Unclear Security

[chalsall]

Originally Posted by richs

This US Navy communications station, shut down in 1993, is about a 20 minute drive from my home and was used to communicate with ballistic missile submarines:

This decommissioned United States Naval Facility is similarly about twenty minutes drive from my home.

We recently used it (after a great deal of upgrade work) to manage the CV19 crisis.

P.S. Dr Sardonicus... What if the "signal" is the lack of a signal?

[Xyzzy]

Originally Posted by Dr Sardonicus

The C-130 is nominally a cargo plane which has been around since the Vietnam War. It has proven to be quite adaptable for a number of specialized uses.

We have flown in a C-130 multiple times in the past. However, we have never landed in one.

[kriesel]

If the "signal transmitter" was a fission reactor, recent Ukrainian experience with Russian shelling & missile strikes on/near reactor complexes & power transmission would indicate an alternate channel would likely be needed. If "civilian" particle detectors were the neutrino signal source, keeping that secret would be challenging, plus the fixed directionality of beamlines is a problem. Subs needing to check in for messages by visiting certain locations would be an exploitable vulnerability. Especially with slow data rates, requiring loitering at 3d coordinates or beam stripes.

[xilman]

Originally Posted by kriesel

Allocating ~2% of its displacement to a neutrino detector's active volume would allow 1 kiloton detector (receiver) size. (Containment structure, shielding/veto of reactor & cosmic backgrounds, cabling, data acquisition etc. would be additional and could exceed 5% in total.)

Why not allocate a cubic kilometre of sea water for your target and examine it with PMTs for modulated flashes?

[kriesel]

As a science experiment, yes but rarely. As a means for clandestine communication, no, it requires the military subs to be in a particular location ("in the beam") and to be enormous. The absorption coefficient of seawater is high enough that PMTs must be spaced closely in the detection medium compared to 1 km. https://www.sciencedirect.com/scienc...2765050600123X Coastal areas have much higher absorption coefficient which would require much closer PMT spacing. https://www.researchgate.net/publica...annel/download

[chalsall]

Originally Posted by kriesel

As a means for clandestine communication, no, it requires the military subs to be in a particular location ("in the beam") and to be enormous.

It has been hypothesized that Whales communicate by way of low-frequency sounds through water. A rather good, and far-reaching, comms channel. Low bandwidth, but a relatively good SNR.

Why can't humans? We already use this to measure earthquakes, tsunamis, etc. Multiple paths can be useful...

[Uncwilly]

Originally Posted by chalsall

Why can't humans? We already use this to measure earthquakes, tsunamis, etc. Multiple paths can be useful...

If governments were, those outside of classified circles might not know for 20-30 years.

[chalsall]

Originally Posted by Uncwilly

If governments were, those outside of classified circles might not know for 20-30 years.

I respectfully disagree.

Anyone (or any system) who understands (or reacts to) even classical physics would have figured this out long ago...

Evolution in action, anyone? 9-)

[Uncwilly]

Originally Posted by chalsall

I respectfully disagree.

Anyone (or any system) who understands (or reacts to) even classical physics would have figured this out long ago...

If your pings at set times are actual recordings of whales how would a random observer know. If today's schedule is for 1234 hours and the ping is recording X, then message is "all is well". Tomorrow's selected time will be 1057 and recording Humpback 23 = all is well. Day after 1313 hrs, gray whale recording #15 = all is well. If not "all is well" recording, look at code book to determine message based upon recording used and recording that followed X minutes later. You can listen for binary pings until your ears bleed. Biologic sounds could slip past the watchers as background noise.

Also, false chatter could be used. Today's message only comes from location ZZ, tomorrow's is the message from station QQ. The subs can tell which direction messages are coming from. Baseball teams have been doing this for decades with signs to batters. Also, NASCAR teams have used similar things, "ignore what the crew chief says in the open, listen for the code word from the spotter."

[chalsall]

Originally Posted by Uncwilly

Also, false chatter could be used.

False chatter would be expected. Wouldn't it?

[Dr Sardonicus]

Originally Posted by chalsall

P.S. Dr Sardonicus... What if the "signal" is the lack of a signal?

"I have new data which may help explain the radio silence, Sir."

"New data? Where from?"

"Our neutrino detector, Sir."

"What does the data indicate?"

"Uh, not good news, Sir. So far we have only come up with two explanations of the data. One is, there was a supernova that was - well, too close."

"What else might explain it?"

"General nuclear war."