Don't bet against Einstein

Precise test of equivalence principle

No deviation from straight Einsteinian gravitation.

The results of the experiments enabled the researchers to set an upper limit of 10-7 on the boson-to-fermion gravitational constant ratio. The researchers also searched for a dependence of gravity acceleration of strontium-87 isotope on the spin direction, but found no evidence for it.
"There are theoretical models predicting that spin and gravity should couple; that is, depending on its spin a particle should behave in different ways in a gravitational field," Tino said. "We found no evidence for that. Since we compared an atom with spin with one without spin, this is a rather stringent test. Also, in our experiment one atom is a boson and the other is a fermion and, again, we found no difference in their behavior in a gravitational field."


Read more at: phys.org...

Oh Gee. I got stuck reading a bunch of articles at Physics.org again.

Interesting article

Well whats your thoughts?
Why should we read this?

a reply to: muSSang

The choice is all yours

a reply to: mbkennel

The only reason a particle (and its spin, referring to its actual physical rotation?,or I know spin refers to the degrees of rotation before the particle is identical to its starting position, so do particles with different spin, are they spinning at all physically, rotating?) would maybe see itself become effected by the gravity field it is coupled to, is depending on the physical movements of a gravity field right?

A massive planet moving through space is constantly changing its local gravitational topology, and so this means an objective view from an arbitrary reference frame, would note as time passes at all the differing points of the local gravity field where the planet is traveling through, that the gravity field would be moving in different directions, different 3 dimensions. So depending on a particles momentum/direction entering, depending where it is coming from, is it possible, depending on its spin, there would yield different results as it entered into the planets altered gravity field?

So if not rotational spin, but the physics spin of 1, -1, 0 etc. Then this idea is kind of like a football right, a football would have half spin, a soccer ball maybe would have 0 spin? So if it is physically coupled to the gravity field, first it would be nice, as its something I have asked and wondered how exactly a particle would be coupled to the gravity field, and secondly, would its spin, like a half spin particle, if it was aimed towards a gravity well, at quarter spin and half spin, would an extra energetic activity be noted? The article says according to their tests and calculations, no?

originally posted by: ImaFungi
a reply to: mbkennel

The only reason a particle (and its spin, referring to its actual physical rotation?,or I know spin refers to the degrees of rotation before the particle is identical to its starting position, so do particles with different spin, are they spinning at all physically, rotating?)

It isn't exactly like classical spin, but it isn't entirely different either.

The Einstein/de Haas experiment (much less well known than it should be) shows that electron spin (as exhibited in large organized nature by ferromagnetism) is "of the same nature" as macroscopic angular momentum.

As far as the experiment, the proposed spin-gravity couplings were from hypothesized (not generally accepted) theories beyond conventional gravitation. The experiment shows that some (or all) aren't right.

This is actually depressing news, along with the results from the LHC recently (orthodox Higgs found, nothing else). The Standard Model is right and we've seen no deviation, and general relativity is right and we haven't seen any deviation, and they still don't play nice together and we don't know how to make them do that in any way that seems to be experimentally verified or verifiable.

As far as your second question, yes there is a gravitational effect from rotating matter known in General Relativity called "gravitomagnetism" or "frame dragging" which has no counterpart in Newtonian gravity. The magnitude of this effect is extremely small, but it has been recently verified by results from an extraordinary satellite experiment called Gravity Probe B.

The spin gravity connection being probed in this experiment is something different and hypothesized to be quantum mechanical, but it appears to be false. Frame dragging is much too small to be observable in any atomic physics experiment.

originally posted by: mbkennel
The Standard Model is right and we've seen no deviation, and general relativity is right and we haven't seen any deviation, and they still don't play nice together and we don't know how to make them do that in any way that seems to be experimentally verified or verifiable.

no deviation, really? cmon... -.-
en.wikipedia.org...
the damn thing is FULL of holes, and we keep making up esoteric powers whenever something doesent fit.

as long as we assume "space" to be empty nothingness this whole thing wont work.
check this out: www.youtube.com...
now im not saying this would be totally right, but an interesting aproach indeed.

/edit: i DO bet vs einstein, bc e=mc² cannot be true, due to the presence of energy in the absence of matter.
it describes the ammount of energy contained in matter, conclusively fails to describe the nature of energy itself tho.
most ppl, including scientists, assume that energy IS matter times c², wich is inapropriate.
matter in motion is the result of energy at work, it can not be an inherent part of what we call energy.

a reply to: mbkennel

Ok cool. Is it thought gravity field is inherently quantized (composed of particles) or part-less, like one universal encompassing continuous fundamental particle?

If it is thought it is inherently quantized, like predictions of graviton, are there theories as to what the mass of the graviton might be?

Are there theories as to on average how close together each graviton is to its neighbors?

Are there theories to how the binding force of the gravitons to one another might work, and what that energy might be, and how it might factor into other factors regarding the nature of gravity?

Are there theories regarding whether or not gravity particles might be able to transform into other particles, or decay into other particles, or if you can start with other fundamental particles and under conditions decay those particles into gravity particles?

a reply to: ImaFungi

All of that is part of the field of 'quantum gravity'. It is assumed that yes there is some quantum modifications for gravity, but despite major theoretical effort there is no consensus theory and no experimental evidence for any of them. There have been many proposals; the field is very complex. The main goal is somehow to connect gravity to the rest of the particles in Standard Model, which explains their own mutual interactions to a high quantitative accuracy.

Presumably if there were an accepted theory validated by experiment, it would be able to answer questions like yours.

a reply to: mbkennel

So, my questions are the main obvious intuitive questions to ask about such a thing, and so in one corner there is the self consistent QM which ignores the existence of gravity, and the other hand is general relativity which ignore existence of QM, and since Einsteins death bed and prior, have there been any narrowing down towards consensus as to what the reality of the situation appears to be?

From what I have been explained about it is that QM (or GR cant remember which), the pesky thing about it deals with all sorts of infinities so they have to create 'cut offs', to make the equations check out, and with the semi arbitrary cut offs, gravity is compatible with QM up until a certain point, the point of approaching ever higher levels of energy, where once again there enter problems with infinities I guess and the lack of checking out.

Now, the first thing I would think to ask is; musn't it be something about QM sitting down to write its self consistent equations and ignoring gravity that makes it difficult to once QM equations are tidy and equal to then try and shove gravity in, isnt it no wonder there is a problem? So musn't the problem be that in the QM equations there is a region of energy/mass that is being neglected and wrongfully appropriated to other constituents that makes the equations and prediction experiments work, but admitting to leaving out values of gravity it is understood that the equation, something about the values must be 'off', in the sense of their labels.

The second thing I would say, is could it be that when approaching high enough energies with materials the reasons the equations break down, and this might be related to black holes because thats what happens at those energies right (?), that material turns into 'the gravity field' itself at high energies, or black holes is the gravity field at its least (or most dense, i am being general obvious and dont know the specifics of how to think about this) dense, so at high energies maybe they are incompatible because energy/mass conservation they are not expecting any energy on the QM side of things to be lost, but really the baryonic matter is lost because it is now transfered into this mysterious essence of (space-time...ew, terrible horribly misunderstood and sketchy ill thought out concept I am sure Einstein would have hours worth of lectures stating why it should be questioned and thoughts about it and its usage changed) gravity field, and so maybe thats why the equations break down.

About the first thing I asked, I have asked this before but didnt get much of a response, but I will try again, just consider what I am actually asking and then give a simple general thoughtful answer, it could be composed of yes or no. Is it possible that at any point QM and Gravity are not compatible, because QM uses probability/ranges in its equations, I believe you know I dont believe the probabilities/ranges used in QM are 'mirrors' of reality, but 'blurred mirrors' of reality giving us a gauge like 'eye balling it', so just give this thought some credence for one moment to answer my question ok; Consider my point of view about the inaccuracy that is probability is not reality itself, but a best means to predict events in reality. Is it possible that, in reality, a particle has exact qualities, therefore no probabilities/ranges associated with it from each planck space and planck second to planck space and planck second, but exact qualities, therefore because the equations do use probabilities, the equations have a great tolerance to energy then actually exists in reality, is it possible that in reality that probability/range doesnt exist and instead is the exactitude, and along with that exactitude is exact qualities for the gravity field, but because the QM uses the entire energy range and ignores gravity quantities and qualities in the equation, when the equation is made to check out, there is no room for gravity?

Here is a crappy example of what im trying to say;
Particle energy value: anywhere from 5 to 10
Particle location value: anywhere from 5 to 10



Now imagine in reality, the particle has energy value of 7, and location of 4, ( I understand location must always be changing reletive to a million different things unless you use a fixed grid)

So now instead of an extra 4 possible values considered in each probability, there is 8 total values left over, that were contributing to the equation being predictably powerful; is it possible that the range of probability, has something to do with where the values of gravity may be? This I feel is an obvious of course! Its like, we know that gravity exists, and is always 'there' when we are doing particle experiments, but we just have no data on it, so we cant include it in the equations, but if the equations are predicting, 'something' about gravity must be included... maybe?

originally posted by: ImaFungi

So, my questions are the main obvious intuitive questions to ask about such a thing, and so in one corner there is the self consistent QM which ignores the existence of gravity, and the other hand is general relativity which ignore existence of QM, and since Einsteins death bed and prior, have there been any narrowing down towards consensus as to what the reality of the situation appears to be?

weve developed string theory, and put ALL our money on that one horse, sums it up pretty much i think.
unfortunatly QM and field theory dont seem to be compatible at all.
yet we do NOT look out for a flaw in the equation, but squeeze and stretch it, add arbitrary value etc until it "somehow" aproximates.

From what I have been explained about it is that QM (or GR cant remember which), the pesky thing about it deals with all sorts of infinities so they have to create 'cut offs', to make the equations check out, and with the semi arbitrary cut offs, gravity is compatible with QM up until a certain point, the point of approaching ever higher levels of energy, where once again there enter problems with infinities I guess and the lack of checking out.

it dosesent really make grav. any more compatible, but the described cut offs are made to obtain results one can work with, and herein lies one of the initial problems.
while we do have to make cutoffs for practical reasons, theory doesent account for those values being cutoff.
every pupil is told that a "coffecup full of vacuum could evaporate all of earths oceans" this tremendous ammount of energy is basically completely ignored.

Now, the first thing I would think to ask is; musn't it be something about QM sitting down to write its self consistent equations and ignoring gravity that makes it difficult to once QM equations are tidy and equal to then try and shove gravity in, isnt it no wonder there is a problem?

the problem is pretty deep rooted really.
we have NO clue at all what gravity really is, and describing something mathematical that you dont understand is more a game of chance.
we know that energy packed into an area of space causes gravity. it doesent seem to matter what manifestation this energy has, its total contributes to its "mass total" and therefore its gravitational pull.
strong force is a good example. some binding-energy that makes up the largest part of a systems total energy(with no evidence other that nuclei stick togeather btw, again a practical, arbitrary thing that could be caused by whoknowswhat).
the underlying mechanic however is a complete mystery, and we cannot describe space-curvature in descrete terms, or even pinpoint wth is curving it to begin with.

So musn't the problem be that in the QM equations there is a region of energy/mass that is being neglected and wrongfully appropriated to other constituents that makes the equations and prediction experiments work, but admitting to leaving out values of gravity it is understood that the equation, something about the values must be 'off', in the sense of their labels.

abso-freakin-lutely. now one of the problems here is science itself!
we have guys and gals who work with field equations, and the other ones being into QM.
both sides now insist in inheriting the proper theory and defend them biting, clawing and screaming.
they certainly seem to lack the ability to sit togeather and reevaluate whats really KNOWN and whats one of the arbitrary factors, to work out a really unified thing.
bc one thing became apparent i the last like 50+ years: QM and FE are most likely not unifiable.

allso, everyone looking into the REAL numbers, including the cutoffs, is being laughed at, pretty similar to when nuclear power was discovered and folx didnt trust the insane ammount of energy maths predicted for fission.
check this out to get a picture of how much energy matter potentially inherits: hiup.org...
i dont toally agree with everything in there, but the derivation of energy seems pretty solid.

The second thing I would say, is could it be that when approaching high enough energies with materials the reasons the equations break down, and this might be related to black holes because thats what happens at those energies right (?)

absolutely, and thats one of the conclusions from the linked paper.
letz say general acceptance wasnt as high, as a look at the numbers might have suggested. *cough*
theres been quite its share of theories concluding that particles must be of singular nature, if that somehow helps to reobtain serenity. :p
en.wikipedia.org... might help shed some insight on it.

regarding your unanswered question:
planck units are derived from physical constants, and physical constants alone (thats actually what makes them so important :p).
a planck lenght is the smallest possible wavelenght, a planck time is the time a photon needs to travel a planck lenght.
there is no such thing as a planck propability, and yes its very well within the realm of possibility that einstein was right when he doubted that "the old one would roll dice".
im not so sure about gravity being the cause of propability, but i too think theres an underlying mechanic we yet just dont understand and consider it "random".

but again, describing something mathematically of wich you dont know the mechanism is a game of chance.
...and we quite frankly dont even know wth energy is.

originally posted by: Dolour

weve developed string theory, and put ALL our money on that one horse, sums it up pretty much i think.
unfortunatly QM and field theory dont seem to be compatible at all.
yet we do NOT look out for a flaw in the equation, but squeeze and stretch it, add arbitrary value etc until it "somehow" aproximates.

Well, that is the job of the theorists right. I personally dont know how its figured out with the computers we have at our access now. If QM equation is 'right' and works, that means even though there is no gravity value included in it by our own doing, 'gravity' value must be included in it right, because gravity is included in reality. So why can not gravity value be assigned in the equation while diminishing the range of probability little by little, this can be done by a super computer, all the possible permutations of value by increments of 0.001 or something, and eventually you will approach the equation equaling itself, with a smaller range where probabilities were, and a closing in on a value for gravity that directly relates to QM equation.

it dosesent really make grav. any more compatible, but the described cut offs are made to obtain results one can work with, and herein lies one of the initial problems.
while we do have to make cutoffs for practical reasons, theory doesent account for those values being cutoff.
every pupil is told that a "coffecup full of vacuum could evaporate all of earths oceans" this tremendous ammount of energy is basically completely ignored.

Yea, I personally dont know what is meant by that. The way I approach that query is by asking; Is there a single point in space that is 'actual, pure, absolute, perfect, true, nothingness'? Or is every single point in the universe, some energetic/material component? Do you understand the meaning and importance of this question?

Because then if you say, 'coffee cup full of vacuum...' , what are you really saying, that there is dense energy/material elements/foundation that exist at all points of the universe, and its so densely packed and so much, that if it could be accessed it would be shown to have a lot of energy.

the problem is pretty deep rooted really.
we have NO clue at all what gravity really is, and describing something mathematical that you dont understand is more a game of chance.
we know that energy packed into an area of space causes gravity. it doesent seem to matter what manifestation this energy has, its total contributes to its "mass total" and therefore its gravitational pull.
strong force is a good example. some binding-energy that makes up the largest part of a systems total energy(with no evidence other that nuclei stick togeather btw, again a practical, arbitrary thing that could be caused by whoknowswhat).
the underlying mechanic however is a complete mystery, and we cannot describe space-curvature in descrete terms, or even pinpoint wth is curving it to begin with.

Yes, I suppose I agree. Though 'space curvature' is really just expressing the most classical obvious potential, that gravity works like some dense liquid or gas, that has tensions and changes as its density changes reletive to a semi separate body within the medium. Getting rid of the cheapness of 2d fabric/sheet models to give an easy vision would be a good start, obvious it must be a 3d phenomenon, so take it to the logical conclusion, instead of a 2d sheet circular area dipping, it would be a 3d medium/manifold spherically displacing.

regarding your unanswered question:
planck units are derived from physical constants, and physical constants alone (thats actually what makes them so important :p).
a planck lenght is the smallest possible wavelenght, a planck time is the time a photon needs to travel a planck lenght.

Yes I only used it as the, to me at least, the smallest known quanta of measurement, to use if even proverbially to express the absolutely small quanta of area i wished to hint at with whatever I was relating to that small area.

there is no such thing as a planck propability, and yes its very well within the realm of possibility that einstein was right when he doubted that "the old one would roll dice".
im not so sure about gravity being the cause of propability, but i too think theres an underlying mechanic we yet just dont understand and consider it "random".

Yes, I do not believe reality itself is 'probability'. I believe from our 'slow' perspective, of us gauging reality over time, there are probabilities of being more wrong and more right at making predictions about reality. But reality itself always is equal to itself at all times, at all, shortest possible time quanta and shortest possible space quanta, reality is 'fluid', if quantized or discrete even, reality is still continuos, in that it always continuously exists.