back to article Brit boffins build 'quantum compass'... say goodbye to those old GPS gizmos, possibly

British boffins have developed a self-contained and tamper-proof "quantum compass" that doesn't rely on GPS signals to provide a highly accurate measure of where it is in the world. The compass is a quantum accelerometer that is capable of measuring tiny shifts in supercooled atoms and so calculate how far and how fast the …

  1. onefang
    Boffin

    It's not a compass.

    It only measures how far it moved, and currently only on one plane. Even once they get it up to three planes, as planned, it still only tells you how far it moved. You need another bit of information, where you started from. No idea how it works when rotating it in place, does it even notice? Though I guess having more of them and doing some calculations tells you if it's rotating. You still need to know which direction you where facing to start with. Not to mention that errors add up over time on these sorts of devices, though perhaps the error is really tiny, it wasn't mentioned.

    You can get that missing info from, oh I dunno, a GPS and a real compass I guess. Or a surveying point and it's records.

    Still, it's cool technology.

  2. Ken Hagan Gold badge

    Re: It's not a compass.

    A surveying point in the home harbour, probably made of concrete, is difficult for the enemy to block or interfere with.

  3. David M

    Re: It's not a compass.

    onefang: your question, "No idea how it works when rotating it in place, does it even notice?", is answered in the video, where it says that they plan to build a version that can measure three orthogonal accelerations, and three rotations.

    It's a shame they don't give any clues about the accuracy, or predictions about the timescale to make something commercially viable,

  4. onefang

    Re: It's not a compass.

    "onefang: your question, "No idea how it works when rotating it in place, does it even notice?", is answered in the video"

    Ah, I skipped watching the video. Back when I only had 30 GBs of Internet a month I would generally skip random videos, to conserve bandwidth. Now that I no longer have that problem, I still have that habit. Slowly breaking the habit.

  5. Ledswinger Silver badge

    Re: It's not a compass.

    It's a shame they don't give any clues about the accuracy, or predictions about the timescale to make something commercially viable,

    The MoD are funding it, so I'll guess never, even if it turns out to have no military applications.

  6. macjules Silver badge

    Re: It's not a compass.

    The MoD are funding it, so I'll guess never, even if it turns out to have no military applications.

    Just so long as it runs on Windows ME or even Windows XP then it will be fine.

  7. katrinab Silver badge

    Re: It's not a compass.

    Surely you have three of these devices, with three different starting points for their movements, then you can triangulate where you are?

  8. Anonymous Coward
    Anonymous Coward

    Re: It's not a compass.

    I didn't watch the video either but 3-axis accelerators are everywhere these days.

  9. Anonymous Coward
    Anonymous Coward

    3-axis accelerators are everywhere

    They are, but not accurate enough (long term) or with enough resolution to use for an intertal platform that doesn't use something else (e.g. gps) to compensate for drift.

  10. Yet Another Anonymous coward Silver badge

    Re: It's not a compass.

    Yes it is a compass.

    A gryo left undisturbed will point in the same direction as the Earth turns. It tells you directly where the true north pole is. It's how you get a heading underground if you wanted to eg. dig a tunnel to France

  11. veti Silver badge

    Re: It's not a compass.

    My guess is that "commercially viable" will be available about the same time as fusion power.

    There's a certain type of boffin - and for reasons that are pretty obvious when you think about it, they're often a type that loves working on govt-funded R&D projects - who think that once they've demonstrated an effect in principle, everything after that is just boring donkey-work. This is the demonstration-in-principle, now it's "just" a matter of bolting six of the things together, reducing space, weight and power requirements by a factor of 10,000, and manufacturing costs by a thousand times that, and fixing all those annoying glitches that they still don't fully understand but managed to work around for demo purposes...

    How hard can it be? - as they said about fusion, back in the '70s.

    And then someone will have to interface it to Android and iOS. That's where things will really get tricky.

  12. Yet Another Anonymous coward Silver badge

    Re: It's not a compass.

    >My guess is that "commercially viable" will be available about the same time as fusion power.

    Depends what you mean by commercially viable.

    To replace the 10c mems accelerometer in your phone = no

    To replace the set of $25,000 laser fog gyros in a submarine/aircraft = not so hard

  13. Anonymous Coward
    Anonymous Coward

    Re: 3-axis accelerators are everywhere

    They have been using compensations not relying on GPS for decades and it has been used with very good results in nuclear submarines that stay submerged for weeks if not months.

  14. e_is_real_i_isnt

    Re: It's not a compass.

    They need to subtract out the rotation of the Earth around its axis, the movement of the Earth around the center of mass between the Earth and the Moon, the movement of the Earth around the Sun, and the Sun around the galaxy. It should be easy.

  15. Sampler

    Space?

    Would this work in space? I mean, once you're outside the GPS satellites it must be pretty tricky to work out where you are, star charts can be so accurate but you'd have to have been there before to know where you are and how to get back?

    But, if you know you've moved A miles on the X axis, B miles on the Y axis and C miles on the Z axis from Earth, you know how to get back.

  16. h4rm0ny Silver badge

    Re: It's not a compass.

    Additionally, the threat of disrupting or hacking GPS that this addresses isn't just a theoretical one. This is how the Iranians captured a US drone some years ago. They flew another plane over the top of it and broadcast fake GPS signals to it causing it to think it was somewhere else and land.

  17. h4rm0ny Silver badge

    Re: It's not a compass.

    It's how you get a heading underground if you wanted to eg. dig a tunnel to France.

    Why couldn't you use a regular compass to get a heading underground?

  18. onefang

    Re: It's not a compass.

    "Why couldn't you use a regular compass to get a heading underground?"

    Depends on what you are digging through or near I guess. Or possibly digging with, that huge metal tunnel digger might be all the compass ever points at.

  19. jake Silver badge

    Re: Space?

    "but you'd have to have been there before to know where you are and how to get back?"

    Nah. Just find a handful of quasars and/or pulsars and do a little easy trig. You can pinpoint yourself pretty much anywhere in known space. (The real known space, not the scifi version.) On the other hand, getting home might take a little more energy than remembering basic High School maths.

    On the gripping hand, I wouldn't mind being on the first ride that would require the above. It would probably be either boring as shit, or the entire crew would be dead ... but what a story to tell if you survived!

  20. jake Silver badge

    Re: It's not a compass.

    "And then someone will have to interface it to Android and iOS. That's where things will really get tricky."

    Nah. That's the easy part. Industrial controllers are a known thing.

  21. Dave 126 Silver badge

    Re: It's not a compass.

    The concept (and practice) is called Dead Reckoning and is used on submarines. However there is no way to avoid Cumulative Errors which limit its accuracy over time. A submarine is moving relatively smoothly compared to a phone in someone's pocket, which is why dead reckoning can't practically be used to augment a phone's GPS (for navigating with a building, for example)

  22. disgustedoftunbridgewells Silver badge

    Re: It's not a compass.

    France? Why would anybody want to dig a tunnel to bloody France?

    I read that when they dug the chunnel they were only inches off course by the time they met up in the middle, which is pretty bloody impressive if you ask me ( I blame the french for those few inches, naturally ).

  23. Teiwaz Silver badge

    Re: It's not a compass.

    And then someone will have to interface it to Android and iOS. That's where things will really get tricky.

    Oh, good, the app makers can use the 'because it's quantum' excuse as to why the app will only work when given every permission under the sun, including inside leg measurements in realtime.

  24. DJO Silver badge

    Re: It's not a compass.

    Why would anybody want to dig a tunnel to bloody France?

    Maybe they were digging a tunnel from France.

  25. onefang

    Re: It's not a compass.

    "I read that when they dug the chunnel they were only inches off course by the time they met up in the middle, which is pretty bloody impressive if you ask me ( I blame the french for those few inches, naturally )."

    Where the diggers from the English side using inches, and the French side using centimeters?

  26. Anonymous Coward
    Anonymous Coward

    Re: It's not a compass.

    "Pirates are now sophisticated enough to cause disruptions to ships, and lure them to rocks or take over and board them, by disrupting GPS,"

    Proper military systems use navigation systems that contain an inertial navigation system (INS) and GPS. INS's measure the accelerations the object has undergone form it's last known position & calculate where it is. (Many have pointed out this "quantum compass" is merely a single axis INS that supposedly has a quantum noise limited integration error.) INS's are not subject to external influences like jamming. They are however, limited by the accumulation of what are essentially round-off errors (or LSB resolution) in the acceleration measurements, and that results in an accumulated position error called "integration error". That accumulated position error gets larger over time and in the course of several hours can be large enough to matter. So top notch military navigation systems use both GPS & INS, and detect GPS jamming by watching whether the GPS reported position exceeds the INS reported position by an amount significantly larger than the INS integration error. (At which point, if say it's a drone, you can have it head towards home using the INS until it clears the GPS interference area, which it will by the time it's near it's home base.)

  27. DropBear Silver badge

    Re: It's not a compass.

    "Many have pointed out this "quantum compass" is merely a single axis INS that supposedly has a quantum noise limited integration error."

    Exactly. This thing isn't any more magical than any inertial positioning system, and it must be subject to accumulating error exactly just as all the others are. Where it may indeed differ substantially is the level of that drift, which may really be astonishingly small for all we (don't) know, much like atomic clocks aren't absolutely precise either*, only mind-bogglingly precise.

    * we could conceivably keep on splitting hairs about the second being defined as a fixed number of atomic oscillations therefore these clocks being infinitely precise and zero drift by definition, but I have a hunch that any practical implementations might just conceivably introduce some further sources of error, no matter how small, making atomic clocks still less than ideally precise.

  28. Michael Habel Silver badge

    Re: It's not a compass.

    Well at least its not running that bloddy Vista thing (Shakes angy fist!).

  29. Brewster's Angle Grinder Silver badge

    Re: It's not a compass.

    "...that supposedly has a quantum noise limited integration error."

    You want measurements accurate down to the Planck scale? Jeez, you guys are hard task masters.

    Seriously, I don't know what they say in the video, but you can accumulate an error of hundreds of thousands of atomic diameters and still be accurate to less than a millimetre.

  30. JassMan Silver badge
    Trollface

    Re: It's not a compass. @disgusted of tunbridgewells

    You can't blame the french for a few inches. If they were at fault it would have been a few centimetres. The fact that the error was is in inches implies that if you can't trust the original positioning, why should you trust the check any further. The only thing known for sure is that there were 10s of millimeters difference between the 2 terminations, since engineers work in SI units as opposed to "imperial" or "metric". Still it was a pretty bloody impressive feat to dig that far without line of sight from one end to the other. Shame that once Brexit takes effect it will take 10 times as long to get to checkin and through customs as it will to get through the tunnel.

  31. Apprentice

    Re: It's not a compass.

    Oh, I guess they haven't thought about all that, I guess they should have consulted Joe Public first as clearly you know better than these well educated scientists. Back to the drawing board it is then.

  32. Snapper

    Re: It's not a compass.

    Could you use a.......oh, I dunno, a big calculator for that?

  33. Red Bren
    Coat

    Re: It's not a compass.

    If they were off course by inches, then that's the fault of the British. If they had been off course by centimetres, then it would be the fault of the French!

  34. Deltics
    Coat

    Re: Space?

    Which then just leaves the question of figuring out where Earth is once you've returned to the spot it was at when you left (assuming that you can either compensate for the expansion of The Universe, the duration of the trip is such that this expansion doesn't amount to a significant drift or that there is no such expansion after all so it simply doesn't figure).

  35. Cookie 8

    Re: It's not a compass.

    If the French were off, wouldn't it be by a few centimetres?

  36. diodesign (Written by Reg staff) Silver badge

    Re: It's not a compass.

    Nah, we're happy with quantum compass. It pretty much explains why in the article. The eggheads call it a quantum compass. It's not a traditional compass. It's a quantum compass.

    C.

  37. Blank Reg Silver badge

    Re: 3-axis accelerators are everywhere

    That depends on your time frame. There are extremely accurate accelerometers used for tracking the movement of soldiers indoors. But that only needs to be accurate for a matter of hours, I don't know how far off it would be after a few days, though I expect it would be adequate for navigating a boat or plane.

  38. Alfred

    Re: It's not a compass.

    "You need another bit of information, where you started from."

    OMG, you've spotted the fatal flaw. Unless... unless... yes, it's just possible that someone could make a note of where they're starting from.

  39. Fungus Bob Silver badge

    Re: It's not a compass.

    "A surveying point in the home harbour, probably made of concrete, is difficult for the enemy to block or interfere with."

    A torpedo could probably render it useless...

  40. BillG Silver badge
    Megaphone

    Galileo, Galileo

    ...Europe made it clear that following Brexit, the UK would no longer gain secure access to Europe's new Galileo GPS system despite years of assisting in the system's development and deployment.

    I don't know the history of Galileo GPS, but this seems spiteful for the EU to treat the UK like this.

  41. Hurn

    Re: It's not a compass.

    The original concept was (is) called SINS: Ship's Inertial Navigation System

    accelerometers sense movement along all 3 axes and track displacement

    It is not Dead Reckoning, but a technological replacement. From over 50 years ago.

    The main difference between SINS's gyroscopes and quantum "compass" is sensitivity (and need for extreme cooling).

  42. Uffish

    Re: "3-axis accelerators are everywhere these days"

    And most especially, they say, in a nice hot cup of tea.

  43. Ken Hagan Gold badge

    "A GPS signal could be spoofed or blocked for instance. When you're thinking about nuclear submarines, it usually best to consider the worst."

    Actually, when you are thinking about submarines, you probably don't want to be using a GPS in your navigation system. A blocked signal is "what happens", not "the worst", because sea-water is basically impenetrable to EM waves.

    And if you are thinking about ballistic missile subs, I hope you've factored into your thoughts the near-certain fact that in just a few years the enemy will be able to track those with one of their mass-produced robotic drones and so their locations while out on patrol will cease to be "totally undetectable" (as they have been for the last half-century or more) and instead be "posted on the internet, by the enemy, just because they can, for shits and giggles".

  44. Spamfast

    Probably won't even need drones - the Chinese may have magnetometers sensitive enough to detect the hull of a sub from the air.

    https://www.newscientist.com/article/2144721-chinas-quantum-submarine-detector-could-seal-south-china-sea/

    Add air-launched torpedos and there goes your nuclear deterrent.

    Remind me again why the UK still insists on paying the US vast sums of money for sub-based ballistic missiles that we can't even launch without getting permission from the White House?

  45. Blane Bramble

    "that we can't even launch without getting permission from the White House?"

    Because that last bit is wrong.

  46. Phil O'Sophical Silver badge
    Coat

    be able to track those with one of their mass-produced robotic drones

    Until the navy starts filling the oceans with mass-produced decoy submarine drones for them to track, that is.

  47. Yet Another Anonymous coward Silver badge

    If you have a balistic missile sub then GPS is useless. All your GPS satelites have already been taken out by the massive thermonuclear first strike of the other guys - unless you were intending to shoot first.

    It's why ICBMs have star trackers not GPS.

  48. h4rm0ny Silver badge

    unless you were intending to shoot first.

    Less of a problem than you might hope. The USA has been pursuing a policy of Nuclear Primacy for some years now. Nuclear Primacy is the capability to first strike so hard there cannot be an effective response. Long, but good, article on this:

    https://www.foreignaffairs.com/articles/united-states/2006-03-01/rise-us-nuclear-primacy

  49. Anonymous Coward
    Anonymous Coward

    Until the navy starts filling the oceans with mass-produced decoy submarine drones for them to track, that is.

    UK Navy? Rather optimistic assumption of capability I am afraid. In order to simulate a sub well and be viable as a decoy the drone should be able to run under water for a sufficient amount of time and/or be suitably sized for the decoy to be difficult to distinguish from the real thing. That requires compact reactor or high power thermoelectric isotope battery technology. A small conventional battery powered drone will be immediately distinguishable on active sonar. While a sub captain will not use active echolocation unless they have no choice as it will give away their position, an unmanned drone will have no such qualms. In fact it, is likely to use that on purpose as a part of psychological warfare against the sub crew: "We see you all the time, we have a weapon's lock all the time and you do not stand a chance of reacting before we blow you up".

    Neither small reactors, nor high power thermoelectric is in the works in the UK. Neither one is in the works in the USA. They are however (both of them) in production in Russia now and according to the Internet rumour mill in final testing stages in China. The west is ~ 10 years behind here.

  50. Big John Silver badge

    > "Until the navy starts filling the oceans with mass-produced decoy submarine drones for them to track, that is."

    I would bet they've had those for years already.

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