[championoftruth (OP)]

As you may have heard the submersible Titan crew are no more and they must have recorded their thoughts and messages and what went wrong on their mobiles and so the question is would those mobiles survive with that information for recovery from the ocean?

[alancalverd]

That's assuming that the sub remained intact or developed a slow leak and simply fell to the bottom. From what I hear, a sudden implosion seems more likely. 

[paul cotter]

With a catastrophic implosion most likely everything would be destroyed.

[championoftruth (OP)]

That's assuming that the sub remained intact or developed a slow leak and simply fell to the bottom. From what I hear, a sudden implosion seems more likely.

mobiles are small and may survive an implosion ...especially the microchips...

[paul cotter]

With the pressure down there salty water ingress is almost certain with subsequent mechanical and corrosion damage.

[championoftruth (OP)]

With the pressure down there salty water ingress is almost certain with subsequent mechanical and corrosion damage.

no oxygen down there due to high pressure. no corrosion. data recovery could extract information.

[Bored chemist]

That's assuming that the sub remained intact or developed a slow leak and simply fell to the bottom. From what I hear, a sudden implosion seems more likely.

mobiles are small and may survive an implosion ...especially the microchips...

In a diesel engine, the piston suddenly compresses the air to about 20 atmospheres. The resulting temperature rise ignites the diesel fuel.

The pressure down near the Titanic is about 350 atmospheres.

If there was a catastrophic failure of the pressure hull, there will not be much left of any phone.

[Bored chemist]

no oxygen down there due to high pressure

What?

[evan_au]

It is now starting to come out that the Titanic was originally discovered because the military was searching the sea floor for some missing submarines (I am not sure if said submarines belonged to their navy, or another one...). Presumably, that would have been followed by an attempt to recover pieces of said submarine.

The military never likes to reveal its hand, but it may have equipment capable of retrieving pieces of equipment from the deep sea floor...

[alancalverd]

mobiles are small and may survive an implosion ...especially the microchips...

But if the sub suddenly collapsed without warning (that's what we mean by catastrophic implosion)  nobody would be giving a commentary on it. The last word on most cockpit voice recorders is "sh1t"* but that comes at the time the foreseeable impact becomes unavoidable.


*almost always in English - the result of mandatory training.

[Bored chemist]

It seems the sub collapsed and if that's the case there wouldn't have been time for anyone to record a "last goodbye".

But, if I was on a trip like that I'd have taken at least one video camera with me.
I guess there were video cameras running at the time of the disaster.

But it's important to recognise what would happen.
The pressure at that depth is about 350 tons per square metre.
An person has an area of the order of 1 square metre and would suddenly find themselves supporting the weight of a passenger train.
And we need to define "suddenly".
People say water is incompressible but actually it's just not very compressible.
So, if the hull failed, the water near it would expand to fill the gap.
That expansion would happen at about the speed of sound in water. Something like 1500 m/sec

So, very roughly, the weight of a passenger train, travelling at the speed of a fighter jet.
(Preceded by a brief flash where the air was heated to about 1300C by compression)

It's going to be tricky to work out what happened.

[alancalverd]

I remain somewhat baffled by the time it took to locate the vessel. Everyone in the business knows where the Titanic is, and one would presume that the mother ship stayed on station during the dive, or at least knew the release point, so the target was somewhere on a curve between known points A and B, allowing for current drift during the descent. TV news coverage alleged lots of aerial searches over a huge area. Have I missed something?

[Bored chemist]

Have I missed something?

Yes.
Currents and the fact that, if they possibly could have, the crew would have surfaced.

[championoftruth (OP)]

mobiles are small and may survive an implosion ...especially the microchips...

But if the sub suddenly collapsed without warning (that's what we mean by catastrophic implosion)  nobody would be giving a commentary on it. The last word on most cockpit voice recorders is "sh1t"* but that comes at the time the foreseeable impact becomes unavoidable.


*almost always in English - the result of mandatory training.

Pressure = force/area.  since a microchip is only about  3cm square hence less pressure on it  and is solid state with no cavities there is a chance of data recovery.

its not clear when the implosion took place ...after a few days or right away?

[Bored chemist]

Pressure = force/area.  since a microchip is only about  3cm square hence less pressure on it 

No
Not less pressure, less force.
And 3 mm square is probably a better estimate.

is solid state with no cavities there is a chance of data recovery.

Never say "never"; I hope I'm wrong.  But I'm betting against it.
There are, in fact, cavities in some forms of chip design. It makes room for the bonding wires and for thermal expansion etc.

The big problem is going to be finding it.

And- it's still like getting hit by a train at the speed of a jet.

[paul cotter]

I very much doubt that even hermetically sealed military spec ics would survive such conditions and almost certainly not with mass produced consumer electronics.

[Bored chemist]

The pressure at that depth is about 350 tons per square metre.

I got the arithmetic wrong- sorry.
It's about 3500 tons per square metre.

So it's like being hit by a stack of 10 hypersonic trains.

[paul cotter]

BC, many years ago I read an article about an alternative to explosives for certain seismic studies initiated in deep water. A hollow glass sphere was attached to weights and dropped into the sea resulting in implosion at depth. I can't remember any data but the energy release was stunning.

[Bored chemist]

I can't remember any data but the energy release was stunning.

Density of water  times local acceleration due to gravity times the depth times volume of vessel.
Or pressure times volume.
For the lost sub, we are talking about a few cubic metres at a pressure of 330 atmospheres (33 MPa) or so.
Something like  A few hundred MJ
The energy released by burning roughly a gallon of diesel.
The clever bit is the speed of release of the energy.
The power is phenomenal.
The implosion might have been as short as a millisecond.
That puts the power in the 100 GW range.
Roughly the same power as the UK electricity supply.

[alancalverd]

 

Currents and the fact that, if they possibly could have, the crew would have surfaced.

The prevailing currents are pretty well known: presumably the mother ship dropped the sub is such a position that would minimise its run to the wreck area. So the first question remains: where was the mother ship? It was clearly in contact or expected to rendezvous with the sub at some time.

Had the crew surfaced from a survivable depth, one might presume that they had at least one registered personal or raft locator beacon between them (I never fly a small plane over water without a PLB and my copilot wears one too - one might assume that professional submariners would take at least as much search and rescue equipment as the average amateur ocean yachtsman).