To add context here, it takes your brain somewhere around 100ms to detect and then another 250 to process pain. So 4ms is not only fast, it's absurdly fast.
To get a sense of how fast it is, go ahead and stub your toe, the time it took to feel it is 100 times longer.
And because what failed was the carbon fibre composite pressure vessel, it probably didn't even give any warnings to make them worried. It would be like squeezing a glass bottle, everything will be perfectly fine until it just instantly shatters.
Did some math based on that number since it seemed pretty insane. That would mean that each side of the outer hull would have been moving inward at about 425mph by my estimate. Seems slower than I would expect by that number, but 4ms is hella fast.
When a submarine hull collapses, it moves inward at about 1,500 miles per hour - that’s 2,200 feet per second. A modern nuclear submarine’s hull radius is about 20 feet. So the time required for complete collapse is 20 / 2,200 seconds = about 1 millisecond.
A human brain responds instinctually to stimulus at about 25 milliseconds. Human rational response (sense→reason→act) is at best 150 milliseconds.
The air inside a sub has a fairly high concentration of hydrocarbon vapors. When the hull collapses it behaves like a very large piston on a very large Diesel engine. The air auto-ignites and an explosion follows the initial rapid implosion. Large blobs of fat (that would be humans) incinerate and are turned to ash and dust quicker than you can blink your eye.
They died by being crushed with enough pressure such that the air inside the sub ignited ie compressed so much it essentially exploded. Death was instant.
Put another way: The matter that made up their bodies was very quickly rearranged into other chemicals; much quicker than the long chain-reactions that make up human thought.
I know a diesel engine works off compression, but it has a fuel. All fires must have oxygen, fuel, and heat. What fuel would they have in the titan to ignite?
Everything (including the passengers) inside the sub could have been fuel for combustion had there been time for the reaction to take place. If I remember correctly the interior of the sub could have temporarily been hotter than the surface of the sun during the implosion. Pretty sure just about everything burns at those temps. But the collapse and gas release from the hull happened so quickly I doubt there was time for anything to ignite.
Ex-people, plastic and so on. With a small room's worth of air it wouldn't have burned long, though.
More significant is just how hot it would get as it collapses. When you suddenly compress an an ideal gas (which air is a lot like) it gets hotter in proportion to it's previous absolute temperature. Room temperature is already 273K, and the pressure down there is hundreds of time larger than at the surface. At some point the law would break down on the way, but you get the basic idea. It was probably as hot as the sun without any help from combustion
If you were to slowly lower an open glass into the ocean, it would gradually fill with water. So i just think its the same with the sub, albeit faster?
Sure, but "faster" here means around the speed of sound, and that's fundamentally a different thing from the playful streams we're used to. The thing was waaay down there when it went.
If there was a tiny little hole somewhere that wasn't getting larger, maybe it would slow down enough to just gradually fill the vessel. In that case, though, it would not have imploded. They found it in pieces and the US Navy heard the pop.
Yeah I guess if you think of the fact it actually went 'boom' you can imagine the water didnt really flow in but rather flew in very fast. There was probably a huge shockwave that killed them instantly