back to article Einstein's brain to be picked by satellites

The European Space Agency is to make the most of two satellite misfires by using them to test Einstein's theory of relativity. Last August, the fifth and sixth Galileo satellites were launched as part of a plan to create a Euro-run GPS system, but the launch didn't go according to plan. A failure in the fourth stage of the …

  1. Martin Budden

    GPS with relativistic nanosecond time differences? Luxury! When I were a lad we 'ad to make do with Decca!

    (Actually, I really liked Decca)

    1. This post has been deleted by its author

    2. Yesnomaybe

      Decca??!! Pah! LORAN was far better!

      1. Ugotta B. Kiddingme

        Decca? LORAN? You were LUCKY!

        We had to use paper maps from the petrol station. And mother Kiddingme could never fold them back correctly, making father Kiddingme ever so cross.

        1. allthecoolshortnamesweretaken

          Re: Decca? LORAN? You were LUCKY!

          "Another thing about Liechtenstein - their road maps are really easy to fold!"

      2. Anonymous Coward
        Anonymous Coward

        "LORAN"

        The unforgettable sound that used to mess up the 160 metre band.

  2. RichardB

    Maybe I've been out of the country too long

    But is "ran 140 parts in a million of a second faster" even English?

    I mean, sure the words are...

    1. Anonymous Coward
      Anonymous Coward

      Re: Maybe I've been out of the country too long

      Part of which, does not this make sense?

    2. Anonymous Coward
      Anonymous Coward

      Re: Maybe I've been out of the country too long

      What the linked article actually says is:

      "Albert Einstein predicted a century ago that time would pass more slowly close to a massive object. It has been verified experimentally, most significantly in 1976 when a hydrogen maser atomic clock on Gravity Probe A was launched 10 000 km into space, confirming the prediction to within 140 parts in a million."

      Which I'm sure we can all agree makes a lot more sense than the plain wrong version in the report.

      1. Yet Another Anonymous coward Silver badge

        Re: Maybe I've been out of the country too long

        And not first in 1976 as the story says. Gravitational redshift was first experimentally tested in a stairway at Harvard in 1959

        1. phuzz Silver badge
          Boffin

          Re: Maybe I've been out of the country too long

          Thanks YAAC! I'd not heard of that before, (the Pound-Rebka experiment for those interested).

    3. JeffyPoooh
      Pint

      Re: Maybe I've been out of the country too long

      Forget the bad English; anyone else notice that it makes no sense numerically?

      "140 parts in a million" is about 12 seconds PER DAY.

      You could measure that with a grandfather clock for gawd's sake (perhaps not in zero g).

      It's OBVIOUSLY INCORRECT as written.

      1. Paul J Turner

        Re: Maybe I've been out of the country too long

        Actually it's right. Suppose they measured the error to picosecond accuracy but the uncertainty was 140 parts per million (I have no idea what the accuracy actually was) then they have a result to within +/- 0.000000000140 of a second.

        1. JeffyPoooh
          Pint

          Re: Maybe I've been out of the country too long

          The original extract was "ran 140 parts in a million of a second faster", which was simply wrong.

      2. Michael Wojcik Silver badge

        Re: Maybe I've been out of the country too long

        You could measure that with a grandfather clock for gawd's sake (perhaps not in zero g).

        Just attach a suitable spring to the pendulum bob, with the other end anchored to the floor of the cabinet. I think that's the only gravity-sensitive part of the typical grandfather clock.

        Hmm, now I'm wondering if that would work. The downward force due to gravity on the pendulum of a grandfather clock is constant to a first approximation, since its distance from the Earth's center of mass doesn't change significantly. But its distance from the proposed spring's attachment point does, and by Hooke's Law that means the force on the bob is going to change proportionally. I don't know much about the actual workings of grandfather clocks (I mean, I know the general theory, but not the practical details), but I suspect the spring would rather dampen the action.

        Maybe two springs, each attached to one corner of the cabinet? Or two springs running vertically along the sides of the cabinet and connected to a cable that runs through a pulley that replaces the bob.

        I'd google "grandfather clock in space", but I'm afraid I'd find something relevant.

  3. TimeMaster T

    Wait. What the ....

    I'm hoping for a "Hmmm, that's odd." discovery in the data.

    The biggest breakthroughs have started with those words.

    Gravity is the one force we really don't understand very well, hence the need for dark mater/energy to explain why really big things don't behave how the math says they should.

    1. Allan George Dyer Silver badge

      Re: Wait. What the ....

      Obligatory xkcd https://xkcd.com/1489/

    2. Christoph

      Re: Wait. What the ....

      And that's how science works.

      Religion: Our book is universal truth because we'll kill anyone who says that it isn't.

      Science: Our latest theory seems to be pretty good, so we'll test it to within an inch of its life to try and find holes in it. If it passes that's very good, because it's more reliable. If it fails that's marvellous, because we've found new knowledge about how the Universe works.

      1. albaleo

        Re: Wait. What the ....

        "And that's how science works."

        Are you sure?

        Science that can be easily verified: We'd better test this theory to an inch of its life because we'll look like fools if we're wrong.

        Science that can't be easily verified: We'll test this theory a bit, and if the results look dodgy, we'll adjust the data, tweak the models, and call anyone who doubts us a denier. After all, we know we're right.

        1. Christoph

          Re: Wait. What the ....

          Sure - scientists are human. And they are subject to all sorts of pressures. Especially the 'publish or perish' idiocy.

          But they do the best they can. And they punish cheating wherever they can.

          Science is a long way from perfect - but it is leaps and bounds better than anything else. And at the end of the day, you can't fool the Universe.

          We are having this discussion on a system that was made possible by an enormous number of scientific and technical advances, each itself made possible by previous advances. Many of us are only alive due to medical advances.

          1. DropBear

            Re: Wait. What the ....

            ...and a great many more are not alive anymore either a) because the relevant medical advances were either somehow not made at all (and don't seem to be forthcoming in the foreseeable future either in spite of many decades of "study"), b) because they could not afford to pay for it or c) because ultimately you're just disposable meat to any doctor and none of them will lose a second of sleep whether you live or die. </rant> Sorry, pet peeve triggered... the rest of your argument is quite valid.

        2. Dave 126 Silver badge

          Re: Wait. What the ....

          >so we'll test it to within [an inch to the power -12] of its life to try and find holes in it

          There, tweaked it it for you! : D

        3. Cuddles Silver badge

          Re: Wait. What the ....

          "And that's how science works."

          "Are you sure?"

          Yes. You are confusing science and scientists. The latter are squishy meatbags susceptible to the full range of human foibles - mistakes, fraud, political pressure, egos, and so on. The former is not. It doesn't matter how much you screw up or fake your results now, when someone repeats the same experiments (or different ones looking at the same thing) next month, next year, or next century, they will find out and correct things. Anti-science nuts love to posit grand conspiracies covering the whole world and running for centuries, but in the real world science is inevitably self-correcting in the long term.

          1. albaleo

            Re: Wait. What the ....

            "You are confusing science and scientists."

            I don't think so. I was responding to the statement, "that's how science works", not "that is science". I think it *works* through the actions of scientists.

            1. Anonymous Custard Silver badge
              Boffin

              Re: Wait. What the ....

              No, the science works all by itself, without any need of assistance from anyone (except mother nature).

              You just need the scientists to try and understand the why and the how, if you so desire to do so.

              The sun is going to come up, set and generally move about in the sky no matter whether you believe celestial mechanics, God and/or a huge Egyptian scarab beetle are causing it.

              1. albaleo

                Re: Wait. What the ....

                "No, the science works all by itself, without any need of assistance from anyone (except mother nature)."

                Perhaps this is a semantic matter, but by all definitions I'm aware of, science is very much in the human realm. We can crudely define it as "our understanding of the natural world". Nature works all by itself; science is encumbered by us fleshy things with our microscopes, rulers, hormones, and correlation formulae.

                Sorry to nark on. My original post was meant to be jocular. I absolutely agree with Christoph's description of science, but I also believe it is an idealized notion. Robert Grant above used the phrase "science mission statement", and I understand his concerns about how it is proselytised. My own view is that what separates (should separate?) science from religion and other non-rational beliefs is ignorance. The religious believe they know everything; scientists are certain they know very little. But finding out just a little bit more is the motivation.

                1. Anonymous Coward
                  Anonymous Coward

                  Re: Wait. What the ....

                  > The religious believe they know everything

                  Some religious perhaps, but what you describe is "superstitious", not necessarily "religious". Most religious people I know are certain they know very little. No argument about it being non-rational though.

              2. Michael Wojcik Silver badge

                Re: Wait. What the ....

                No, the science works all by itself, without any need of assistance from anyone (except mother nature).

                And you are confusing science and the physical universe it describes.

                Even (non-naive) realists don't believe science is the physical universe - they just think it can (ideally) be an accurate description of things that are true ("facts") about the physical universe, and a set of protocols for discovering those facts. ("Discovering" in this sense implies some degree of realism.)

                Conversely, very few constructivists or other anti-realists believe there is no indexical relationship whatsoever between scientific epistemology and material existence, even if they posit the latter as not directly knowable. But that's another question.

          2. Anonymous Coward
            Anonymous Coward

            Re: Wait. What the ....

            Just never forget that 'science is self-correcting', ...

            Which directly implies that some peer-reviewed, journal -published, generally-accepted scientific facts are actually 'yet to be corrected', in other words WRONG.

            (No, this is not a climate 'denier' rant.)

            My target is more often the ever-changing HEALTH / DIETARY crap "science" which is literally more often wrong than right. Moderation and common sense is literally more accurate in the long run. They've done nearly as much harm as good with their rubbish science.

            The Economist 'Trouble at the Lab' article provides background info.

        4. druck Silver badge
          Unhappy

          Re: Wait. What the ....

          albaleo wrote:

          Science that can't be easily verified: We'll test this theory a bit, and if the results look dodgy, we'll adjust the data, tweak the models, and call anyone who doubts us a denier. After all, we know we're right.

          That's why climate change is a religion, not a science.

          1. Indolent Wretch

            Re: Wait. What the ....

            Climate change denial is a religion.

            Climate change is basic frikking physics.

            1. Anonymous Coward
              Anonymous Coward

              Re: Wait. What the ....

              Who demands we all accept that "The science is settled!"?

              The Warmists or the Skeptics?

              1. Christoph

                Re: Wait. What the ....

                "Who demands we all accept that "The science is settled!"?

                The Warmists or the Skeptics?"

                ROFL!

                The science is settled because the data and evidence overwhelmingly shows that anthropogenic climate change is actually happening, to a very dangerous extent, and is getting rapidly worse.

                Are you seriously saying that this should be doubted because the evidence is so good?

                That you would only take it seriously if there was less evidence?

                That the 'Skeptics' are correct because they can't substantiate their case with actual evidence?

      2. Robert Grant Silver badge

        Re: Wait. What the ....

        You're comparing an ideal of science against a pessimistic view of religion? Amazing how many people have memorised the science mission statement, and proselytise every chance they get. 100 years ago you'd have been a missionary!

  4. Gordon 10 Silver badge

    Will the insurers try to claw back some cash?

    As above.

    1. imanidiot Silver badge

      Re: Will the insurers try to claw back some cash?

      Probably not, as these measurements have nothing to do with the intended or envisioned use of the satelite this is not a matter that involves any relevant insurance.

    2. arctic_haze

      Re: Will the insurers try to claw back some cash?

      I would bet some money they were not insured. NASA does not insure its launches and I would expect ESA to follow this practice. The reason is in the long run you must be paying more for insuring than not insuring. The difference is the insurer's premium.

      It is very similar to why car rental companies are "self insured" (that is they are mot insured at all). I the long run they have to lose money insuring their cars - and they operate in the long sun (as do the space agencies). You need insurance only if the costs of a single mishap can be too much for you to handle and for state run agencies on yearly budget a single failure in not a financial catastrophe.

  5. Carl W

    Improved GPS accuracy?

    Since GPS receivers have to make GR corrections already, will an improved understanding of GR lead to better GPS accuracy?

    1. Chemist

      Re: Improved GPS accuracy?

      "will an improved understanding of GR lead to better GPS accuracy?"

      Assuming the corrections applied now are those of GR theory only if something is sig. wrong with the theory will corrections need to be changed

      1. Little Mouse Silver badge

        Re: Improved GPS accuracy?

        Or, even better, maybe giving my SatNav a better understanding of the concept of time? (or at least, an ETA that somehow matches practical reality?)

        1. Toltec

          Re: Improved GPS accuracy?

          @ Little Mouse

          You can of course tweak the average speeds on various types of road that it uses to calculate the journey time. I find Copilot times pretty good when setup, compared to default values which see you arriving 10-15% earlier than calculated. (Sat nav capabilities vary and are available from other vendors).

    2. phy445

      Re: Improved GPS accuracy?

      For once I haven't been to the cited article to check things, but I think this is more about the science than any improvements to GPS.

      There is a lot of interest in test General Relativity to its limits. Over the years "boffins" (in Reg speak) have produced lots of little refinements to GR that predict pretty much the same results as Albert, but with subtle (hard to measure) differences. Which, if any, of these more sophisticated models is right is interesting science wise. I doubt that the real world impact will be that great because wobbles in satellite orbits and other factors will mask these very minor corrections-if they didn't then we'd be able to measure them already using the GPS system.

  6. Anonymous Coward
    Anonymous Coward

    Sun and moon

    As the sun and moon cause dynamic distortion of the Earth's surface - does that also vary the gravity experienced by GPS satellites as they pass over those points? Or does the changed gravitational pull of those two bodies on the satellite cancel it out?

    1. John Mangan

      Re: Sun and moon

      My suspicion is that the variation caused by the distortion would be much too small to register on this experiment. Given that the difference in time between two altitudes for the entire mass of the Earth is 140 parts per million I think any distortion will add the tiniest of variations to that.

      But, I could be wrong.

      1. JeffyPoooh
        Pint

        Re: Sun and moon

        JM "Given that the difference in time between two altitudes for the entire mass of the Earth is 140 parts per million I think any distortion will add the tiniest of variations to that."

        Check your math.

        140 ppm is about 12s per day of your purported "difference in time between two altitudes".

        We would have noticed that, even with a grandfather clock.

        The article was written incorrectly.

    2. Little Mouse Silver badge

      Re: Sun and moon

      The Sun and Moon may distort the shape of the Earth, but Shirley it's the mass that matters?

      1. John Mangan

        Re: Sun and moon

        "The Sun and Moon may distort the shape of the Earth, but Shirley it's the mass that matters?"

        The distortion will mean that some of that mass will be closer to, or further from, the satellites than on average and therefore there will be variation in the gravitational field and variation in the relativistic effects.

        1. Little Mouse Silver badge

          Re: Sun and moon

          My old physics teacher would turn in his grave after spending a lifetime forcing us that it's only the centre of gravity that counts. But that's theoretical physics for you.

          That said, even that must shift around a bit in a three-body system. Then factor in all the other bodies moving around out there. And the fact that the masses of the Sun, Earth and Moon are always changing.

          So I concede that there will always be some distortion.

          "In theory, there is no difference between theory and practice. But in practice, there is."

    3. LDS Silver badge

      Re: Sun and moon

      The distribution of mass around Earth, which is not constant (i.e. pass over the Everest and you get more nearer mass, while on deep Oceans you get less...) is enough to be taken into account also in this kind of measures, IIRC. Also, Earth is not a perfect sphere.

  7. Chris Miller

    Totes respeck to AE

    But I'd have said great physicist rather than great mathematician (in which field he was good, but he wasn't great).

    1. Anonymous Coward
      Anonymous Coward

      Re: Totes respeck to AE

      I seem to recall some other mathematician (whose name escapes me) referred to Einstein as a 'lazy dog' in reference to his maths.

      1. Dave 126 Silver badge

        Re: Totes respeck to AE

        And of a musician, who when playing violin with Einstein, declared in exasperation "My God Albert, can't you count?!"

    2. phy445

      Re: Totes respeck to AE

      Indeed he was pretty good at maths, but I understand that the hard work in getting the maths for general relativity sorted was done by Mrs Einstein (insert comment about equality here)

  8. The entire Radio 1 playlist commitee
    Meh

    I can't wait for the mainstream media to report on the findings.

    "European team of scientists finally prove Einstein was right"

    1. Indolent Wretch

      They may still do better than the guy who butchered the writing in this article.

  9. Crisp

    Unexpected Science

    Picture the scene:

    You're quite happily going about your day when suddenly...

    Unexpected Science!

    1. Ben Holmes

      Re: Unexpected Science

      Sounds like every session of Kerbal Space Program I have...

  10. David Pollard

    'Predictions' are what they checked

    ... scientists on Earth can check Einstein's calculations.

  11. allthecoolshortnamesweretaken

    Re verifying the theory

    there also was the Hafele-Keating experiment in 1971:

    https://en.wikipedia.org/wiki/Hafele%E2%80%93Keating_experiment

POST COMMENT House rules

Not a member of The Register? Create a new account here.

  • Enter your comment

  • Add an icon

Anonymous cowards cannot choose their icon

Other stories you might like

Biting the hand that feeds IT © 1998–2022