171–179 of 179 posts
I've bookmarked the page and will definitely return.
A question about ELF and VLF for whoever knows: I just finished reading Thunderstruck (Erik Larson, author of Devil in the White City ), which I don't recommend. It ineffectively juxtaposes the story of Marconi with Hawley Crippen, a murderer in London whose case became famous around 1910. (I say "ineffectively" because their stories really don't intersect, IMHO) The book goes on and on about all the demos and tests…
I think he was using MF and HF for most of his work, but I'm not sure[1]. The story about discovering higher frequencies remove the need for longer antennas lat in his career seems garbled since the he discovered early on that longer antennas allowed for longer distance communication. 1: His first claimed transatlantic transmissions were definitely MF.
1: https://en.wikipedia.org/wiki/Spark-gap_transmitter#The_%22s...
On this: > Instead, the battle of submarine silence has mostly revolved around obscure technical problems of fluid dynamics, since one of the loudest noises made by submarines is the cavitation around the screw. I don't know if this is true today, but at least years ago the low-noise design of the screw on modern US submarines was classified, and so the screw was covered by a sheath whenever a submarine was out of th…
https://twitter.com/toughsf/status/1024083748407713792?lang=...
https://www.researchgate.net/publication/302920496_Numerical...
https://www.thedrive.com/the-war-zone/31708/veteran-sonarman...
https://www.globecomposite.com/blog/x-factor-columbia-class-...
https://www.sciencedirect.com/science/article/pii/S209267821...
I wonder if an active sonar array would be desirable. It would of course be easy to locate the beacons but they would probably be relatively cheap. Also, that much sonar noise would probably be bad for marine life. Would it give us capabilities we currently do not have?
It's not just the location of the active beacon that you're giving away. It also tells the enemy in which regions of the world's oceans you are listening.
But meanwhile I think I figured out that such an array would be a major issue because once the locations of the beacons is known, they will effectively turn every passive sonar into active sonar. Therefore it can not provide an asymmetrical informational advantage even if the investment would be asymmetrical.
> It is unwise, in the course of a search and rescue operation, to report that you think the vessel was irrecoverably lost. I made this point several times on social media during the Titan incident but it fell on deaf ears; it seemed crazy to me that people were accusing the US Navy of some nefarious cover-up regarding possible acoustic detection of implosion. Anyone who’s ever worked with any type of signal analysis…
I'd rather the Navy be pretty sure they were dead and tell me, instead of keeping it to themselves just because they might be wrong. No one was saying don't look, people were annoyed they pretended they knew nothing when they where 99% sure the sub imploded.
Earlier quoted context omitted.
I'd rather the Navy be pretty sure they were dead and tell me, instead of keeping it to themselves just because they might be wrong. No one was saying don't look, people were annoyed they pretended they knew nothing when they where 99% sure the sub imploded.
I thought the timing of the announcement was interesting. The implosion was not confirmed until the last few hours of the oxygen countdown media frenzy.
The timing of the announcement was based on a recovery vessel arriving at the site and very quickly finding the wreckage.
The fact that they happened to be close together is coincidence unless you can provide strong evidence otherwise.
Earlier quoted context omitted.
It's not just the location of the active beacon that you're giving away. It also tells the enemy in which regions of the world's oceans you are listening.
If you cover the entire ocean than that is not an issue. But meanwhile I think I figured out that such an array would be a major issue because once the locations of the beacons is known, they will effectively turn every passive sonar into active sonar. Therefore it can not provide an asymmetrical informational advantage even if the investment would be asymmetrical.
Covering all oceans with active sonar will probably kill a lot of marine wildlife.
Not to mention all your beacons in enemy waters will be destroyed, if not many more.
Earlier quoted context omitted.
If you cover the entire ocean than that is not an issue. But meanwhile I think I figured out that such an array would be a major issue because once the locations of the beacons is known, they will effectively turn every passive sonar into active sonar. Therefore it can not provide an asymmetrical informational advantage even if the investment would be asymmetrical.
> If you cover the entire ocean than that is not an issue. Covering all oceans with active sonar will probably kill a lot of marine wildlife. Not to mention all your beacons in enemy waters will be destroyed, if not many more.
> Instead, the battle of submarine silence has mostly revolved around obscure technical problems of fluid dynamics, since one of the loudest noises made by submarines is the cavitation around the screw. Cavitation is loud, but usually only happens if they're running full out. What they're really listening for now are reactor plant noises. > I don't know if this is true today, but at least years ago the low-noise desi…
reactor plant noises? Would like to hear more about this! Assuming the reaction itself is silent (?) what kinds of sounds is the reactor making and what are the challenges in quieting them?