April 7, 2016

Quantum Entanglement for Submarines made Easy

The US Government, more precisely the USN, wishes to patent "quantum entanglement" technology
 for submarine positioning, navigation, ASW and mine detection. It is meant to be undetectable by enemies. See the funky video below - groovy music!


Submarines under Arctic ice apparently rely on inertial guidance to position and navigate. This is because thick ice can block the positioning signals that submarines usually rely on. Those signals may be from GPS satellites or VLF stations and other frequency range submarine radiocommunications. Ice also blocks a submarine's extended antenna or antenna buoys.

Using active sonar to avoid banging into things is too indiscrete and hurts cute dolphins and whales' hearing.

So the US Government wishes to patent quantum entanglement which is, in theory, so far, undetectable by an enemy. But Russian scientists, or spies, love a challenge.

Perhaps the US and UK have also thought of using the method for seafloor sensors in the littorals to detect wandering enemy subs?



Pete

14 comments:

Josh said...

Submarine guidance has long been inertial since nuke boats began traveling submerged for extended periods. The modern mechanism I believe is the laser ring gyro, but submerged navigation always gets increasingly inaccurate the longer the boat is continuously submerged. Surfacing allows for a position update to the system to correct for drift, be it using LORAN, TRANSIT, or now NAVSTAR. This just requires a mast to breach; there might be tethered buoys that can accomplish this now.

MHalblaub said...

Dear Pete,
According to my knowledge the trick with entangled photons works differently. The emitted photon does not even have to be received again by the submarine. The change of a quantum mechanical state will be instantly transmitted to the other photon. - yep even faster than light.

Therefor an entangled search light could be much darker ...

The problem remains that it is still light an could be absorbed very quickly by dirty water.

Regards,
MHalblaub

Ztev Konrad said...

What would those positioning signals received underwater be ? VLF can go say 30m but its one way as the broadcast antenna is a few sq km in size and can only be at a low rate.
en.wikipedia.org/wiki/Communication_with_submarines#Extremely_low_frequency

imacca said...

Better living through theoretical physics huh!

Having read the linked article it does make a certain amount of sense. No-one else can detect your photon because they dont have the matching entangled one as a reference. But building the kit to do it reliably is going to be a non trivial challenge. Can you imagine the sheer computing power thats going to be needed to keep track of whats happening in such a device??

" According to my knowledge the trick with entangled photons works differently. The emitted photon does not even have to be received again by the submarine. "

Yeah, thats my understanding of entanglement as well.

Vigilis said...

Hi Pete

Why did Coca Cola NOT patent its trademark's recipe? --- Because said trade secret would have become publicly available to competitors.

Who actually believes any Top Secret advantage of the U.S. Silent Service would not only rely on a patent, but be accompanied by press coverage? Not I, unless the patent is another invitation for China, Iran, Russia, etc. to throw vast sums of military spending down fruitless black holes.

The patent in question is certainly tantalizing, but criteria for patentability better quite the red herring.

Finally, let me ask when was the last time any military patent ever blocked a rival military from theft?

With all of that in mind, MHalblaub's reservation about entangled photons makes even more sense.

Regards,
Vigilis

Peter Coates said...

Hi Ztev

Positioning signals could be from several ground stations simultaeously to achieve triangulation. An occasionally reeled out long line antenna may "float" in that 30m zone.

Long line antennas floating, for short time. may receive useful GPS sat signals.

Yes, to maintain discretion subs don't transmit. Perhaps receive:
- positioning signals
- important encoded news/orders eg "we are at war" "watch out for the SSN, ASW ship, SSK, SSBN in
XXXX area"
- in extremis Launch Codes.

Probably only in emergencies would subs transmit. Here's an emergency which may have lead to rapid transmissions because probably one or both SSBNs could not continue their on station missions https://en.wikipedia.org/wiki/HMS_Vanguard_and_Le_Triomphant_submarine_collision

Regards

Pete

Ztev Konrad said...

Picking up GPS signals via a trailing wire wouldnt be recommended.
"The two most popular types of antennas used in GPS receivers are "patch" and "quadrifilar helix" or "quad helix" for short."
Those used in the maritime environment are normally an 'upside down plate' which contains the aerial array or patch.
The details of quad helixs are here
http://orbanmicrowave.com/wp-content/uploads/2015/03/TheBasicsofQuadrifilarHelixAntennas.pdf
It would seem that a floating cable that consists of an 'air core helix' of around 18mm diameter could work, but passing that signal from the surface to the inside of the submarine maybe 10s metres away could be difficult.

Peter Coates said...

Hi Vigilis

Yes I think the US government may have ulterior motives with this unnecessarily publicized/declassified patent.

Perhaps to deceive strategic and economic competitors. And also its a good news, good PR story, for the US Navy, wider DoD and US research generally.

US tax dollars going for a good high tech science cause and all.

You've made some really good points about the actually manned "unmanned" and highly vulnerable ACTUV at http://aquilinefocus.blogspot.com.au/2016/04/submarine-questions-of-week-5-april-2016.html .

Regards

Pete

MHalblaub said...

Here a exiting solution already implemented on U35 and U36:
http://www.gabler-maschinenbau.de/maschinenbau/en/entwicklungen/zivilemeerestechnik/index.html
It is the strange looking piece of hardware at the end of the sail.

Regards,
MHalblaub

Peter Coates said...

Hi MHalblaub

http://www.gabler-maschinenbau.de/maschinenbau/en/entwicklungen/zivilemeerestechnik/index.html talks about a few things.

Do you mainly mean CALLISTO? http://www.gabler-maschinenbau.de/maschinenbau/en/entwicklungen/kommunikationssysteme/

"taken under contract for Class 212A, 2nd batch submarines in April 2007. The CALLISTO communication system consists of a hoistable mast with an integrated buoy, and can also be used in surfaced conditions or at periscope depth as a conventional communication mast.

When the submarine is deep submerged, the buoy rises to the surface as the cable pays out, after the retaining elements have been released. As soon as the antenna is above the water surface, the system establishes communication abilities in the UHF SATCOM, UHF LOS, VHF and HF reception frequencies as well as GPS L1/L2. Automatic adjustment of the cable length allows the submarine to maintain speed and depth as desired."

Regards

Pete

Anonymous said...

Cables, buoys and masts do not work uder an ice cap.
KQN

Peter Coates said...

Hi KQN

An excellent observation. In line with the second paragraph of my article.

Pete

MHalblaub said...

The ice cap is just about 2 or 3 m thick. That's all.

Regards,
MHalblaub

Peter Coates said...

Hi MHalblaub [10/4/16 10:34 PM]

2 to 3 meters is still thick enough to stop buoys and floating antenna wires getting through

probably still requiring subs to break through which would require the submarine stopping and may be a noisy operation and visible to aircraft, UAVs and satellites

I don't know to what extent 2 or 3 meters may obscure GPS, UFH and other "submarine frequency" radio waves

Regards

Pete