A violation of Einstein's theory -- wow -- physics doesn't get more exciting than that. Or so the science punditry has it. A few days ago the OPERA (The Oscillation Project with Emulsion-tRacking Apparatus) experiment in Italy announced they had measured particles to be traveling faster than the speed of light. The implications of this discovery could be sensational -- if it is actually correct and if the least conservative interpretation of the result -- faster than light travel with consequent time travel possibilities -- turns out to be right.
That's unlikely. As I discuss in my book Knocking on Heaven's Door: How Physics and Scientific Thinking Illuminate the Universe and the Modern World -- physics in progress is often messy. It's not always the pristine laws and predictions of those laws that many envision when describing science. Scientific research involves going beyond the well-trodden and well-tested ideas and theories that form the core of scientific knowledge. During the time scientists are working things out, some results will be right and others will be wrong. Over time the right results will emerge.
Going beyond the well-established core of knowledge requires experiments that are often at the limit of technology. It also involves ideas that are internally consistent but that we don't yet know to be realized in the universe. These ideas can be very different from existing scientific theories. But they can be essential in more extreme regimes of distance or precision than were previously possible to observe. Such new theories wouldn't negate the successful predictions from before. Even if more fundamental, they would be necessary only when experiments reach the level of precision at which they could make a difference.
That means that the experiment itself could be wrong because the technology or other aspects of the experiment were not fully understood. Or they could be right in which case existing physical theory is an approximation of a more exact and fundamental theory that underlies it. This particular result could even be consistent with an exotic version of the warped extra-dimensional theory that Raman Sundrum and I developed and that I also explain in my book.
So let's step back and consider what this experiment tells us. It attempted to measure the speed of particles called neutrinos. Neutrinos -- like all other elementary particles -- are defined by their charges. They have the root neutral in their name, and indeed they have zero electric charge so they are impervious to the electromagnetic force. They also don't interact under the strong force -- the powerful force that holds particles called quarks together inside a proton or neutron. But neutrinos do interact -- albeit very weakly. In fact, the force through which they interact is known as the weak force. This is the force responsible for nuclear beta decay, which, for example, permits a neutron to decay into a proton, electron, and a third particle -- the neutrino which without extremely carefully designed experiments leaves no observable signatures of its own (strictly speaking, it is the neutrino's antiparticle known as the antineutrino).
Because they interact only weakly, neutrinos are difficult to detect and measure. But difficult and impossible are not the same thing. Experimenters have found clever ways to detect a tiny fraction of the neutrinos in enormous shielded detection devices. The detectors are huge in order to provide more opportunities for neutrinos to interact in order to compensate for the weakness of the interaction. And they are shielded (and buried deep underground) so cosmic rays won't confuse the neutrinos signal they wish to measure.
Physicists are interested in measuring neutrino properties because they tell us about the structure of the Standard Model, the well-tested theory that describes matter's most basic elements and interactions. They measure neutrino masses, as well as a very interesting property of neutrinos known as neutrino oscillation -- the fact that neutrinos can oscillate back and forth into each other -- that is one type of neutrino can get transmuted into another type as they travel along through space or matter.
Physicists want to measure how often this happens and they therefore have set up experiments in which neutrinos of one type get produced in one location and neutrinos of another type are detected elsewhere. How far away they put the detector depends on how big a distance is needed for an oscillation to occur.
Which brings us back to the OPERA experiment. Neutrinos are produced at CERN, the particle physics facility near Geneva that also houses the Large Hadron Collider. And they are detected in a big device located in the Gran Sasso cavern in central Italy, 730 km southeast from CERN. The experimenters make detailed measurements of everything they can, including the distance between the experiments and how long it takes for neutrinos to traverse this distance, which in principle tells about the neutrino mass. The measurements are very challenging and the experimenters are to be applauded for taking on this daunting task.
But the experimenters measured something much more surprising than the value of the neutrino mass. They found their neutrinos traveled faster than the speed of light in a vacuum. They measured distance and they measured time and divided one by the other and found a speed that is bigger than Einstein's theory suggests. The question is what does it mean?
Most likely it means the experimenters made a mistake. Most physicists like myself won't believe the result until every possible caveat has been investigated and/or the result is confirmed elsewhere. It's just too big a result to take lightly. And the experiment requires measuring distance and timing at the level of one part in one hundred thousand. It's especially difficult because it's hard to match the emitted and detected neutrinos. Statistical methods are required. It's tough.
But what about the unlikely possibility that the experimental result is correct? What would that mean? Travel at faster than the speed of light certainly can have dramatic implications that are difficult to understand, such as time travel. But the more conservative possibility is that Einstein is not entirely wrong. Returning to one of the themes in my book, it is that the assumptions on which he built his theory were only approximate and break down at some point.
One example is the symmetry on which the theory is based, which says that the laws of physics are equivalent not only in any direction of space but also for any fixed velocity -- that is physics done with constant speed works the same as physics when everything is at rest. But although so far no one has observed any evidence for it, in principle that symmetry can be violated. And when that happens particles might possibly travel at speeds greater than that of light. Physicists have hypothesized several sources of such symmetry-violation but one of the most interesting might occur if there is an extra dimension of space -- that is one dimension beyond the three (up-down, left-right, forward-backward) that we experience in our daily lives.
I talk a lot about why we might have such an extra dimension and why we wouldn't see it directly even if it exists in my older book Warped Passages and my newer one Knocking on Heaven's Door, which covers both the physics itself and the scientific underpinnings of the way scientists think. The reason the model Raman and I developed is relevant to the neutrino measurement is that it's a lot simpler to violate symmetries in a way that is compatible with all other measurement if there's an extra dimension. In fact physicists have constructed just such a model of spacetime that obeys all the known physical laws. So if faster than light travel happens, it could be very exciting for Raman and me.
Even so, exciting as it sounds, we're not too optimistic our theory will be discovered this way. This neutrino result has just too many ways to go wrong and even requires special assumptions to be compatible with other preexisting measurements about neutrinos.
Fortunately there are other ways to test our hypothesis. That's what the LHC will do and it's one of many things I hope I convey in my new book Knocking on Heaven's Door. Understanding physics and especially the true nature of science can enrich all of our lives and encourage better understanding of issues in today's world as well.
Kevin Bermeister: Time Travel, Your Mother and the Limits of Science
I saw Dr. Randall years ago when she was discussing her earlier book. I recall she was talking at NYC Library and I was watching it on late night TV in Holland.....dang....she rocked! Made me want to go back to school.
Research demonstrates that space has an "elastic drag". Space does not itself absorb Kinetic energy but it does react to it.
As I understand it, space will deform as a particle moves through it proportionally to the amount of energy the particle contains.
For an example, A photon with a given kinetic energy travels at (c) and space deforms around the particle. If you could impart more kinetic energy to the photon it would go from a lower energy to a higher energy state but would still be at the same velocity (c).
The energy level influences spatial deformation that results in the particle effectively traveling a greater distance and energy energy in excess of (c) increases the amplitude of the generated wave effect preceding the particle.
Space being affected by but unable to absorb energy can still influence the particles path. If the wave effect is refracted the path of least resistance for the particle is to follow the wave rather than generate a new one.
Perhaps with neutrinos the tackiness of space is also affected. It's postulated that neutrinos aren't made of as many base particles so have less "friction". perhaps like the difference between ice skating across a pond rather than having to swim it.
No. You are wrong.
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Einstein called non-locality "spooky action at a distance".
Come on I have better things to do.
(For those not familiar with the term isomorphism--> http://en.wikipedia.org/wiki/Isomorphism)
I can explain a bit more (to my limited understanding) if anybody wishes.
This could very well be a limitation of our technology or a deeper manifestation of the "measurement problem" in Physics.
I think most science boils down to simple concepts that are shrouded in the jargon of the field. A good public science writer breaks this down to the core concepts.
Of course, it is quite human for the "expert" to revel in this seeming obscurity and inaccessability of a science or technical topic at the expense of the publics education...to be human is to be an APE pounding his chest.
Most people mistake physics for a collection of facts and terminology. It is not. In my view, physics is a new way of thinking. So, unless you train yourself to appreciate this way of thinking, understanding how nature is described by physics will be unsatisfying. Writing a clear article about an advanced topic is a huge challenge in any field and this is true 10x over when you try to describe nature.
As for jargon, I agree with you. There is no need to obscure the picture with unnecessary jargon (very common in the life-sciences).
The "infinite mass through acceleration" question has been demonstrated to be true - mass increases with acceleration, due to the invested energy (which is, after all, mass). At light speed, it takes so much energy to continue to accelerate, that the particle being accelerated looks like an infinite mass (at the limit) - no light-speed violations for massive particles!
Photons in flight do not experience time - they are timeless and changeless (as far as anyone knows). They transfer energy packets - or mass, if you like - to worthy particles that can receive it.
Space-Time is another matter (pun) altogether.
The special relativity equations do indeed break down at the infinities - the singularities - this is what we're studying and tallking about today. Right Now. You are part of it.
Whence comes mass - therein lies the rub.
I'm glad you agree that photons do not experience time. I've been thinking about that point for years. It would explain entanglement and the behavior of the single particle at-a-time behavior observed during the double slit experiment. Probably explains a lot of other things. Aside: What if there is a species somewhere in the Universe that evolved to be purely light-based. Would this mean that they could be all places and all times? Best Regards.
Oh please, did you ACTUALLY make such a prediction, do you have a model that in fact describes why such a measurement would be made as part of your theory? How convenient to back track into this to hitch your less than convincing argument. BTW, you seem to have left out that the Opera researchers repeated the same result over 15000 times.....small detail.
The fact that the Opera researchers repeated their results 15000 times over with the same results only illustrates Einstien's comment - "Doing the same thing over and over, and expecting change, is the definition of insanity".
Measuring 15,000 events using the same bent ruler would not get you the correct result.
I really hope this is all a big mistake...cuz if it isn't....DARPA is going to turn it into a big hairy weapon!!!
circular logic indeed.
My brother and I have conducted experiments measuring the speed of magnetic fields and electrostatic fields, and found that both propagate instantaneously (or at least almost instantaneously), but the scientic community does not accept our results because they contradict certain theories.
Anyway, check out our experiments: http://www.wbabin.net/physics/erdmann.pdf
Regards,
Adolf
As far as neutrinos, the have a very small mass, but are not massless. First hypothesized to solve the missing mass problem in nuclear interactions (when some particles decay into others, the sum of the masses of the products is SLIGHTLY less than the original particle, which violates all sorts of conservation laws), the idea was an electrically neutral particle flew off, taking some energy with it,(energy being related to mass by Einstein's famous E=MC 2 equation)
The neat thing about neutrinos is being without charge is they rarely, NOT NEVER, but rarely interact with normal matter, one has to hit an atom right on the head to cause a reaction, which is like trying to hit a ping pong ball somewhere in a football field, Since matter, is on a microscopic level mostly empty space, they go right through.
The trick in an experiment like the one at CERN is to generate zillions of them, aim them at a specific location, so the 18 yard thick lead and superconducting detector can catch a few just by
Marshall Hagy
Chicago