thread. What you think jbondo?

brotherthebig.

Some good stuff!

Thanks for the contribution.

well i dont think that not being able to travel back in time before the machine was made is because time travel didnt exist back then, its because you would have nowhere to materialize.

I also wouldnt be surprised if they turned the machine on and nothing happened, because someone has to go to the future and send something back in the first place.