Was watching this video about the Titan disaster and they mentioned the sound of the submarine imploding was heard before some other communication arrived?
Now, that doesn’t make sense to me? Does it make sense to you? Just wondering??
The report I just read said that the sound of the implosion travelled faster than the radio chatter.
EDIT - actually it also says it in the report you posted. See the para near the bottom.
1 Like
Pressure disturbances created by bombs (on the air) travel faster than the speed of sound, so you might be blown up by an explosion before you actually hear it.
To all the physicists around, is that the same in water?
1 Like
well, the sound would have travelled quickly at around 1400 meters per second. so should have taken about 2 seconds to arrive.
the message timing would depend on how it is transmitted, whether via any intermediaries e.g. satellites and would depend on the latency of the systems.
1 Like
It does not make sense, but the delay may be explained anyway.
The ocean is not homogeneous. The sub imploded right below the Gulf Stream. Thus, there ocean water temperature, salinity and therefore density varies a lot. At any interface between two different waters, there’s a chance for refraction.
How does this relates to the sub? The Titan used a USBL (ultra-short baseline) acoustic system for communication with the surface according to this article.
Thus, sound signals from the sub can refract in then ocean waters, change direction, arrive incomplete or never arrive to the ship in the surface. The way to overcome the refraction problem is to send the message several times. Thus, the receiver has to “listen” for a while (collect data), and then process the received sound signals to reconstruct the message.
This period of “listening” for sound signals from the sub may explain the delay. We’re used to instant communication in our daily lives, but the message of “dropping two wts” may have taken a few seconds from the initial part of the message, repeating it, the receiver listening for a few seconds and then processing.
1 Like
This just sucked me into reading a bit more about the whole subject (the physics, not the sub) and it’s quite fascinating. Here’s a quote I particularly liked:
Shocks waves are near discontinuous changes in pressure, velocity, temperature and density in the fluid (changes occur over 6 or so mean free paths between molecules). To the stationary observer, they can appear to be moving faster than the speed of sound, though they will always be traveling below the speed of sound in the medium out of which they are propagating, even if they are traveling faster the speed of sound in the medium into which they are propagating.
Reference: Difference between blast, shock, pressure and sound waves?
It is an interesting topic.
For instance you can hear a fast propellor driven boat or ship scream for miles underwater whereas a paddle wheeler is silent..
Whales talk to each other across oceans and I think that there is a link between whales and dolphins grounding and military sonar.
I got hit by a civilian submarines sonar while free diving on Malta and it made me feel nauseous.
I never saw any of his films, but I was very impressed with James Cameron’s interview on the topic of Titan:
