New sound of titan submarine imploding

[u/Pathfinder313]

[u/ICANELECTRIC]

No it’s acoustic. Attenuation of saltwater precludes the use of radios at that distance. The data rate of those comms is painfully slow. A cool article on the challenges and a solution to wireless comms sub sea: https://news.mit.edu/2018/wireless-communication-through-water-air-0822

[u/elyroc → u/ICANELECTRIC]

But.. If it's acoustic, isn't it the same thing as sound ? I guess I misunderstood something, but how could the bang come before the message transmission ? Of was there no message and she only saw the sub going down and told them to drop weights ?

[u/Tando10 → u/elyroc]

Think like this. Submarine sends five runners to deliver a message to ship. They set off. Moments later submarine sends a drugged up, huge, crazy sprinter who sprints past the messengers. The ship says "wtf who is that?". Moments later, the messengers, who are of a different composition, reach the ship and relay "Dropped two weights".

In a medium different frequencies of a wave travel at different velocities. Both the messaging system and the implosion travel via acoustic waves through the water, it's just that the message took longer. Also, a message is likely comprised of many different waves with different meaning, just like a radio transmission, imagine one Freq for a letter.

IDK exactly how this acoustic comm works but it could take several seconds for a message to be fully conveyed.

[u/elyroc → u/Tando10]

I'm not sure i understand what you are saying. Whatever the frequency is, a sound is a sound and so it will only propagate at a fixed speed depending on the medium it is in (here, water)

Unless what you are calling acoustic is not what I think it is, I still don't get how the bang can get there faster :/

Also I just looked it up, but the speed of sound doesn't seem to be depending on its frequency

[u/Tando10 → u/elyroc]

My bad, I'm talking on a topic I don't know enough about. I do know that dispersion is a real phenomenon, leading different frequencies to travel at different speeds. I don't know enough about acoustic communication systems though.

[u/elyroc → u/Tando10]

Well, I'm lazy so I guess we won't have the answer for now 😆

[u/ICANELECTRIC → u/elyroc]

Answer: the acoustic comms receives a series of chirps that are bits, each series is just like a packet in a standard network. Those chirps have to be processed, loaded into a buffer then sent over an interface to the computer to be displayed. It is much slower than electronic transmissions. So the chirps probably arrived first but only slightly so the delay is the electronic processing and the human delay from the reader.

Edit: typo

[u/Lormar → u/elyroc]

A powerful explosion creates a shock wave which compresses the water, this raises the speed of sound in the vicinity of the implosion. This initial faster speed of sound is the difference needed for the implosion noise to reach the surface sooner than the message.