From NASA Science News January 15, 2010: Last year, when NASA’s IBEX (Interstellar Boundary Explorer) spacecraft discovered a giant ribbon at the edge of the solar system, researchers were mystified. They called it a “shocking result” and puzzled over its origin.
Now the mystery may have been solved.
“We believe the ribbon is a reflection,” says Jacob Heerikhuisen, a NASA Heliophysics Guest Investigator from the University of Alabama in Huntsville. “It is where solar wind particles heading out into interstellar space are reflected back into the solar system by a galactic magnetic field.”
Heerikhuisen is the lead author of a paper reporting the results in the Jan. 10th edition of the Astrophysical Journal Letters.
“This is an important finding,” says Arik Posner, IBEX program scientist at NASA Headquarters. “Interstellar space just beyond the edge of the solar system is mostly unexplored territory. Now we know, there could be a strong, well-organized magnetic field sitting right on our doorstep.”
The IBEX data fit in nicely with recent results from Voyager. Voyager 1 and 2 are near the edge of the solar system and they also have sensed strong* magnetism nearby. Voyager measurements are relatively local to the spacecraft, however. IBEX is filling in the “big picture.” The ribbon it sees is vast and stretches almost all the way across the sky, suggesting that the magnetic field behind it must be equally vast.
Although maps of the ribbon (see below) seem to show a luminous body, the ribbon emits no light. Instead, it makes itself known via particles called “energetic neutral atoms” (ENAs)–mainly garden-variety hydrogen atoms. The ribbon emits these particles, which are picked up by IBEX in Earth orbit.
Above: A comparison of IBEX observations (left) with a 3D magnetic reflection model (right). More images: data, model.
The reflection process posited by Heerikhuisen et al. is a bit complicated, involving multiple “charge exchange” reactions between protons and hydrogen atoms. The upshot, however, is simple. Particles from the solar wind that escape the solar system are met ~100 astronomical units (~15 billion kilometers) away by an interstellar magnetic field. Magnetic forces intercept the escaping particles and sling them right back where they came from.
“If this mechanism is correct–and not everyone agrees–then the shape of the ribbon is telling us a lot about the orientation of the magnetic field in our corner of the Milky Way galaxy,” notes Heerikhuisen.
And upon this field, the future may hinge.
The solar system is passing through a region of the Milky Way filled with cosmic rays and interstellar clouds. The magnetic field of our own sun, inflated by the solar wind into a bubble called the “heliosphere,” substantially protects us from these things. However, the bubble itself is vulnerable to external fields. A strong magnetic field just outside the solar system could press against the heliosphere and interact with it in unknown ways. Will this strengthen our natural shielding—or weaken it? No one can say.
Right: An artist’s concept of interstellar clouds in the galactic neighborhood of the sun. [more]
“IBEX will monitor the ribbon closely in the months and years ahead,” says Posner. “We could see the shape of the ribbon change—and that would show us how we are interacting with the galaxy beyond.”
It seems we can learn a lot by looking in the mirror. Stay tuned to Science@NASA for updates.
h/t to Leif Svalgaard
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Leif Svalgaard (17:13:49) :
first you declare that honest science goes out the window if one accepts the high-precision modern tests of SR
I didn’t say that or anything like it. Your tendency to twist other peoples words reflects badly on you. I said that honest physics goes out of the window if valid conflicting results are swept under the carpet.
Your argument that Miller must be wrong because special relativity appears to be correct within the set of assumptions which flow from it contains an obvious logical fallacy. It is a circular argument.
This is why it may be possible to reconcile Einstein’s a priori reasoning and Miller’s empirical results within a better overarching theory.
It is a hallmark of pseudo-science to uncritically suspend disbelief and rigorous science, and not just for one aspect but in case after case of dubious claims.
It is a hallmark of propagandists that they seek to promote their own interpretation of reality by undermining other viewpoints with personal attacks and the twisting of other peoples words.
You are, it seems, a prime example.
Ditto.
Evans (09:27:10) : “Dr. Svalgaard, you have forfeited your credibility.”
Evans (10:09:50) : “Of course, fair-minded readers have to come to their own conclusion.”
Dr. Svalgaard: “And if they come to the conclusion accepted by modern space physics, they are not ‘fair-minded’ then?”
Typical from Dr. Svalgaard: Twist an opposing interlocutor’s statement.
No, I was referring to your discussion tactics.
tallbloke (00:24:36) :”I didn’t say that or anything like it. Your tendency to twist other peoples words reflects badly on you. I said that honest physics goes out of the window if valid conflicting results are swept under the carpet.”
Svalgaard: “It is a hallmark of pseudo-science to uncritically suspend disbelief and rigorous science, and not just for one aspect but in case after case of dubious claims.”
tallbloke: “It is a hallmark of propagandists that they seek to promote their own interpretation of reality by undermining other viewpoints with personal attacks and the twisting of other peoples words.”
All too true.
Tallbloke
I do not think that there exists a physicist who would not be attracted as if by a magnet by valid data that would dispute the known laws of physics and/or show unexpected results. A demonstrated experiment of levitation for example would draw all physicists into delving deeply in the experiment and the error analysis.
I remember when cold fusion broke out, how we all in my institute were absolutely mesmerized and read up on it and some solid state physicists tried to replicate it. For me, for example, the disillusionment came not from the repeat experiments but from the realization that the energy released was not of the order of magnitude of nuclear energy but of chemical energy: i.e. it was a property of the crystal releasing stored energy. And it was a disillusionment. I wanted it to be true as I think most physicists.
What Leif and I are saying is that the experiments of Miller and Galaev do not have the full rigorous error propagation that is necessary for the claims made, and are noise within errors, in contrast to numerous new measurements of the lazer and atomic clock age. On top of that, SR is used and evident in all of current physics.
It might be that at some level of significance an ether can be demonstrated, this has not been done by these experiments, and it will not be the ether that 19th century physics thought was necessary for the propagation of electromagnetic waves.
tallbloke (00:24:36) :
I said that honest physics goes out of the window if valid conflicting results are swept under the carpet.
This is what you said:
tallbloke (13:03:29) :
“So Miller goes under the carpet”
And honest physics goes out of the window.
Nothing about ‘valid etc’. And the word ‘honest’ does not belong in the discussion. If a conclusion drawn from an experiment disagrees with dozens of later experiments, it is good science to dismiss it. You were saying that that is not honest.
because special relativity appears to be correct within the set of assumptions which flow from it contains an obvious logical fallacy
Nonsense, assumptions do not flow from a theory, but precede it. SR has a domain of applicability [non-accelerating frame of reference] and Miller’s experiment fall within that.
It is a hallmark of propagandists that they seek to promote their own interpretation of reality
This is the interpretation that underpin all of modern physics, so is hardly anybody’s ‘own’.
James F. Evans (04:19:02) :
Evans (09:27:10) : “Dr. Svalgaard, you have forfeited your credibility.”
Talking about personal attacks…
anna v (05:51:01) :
It might be that at some level of significance an ether can be demonstrated, this has not been done by these experiments
And as http://arxiv.org/PS_cache/physics/pdf/0506/0506168v1.pdf mention, “special relativity is today underpinning all of present day physics, ranging from the standard model of particle physics (including nuclear and atomic physics) to general relativity and astronomy. That fact continues to push experimentalists to search for new experiments, or improve on previous ones, in order to uncover a possible violation of special relativity, as that would most certainly lead the way to a new conception of physics and of the universe surrounding us. Additional incentive for such tests comes from unification theories (e.g. string theories, loop quantum gravity), some of which [2, 3, 4] suggest a violation of special relativity at some, a priori unknown, level.”
So, in contrast to the notion that something is swept under the carpet and honest science thrown out of the window, experimentalists are more than ever pushing for ways to find violations of SR. To date none has been found, but the hunt is on.
Miller et al. are not accepted as valid because of the lack of proper error analysis, simple as that.
anna v (05:51:01) :
What Leif and I are saying is that the experiments of Miller and Galaev do not have the full rigorous error propagation that is necessary for the claims made, and are noise within errors, in contrast to numerous new measurements of the lazer and atomic clock age. On top of that, SR is used and evident in all of current physics.
Hi Anna. According to the analysis I have been reading, there is a consistent signal emerging from Millers averaged results from Mount Wilson, where he got a much stronger signal than in the basement at Case. If the Mount Wilson results are diluted with the Case results, it weakens the result, though it doesn’t eliminate the signal completely. I hear what you and Leif are saying about the way statistical methods have improved since Miller’s day though.
Ironically, the inventor of the atomic clock, Louis Essen, also thought Einstein got it wrong. http://www.btinternet.com/~time.lord/Relativity.html
He notes wryly that although his papers passed peer review, they never got published, and it was hinted to him that his career might be affected if he pushed the issue. Such are the pressures to conform to orthodoxy. He improved on Michelson’s estimate of the speed of light, and got it right to within 45m/s 20 years ahead of the laser interferometry result in use as today’s standard. A remarkable result.
It might be that at some level of significance an ether can be demonstrated, this has not been done by these experiments, and it will not be the ether that 19th century physics thought was necessary for the propagation of electromagnetic waves.
Miller himself concluded that the ether he believed he was measuring was not the rigid transmissive transverse wave propagating medium of the C19th, as it was entrained with the earth’s motion according to his interpretation of his results.
Another possibility which has been put forward is that Miller wasn’t measuring a change in the speed of light, but a directional change in the force of gravity, acting on the arms of his interferometer.
http://arxiv.org/ftp/physics/papers/0202/0202058.pdf
I find all these discussions interesting, and inconclusive. The point is, even if the signal was smaller than the error, there was a consistent sidereal pattern to the results, and the likelihood of that being random noise over the number of runs he did is very low.
By the way, it seems Henri Becquerel was working with the assumption that E=mc^2 in 1900, five years before Einstein’s much trumpeted ‘insight’. J.C. Maxwell speculated a lot about ether theories too. The history of science is much messier than the rewritten history fed to physics undergrads makes it seem.
Leif Svalgaard (06:09:20) :
If a conclusion drawn from an experiment disagrees with dozens of later experiments, it is good science to dismiss it. You were saying that that is not honest.
Dismissing Miller’s results on the basis that they were temperature effects was not honest, as Shankland knew it to be untrue.
assumptions do not flow from a theory, but precede it. SR has a domain of applicability [non-accelerating frame of reference] and Miller’s experiment fall within that.
Yes, I mis-phrased. If you start with the assumption that c is constant, Millers interpretation of his own results will inevitably conflict with it. As I mentioned to Anna, thereare other possible interpretations, so we shouldn’t throw the broomstick out with the bathwater, or sweep the baby under the carpet. or something like that. 🙂
It is a hallmark of propagandists that they seek to promote their own interpretation of reality
This is the interpretation that underpin all of modern physics, so is hardly anybody’s ‘own’.
This is the eternal tension between funded institutions which need to present a ‘united front with a consistent theory’ and scientists who make discoveries at odds with them. We should simply acknowledge this truism, recognise the uncertainties which underlie the assumptions, and not be sucked in by our own or any institution’s braggadacio. We must leave room for differing interpretations of data. Even thought experimentalists like Einstein and today’s string theorists.
tallbloke (08:30:46) :
We must leave room for differing interpretations of data.
Only if the data is solid and the analysis proper, none of which applies to Miller’s. It is every scientists dream to prove Einstein wrong, so no-one is presenting a united front. And there is no tension of that sort at all in physics. If a funded institution can prove Einstein wrong, its funding far into the future would be ensured.
tallbloke (08:30:46) :
Dismissing Miller’s results on the basis that they were temperature effects was not honest, as Shankland knew it to be untrue.
Link, please, to this assertion that Shankland was a liar, or what he ‘knew’. You are trying to cast doubt of another person’s work, by calling him dishonest.
And, Shankland is just a straw man here, as none of the accepted tests of SR rely on him and his work.
anna v (05:51:01) :
What Leif and I are saying is that the experiments of Miller and Galaev do not have the full rigorous error propagation that is necessary for the claims made, and are noise within errors
Galaev 2002:
The confi dence intervals of
the measured values were calculated with the known
methods explained, for example, in the work [30]. The
calculations were performed with the estimation reliability
equal to 0.95.
What is your objection?
The confi dence intervals of
the measured values were calculated with the known
methods explained, for example, in the work [30].
[30] L.Z. Rumshisky. \Mathematical processing of the experiment
results.” Nauka, Moskow, 1971, 192 pp. (in
Russia).
I have to confess I’m not intimately acquainted with this work. 🙂
tallbloke (09:15:03) :
The calculations were performed with the estimation reliability
equal to 0.95.
First, that is a rather low reliability. We usually do not consider a result statistically significant if the level is below 0.95 [one sigma], so Galaev is just on the edge, meaning that there is a 34% chance that the result is spurious.
Second, the reduction of the data is complicated, having to make assumptions about [as Galaev says] “the ether steady turbulent stream in the […] dielectric housing” [a cardboard box]. He asserts that “the value wpac does not differ essentially from the ether exterior stream velocity Wh”, but there is no analysis of the errorbars on either of these, so such an assertion may not be justified. There are many other approximations and assumptions throughout the paper, so no wonder that the scientific world was taken with storm when the paper was published.
Leif Svalgaard (09:50:38) :
so no wonder that the scientific world was not taken with storm when the paper was published.
Here is a nice ppt talk of Roberts:
I like his summary on page 43
Amateurs look for patterns, professionals look at errorbars.
Evans: “Dr. Svalgaard, you have forfeited your credibility.”
Dr. Svalgaard: “Talking about personal attacks…”
No, it’s an assessment and conclusion based on your discussion tactics.
REPLY: OK take a time out. I’m tired of moderating this. – Anthony
anna v (11:20:22) :
Here is a nice ppt talk of Roberts:
I like his summary on page 43
Amateurs look for patterns, professionals look at errorbars.
Skeptics check under the carpet.