Physicists offer foundation for uprooting a hallowed principle of physics

Jan 05, 2009

Physicists at Indiana University have developed a promising new way to identify a possible abnormality in a fundamental building block of Einstein's theory of relativity known as "Lorentz invariance." If confirmed, the abnormality would disprove the basic tenet that the laws of physics remain the same for any two objects traveling at a constant speed or rotated relative to one another.

IU distinguished physics professor Alan Kostelecky and graduate student Jay Tasson take on the long-held notion of the exact symmetry promulgated in Einstein's 1905 theory and show in a paper to be published in the Jan. 9 issue of Physical Review Letters that there may be unexpected violations of Lorentz invariance that can be detected in specialized experiments.

"It is surprising and delightful that comparatively large relativity violations could still be awaiting discovery despite a century of precision testing," said Kostelecky. "Discovering them would be like finding a camel in a haystack instead of a needle."

If the findings help reveal the first evidence of Lorentz violations, it would prove relativity is not exact. Space-time would not look the same in all directions and there would be measurable relativity violations, however minuscule.

The violations can be understood as preferred directions in empty space-time caused by a mesh-like vacuum of background fields. These would be separate from the entirety of known particles and forces, which are explained by a theory called the Standard Model that includes Einstein's theory of relativity.

The background fields are predicted by a generalization of this theory called the Standard Model Extension, developed by Kostelecky to describe all hypothetical relativity violations.

Hard to detect, each background field offers its own universal standard for determining whether or not an object is moving, or in which direction it is going. If a field interacts with certain particles, then the behavior of those particles changes and can reveal the relativity violations caused by the field. Gravity distorts the fields, and this produces particle behaviors that can reveal otherwise hidden violations.

The new violations change the gravitational properties of objects depending on their motion and composition. Objects on the Earth are always moving differently in different seasons because the Earth revolves around the Sun, so apples could fall faster in some seasons than others. Also, different objects like apples and oranges may fall differently.

"No dedicated experiment has yet sought a seasonal variation of the rate of an object's fall in the Earth's gravity," said Kostelecky. "Since Newton's time over 300 years ago, apples have been assumed to fall at the same rate in the summer and the winter."

Spotting these minute variances is another matter as the differences in rate of fall would be tiny because gravity is a weak force. The new paper catalogues possible experiments that could detect the effects. Among them are ones studying gravitational properties of matter on the Earth and in space.

The Standard Model Extension predicts that a particle and an antiparticle would interact differently with the background fields, which means matter and antimatter would feel gravity differently. So, an apple and an anti-apple could fall at different rates, too.

"The gravitational properties of antimatter remain largely unexplored," said Kostelecky. "If an apple and an anti-apple were dropped simultaneously from the leaning Tower of Pisa, nobody knows whether they would hit the ground at the same or different times."

Animation using Kostelecky's Standard Model Extenstion to predict how apples might fall differently can be viewed at www.physics.indiana.edu/~koste… ec/movies/agrav3.avi .

Paper: link.aps.org/abstract/PRL/v102/e010402 .

Source: Indiana University

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Alexa
Jan 05, 2009
This comment has been removed by a moderator.
GrayMouser
5 / 5 (4) Jan 05, 2009
They ignore the Michelson-Morley-Miller results for variations in the velocity of light over the year (and at various altitudes) which would prove that there are other considerations.
Alexa
Jan 05, 2009
This comment has been removed by a moderator.
Alexa
1 / 5 (3) Jan 05, 2009
While I'm familiar with Kostelecky theory for many years, I've never met with "mesh-like vacuum" concept in it. From where and why he brought it into theory right now?
phystic
not rated yet Jan 05, 2009
interesting
brant
not rated yet Jan 05, 2009
How about Dayton Miller?

He did ~200,000! measurements vs MM 63.

There is a sidereal signal in data...
QubitTamer
1 / 5 (2) Jan 05, 2009
The more we research the more we discover that there is more chaos than constant in our realm. It is somewhat comforting to know that the universe refuses to be neatly packaged and quantified for our little monkey brains.
WolfAtTheDoor
4 / 5 (4) Jan 05, 2009
"Standard Model Extension, developed by Kostelecky to describe all hypothetical relativity violations."


This sounds to me like his attempt at making his theory palatable to the "Einstein can do no wrong" crowd. It's like adding a note at the end of the standard model that says "PS - By the way, what you just read is not completely valid."

The bottom line is it's amazing how LITTLE we know about gravity.
fleem
not rated yet Jan 06, 2009
Even in the standard model and among the 'Einstein can do no wrong' crowd there is some confusion over the role of absolute space. Specifically, the momentum of the universe, Mach's principle, a straight line can be defined only as relative to the other matter in the universe--that sort of thing. The real clincher is that the total kinetic energy of the universe "increases" for an object moving relative to the momentum of the universe, which in essence places that object in a gravity well. We've been ignoring Mach's principle for convenience sake, but ignoring Mach's principle doesn't make it go away! Don't get me wrong, I'm just as much a card-carrying member of the "Einstein can do no wrong" crowd as anyone. But there are still questions to be asked. For example, there are subtle higher-order oddities in GR that might seem to be dependent on the absolute energy density (gravitational potential), which changes according to one's absolute speed relative to the momentum of the universe.
-fleem

johanfprins
1 / 5 (1) Jan 06, 2009
Specifically, the momentum of the universe,


Can you define this concept please?
fleem
3 / 5 (2) Jan 06, 2009
"Can you define [the momentum of the universe] please? "

The momentum of the universe is certainly relative to the observer. However, the magnitude of that momentum in the eyes of a given observer varies with the velocity of the observer (relative to any given reference frame). There is a "preferred" velocity in which the magnitude of the momentum of the universe is zero.

In a closed universe, the kinetic energy of the universe appears greater for an observer moving relative to that preferred IRF. There is some question even among the standard model crowd about the role of that preferred velocity--for example, should we consider it affecting the observer's gravitational potential energy relative to an observer in some other inertial reference frame. Admittedly the effect is extremely slight, if there is any. On a side note, I believe the apparent paradox lies in a misinterpretation of the concept of "kinetic energy". In other words, that question among even proponents of pure GR have forgotten that kinetic energy is something that resides ~between~ two closed massive systems--you can't extract kinetic energy from a moving object without using a machine attached to a massive stationary object. (the same applies to potential energy, for that matter--you can't extract potential energy unless a machine connects to both objects between which the potential energy exists). This, then, gives rise to the question, "Where exactly ~is~ the kinetic or potential energy of a two-body system? Is it located within one object, the other object, or between the two".

We get so used to thinking of kinetic energy residing within an object moving relative to ourselves, that we forget such fundamental, but paramount, questions.

Anyway that is where the confusion lies. By stating that there is some question even among proponents of GR, I do not mean to imply I question GR--except maybe I'd like a clarification of some of the fundamental concepts like "where is a given amount of kinetic energy actually ~located~"--which is sometimes ignored in the community.

-fleem
neurogalactus
not rated yet Jan 06, 2009
fleem,

I am a layperson about GR, so please forgive me in advance all mistakes and misconceptions I might make. What I want to point at is the very concept of spacetime. GR speaks of gravity being a distortion/curvature of the spacetime fabric. But there is no theory that even attempts to define spacetime itself. That is to say, how to define distance or time interval? What are they? If we take two separate points in space, two separate points in time, or two separate events in spacetime, what determines their separation? What IS that separation? I would believe some sort of flux relation; a dynamic process. Our human experience makes us take the sense of space and time for granted, as a given, subject to no explanation. But in my opinion, answering that question is fundamental for understanding gravity. Because if gravity is a curvature of spacetime, then we'll never comprehend what gravity is without explaining spacetime in the first place. Also, there is a popular assumption that spacetime is a 4-dimensional reality, where a time axis is perpendicular to the 3-spatial axes. But, as I understand, GR tell us that spacetime is a unified entity, without division between spatial and temporal dimensions. This is somehow contrary to our daily experience (and most importantly: thermodynamics), where space and time have different symmetries (invariance in space vs arrow of time). But what if this is only an illusion? That is, spacetime as a single, unified dimensional system is highly symmetric, but perhaps not based on classical (non)euclidean cartesian model, but something much more complex (bootstrap logarithmic distribution? rotational symmetry? polyhedral symmetry?). In any case, such a system would in fact be a 3D system of dimensions, whose manifestation in our daily experience makes us distinguish spatial and temporal components, which truly are just different "angles" at which we perceive reality.

I know this is a bit confusing, but the bottom line is: we have no explanation of spatial and/or temporal separatedness (distance).

Also: If we want to be accurate, can we be speaking of points in spacetime, or just regions thereof? In other words: if such qualities as momentum or distance are inherently relative and dynamic, does it make sense to speak of points?

fleem & others, I look forward to your comments and smashing critique showing how horribly I'm wrong... ;)
fleem
3 / 5 (2) Jan 06, 2009
neurogalactus you're absolutely right, the vast majority of physicist never question the axioms of science. Of course, that is their prerogative, but I can still complain about them ignoring those axioms! For questioning axioms is the only way science advances.

Now to wax more philosophical, here's my take on GR:

GR is strictly a classical theory. It assumes there are continua like manifolds and so on. There aren't. There's no such thing as a continuum. We've all been laughing at Zeno's paradox, but its time the smiles faded. The universe is discrete. (Now by discrete I don't mean there's a mesh in space-time. I simply mean there are indivisible interactions of particles which are what ~define~ space-time rather than "reside" in space-time).

Space-time is strictly a classical concept that has no place in quantum mechanics (or at least without major revision). Certainly quantum mechanical interactions take place with a certain order that obeys causality, but why do we even say there is such a global thing as "time"? Well, because when we look at two macroscopic clocks sitting on a shelf which are ticking at the same rate, we assume there is a ~global~ "field" that forces those clocks to tick at the same rate. However, those clocks are part of the same system--they are exchanging myriad virtual photons because they are so large, near each other, and yes, even hot. That's why they tick at the same rate. If we make tiny clocks and cool them way down, we see their time rates are much more independent.

So space-time is a man-made concept (continuum) which is really only useful in describing an ~average~ pattern of interactions among many particles.

-fleem
Alexa
1 / 5 (1) Jan 06, 2009
..attempt at making his theory palatable to the "Einstein can do no wrong" crowd....

Indeed. We cannot derive the Lorentz invariance violation by using of theory based on relativity and Lorentz invariance by formally clean way without usage of black magic. It's virtually impossible to derive 1=2 by using of 1=1.
Alexa
1 / 5 (1) Jan 06, 2009
The only way how to derive the existence 10E 500 solutions (roughly corresponding to a number of particles existing in observable Universe!) - and to say, one of this solutions is definitelly right.

This is basically string and quantum gravity approach. I.e. to guess the solution - which can be done by a much cheaper way, indeed.
googleplex
3.3 / 5 (3) Jan 06, 2009
Ever since i started studying physics I have been astounded by how little we know. My first questions to my physics professors what is a photon and being met with a blank face and flim-flam response. I also asked if anything can have negative mass e.g. anti-matter... again blank looks. It's like they have shame in admitting that we don't know. I have to credit Feynman for quite categorically stating what he did not know.
As for gravity we have no clue. We don't even know what the carrier particle is - or even if there is one. Time is just as elusive as gravity.
I believe that there is a link between charge and gravity. Look at the equations and they are earily similar. That is not just coincidence.
Newtons Law for Gravity
http://en.wikiped...vitation
Coulombs Law
http://en.wikiped...’s_law
Noumenon
4.9 / 5 (44) Jan 06, 2009
Right fleem, but rather than space-time being made-made in the since of it being only invented for convenience, ...I would suggest that if we realize that phenomenal reality inescapably involves a subjective component, we should expect conceptual artifacts originating from the mental ordering or form in which that reality must be understood given the nature of the mind.

In the process of obtaining knowledge of reality, we by necessity, conform it within pre-existing mental paradigms; causality, space-time. These concepts are not applicable outside that realm in which our minds have evolved to operate on.
OregonWind
1 / 5 (1) Jan 06, 2009
'As for gravity we have no clue. We don't even know what the carrier particle is - or even if there is one.'

It is supposed to be the graviton but if it exists it is too weak to be detected easily and so far nobody was able to craft an experiment to test the existence of gravitons but if quantum gravity is right then gravitons should exist.

Sometimes I get the impression that general relativity should undergo a different mathematical formalism. However, you are right there are many concepts in physics which have no 'concrete' definition. The only reasonable approach is mathematics, mainly when we are dealing with the foundations of space-time and matter. If you are going to be a theoretical physicist, for example, then math is the best way of dealing with the strange worlds of QM and GR.

No wonder that the mystics love quantum mechanics. :)

Alexa
1 / 5 (1) Jan 06, 2009
Look at the equations and they are earily similar. That is not just coincidence.
You can be indeed right, but similarity is exactly, what the coincidence means. Correlation does not imply causation. Many analogies are just homologies under more thorough investigation.
fleem
3 / 5 (2) Jan 06, 2009
Noumenon - "These concepts are not applicable outside that realm in which our minds have evolved to operate on."

Yep. Of course its all we have to go by so we continue to play the game :)

However there is one "axiom" that proves itself, and that is "I think therefore I am", which proves the statement, "there is order". Beyond that its just a game of probabilities, because there is no such thing as a deductive proof without axioms (assumed laws). Thus two plus two ~probably~ equals four, but it might not always equal four. For that matter two might not always equal two.

However, I like to hope that there ~might~ someday be a way to take "I think therefore I am" and arrive at a TOE ~without~ axioms. Now THAT would be something.

-fleem
Noumenon
4.9 / 5 (43) Jan 06, 2009
fleem - "there is no such thing as a deductive proof without axioms (assumed laws)."

Yes, deductive propositions are self contained and true by virtue of the starting definitions (like Descartes line), and cannot tell us, in themselves, anything new about reality. Hume showed that there is no analytic link between cause and effect, only constant conjunction of observed events, so our inductive knowledge can only be certain by at best a high degree of probability.

Even if a TOE existed it would still be delimited by mental constructs and would be in a form dependant on mental ordering. If we had an invisible dog, or Louis Carroll's invisible cheshire cat, our knowledge would only be about the leash. :) What's important of course us that we can make predictions, but the point is certain concepts are not the reality itself but a means of ordering that reality for thought.
Atomsview
not rated yet Jan 06, 2009
Hi googleplex, Newtons law of gravity can equal Coulombs electrical law under certain conditions. Charge equal current multiplied by time ( Q = I x t). Orbiting particles ( electrons and positrons ) cause eclipses between nuclei of atoms. These eclipses cause atoms to have net charges (gravity).
Nartoon
1 / 5 (1) Jan 06, 2009
Very interesting how these Physicists keep testing and retesting theories that are all but carved in stone, yet the AGW group do not want to retest anything--the science is proven; just think what would happen in science if everyone acted that way!
earls
not rated yet Jan 07, 2009
So is Gravity a net positive or negative charge, Atomsview? Shouldn't be be able to produce an opposite net charge for take off?
Atomsview
not rated yet Jan 07, 2009
Hi earls, repulsion aoccurs between atoms and antiatoms. The DAPNIA, ALPHA, CERN and FERMILAB experiments will show a repulsion of antihydrogen by earth's gravity. A small weight loss can be measured on objects with a high charge of electrons: try it, if you have a lab.
BXCellent
not rated yet Jan 07, 2009
A question I have never resolved is why gravity is still considered a force, and why it is necessary to invent a force carrying particle. According to GR, gravity is the name given to the way mass/energy curves space-time and the way space-time causes mass/energy to move. The "force of gravity" is simply mass/energy following curved space-time to the lowest energy potential. So why invoke a force or a force carrying particle?

As is mentioned above, the core of the problem is understanding what space-time is, what is it made of, what is the quantum of discrete space-time.

Unfortunately for string theorists this approach negates one of the raison-d'etres for string theory - the requirement of a spin-2 particle resembling the graviton. As much of physics is ruled by string theorists, huge amounts of research into space-time rather than new particles predicted by string theory are not carried out.
EHDowdye
not rated yet Jan 07, 2009
On the above topic "Physicists offer foundation for uprooting a hallowed principle of physics", the following may be of interest on the latest findings on gravitational lensing.

There is now solid evidence that a direct interaction between gravitation and electromagnetism does not take place.

ABSTRACT "Time resolved images from the center of the Galaxy appear to counter General Relativity", Dowdye, Jr., E.H., http://adsabs.har...28..186D

For decades now some very important fundament principles of mathematical Physics have been incorrectly applied to the theory of gravitational lensing or just simply ignored. From astrophysical observations it is apparent that the current understanding of the effects that gravitation should have on light is fundamentally incorrect. Astrophysical observations pertaining to lensing are consistent with effects due to an indirect interaction involving an interfering media, not a direct interaction taking place in vacuum space. It is however theoretically possible that current technical means may not permit a distinction to be made between an indirect and a direct interaction between gravitation and light. The thin plasma atmosphere of the sun represents an indirect interaction between the gravitational field of the sun and the rays of light from the stars. There is convincing observational evidence that a direct interaction between light and gravitation is yet to be observed. Historically, the observed evidence for light bending occurred predominantly near the plasma rim of the sun, not in the vacuum space far above the rim. The events taking place at the site of Sagittarius A* presents convincing observational evidence that a direct interaction between rays of light and gravitation in vacuum space simply does not take place. This is clearly revealed in the time resolved images of the rapidly moving stellar objects orbiting about Sagittarius A*, a region at the galactic core believed to be a super massive black hole. This is a region that has been under intense observations by the Astrophysicists since 1992. A clear lack of observational evidence for optical lensing due to gravitation is apparent when examining the undistorted images of the stars moving along Keplar paths about Sagittarius A*. The space in the immediate vicinity of a black hole is by definition an extremely good vacuum. The evidence for this is clearly seen in the highly elliptical orbital paths of the rapidly moving stars orbiting about the galactic core mass. The presence of any material media near the galactic core mass would conceivably perturb the motion of the stellar object s16 moving with fractional light velocities, thus causing it to rapidly disintegrate. Astrophysical observations reveal that s16 has a velocity approaching 3 % of the velocity of light when passing to within a periastron distance corresponding to 60 astronomical units from the black hole thus giving solid evidence that the space in this region has to be, without a doubt, an extremely good vacuum. It follows from this that a direct interaction between the light emitted from the orbiting stars and the gravitation of this super massive galactic core at the site of Sagisttarius A* is yet to be observed.

For details see: http://www.extinc...ings.htm

A paper on this subject has been published in the renown refereed journal Astronomische Nachrichten, "Time resolved images from the center of the Galaxy appear to counter General Relativity", Dowdye, Jr., E.H., Astronomische Nachrichten, 328, Issue 2, 2007,pp 186 -191
Alexa
not rated yet Jan 07, 2009
Do you have some real photos of star in periastron? Not some computer generated animations...
NeilFarbstein
not rated yet Jan 07, 2009
They are assuming that the stars orbiting the black hole have been in stable orbits, not unstable orbits. That may throw a monkey wrench into their calculations.
ehdowdye2
not rated yet Jan 08, 2009
Hello Alexa:

For real astrophysical data and collected images/movies see link to

Max-Planck-Institut für extraterrestrische Physik:

For details: http://www.mpe.mpg.de

Movie Image: http://www.extinc...2003.gif
You wrote:
Do you have some real photos of star in periastron? Not some computer generated animations...

Regards

EHD
Alexa
not rated yet Jan 10, 2009
By another words, YOU have nothing.
googleplex
not rated yet Jan 20, 2009
Hi earls, repulsion aoccurs between atoms and antiatoms. The DAPNIA, ALPHA, CERN and FERMILAB experiments will show a repulsion of antihydrogen by earth's gravity. A small weight loss can be measured on objects with a high charge of electrons: try it, if you have a lab.

Are you an armchair physicist or a real one i.e. PhD in physics?