Has Gravity Probe B been a Big Flop?

Gravity Probe B (GPB) is a huge project of NASA and Standford university, in which a satellite carrying four ultra-sensitive gyroscopes were put into orbit around Earth. The idea was to test two of Einstein’s General Theory of Relativity (GR) effects: the geodetic effect and inertial frame dragging.

The geodetic effect represents the effect that the curvature of spacetime have on a spinning, moving body, as predicted by GR. The geodetic effect is relatively large and should not have posed any problems for GPB to detect.

Inertial frame dragging is a GR prediction that the rotation of an object would alter space and time, dragging a nearby object out of position compared to the predictions of Newtonian physics. The predicted effect is incredibly small — about one part in a few trillion, according to Wikipedia.

Although the Wikipedia article on the geodetic effect states that it has been confirmed to the 1% level, there is evidence that the best value that they obtained are not in agreement with Einstein’s GR! This NASA/Stanford slide: http://colloquia.physics.cornell.edu/11-12-2007/cornellpres_files/v3_slide0426.htm
is showing that to a 1 sigma error confidence level the results for the geodetic precession are inconsistent with GR.

There were two unexpected sources of error affecting the gyros that almost ruined the whole effort, but the project scientists are confident that they can filter out the errors and reveal the true data. They are still struggling with the geodetic effect, never mind the very much smaller frame dragging effect.

So what if this whole effort turns out one big waste of money, with no clear result?

SL: Your Aerospace Watchdog

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69 thoughts on “Has Gravity Probe B been a Big Flop?”

  1. Will and usually not disclosed to the public until 40 years after the fact is very annoying, same with archeological finds, not disclosed to the public either I find that highly annoying. Most of the public doesn’t even know or realize that NEW YORK had tons of giant skeletons and were over 10k years old. NEW YORK GIANTS! So funny how the most obvious thing is completely obscure to the many so busy with their lives….

  2. The problem with GPB is that its reputation is now tarnished. Whatever the scientists may come up with as results will always be met with a certain degree of skepticism.

    As an engineer, I feel sorry for the scientists – this has been an engineering failure to some degree, since the ‘most perfect gyros in the world’ did not work so perfectly!

    However, I still think that NASA will allow the data to be processed to a conclusion, even if that means that failure is conceded by the scientists. After that, the ‘tons’ of data will be put into the public domain, where it will probably be utilized and perhaps abused for decades to come.


    Burt Jordaan (www.Relativity-4-Engineers.com)

  3. People may miss the tongue in cheek tone here.

    As you note, the decision was a budgetary one, not a scientific one. The scientists recommended further funding.

    I’ll pitch in ten bucks to complete the analysis if another 379,999 people join me. Or we could do it by spending 20 cents per taxpayer.

    Fred Bortz — Science and technology books for young readers (www.fredbortz.com) and Science book reviews (www.scienceshelf.com)

  4. Now it’s ‘official’!

    GP-B STATUS UPDATE — MAY 23, 2008
    In March 2008 at NASA’s invitation, we submitted a proposal to the Science Mission Directorate, Astrophysics Division Senior Review of Operating Missions (Sr. Review), requesting a final 18-month (October 2008 through March 2010), $3.8M extension of GP-B to complete the data analysis and publish the results. In April, as part of the Sr. Review process, GP-B Principal Investigator, Francis Everitt, and Program Manager, William Bencze, made a presentation to the Sr. Review Committee at NASA Headquarters, where it appeared to have been favorably received.

    Thus, we were greatly surprised last week to discover that the Sr. Review had recommended that NASA not grant our final funding extension, particularly since another NASA committee–the GP-B Science Advisory Committee, chaired by relativistic physicist Clifford Will–stated in its report following the November 2007 meeting: “The SAC was impressed with the truly extraordinary progress that has been made in data analysis since SAC-16 [Mar 2007] Å and we now agree that GP-B is on an accelerating path toward reaching good science results.”

    The Sr. Review evaluation is an unexpected setback, but we are determined to push ahead and drive to the very best possible result within the resources available.

    The science team may still prevail, though. If they ‘only’ need $3.8M to complete the analysis (while $800M has been spent on the mission), it seems silly to pull the plug now. Or is it a case of no good money after bad money?

    Burt Jordaan (www.Relativity-4-Engineers.com)

  5. It is me, Jin He, the anonymous software seller.

    Please go to http://www.truthmost.com for details.

    What is happiness? What is depression?
    What is friendship? What is hatred?
    What is conscience? What is evil?
    What is life? What is death?
    Over thousands of years, we human beings have not found the consensus answer.
    We, the spoiled babies, have torn up the increasingly weak mother: the earth.

    Ah, babies, it is time to lift up your heads, look at the wide and deep universe,
    and trace down the blood lineage of your mother:
    It is the bending hands of Milky Way — the spiral arms – that hug Earth.
    It is the broad chest of Milky Way — the galactic disk – that shields the sun,

    Are your hands and your chest related? Yes, there is your heart!
    Are the Milky Way’s hands and chest related? Yes, that is the meaning of the whole universe!
    It provides the answer to all your questions.

    Very luckily, here is a very simple ($3.8) computer software.
    It says that galaxies’ hands and chests are related. It provides nine real images of galaxies.
    You can personally prove if the relation is true or false, solely based on the images and the software!!

  6. Save your efforts, folks!

    Clicking the link gets you to a bunch of hokum with the heading, “EXPLORING the Origin of Life and Conscience!”

    When I read it, my plastic bust of Einstein toppled over and burst into flame :) Fortunately, my plastic Beethoven saved him.

    Fred Bortz — Science and technology books for young readers (www.fredbortz.com) and Science book reviews (www.scienceshelf.com)

  7. Jin He,

    David Halliday’s advice is excellent.

    You might also be able to benefit from Renaisauce’s recent post, which was inspired by this discussion.

    The “Galileo Complex,” as Renaisauce calls it, is definitely a curable condition.

    Fred Bortz — Science and technology books for young readers (www.fredbortz.com) and Science book reviews (www.scienceshelf.com)

  8. If you want to use some software to disprove Einstein then it will almost certainly need to be free and open source, so anyone can delve into the code to double and triple check the code to make sure it is doing what you claim it is (or else it would have to be so easy for anyone to replicate, from your description of what it does, that any reasonable implementation will reproduce what your version does).

    This is necessary because one requirement of science is reproducibility!

    So, other than some entertainment value, I’m hard pressed to see how you can fulfill the requirements of science, especially if you are trying to challenge a well established theory (regardless of authorship), and “make [a] profit”. (I know, it tends to keep most of us scientists on the poor side.)

    Now, it is good that you have expressed your “challenge” as “If it is right then Einstein is wrong.” Of course I hope you recognize that the burden is on you to show whether the “software with real images” is “right”. In science, the crux of any test of “right” is determined by comparison with actual experiments and/or observations of nature. No other test is meaningful—nature is the ultimate arbiter.

    I certainly don’t know what the nature of you software is, or what you mean by “real” images, nor do I know anything about this paper you say had what you felt was a key point “against” Einstein removed is about. I really don’t even know, from what you’ve said, whether the two are very closely related (though I would guess that they may well be).

    If you are trying to suggest that one or more of Einstein’s theories suggests some unbelievable result, then the issue may simply boil down to opinion on what is “believable”. If you are trying to suggest that one or more of Einstein’s theories predicts something that conflicts with observations, then that’s not a bad start, though you’ll have to be prepared to have others show how additional considerations make a sufficient difference as to bring Einstein’s predictions in line with observations. (His theories have withstood so many such challenges that it is difficult to believe that if this conflict were the case that this would not already be widely noised about.)

    On the other hand, if you are trying to suggest some alternate theory, you have much more work to do. As I’ve said, any alternative theory must first show that it matches all previous experiments and observations. Fortunately, this is not quite as difficult as it may at first appear, so long as there are viable theories already in existence that do match such: This requirement then reduces to showing that in an appropriate limit (one appropriate for the regime for which such observations/experiments have been carried out), the new theory reduces to the alternate (this is how Special and General Relativity, and Quantum Mechanics/Field-Theory fulfilled this requirement).

    Then you graduate to showing how the new theory predicts testable phenomena that differ from the former theory/theories. (You may even show how the new theory matches former observations/experiments without having to add additional assumptions, such as Dark Matter/Energy or some such.)

    This is the way science progresses, this is how scientific revolutions are “fought” and “won”.


    P.S. While some “Einstein camp” may “be angry at” you, I don’t see anyone other than some highly unstable type trying to kill you, in any literal sense. Now, can you expect to have your ideas criticized, receiving a great deal of critical scrutiny? Almost certainly. Extraordinary claims require extraordinary levels of “proof”.

    You should expect that your ideas will receive quite a “beating”, being “bashed” from all possible sides against competing ideas. This is not intended to be any form of personal attach (unless you make it so, either by the way you take it and respond, or the tone you take when making your challenges—so be careful, and control your emotions). What it is intended to do is make sure that only the strongest ideas survive, and, even then, as many of the “rough” spots are smoothed out as possible. (Think of it as a testing and polishing process.)

    So, admittedly, this is not for the faint of heart. This is only for those that truly believe (as objectively as they can possibly muster) that they have a better idea.

    So good luck.

  9. Jin He,

    First of all, there is no “Einstein camp.” There are people who find his work compelling and interesting and spend a lot of time exploring its implications, but no serious scientist believes any theory to be beyond challenge.

    Like David, I’m not an academic scientist, though I spent 20 years of my working life in an academic environment, much of it in liaison work between researchers and other professionals (sponsors, educators, etc.)

    I suspect that the deletion you refer to was probably an error that needed to be corrected, but you are so upset about it that you can’t see the error.

    In any case, I have experience working with editors and publishers. If they own the copyright, there is little you can do. If you have the copyright, you should have been offered the chance to approve or disapprove before publication.

    In this case, it sounds like the correction was necessary for the paper to be published.

    But in any case, it is an issue between you and your editor. Ranting and spewing insults, as you did here, just makes you look like a jerk with a huge chip on his shoulder.

    If that description fits, then you need to change the way you interact with others. If it doesn’t fit, then you need to figure out why you acted like a jerk with a huge chip on his shoulder in this one case.

    By the way, you might want to look at a recent book I wrote for high school and college libraries, Physics: Decade by Decade in the 20th-century science set from Facts on File (2007).

    Fred Bortz — Science and technology books for young readers (www.fredbortz.com) and Science book reviews (www.scienceshelf.com)

  10. Re Halliday:

    I do not want recall the bad exerience, e.g., a paper was published when the part against Einstein was deleted.
    My urgent question is: how should I do?

    I made a piece of software with real images. If it is right then Einstein is wrong. The point is that everyone can play the software and judge if it is right.

    I would like to make the software to be free but I want to make profit of it for the reason you know.

    But the critical problem is: will the Einstein camp be angry at me, and kill me if I make the software public?

  11. I can’t speak for Fred, but I’m no faculty scientist. I’m one of those non-faculty scientists you claim are the saviors of us all.

    No, Fred is absolutely right, we, as scientists, are quite open to those theories that pass the test of matching experiments, both past and present, and will continue to consider such theories as potentially viable so long as they do pass said test. (Of course we’ll tend to the most simple theory/explanation, all else being equal. Good ol’ Occam’s razor.)

    There are a number of viable alternatives to General Relativity (GR) as contenders for a theory of gravity. All but one, that I know of (that have risen to the point of viability), have “tweak-able” parameters, and their parameters keep getting pushed closer and closer to being identical with General Relativity.

    On the Quantum Mechanics (QM) side: I have often lamented that Quantum Mechanics is “too good for its own good”, meaning that there are no viable alternatives (no alternatives have been able to be at least as good as Quantum Mechanics at matching experiments). If there exists a viable alternative (one that matches all experiments done so far), I’m more than willing to check it out!

    Most serious physicists, I believe, recognize that while we have these two great theories (GR and QM), which are unsurpassed in their respective realms, there’s a problem when venturing into realms that, logically, should require both or some combination thereof. GR and QM don’t play well together! So there “must” be something missing, or something better.

    The search for that “something better” has been going on for at least 50 years (maybe nearly 100 years, now, depending on when you “start the clock”). Unfortunately, I don’t consider any of the alternatives I know of, at this time, to be quite there, yet. (Loop Quantum Gravity has some appeal to me, but I don’t ascribe to it, yet. I have my own ideas, but they’re not quite to the theory stage, yet. The problem would be far easier to solve if we had some viable experiments within this realm where both QM and GR should be used, but we don’t have particle accelerators that are nearly powerful enough; and while some Cosmic Rays may be powerful enough it’s very hard to get good statistics. If we could come by a nice microscopic “black hole” on which we could do experiments, that would really fit the bill!)

    So, while we are open to viable new ideas, the hard hurdle that most seem unwilling or unable to pass is being able to match all known experiments. However, that is the critical point that must be satisfied by all theories that wish to be considered as viable. (Even GR and QM had to each satisfy this hurdle before they could be considered.)

    So, if you know of something that satisfies this criteria, I’m all ears.


  12. An important scientific innovation rarely makes its way by gradually winning over and converting its opponents: it rarely happens that Saul becomes Paul. What does happen is that its opponents gradually die out, and that the growing generation is familiarised with the ideas from the beginning

  13. First, I think it’s awesome that somebody responded to Fred’s discussion on rants by ranting. Second, I think it’s awesome that the dude thinks that he’s unemployed because science isn’t democratic. I suggest that going to a faculty board and calling their research a false bible isn’t going to win you points with the committee. Third, is the Time Tunnel a man-made bible, or a 60’s TV show?

    However, if there are those of you who think that the democratization of scientific law is acceptable, I want you to know that I fully support you. I think its about time that we have a voice in simplifying the laws of physics a little. The tax code is easy by comparison. Therefore, I officially announce that I nominate myself a Superdelegate for the Election Board of Scientific Law.

    I appreciate your support. I won’t let you down.

  14. To Fred Bortz THE Science and technology books for young readers:
    To David Halliday THE serious and careful scientist:

    HOW TO VOTE????
    Is there a democratic mechanism in scientific community?
    No!! That is why there are millions of people who want to join faculty. No one can fire the members of faculty if they keep being compromized.

    We non-faculty scientists do not have anything to lose, because we want to challenge the eternal theory of everything: BIG BANG, GENERAL RELATIVITY, TIME TUNNEL and other man-made bibles, which promise (?) to explain everything: life, conscience, man and women, how many atoms in human body, etc.

    You respectable faculty SCIENTISTS have a burden: your man-made bibles are supposed and are controled to be eternal and ever-correct!!

    Are you certain of your bibles? No!! Otherwise you would not visit this blog spot!!!!!!

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