The article uses a lot of metaphor. Please (non-physicist) readers, don't take this to mean that light actually has mass or directly interacts with other photons. They created a system that behaves *as if* these things happen.

If I read this correctly the photons change the probability of direction of reflection/reemission in a way that the probability is higher that they will move towards one another. (While imparting a net momentum on the rubidium atoms away from that path to keep momentum conserved)

Could be used in laser cooling as you can send in photons in a way that you can bias the exit flight paths and hence the momentum you want to take from a to-be-cooled substance.

With detectors at the other end you could even build a logic gate with this.

Fascinating stuff.

Please (non-physicist) readers, don't take this to mean that light actually has mass or directly interacts with other photons. They created a system that behaves *as if* these things happen.

Really? I am a physicist reader & I know energy fields have associated gravity fields. Why is that? Maybe "toot" knows & he can explain in to us.......?

I wonder if "toot" might know that when a photon is emitted from an atom, the atom becomes lighter by the quantity of the transformed mass, a lighter atom means less gravity associated with that atom because the transformed mass carried it away. We studied this in nuclear reactor design in engineering school.

Well the stress energy tensor does interact with the curvature tensor (ie, energy curves space-time around it), but that doesn't mean the light itself has mass.

The article uses a lot of metaphor. Please (non-physicist) readers, don't take this to mean that light actually has mass or directly interacts with other photons. They created a system that behaves *as if* these things happen.

Seconded. Naturally, a site like physorg can't be expected to just regurgitate the raw science - their raison d'être is translating science to the masses. But yes, caution is very much warranted. Even the researcher described it as an actual state of matter ... and maybe that's appropriate, though from what I'm reading that also seems like more of an analogy than anything.

Regardless, this is *super* cool stuff.

Please (non-physicist) readers, don't take this to mean that light actually has mass or directly interacts with other photons. They created a system that behaves *as if* these things happen.

Really? I am a physicist reader & I know energy fields have associated gravity fields. Why is that? Maybe "toot" knows & he can explain in to us.......?

I wonder if "toot" might know that when a photon is emitted from an atom, the atom becomes lighter by the quantity of the transformed mass, a lighter atom means less gravity associated with that atom because the transformed mass carried it away. We studied this in nuclear reactor design in engineering school.

What is your point here? Shavera is merely recommending caution in taking physorg's description too literally. He is not spouting pseudoscience, suggesting the described research is impossible, or anything else that should be controversial in nature ... not sure what set you off here.

Seconded. Naturally, a site like physorg can't be expected to just regurgitate the raw science - their raison d'être is translating science to the masses.

No its not. They rarely translate anything. They mainly reprint press releases. There isnt even a byline for this article.

If you google the following sentence from the article:

"Harvard and MIT scientists are challenging the conventional wisdom about light, and they didn't need to go to a galaxy far, far away to do it."

-you see that it appears on dozens of websites including sciencedaily and fox news.

This may be a stupid question, but "causing the photon to slow dramatically"- what about the speed of light? How do photons slow down?

This may be a stupid question, but "causing the photon to slow dramatically"- what about the speed of light? How do photons slow down?

The speed depends on the medium through which it is propagating.
http://www.news.h...ght.html

"How do photons slow down?"

Wikipedia has a nice breakdown under "refractive index." The microscopic explanation in that article is what you're probably looking for.

@ rkolter

...they created a medium (rarified gas, near absolute zero in this case) where the speed of light is measured to be very, very slow.

So, in the case where a distant galaxy is viewed after light has passed by a nearer intervening galaxy surrounded by "rarified gas, near absolute zero...", naturally a lot denser nearer the galaxy and rarer further away, would you expect refraction to take place? If so, does this mean that "gravitational lensing" does not produce the multiple images of the distant galaxy, but refraction by the nearer galaxy's gas "lens" does? Oh dear, this could upset a lot of people....

So, in the case where a distant galaxy is viewed after light has passed by a nearer intervening galaxy surrounded by "rarified gas, near absolute zero...", naturally a lot denser nearer the galaxy and rarer further away, would you expect refraction to take place? If so, does this mean that "gravitational lensing" does not produce the multiple images of the distant galaxy, but refraction by the nearer galaxy's gas "lens" does? Oh dear, this could upset a lot of people....

Any first year physics student could tell ya that refraction bends each color of the spectrum at slightly different angles, and gravitational lensing bends ALL colors at the SAME angle. This is geometric optics at it's most basic level. That's why they are so easy to tell apart.

Ya should have read one of those authors ya were relentlessly quoting a while back.

It seems to me that calling them "photons" in such a medium is more than a little erroneous. The massless particles we usually think of photons as being can only exist at the speed of light, in a vacuum, and experience their entire history in an instant.

Is it really appropriate to refer to these quantizations of the non-vacuum electric fields within the medium as "photons", or should we think of them as something that the photons create in the medium when they enter it, to be reconverted to true photons as they exit?

Although, admittedly, we might take that attiude with every light source we experience in our thin but non-vacuum atmosphere. But I'm inclined to agree with the comment "They created a system that behaves *as if* these things happen. "

"...a distant galaxy is viewed after light has passed by a nearer intervening galaxy surrounded by "rarified gas, near absolute zero..."

Reg, observations show that galaxies are surrounded by very _hot_ gaseous halos, known as galactic coronae:

http://archive.st...de6.html

http://www.news.wisc.edu/3536

http://ned.ipac.c...ge5.html

http://arxiv.org/.../0505299

Do try to keep up.

The reason they form the never-before-seen (photon) molecules?

Actually the experiments with cold atoms aren't solely equivalent to experiments with photons in vacuum - this environment is much denser and its excitons have non-zero rest mass - pretty well, like the rubidium atoms by itself. .... These photon molecules are an analogy of glueballs (clusters of gluons) inside of quark gluon plasma, which were observed during particle collisions. In AWT the highly energetic gamma ray photons can condense too in form of gamma ray burst, which do propagate across whole universe as a single body. These observations point to nonzero mass of photons in vacuum too.

Great stuff, Franklins! You're very close, mate! In my ToE I identify and explain BOTH the 'mechanism' and the 'composite field' (observed already) which becomes even more powerful/effective in BEC and other superconducting & superfluidic energy-mass contexts. You're definitely on the right track! Kudos. :)

Well the stress energy tensor does interact with the curvature tensor (ie, energy curves space-time around it), but that doesn't mean the light itself has mass.

But the mass must be contained with it, or we would violate the E=MC2 mass energy equivalence. For example, during supernovae explosions the mass of whole Sun is radiated in form of gamma rays in a brief moment, so it cannot disappear suddenly just because of relativity. IMO the gamma ray photons exhibit their own weak gravity field, which propagates with superluminal speed around them at distance.

Again, you've got it all taped, Franklins! Obviously the 'gravity waves' being looked for are associated with the expelled energies (in whatever form), which only 'manifest' that gravity effect when slowed and 'localized' into some energy-matter system which does not 'outrun' its own associated 'gravity effect' at the speed of light. You're on a roll, mate. Cheers!

..but "causing the photon to slow dramatically"- what about the speed of light? How do photons slow down?

They don't, they only go at speed c, always. In a material there is a probability that a particular atom absorbs and a probability that it reemits a photon. Since it is probability based it does not occur instantaneously. Even the direction is probability based in that the amplitudes of the wavefuction for each possibility, can add constructively or destructively,... giving a particular direction based on the frequency the most likely one. I don't think it even makes sense really to say its "the same photon" going through the material, but everyone says that.

In the wave picture (classical), the incoming light wave jiggles atomic charges (or molecular dipoles) which then re-radiate in the same frequency, but delayed in phase,... the sum of the incoming wave and the delayed phase re-radiated wave results in a "slowed" light wave as compared to the original one.

Since it is probability based it does not occur instantaneously.

The problem with such an explanation is, this mechanism would lead into gigantic scattering of light, because atoms would re-emit the light in random directions.

The wave function (phase) amplitudes for those possibilities sum destructively, and so cancel out,.... sum of many possible atom absorption/emissions states at once.

,... the phase is the same wavefunction component responsible for the interference fringes in the two slit experiment. It has no physical basis except to add or subtract probabilities. Each atomic layer considered at a time with each atom having a probability amplitude associated with it in absorbing and emitting the photon,...

,... the phase is the same wavefunction component responsible for the interference fringes in the two slit experiment. It has no physical basis except to add or subtract probabilities. Each atomic layer considered at a time with each atom having a probability amplitude associated with it in absorbing and emitting the photon,...

Actually in this instance Zeph is correct. The photons passing through a medium are NOT absorbed and re-emitted. That is not what slows the photon down. The only absorption that will take place is with electrons which happen to have the ability to absorb that PARTICULAR photon's quanta of energy. If it can't then the photon is merely nudged aside.

It's the same concept that allows certain substances to act as filters, some substances are opaque, others not at all. The chemistry of the medium determines how much it will slow, whether or not it will be absorbed, it's not determined by the wave probabilities.

Ooooohhhhhh, your right, I think I was thinking of Feynman's discussion of light reflecting or transmitting at the surfaces of glass. Never mind then.

So if the potential is "create complex three-dimensional structures – such as crystals – wholly out of light," then this also allows for the possibility of photonic quantum computers, and taken a step farther, 'artificial' intelligence or possibly a new evolutionary step toward massless 'light beings.' I love it when science fiction comes true!

In other words, contrary to the title of the article, the scientists did not produce a novel state of matter.

The authors didn't even create a novel title for their dumbed down article.

This comment has been removed by a moderator.

The photons that go in are not the photons that come out together. My understanding is that a photon goes in, its energy travels through the medium at a speed less than light (and as photons between atoms), and a photon comes out. The fact that the energies seemingly interact through properties of the atoms is pretty cool.

Eh, the article seems dumbed-down to below the level where meaningful information can be transmitted. Too much metaphor, not enough physics.

Hey, maybe if two such articles are transmitted simultaneously through chilled readers' brains, they'll emerge as a single entangled nonsensical article!

Actually, if you send enough nonsensical articles into readers brains you eventually get AWT.

can be produced by gamma rays doesn't that imply that the particles are made of the fundamental em?

I think 'made up of' is too strong. The two forms are interchangeable (E=mc^2 and all that jazz). To me that speaks of a more fundamental concept (energy) showing up in various guises - not EM (or matter) being more fundamental.

Does this article therefore show that we ARE progressing in the direction of being able to use photons to produce material objects

To create a photon you have to take the energy from somewhere. This usually means that you have to convert a bit of mass into energy in the first place. So at best (with a 10% efficient process) we'd get a 'reformation' of energy (converting from one type of substance into another). But since photons tend to create particle/antiparticle pairs (conservation of charge) it's a long way to create objects (because you have to make sure the two don't meet again)

This may be a stupid question, but "causing the photon to slow dramatically"- what about the speed of light? How do photons slow down?

The speed of light *in a vacuum* is a constant, but that doesn't mean that all light always travels at that speed. If you do a search back through Physorg's archives for instance, some researchers recently slowed light in an experiment down to walking pace (I'm not joking!).

Am I the only one who thinks the name Lukin rings any bells?

It does! That's the first thing that struck me.

Interesting article. Many UFO sightings report beams of light that act strangely. Some report the beam coming to an abrupt end like a light saber.

@QStar
Nice to hear from you, I expected you to emerge from your shell as soon as I posted anything controversial.

Any first year physics student could tell ya that refraction bends each color of the spectrum at slightly different angles, and gravitational lensing bends ALL colors at the SAME angle.

The amount of differential between different colours in refraction depends on the density and other properties of the medium. With gas, the differential is VERY small, but accounts for the slight fuzziness of the images conveniently ascribed to the "inadequacy of our current optics".
A little thought about the VERY SMALL angle of refraction in so-called gravitational-lensing would be appreciated, rather than you trotting out your usual establishment refrains.
@ yyz

Reg, observations show that galaxies are surrounded by very _hot_ gaseous halos, known as galactic coronae

Not all of them, my boy....the outer shell causing the refraction, not the hot inner part, is cold.

@QStar
Nice to hear from you, I expected you to emerge from your shell as soon as I posted anything controversial.

It's not controversial, it's well understood physics,,,, are just wrong.

Any first year physics student could tell ya that refraction bends each color of the spectrum at slightly different angles, and gravitational lensing bends ALL colors at the SAME angle.

The amount of differential between different colours in refraction depends on the density and other properties of the medium..

No, the difference in refraction angle is dependent on the wavelength. In refraction, each wavelength refracts at a different angle. In gravitational lensing each wavelength bends at the exact same angle.

A little thought about the VERY SMALL angle of refraction in so-called gravitational-lensing would be appreciated, rather than you trotting out your usual establishment refrains.

Producing rings, or multiple images is small? Uh huh,,,

http://www.popsci...omments-
PHYSORG next

This is yet another example of Art Winfree's law of coupled oscillators. The photon "molecules" are a simple case of a coupled antisynchronous two oscillator system. See my many prior Physorg posts on Winfree's law. The article explains well the conditions that make the coupling possible, but the article and the many comments above show that physicists are unaware of Winfree's law.

http://www.popsci...omments-
PHYSORG next

From your link,....

...disagreements between commenters impacted readers' perception of science.

If you carry out those results to their logical end--commenters shape public opinion; public opinion shapes public policy; public policy shapes how and whether and what research gets funded--you start to see why we feel compelled to hit the "off" switch.

Yes I do. You're not so much about conveying science news as you are about "controlling the message",... which enters into the realm of propaganda and indoctrination, which doesn't work if there is free debate and personal intellectual accountability.

That's rich coming from Noumenon. This is the guy that will post 500 words to obfuscate his trash opinion that could have been expressed in 10 words. He is a sophist of the highest degree and has no appreciation for or desire to advance science. He is the type of poster Popsci had to shut their comments down over.

That's not the whole story. Noumenon freely admits his desired goal is to shut down the comments section here. He seems to be angry that so many intelligent people don't share his horrible trash opinions, and he wants to take it out on the site and its moderators.

He has effectively won too. Most of the people that engage in sockpuppetry here follow his model, in many cases to oppose him. This has lead to the moderators all but abandoning the site. The ONE silver lining is that he gets very angry when others use his tactics against him. I suggest everyone do the same.

Since I have defeated Obama_socks, I must move on to greener pastures.

I found a grammar mistake. Hire me.

FrankHerbert, stop with the ad-hominem bs,... it is you who has been trashing this site, and everyone knows it.

I only have the power of expressing my opinion here like everyone else. That's it. There is an upper limit to how much this should effect you, if you are secure in your own point of view.

If you don't agree with a post of mine then make a counter argument. I am corrected some times here and am grateful for it. Otherwise, just relax and enjoy basking in the magnificence of my erudition.

Your primary reason for being here is to promote your political agenda, defend those who express the same, and troll those who don't. The only people who don't see that are those who benefit from your trolling e.g. ryggesogn2.

You spend more time with your off topic rants about people voting down your comments "without reading them" than you do on actual science. One usually doesn't need to read more than a few words into your posts to determine whether they are political trash or not. When you do attempt to talk science, your posts end up such a garbled mess they are indecipherable. The use of philosophical buzz words does not make you intelligent nor correct.

When you do attempt to talk science, your posts end up such a garbled mess they are indecipherable. The use of philosophical buzz words does not make you intelligent nor correct.

Why would you spend time troll rating and "generalizing the character of my posts" in an subjective and ad-hominem fashion, when you instead could have provided counter arguments?

I have posted many times on GR, QM, and have never proposed a new crank tertheory. I can provide references to my posts on philosophy of physics,... so those posts are well established as well, despite your personal ignorance causing them to appear "indecipherable".

All I see from you is more of your vague Jerry-Springer character assassination BS, with zero substance.

No, the difference in refraction angle is dependent on the wavelength. In refraction, each wavelength refracts at a different angle.

Yes, obviously refraction depends on wavelength, but the amount of refraction in general depends on the refracting medium. If the average refraction is small, the difference between the amount of refraction of two wavelengths will be very small.

In gravitational lensing each wavelength bends at the exact same angle.

You know this for a fact, do you?

Producing rings, or multiple images is small? Uh huh,,,

Rings and multiple images are more likely produced by an irregularly shaped convex lens than gravity, which should act like one central point at the centre of mass for any light passing at a distance.

No, the difference in refraction angle is dependent on the wavelength. In refraction, each wavelength refracts at a different angle.

If the average refraction is small, the difference between the amount of refraction of two wavelengths will be very small.

But in gravitational lensing the difference is ZERO.Ya did know that we have spectroscopes that are so sensitive we actually use microscopes to view the output?

In gravitational lensing each wavelength bends at the exact same angle.

You know this for a fact, do you?

Yes indeedy. Seen it with my own eyes.

Producing rings, or multiple images is small? Uh huh,,,

Rings and multiple images are more likely produced by an irregularly shaped convex lens than gravity, which should act like one central point at the centre of mass for any light passing at a distance.

Again, that's not so. Gravity affects all wavelengths equally. Refraction does not. It's SO easy to tell the difference.

@Q-Star

But in gravitational lensing the difference is ZERO.

Given that refraction is different for each wavelength in any medium due to propagation in the medium at a different speed (demonstrated in many experiments) and given that a perfect vacuum is unobtainable even in intergalactic space, then photons of different wavelengths will be travelling at different speeds past a gravitational point and will therefore be deflected at different angles. Therefore your statement is illogical. I suggest that the electronic measures introduced to eradicate optic lens imperfections actually distort what is seen, and you are viewing a computer generated simulation rather than reality.

Gravity affects all wavelengths equally.

It shouldn't, though, should it?

Yes indeedy. Seen it with my own eyes.

Should have gone to Specsavers....

Given that refraction is different for each wavelength in any medium due to propagation in the medium at a different speed (demonstrated in many experiments)

What?

then photons of different wavelengths will be travelling at different speeds past a gravitational point and will therefore be deflected at different angles.

What?

Therefore your statement is illogical. I suggest that the electronic measures introduced to eradicate optic lens imperfections actually distort what is seen, and you are viewing a computer generated simulation rather than reality.

What? Electronic measures? Optic lens imperfections? Computer generated simulation? Gobbledygook?

Gravity affects all wavelengths equally.

It shouldn't, though, should it?

Why shouldn't it? We observe that it does. Is this some stuff ya read on a crank website or crank video? It sounds like the gobbledygook of Ken Hughes et al.

This is the most basic geometrical optics.

I see, you're hearing about dispersion first time. It's not possible to discuss any deeper things with you, after then.

We're not discussing dispersion, after then. We were discussing refraction. Deep, I know, but try to keep up.

I see, you even don't understand the difference between refraction and dispersion. You never heard of refraction different for each wavelength due to propagation of light in the medium at a different speed, do you?

Of course I have Zeph. That is exactly the point I was trying to make with the fellow. It's exactly why gravitational lensing and geometrical lensing are so very easy to tell apart.

The fellow hates any thing that has "gravity" mentioned in it. I was merely pointing out the fact he picked the single best evidence for dark matter there is. It's the only evidence that is incontrovertible using any known physics. Galaxy rotation, cluster mechanics, etc, have at least some modicum of question (if ya are willing to entertain MOND or TeVeS solutions), but there is NO viable alternative to dark matter in gravitational lensing without completely discounting ALL of GR and ALL geometric optics.

It's exactly why gravitational lensing and geometrical lensing are so very easy to tell apart

Geometric lenses may not exhibit dispersion too. The sign of dispersion may be both positive, both negative or close to zero. Vacuum is behaving like the metamaterial, in which the normal dispersion is balanced with anomalous dispersion in similar way, like the rain inside of http://aetherwave...les.html between rainbows during heavy rain.

Ya are entirely correct there Zeph, until ya inserted a link to the AWT.

Hmm. I see multiple erroneous comments from all sides. At any rate, lensing due to cold galactic halos should be at the level of a homework problem at the advanced undergrad or grad-student level. I mean, I assume that there is some "well known" asymptotic formulas for refraction and dispersion through cold, low-density gasses. Isn't that formula googlable, somewhere, or in some atomic physics text? After that, you just plug in the number for the observed angle of refraction, crank the formula, see what the needed density (and maybe temperature) needs to be, compute the total mass of the needed gas, and see if that's plausible.

Presumably, if there's significant chromatic abberation, that would also become clear. If the answers are plausible, there would then be a huge WTF with regards to gravitational lensing. Are there really that many astronomers who never bothered to double-check such results, you think?

At any rate, lensing due to cold galactic halos should be at the level of a homework problem at the advanced undergrad or grad-student level. I mean, I assume that there is some "well known" asymptotic formulas for refraction and dispersion through cold, low-density gasses.

That is the point. The behavior of light due to refraction, is quite different than that due to gravitational lensing.

Presumably, if there's significant chromatic abberation, that would also become clear.

Now ya got it, there is NO observed chromatic aberration in gravitational lensing.

Are there really that many astronomers who never bothered to double-check such results, you think?

They did bother, ad nausium, as undergrads. In laboratory practical after laboratory practical

Are there really that many internet amateurs who think that people who have studied these things over decades would "overlook" the obvious? That's the question ya should be asking.

My first comment, which is factual, got rated a 1 with 7 votes. Strange so I checked it and 6 of the 7 names have never made a comment. And then I noticed that those same names appear in every low rated comment I've made. And one, VendicarH, has voted every single comment in my activity page a one. You would think there would be fewer morons here. Like if it really bothered me I'd just get another name. lol

Here are the voters for my previous comment, only shavera has posted a comment, I'm assuming the rest are fake.

shavera | open | toot | Colombe | Father Brrenk | VendicarH | Dalriada |

@Q-Star

....the single best evidence for dark matter there is. It's the only evidence that is incontrovertible using any known physics.

So gravitational lensing only works if Dark Matter exists. And gravitational lensing is the single best evidence for Dark Matter.
Your logic is up to your usual standard, Q-Star.
I repeat, there ain't no Dark Matter, Dark Energy, Gravity, Gravity Waves, Gravitons, Gravitinos, etc. Let me know as soon as you find any evidence to the contrary!

Really? I am a physicist reader & I know energy fields have associated gravity fields. Why is that? Maybe "toot" knows & he can explain in to us.......?

I wonder if "toot" might know that when a photon is emitted from an atom, the atom becomes lighter by the quantity of the transformed mass, a lighter atom means less gravity associated with that atom because the transformed mass carried it away. We studied this in nuclear reactor design in engineering school.

Mass has energy equivalence, but the form of the energy carried away by an emitted photon is momentum - relativistic mass, measured in units of h-bar. The amount of energy carried away determines the wavelength of the photon, not its velocity. This relativistic mass of the photon is only relevant to its interaction energy with other mass. Photons do not gravitate.

A common, related misapprehension is that the mass of a compressed spring increases.. "mass equivalence" does NOT imply energy per se is "massive". ;)

This may be a stupid question, but "causing the photon to slow dramatically"- what about the speed of light? How do photons slow down?

The speed depends on the medium through which it is propagating.
http://www.news.h...ght.html

The speed of light is constant in its own reference frame - by definition, it can only exist at C. All "slow light" phenomena are due to the light taking a protracted path through the material.

In an extreme example, a single photon enclosed in a bubble with total internal reflection and a diameter equal to the wavelength would appear stationary to an outside observer. Its velocity is still C though...

Mass has energy equivalence, but the form of the energy carried away by an emitted photon is momentum - [...] This relativistic mass of the photon is only relevant to its interaction energy with other mass. Photons do not gravitate.

Is not that the stress-energy tensor in GR includes components of momentum and energy density, say otherwise? All forms of energy should .gravitate', even pressure.

Mass has energy equivalence, but the form of the energy carried away by an emitted photon is momentum - [...] This relativistic mass of the photon is only relevant to its interaction energy with other mass. Photons do not gravitate.

Is not that the stress-energy tensor in GR includes components of momentum and energy density, say otherwise? All forms of energy should .gravitate', even pressure.

That is correct, in GR there no pure distinction between mass & energy. Pressure is simply a manifestation of kinetic energy of particles, thermal energy. Gravity interacts with everything, matter AND energy, it affects the spacetime in which all matter AND energy exists in.

So gravitational lensing only works if Dark Matter exists.

No.

I repeat, there ain't no Dark Matter, Dark Energy, Gravity, Gravity Waves, Gravitons, Gravitinos, etc. Let me know as soon as you find any evidence to the contrary!

On previous occasions, you were asked kindly to drop a stone on your foot. It's that effect that is called "gravity", therefore it does not make logical sense to say "there [is] no Gravity".

I don't wish to derail the thread too far with this, however i have a nagging doubt that says 'energy' has to be defined in relation to some other component of the system in question - that is, something can only have energy in relation to something else.

Consider the mass of a system comprising a rubber balloon and bellows connected by a pipe with a valve; if work is done at the bellows, fluid moves into the balloon and so it has energy relative to the lower pressure in the bellows.

Does the system's net mass change if we open the valve? What if we clamp the bellows shut, then open the valve - does the bellow's gravitational interaction increase?

I regard pressure more in terms of EM force than KE / heat, but the notion of a gravity acting upon it just seems like a non-sequitir.. Gravity is an interaction between masses, as magnetism is to charge. I think we're confusing "mass equivalence" and "mass" here..

I don't with to argue with Einstein, just this interpretation..

@Noumenon

On previous occasions, you were asked kindly to drop a stone on your foot. It's that effect that is called "gravity", therefore it does not make logical sense to say "there [is] no Gravity".

True, that "effect" is called "gravity". The argument is that gravity does not exist as a force. The stone strikes your foot because the Earth, you, and the stone are all expanding, and the expanding Earth thrusts your foot up against the stone.

I regard pressure more in terms of EM force than KE / heat, but the notion of a gravity acting upon it just seems like a non-sequitir.. Gravity is an interaction between masses, as magnetism is to charge. I think we're confusing "mass equivalence" and "mass" here..

Not in GR. In a neutron star (of the right mass for the example), pressure becomes a significant additional source of gravitation, and acts as a runaway feedback mechanism, resulting in an inevitable collapse to a black hole,... where given the starting mass-only-source of gravity, it wouldn't have.

something can only have energy in relation to something else.

Only in relation to how that energy interacts with something else. Energy is the ability to preform work. The most intuitive way to visualize it is it is an ability, a property.

Does the system's net mass change if we open the valve? What if we clamp the bellows shut, then open the valve - does the bellow's gravitational interaction increase?

Gravitation is only ONE manifestation of energy. The mass doesn't necessarily change. But if ya transfer energy, SOMETHING must change.

I regard pressure more in terms of EM force than KE / heat, but the notion of a gravity acting upon it just seems like a non-sequitir.. Gravity is an interaction between masses, as magnetism is to charge.

Pressure is often defined by mass density and heat. It is a measure of force/area. Gravity affects the massless photon, in gravitational lensing, in gravitational redshift.

@Noumenon

On previous occasions, you were asked kindly to drop a stone on your foot. It's that effect that is called "gravity", therefore it does not make logical sense to say "there [is] no Gravity".

True, that "effect" is called "gravity". The argument is that gravity does not exist as a force. The stone strikes your foot because the Earth, you, and the stone are all expanding, and the expanding Earth thrusts your foot up against the stone.

General relativity does not describe gravity it in terms of force either but still calls it gravitation,... nor denies that it exists.

Can someone tell me why all EM frequencies bend equal under gravity when each frequency has a different energy? Then if you would be so kind as to explain also why we say a EM has no mass if gravity can bend light.

I'll be honest I think it has more to do with with how the electron shells transpose the energy imparted by the photons at cold temps because there is maybe something about QM we just don't understand yet at very low temps that made them seem to combine as seen here in this article. To me (and I know this isn't really a science view) it feels that the things we see at very low temps when we dampen the noise so we can view QM where light slows can also slow the change in a electron moving from one shell to the next. Or maybe just maybe both photons can move an electron to a higher shell and when that electron comes back down both are given back off (conserved) in a case where we were sure it takes only one electron. Im sure we can all agree we really don't know yet.

Can someone tell me why all EM frequencies bend equal under gravity when each frequency has a different energy? Then if you would be so kind as to explain also why we say a EM has no mass if gravity can bend light.

Gravity does not bend light. Gravity is curvature of spacetime. The photons (light) travel the curved paths through spacetime. That is why the photons don't disperse at different angles/wavelengths in the presence of gravity. The curvature is the same for each of the wavelengths. They each travel the same path.

In an optical lens light disperses because the medium interacts more strongly with one frequency than another.

Now that I have more room... We assume that the electron jumps from one shell to the next with no time between. So at any temp above absolute zero lets say the electron has speed enough to decide if the energy of a EM fits it's needs or be absorbed then given off. If light travels at different speeds within different material then also why can't the speed of an electron changing between shells be changed and if that works out to be true why not a double kick of photons??? bottom line if light can change speed within any one thing why can't the the jumping of shells for electrons. At high temps things happen very fast and the right one seems to only work but slow it down and the electron has not enough time to reject it before its looking at both thinks its enough moves up and then later drops back down releasing both like we would let go of two rocks with one hand...

Gravity does not bend light. Gravity is curvature of spacetime.

Yes thank you that slipped from me for the moment, I'm sorry your right. That would allow for all frequencies. Still if EM's all have energy why not mass?

"Gravity does not bend light. Gravity is curvature of spacetime." ya know something... If string theory says that gravity is a string bound to this 3D+1 universe with only one end tied here and the other off in some wild dimension couldn't space time be curved by the ends of those strings trying to recombine? The larger a objects mass the more ends that dangle over there the stronger the combined total local force the more bending of space time??? Something to think about anyway. Wish I had the math to see if its right but I lost those skills.

The photonic "molecule" described in this article is quite similar to a Cooper pair, as in BCS superconductivity. I'm surprised that the authors did not mention the similarity, and surprised further that none of the 82 prior comments mention the similarity.

I'll go one step further. The similarity is not superficial. Art Winfree's law of coupled oscillators, which dates to 1967, explains both. Winfree proposed that periodic oscillators have a tendency to couple in various ways. The simplest way is a two oscillator system in which the two couple exactly anti-synchronously. (Think 0 degrees and 180 degrees--exactly.)

Winfree's law is well developed mathematically: Kuramoto, Strogatz and Mirollo have followed in his math footsteps. Winfree applied his law only to biology. Ermentrout has extended Winfree's biological investigations. For many years, I have proposed that Winfree's law applies extensively in physics--to all phases of matter and their transitions, for example.

@Macksb

For many years, I have proposed that Winfree's law applies extensively in physics--to all phases of matter and their transitions, for example.

I agree. In my view, matter comes into existence when two or more fundamental particles interact. Without that interaction, nothing exists in our universe. When the interaction takes place, matter exists in our universe. I have long argued against the existence of Dark Matter, but, should it exist, I suggest it could be matter springing into existence when two or more fundamental particles interact briefly then disappearing when the interaction ceases. When the interaction persists, matter remains in existence. Visualise two planets passing by each other, if the relative velocity is too great, the interaction is brief. If the relative velocity is lower, they orbit each other, and matter persists in our universe. As most encounters are brief, DM slips in and out of our universe, in far greater proportion than enduring encounters.

"Gravity does not bend light. Gravity is curvature of spacetime." ya know something... If string theory says that gravity is a string bound to this 3D+1 universe with only one end tied here and the other off in some wild dimension couldn't space time be curved by the ends of those strings trying to recombine? The larger a objects mass the more ends that dangle over there the stronger the combined total local force the more bending of space time??? Something to think about anyway. Wish I had the math to see if its right but I lost those skills.

When ya can tie the quantum world to GR, with a model that works, ya can step up and collect your Nobel Prize. That is the Holy Grail of Physics at this time. Hundreds of very smart people are working on it, and have been working on it for decades.

Yes thank you that slipped from me for the moment, I'm sorry your right. That would allow for all frequencies. Still if EM's all have energy why not mass?

What do ya mean by "EM's all have energy"? Photons mediate electromagnet fields, but they do not have a mass. Electromagnet fields don't have mass, though the objects that create them do. Energy is the ability to do work. A quality of a thing that allows it to interact with other things,,,, it's a quantifiable attribute of physical things.

Can anyone who knows a decent amount about this tell me if it's a Bose-Einstein Condensate?

Not in GR. In a neutron star (of the right mass for the example), pressure becomes a significant additional source of gravitation, and acts as a runaway feedback mechanism, resulting in an inevitable collapse to a black hole,... where given the starting mass-only-source of gravity, it wouldn't have.

Again i struggle with this! Pressure eventually becomes quantum (due to Pauli exclusion) but surely a shrinking star's increasing density is the reason for increased gravity?

The problem i have is that if we loosely accept that "energy" gravitates, folks like Benni, above, conclude that photons do, too, and then use this conclusion to hypothesise about dark matter / energy / accelerating lambda etc..

Besides, if light gravitates (and this is distinct from lensing) then the combined light of distant, disparate sources (such as stars in a galaxy) would merge into irreducibly-narrow beams!

Again i struggle with this! Pressure eventually becomes quantum (due to Pauli exclusion) but surely a shrinking star's increasing density is the reason for increased gravity?

The gravity doesn't "increase" due to increasing density. Gravity is mass dependent.

The problem i have is that if we loosely accept that "energy" gravitates, folks like Benni, above, conclude that photons do, too, and then use this conclusion to hypothesise about dark matter / energy / accelerating lambda etc..

No need to loosely accept that "energy" gravitates. We directly observe it. Gravity is source a of energy. Dark matter doesn't seem to interact electromagnetically. Acceleration is directly observed also.

disparate sources (such as stars in a galaxy) would merge into irreducibly-narrow beams!

The fundamental force which drives light (EM) is 40 order of magnitudes greater than gravity. A massless particle can't compete with some assistance from massive particles.

@ Mr. Vibrating,

If the sun were to be instantly reduced the density required to become a black hole, the Earth would still experience the same gravitational field that it does now. The Earth's orbit would remain the same,,, if the Sun's mass remained the same, the gravity experienced at any distance "r" would remain the same.

When ya try to tie the quantum effects of particles to macro effects of gravity, ya are going to run into failures in the science. Very smart people have been working on it for almost a century now.

Only in relation to how that energy interacts with something else. Energy is the ability to preform work. The most intuitive way to visualize it is it is an ability, a property.

Yes, it's potential.. and thus relative. A loaded spring has mechanical PE, but negligible EM PE, say.

Gravitation is only ONE manifestation of energy. The mass doesn't necessarily change. But if ya transfer energy, SOMETHING must change.

Kinda, GMH would be the energy term. But a closed system's balance of energy should have no effect on its gravitational susceptibility..

Pressure is often defined by mass density and heat. It is a measure of force/area. Gravity affects the massless photon, in gravitational lensing, in gravitational redshift.

Yes, p=F/A, and likewise F=MA, but mass doesn't increase with pressure, and gravity acts upon spacetime - the substrate, not the pertubations within it.

Light doesn't gravitate, anymoreso than subjective energy terms.

The photonic "molecule" described in this article is quite similar to a Cooper pair, as in BCS superconductivity. I'm surprised that the authors did not mention the similarity, and surprised further that none of the 82 prior comments mention the similarity.

Interesting thought, but isn't cooper pairing most significant in that it allows fermions to 'cross' the Pauli exclusion barrier, by combining their half-integer spins into whole-number mutiples? Ie. it's not the spin-binding that's so important, as the resulting superposition capability - which photons already have. Hence it's not quite the same class of phase transition, but something new and distinct..

@ Mr. Vibrating,,

I think that maybe what is stumping ya is the E = mc^2 thing,,,, energy is not an independent "thing". All energy is associated WITH a particle of some type. It is an attribute of something, not a something that has an independent existence. E = mc^2 is a mass-energy equivalence relationship.

If ya convert mass to energy, that energy is still associated with a particle. Be it a photon, and alpha particle, beta particle, or some other massive particle or even spacetime itself. Energy is ALWAYS tied to some "platform", tied to some "thing" which possesses that "energy".

but mass doesn't increase with pressure

But energy does, and 'flow of momentum', pressure, is expressed in Einsteins Stress-Energy tensor and is in proportion to the curvature tensor on the other side of the equation.

gravity acts upon spacetime - the substrate, not the pertubations within it.

No, gravitation IS perturbations of space-time.

Energy is ALWAYS tied to some "platform", tied to some "thing" which possesses that "energy".

In qm context, energy is always associated with an observable thing.

I agree. In my view, matter comes into existence when two or more fundamental particles interact. Without that interaction, nothing exists in our universe. When the interaction takes place, matter exists in our universe. I have long argued against the existence of Dark Matter, but, should it exist, I suggest it could be matter springing into existence when two or more fundamental particles interact briefly then disappearing when the interaction ceases. When the interaction persists, matter remains in existence. Visualise two planets passing by each other, if the relative velocity is too great, the interaction is brief. If the relative velocity is lower, they orbit each other, and matter persists in our universe. As most encounters are brief, DM slips in and out of our universe, in far greater proportion than enduring encounters.

I like this line of thought - after all, conservation, per Noether, is dependent upon temporal invariance. Transient interactions might skew net mass..

Gravity is a form of energy. Orbits decay as gravity waves are emitted.

Can anyone who knows a decent amount about this tell me if it's a Bose-Einstein Condensate?

I'm certainly no expert, but the answer i think is 'no' - a BSE is distinct in that it's a phase change from a superposition-exclusive to a superposition-capable state of matter.. where fermions combine their like-spins to take on the properties of bosons..

A loaded spring has mechanical PE, but negligible EM PE, say.

A loaded springs entire mechanical energy is a reflection of electromagnetism. That is what provides the force it contains.

GMH would be the energy term. But a closed system's balance of energy should have no effect on its gravitational susceptibility..

If the system is "closed" that is correct. But the gravitation comes from "outside" the system if mass or height if variable.

Yes, p=F/A, and likewise F=MA, but mass doesn't increase with pressure,

That depends on the scale under consideration. But if it does, it is because of a contribution of matter or energy from "outside".

Light doesn't gravitate, anymoreso than subjective energy terms.

Of course it does, it is often included in balance sheets of "stuff" when doing the maths. But it is a minuscule contribution when compared to other "stuffs". In the early universe radiation in the form of photons dominated over matter.

The gravity doesn't "increase" due to increasing density. Gravity is mass dependent.

I mean field densities, obvioushly..

No need to loosely accept that "energy" gravitates. We directly observe it. Gravity is source a of energy. Dark matter doesn't seem to interact electromagnetically. Acceleration is directly observed also.

Again, G is a force, not an energy term, which would require mass and displacement variables in addition to gravity. The notion that energy has some kind of objective existence able to cause spacetime curvature just seems oxymoronic.

disparate sources (such as stars in a galaxy) would merge into irreducibly-narrow beams!

The fundamental force which drives light (EM) is 40 order of magnitudes greater than gravity. A massless particle can't compete with some assistance from massive particles.
Not sure what you're saying - that massive matter inhibits gravitation of massless matter? Either massless matter gravitates or it doesn't..

@ Mr. Vibrating,

If the sun were to be instantly reduced the density required to become a black hole, the Earth would still experience the same gravitational field that it does now. The Earth's orbit would remain the same,,, if the Sun's mass remained the same, the gravity experienced at any distance "r" would remain the same.

Exactly my point, and so refuting Noumenon's above assertions to the contrary.

When ya try to tie the quantum effects of particles to macro effects of gravity, ya are going to run into failures in the science. Very smart people have been working on it for almost a century now.

S'truth.. Precisely my reservation re. gravitating photons.. and what seems to me the misguided notion of all energy terms all being subject to gravity..

@ Mr. Vibrating,,

I think that maybe what is stumping ya is the E = mc^2 thing,,,, energy is not an independent "thing". All energy is associated WITH a particle of some type. It is an attribute of something, not a something that has an independent existence. E = mc^2 is a mass-energy equivalence relationship.

If ya convert mass to energy, that energy is still associated with a particle. Be it a photon, and alpha particle, beta particle, or some other massive particle or even spacetime itself. Energy is ALWAYS tied to some "platform", tied to some "thing" which possesses that "energy".

Yes, this is precisely the nub of the gist of my contentions.. i think.. and which renders the notion of any such energy terms 'gravitating' a little bit too hand-wavy, for me...

The fundamental force which drives light (EM) is 40 order of magnitudes greater than gravity. A massless particle can't compete without some assistance from massive particles.

Not sure what you're saying - that massive matter inhibits gravitation of massless matter? Either massless matter gravitates or it doesn't..

It does "gravitate". But it is a minuscule amount due to the fact it is massless. This is experimentally well tested science. Nothing controversial about it at all.

If ya convert mass to energy, that energy is still associated with a particle. Be it a photon, and alpha particle, beta particle, or some other massive particle or even spacetime itself. Energy is ALWAYS tied to some "platform", tied to some "thing" which possesses that "energy".

Yes, this is precisely the nub of the gist of my contentions.. i think.. and which renders the notion of any such energy terms 'gravitating' a little bit too hand-wavy, for me...

It's well tested science. E = mc^2 is about as robust and consistent as anything in modern physics. It's not hand waving at all. It's tested on the quantum level, in fusion reactions, where mass goes down after a quanta energy is extracted. And mass goes up when a quantum of energy is added. One 4Helium weights less than four 1Hydrogen nuclei.. There are many examples in routine physics which are not "hand waving".

but mass doesn't increase with pressure

But energy does, and 'flow of momentum', pressure, is expressed in Einsteins Stress-Energy tensor and is in proportion to the curvature tensor on the other side of the equation.

Again, this is confusing relativistic mass with physical mass - the relativistic kind only applies in the interaction with matter, not in some disembodied, ethereal form. Photons do not gravitate, and relativistic mass only has relevance to their interactions with other matter.

Can you describe a physical mechanism by which a loaded spring's gravitation increases? What factors within its structure might cause this?

gravity acts upon spacetime - the substrate, not the pertubations within it.

No, gravitation IS perturbations of space-time.

Yes, but it's spacetime that's being directly influenced, not the actual photons, which in their own frame always propagate in straight lines.

Or else we might have our lightsabres already..

It's well tested science. E = mc^2 is about as robust and consistent as anything in modern physics. It's not hand waving at all. It's tested on the quantum level, in fusion reactions, where mass goes down after a quanta energy is extracted. And mass goes up when a quantum of energy is added. One 4Helium weights less than four 1Hydrogen nuclei.. There are many examples in routine physics which are not "hand waving".

But the argument here is that energy itself gravitates, which is a misapprehension of relativistic mass. Mass equivalence does NOT imply all energy gravitates. Radiation carries mass away, but that relativistic mass is only subject to gravity when it interacts with something else.

Essentially you're arguing that parallel light beams in flat space will eventually converge, yet this most definitely runs counter to all observations and experiments...and, i'm arguing, all coherent theory!

Can you describe a physical mechanism by which a loaded spring's gravitation increases? What factors within its structure might cause this?

If the electrons in the material are driven to higher energy states, the mass will go up. If the mass goes up, the gravitation goes up. It is a minuscule thing. But it is very well understood and tested physics. When the spring is sprung, then energy is released from the system, and it's mass will decrease as the electrons settle to less energetic states. When an electron falls to a less energetic state, energy is carried away by a photon, that loss of energy ALWAYS has a reduction of mass associated with it.

If the sun were to be instantly reduced the density required to become a black hole, the Earth would still experience the same gravitational field that it does now. The Earth's orbit would remain the same,,, if the Sun's mass remained the same, the gravity experienced at any distance "r" would remain the same.

Exactly my point, and so refuting Noumenon's above assertions to the contrary.

It does not refute what I said. In other words, because pressure itself induces gravitation, there is a threshold limit of maximum density where there can not be any stable configuration of matter,.. thus leading to a black hole.

In the accelerated expansion of universe case, 'dark energy' (vacuum energy ~ cosmological constant, whatever) must be a negative pressure contribution to gravitation, IOW, pressure, negative or positive causes gravitation.

@Q-Star

Again, i think you're just re-stating the commonly-held misunderstanding i'm trying to counter - the mass of the system is constant, hence the loaded and unloaded spring are subject to equal gravity.

Besides, i'd attribute the form of energy in sprung tension to inter-molecular (ie. essentially EM) force gradients, rather than electron energy levels - it's the atomic/molecular density that gets warped.

Certainly, during the act of changing - while the spring is in motion, loading or unloading - then relativistic mass applies and thus so will its gravitational interaction, albeit by infinitesimal degree, as you say. But the static loaded spring only has increased PE, and this is excluded from the stress energy tensor - which applies to KE, specifically in its interaction with matter.

Show me where parallel light beams converge in flat space and i'll accept that all energy, per se, gravitates.... clearly however this is a nonsense, and there can be no paradoxes..!

It does not refute what I said. In other words, because pressure itself induces gravitation, there is a threshold limit of maximum density where there can not be any stable configuration of matter,.. thus leading to a black hole.

Pressure in and of itself is PE, and thus inapplicable to the stress-energy-momentum tensor.

Pressure is an effect of gravitation, not a cause..!

In the accelerated expansion of universe case, 'dark energy' (vacuum energy ~ cosmological constant, whatever) must be a negative pressure contribution to gravitation, IOW, pressure, negative or positive causes gravitation.

Now you seem to be conflating force, pressure and energy! Yes, i agree DE may be regarded in terms of pressure, as might gravity, but it's the energy source driving this pressure that's anomalous.

Besides, If your hypotheses that 'all energy gravitates' were correct, surely DE would add to the universe's net gravity, rather than subtracting from it..?

Again, i think you're just re-stating the commonly-held misunderstanding i'm trying to counter -

Take a spherical cow in a vacuum,,,

Besides, i'd attribute the form of energy in sprung tension to inter-molecular (ie. essentially EM) force gradients, rather than electron energy levels - it's the atomic/molecular density that gets warped.

What do ya think causes EM force gradients?

But the static loaded spring only has increased PE, and this is excluded from the stress energy tensor - which applies to KE, specifically in its interaction with matter.

It's only excluded because of it's minuscule magnitude.

Show me where parallel light beams converge in flat space.... clearly however this is a nonsense, and there can be no paradoxes..!

Not nonsense & no paradox. Spacetime is not flat. 40 orders of magnitude separates the EM energy and gravitational energy of a photon. 40 decimal places separate the magnitude of the two phenomena.

It does not refute what I said. In other words, because pressure itself induces gravitation, there is a threshold limit of maximum density where there can not be any stable configuration of matter,.. thus leading to a black hole.

Pressure in and of itself is PE, and thus inapplicable to the stress-energy-momentum tensor.

You are just factually incorrect, as you can see from the components of the energy-momentum tensor. The trace component that is 'flow of momentum' IS pressure. As you can see also, the stress of the spring adds to gravity. (but of course the spring would break apart long before any significant measure of gravity could be generated).

If your hypotheses that 'all energy gravitates' were correct, surely DE would add to the universe's net gravity, rather than subtracting from it..?

Not if the pressure is negative, as I pointed out.

Gravity is a form of energy. Orbits decay as gravity waves are emitted.

LOL no, gravity is a force or an acceleration if you prefer, but not an energy form. Never an energy form.

To make an energy term out of it requires the inclusion of some mass, and displacement.

And an orbit decays because either the orbiting body has lost momentum, or because the gravitational force has increased. Assuming that by "decay" you mean "to fall inwards".

Besides if the removal of energy from the system by the action of gravity waves causes gravity to increase, then your hypothesis might better be stated as "gravity is the absence of energy". It'd just be more self-consistent, if no less misguided... ;)

Gravity is a form of energy. Orbits decay as gravity waves are emitted.

LOL no, gravity is a force or an acceleration if you prefer, but not an energy form. Never an energy form.

Actually he is correct. and you are factually incorrect again. Two orbiting neutron stars are in fact observed to lose orbital energy. As you can see here, the points are observation data, while the curved line is what is predicted using GR and the notion that gravitational waves carry away energy of the system.

Besides if the removal of energy from the system by the action of gravity waves causes gravity to increase

That's not what was stated, the orbital period decreases.

What do ya think causes EM force gradients?

Variable virtual photon fluxes exchanging quanta of positively and negatively signed ambient momentum in units of h-bar between charges in relative motion, per QED and SR etc.

Again though, this simply underscores why this relativistic momentum only counts during the transition phase. It's transient and inapplicable to the static system.

It's only excluded because of it's minuscule magnitude.

Mmm no i think it's question of static vs dynamic states, as described. The clues are right there in the term "relativistic momentum" - energy and mass are equivalent in that they're covariant, or conjugate, whatever the right term is; more of one = less of the other.

Not nonsense & no paradox. Spacetime is not flat. 40 orders of magnitude separates the EM energy and gravitational energy of a photon...

Not flat at local scales, but certainly is at general scales - we'd see light gravitating within the observable horizon..

You are just factually incorrect, as you can see from the http://i.stack.imgur.com/qAzuU.png The trace component that is 'flow of momentum' IS pressure. As you can see also, the stress of the spring adds to gravity. (but of course the spring would break apart long before any significant measure of gravity could be generated).

Again though it is this very interpretation i'm contesting, since it leads to clear paradoxes, as i've laboured already.. gravity acts upon the stressing or unstressing of the spring, not the internal state of either result.

Or forget springs and consider magnets - does gravity act upon entropy levels? This way, madness lies.. and mutually self-gravitating light beams would just be the beginning..

Not if the pressure is negative, as I pointed out.

Au contraire, you stated "IOW, pressure, negative or positive causes gravitation." - hence DE adds to the net gravity.. while also subtracting from it.. another paradox.

PE does not gravitate.

Gravity is a form of energy. Orbits decay as gravity waves are emitted.

LOL no, gravity is a force or an acceleration if you prefer, but not an energy form. Never an energy form.

Actually he is correct. and you are factually incorrect again. Two orbiting neutron stars are in fact observed to lose orbital energy. As you can see, the points are observation data, while the curved line is what is predicted using GR and the notion that gravitational waves carry away energy of the system.

That's not what was stated, the orbital period decreases.

Again, an ENERGY TERM implies a line integral of forces and displacements.. it's the energy under the curve, not the bloomin' axes.

If the force component DECREASED, binaries would drift apart! Hence GW's carry away the spatial component, not the G or M elements. Otto's claim that "Gravity is a form of energy." [..because..] "Orbits decay as gravity waves are emitted." is a non-sequitir, and "not even wrong".

The central argument here that all energy forms gravitate is based on a misapplication of GR. Photons carry energy, but they are not "energy" in and of themselves, and there is no gravitational interaction between parallel photons of any wavelength at any scale in a Euclidean universe. Were this otherwise then we'd read about it all the time, it would be a significant factor in determining distances and would mess up the whole "smaller - further away" dynamic. Since sizes of distant galaxies and groups correlate well to distances inferred via eg. type 1a observations, Occam would suggest something's amiss in our interpretation, and it's this robotic misapplication of the equivalence principle without consideration of the implications..

Light HAS energy. But light ISN'T energy itself. Energy doesn't gravitate, and neither does light. Gravity is a curvature of spacetime, an energy density fluctuation, force or acceleration.. but it isn't energy, and doesn't self-gravitate either.

LOL, taking Nounenon and Otto's suggestions together, any gravity well would form an instant closed-feedback loop, and the universe would have disappeared up it's own at the first instant...

If there's no more arguments (for now) then, notwithstanding that there are many ways of defining energy, where we denote it as "the potential to perform work", it is not subject to gravity.

LOL, taking Nounenon and Otto's suggestions together, any gravity well would form an instant closed-feedback loop, and the universe would have disappeared up it's own at the first instant...

Why?

This sounds somewhat confusingly, don't you think? In AWT the photons do indeed gravitate - the more, the more energetic they are. The photons of CMBR wavelength are essentially indistinguishable from CMBR background and they ignore the gravity field in essence (Hawking radiation), but the gamma ray photons do propagate like well defined particles and they're not only subject of gravitation, but they're doing gravity too. It's observable with luminosity of distant gamma bursts, which do propagate across whole Universe as rays and the self-gravitation of photons would explain it at least partially.

As noted earlier, by Q-Star and myself, photons have energy relative to some matter they interact with. They have no energy relative to one another - even if they're considered as fluctuations of an aether. I don't know anything about AWT but is that gamma ray anomaly you mention temporal, or spatial? ie. a k-capture type effect, bow shock interference etc., rather than lensing?

LOL, taking Nounenon and Otto's suggestions together, any gravity well would form an instant closed-feedback loop, and the universe would have disappeared up it's own at the first instant...

Why?

Otto says gravity is energy and you say energy gravitates. If you were both correct, the universe would be tiny and shrinking fast..

The energetic photons differ from harmonic Maxwell wave at the first look. They do propagate like the laser beams, which enables for example the construction of Leksell's gamma knife. Which means, once you collimate the single gamma ray photon, its path is not subject of Abbe's diffraction limit anymore. It propagates like the particle along well defined path for ever. Which brings the question, what such particles would do, if they would travel along parallel paths near each other. IMO they should revolve each other like any other massive particles and it's time to test it experimentally.

Hmmm, so an old CRT tweaked up into the UV and a couple of anti-parallel polarisation filters should reveal any rotation over sufficient distance. Maybe a long tube, with CRT and horizontal filter one end, and vertical filter over a phosphor screen at the other end.

Then you'd be able to show the rotation was a function of photon energy and distance, and fully characterise it..? ;)

Soz missed this earlier:

A loaded springs entire mechanical energy is a reflection of electromagnetism. That is what provides the force it contains.

yes but its change in PE wrt an applied H field is nil. Point is, PE is subjective, relative. Gravity can't act on notional properties. A loaded spring only has PE if there's some future prospect of it unloading.

If the system is "closed" that is correct. But the gravitation comes from "outside" the system if mass or height is variable.

Yes!

That depends on the scale under consideration. But if it does, it is because of a contribution of matter or energy from "outside".

Agreed.

Of course it does, it is often included in balance sheets of "stuff" when doing the maths. But it is a minuscule contribution.... In the early universe radiation in the form of photons dominated over matter.

You mean relativistic mass was greater than the rest mass, or else net gravity would decrease inversely to net entropy.

Otto's claim... "not even wrong"

Sorry mr vibrator you can lol and philo-ize all you want but of course these things are not MY conclusions but those of scientists.

"Gravitational waves carry energy away from their sources and, in the case of orbiting bodies, this is associated with an inspiral or decrease in orbit. Imagine for example a simple system of two masses — such as the Earth-Sun system — moving slowly compared to the speed of light in circular orbits. Assume that these two blahblah"

"Orbital lifetime is one of the most important properties of gravitational radiation sources. It determines the average number of binary stars in the universe that are close enough to be detected. Short lifetime binaries are strong sources of gravitational radiation but are blahblah"
http://en.wikiped...al_waves

-I think these scientists would conclude that what you are saying is not even close to not even wrong.

If you were both correct, the universe would be tiny and shrinking fast..

I think perhaps this might describe your intellect? You pretend to know a lot about the subject, but dont seem to be aware of the standard and widely-accepted explanation for the source of gravity waves.

Why is that?

If you were schooled in the subject you would already have some counter-explanation in defense of your theories. But gravity waves from orbital decay seems to be new info to you.

How come?

I know what youre going to say - gravity waves havent been detected directly yet. But they are getting very close.
http://en.wikiped...detector
http://phys.org/n...ity.html

@MrV

You mean relativistic mass was greater than the rest mass, or else net gravity would decrease inversely to net entropy.

And this is just ONE of the illogical things about gravity considered as a force.
Why is it that, if you weigh a lump of lead on the surface of the Earth to be X gms., and you then hoist it up a pole of length L and weigh it again (using a spring balance, of course!), it weighs exactly the same X gms. But the "law" of gravity says that the force on it should be less, if the radius of the earth is R, then it should weigh F=Xgms=GEX/RR where E is the mass of the Earth. When hoisted up the pole, it should weigh F=GEX/(R+L)(R+L), which is LESS than X ----- but it still weighs Xgms.......
If you do this experiment yourself, you will need to go to the North or South Pole unless your maths is good!
@TheGhost

gravity waves haven't been detected directly yet. But they are getting very close.

Ain't no such thing as gravity waves, gravity is not a force.

Why is it that, if you weigh a lump of lead on the surface of the Earth to be X gms., and you then hoist it up a pole of length L and weigh it again (using a spring balance, of course!), it weighs exactly the same X gms. But the "law" of gravity says that the force on it should be less, if the radius of the earth is R, then it should weigh F=Xgms=GEX/RR where E is the mass of the Earth. When hoisted up the pole, it should weigh F=GEX/(R+L)(R+L), which is LESS than X ----- but it still weighs Xgms...

Pssst, Reggie,,,, X grams is a measure of mass. It will not change regardless of where ya hoist it. But if ya use a scale with enough resolution, ya will notice that the weight (in newtons) is less after ya hoist up a really high pole. Don't take my word for it. Google it up, variations in gravity have been measured to very minute precision. Altitude is one of the easier variations to measure. It's been done.

Have ya been listening to those silly Ken Hughes videos again?

@Q-Star

Pssst, Reggie,,,, X grams is a measure of mass. It will not change regardless of where ya hoist it.

Damn, I was hoping to get people hoisting weights up poles all over the planet.....

OK, as with others posting here, I am not a physicist. However, I am a Chem Engineer and I have three patents, so I don't classify myself as stupid either. Therefore, I must just be ignorant, and I need someone to elucidate (not hallucinate) me on these Three questions:

1) Didn't Einstein's proposal and the subsequent observation of starlight bending around the sun during an eclipse in ~1905 prove that light, aka a photon, does have mass???

2) If light does have mass, would it not be "pulled" or slowed (almost imperceptibly) by the mass of the Universe, in much the same way that it is slowed as it passes through dense objects? and then

3) Wouldn't that slowing impart a red shift to more distant objects and the false impression of an expanding universe?

What am I missing here?

Didn't Einstein's proposal and the subsequent observation of starlight bending around the sun during an eclipse in ~1905 prove that light, aka a photon, does have mass???

(Just for historical accuracy. The early observations of bending light during an eclipse were well within the error of the experimental setup. It was only much later that there was unequivocal proof of bending)
What these experiments showed is that space is curved. Light always travels in a straight line.

Wouldn't that slowing impart a red shift to more distant objects

Light does get redshifted if it escapes from a gravitational field (it doesn't slow down).
When it just passes a gravitational field it gets blueshifted on the approach and redshifted on the way out (no net effect).
The further out we look the more redshift we see. If the universe weren't expanding we would see an identical redshift no matter whether a galaxy was close or far away from us.

"Why is it that, if you weigh a lump of lead on the surface of the Earth to be X gms., and you then hoist it up a pole of length L and weigh it again (using a spring balance, of course!), it weighs exactly the same X gms.

1. A gram is a unit of mass, not weight. Weight is a force. A gram is a gram, whether on the moon or on the Earth. A spring balance does correctly measure force though.
2. The weight of objects does reduce as you move away from the center of the earth. You can find maps online to see how much less the force due to gravity is on mountain peaks. Just google gravity map and look at all the pretty pictures.

What do *you* think gravity is? Whatever it is, its net effect is a force between objects. To arrogantly assume that whatever causes that force can't vary like a wave is assuming a lot with no sound basis.

Didn't Einstein's proposal and the subsequent observation of starlight bending around the sun during an eclipse in ~1905 prove that light, aka a photon, does have mass???

(Just for historical accuracy. The early observations of bending light during an eclipse were well within the error of the experimental setup. It was only much later that there was unequivocal proof of bending)
What these experiments showed is that space is curved. Light always travels in a straight line.

Interestingly, the bending path of light near a massive body was already known (not observed though) a hundred years before Einstein, based on Newtonian mechanics and the assumption of light as a particle. In fact, Einstein's initial calculations (in 1911) arrived at about the same value(!). Only as GR developed further, was it determined that the deflection would be twice the Newtonian amount.

... luckily for Einstein, the first few observational attempts were unreliable, because had they been sufficiently accurate, they would have proven Einstein wrong (<1915).

@meBigGuy

What do *you* think gravity is?

I think all matter in our universe is expanding at the same rate, including you and me. TIme is related to the stage of expansion, and TIme passes as matter expands. "Gravity" is the force necessary to accelerate two objects away from each other in order to maintain the relative separation of the objects. So, gravity is not a force, but we perceive an effect as if it was. Although I admit to making facetious comments and suggestions not to be taken seriously, in this particular case I am serious. There are several articles available via Google to refute this theory, but if you apply reasonable logic against them they are spurious. There is no "proof" of the existence of gravity which cannot be ascribed equally to expansion theory.

@meBigGuy

What do *you* think gravity is?

I think all matter in our universe is expanding at the same rate, including you and me. TIme is related to the stage of expansion, and TIme passes as matter expands. "Gravity" is the force necessary to accelerate two objects away from each other in order to maintain the relative separation of the objects. So, gravity is not a force, but we perceive an effect as if it was. Although I admit to making facetious comments and suggestions not to be taken seriously, in this particular case I am serious. There are several articles available via Google to refute this theory, but if you apply reasonable logic against them they are spurious. There is no "proof" of the existence of gravity which cannot be ascribed equally to expansion theory.

But gravity is so much weaker than the forces holding atoms and molecules together, so objects would not expand also.

Beware that a gang of Harvard "researchers" has already stole in Nature journals and, with further support of the MIT's ones, in ASC Nano Lett both the ideas and money of taxpayers. There are numerous swindlers from David H. Koch Inst. for Integrative Cancer Research and Dept of Chemical Engineering, also with Dept of Chemistry and Chem. Biology and School of Eng and Applied Science of Harvard University at http://issuu.com/...vard_mit .
Their plagiarisms titled Macroporous nanowire nanoelectronic scaffolds for synthetic tissues (DOI: 10.1038/NMAT3404) and Outside Looking In: Nanotube Transistor Intracellular Sensors (dx.doi.org/10.1021/nl301623p) were funded by NIH Director's Pioneer Award (1DP1OD003900) and a McKnight Foundation Technological Innovations in Neurosc Award, also a Biotechnology Research Endowment from the Dep. of Anesthesiology at Children's Hospital Boston and NIH grant GM073626, DE013023, and DE016516.

Beware that a gang of Harvard "researchers" has already stole in Nature journals and, with further support of the MIT's ones, in ASC Nano Lett both the ideas and money of taxpayers. There are numerous swindlers from David H. Koch Inst. for Integrative Cancer Research and Dept of Chemical Engineering, also with Dept of Chemistry and Chem. Biology and School of Eng and Applied Science of Harvard University at http://issuu.com/...vard_mit .
Their plagiarisms titled Macroporous nanowire nanoelectronic scaffolds for synthetic tissues (DOI: 10.1038/NMAT3404) and Outside Looking In: Nanotube Transistor Intracellular Sensors (dx.doi.org/10.1021/nl301623p) were funded by NIH Director's Pioneer Award (1DP1OD003900) and a McKnight Foundation Technological Innovations in Neurosc Award, also a Biotechnology Research Endowment from the Dep. of Anesthesiology at Children's Hospital Boston and NIH grant GM073626, DE013023, and DE016516.

Oh yeah? Maybe ya should hire a lawyer.

Yes, I suppose to get a couple of tens mlns!

Perhaps photons are the constituents of all matter. It would explain mass-energy equivalence and the absolute speed of light. I wrote a hypothesis based on the very axiom that photons can form "molecules", and I'm not surprised to find it verified. It does add to my frustration that I have no way of proving my hypothesis or getting it to be heard. I'm a philosopher, not a physicist. I work from a top-down approach rather than a bottom-up approach. I don't have figures to back my hypothesis with. All I know is that it all fits together. All the paradoxes of quantum mechanics make sense if I apply this hypothesis. You can find the full text by Googling "infinitarianism quantum thermodynamics".

The discovery, Lukin said, runs contrary to decades of accepted wisdom about the nature of light. Photons have long been described as massless particles which don't interact with each other -- shine two laser beams at each other, he said, and they simply pass through one another.

Well, ya have worked your up to the snip & glue level,,,, keep up the good work.
.

smoke restoration monterey

No, the smoke will still interfere with the laser beam, even in Monterey. Next question?