Saturday, 19 April 2014

Here be Dragons

In the not too recent past, large blanks where a feature of any globe. There are still places no one has been on the ground, but we have photographs of them from space, the same isn't true under the sea. Despite Google Earth's course depiction of the seabed, we know very little of the detail.
The common conception of the sea, is limited to the surface, only the most ingrained oceanographer will consider the volume of the sea as a matter of course. For some of us stories of people swimming from liners, in the deep ocean, may suddenly induce a queasy feeling and the sensations associated with being in some inappropriate situation. Suddenly likening ourselves to hovering 4 miles up in the sky, without a parachute or perhaps trapped half way through a trap door with our feet dangling into the darker parts of Mordor.
The search for the unfortunate remains of MH370 have brought a lack of thought and lack of comprehension by the public to the fore. Frequent slightly unhinged call claiming it is madness that we know more about the Moon or Mars, than the depths of the sea. We do have some good photos of the surface of Mars, but that is about it, considerably more is known about the composition of the surface of the bottom of the sea, multiple samples have been returned from the deep, the first man-made object to reach the bottom of the Challenger deep and return to the surface, may only have been a lead weight, but it was in 1875. So far, nothing has been returned from further away than the moon.
Travelling in space involves going from a pressure of 1 atmosphere, on the surface to zero in space. That means that the spacecraft has to resist the gas inside from pushing out the walls, the gas is pushing out at 1.033 kgf per square centimetre. As a submarine dives, for every 10 meters it goes down, it has to resist the water pushing in at an extra 1.033 kgf per square centimetre. That is a submarine at 10 meters is resisting a pressure the same as a spacecraft in orbit at 20 meters it is resisting twice as much. The Challenger Deep is 10,916m deep, so down there, to maintain 1 atmosphere for the crew, the submarine has to resist some 1,091 times the pressure of a space ship. It has to do this while being able to float, if you want to get back to the surface.
There have only been 2 manned visits to the Challenger deep, one by the Bathyscaphe’s Trieste in 1960 and one by James Cameron in his Deepsea Challenger. The bit which the pilot was in was a 1.1 m sphere with 64 mm thick walls of steel. To make a sphere of larger diameter takes thick walls. Several other visits have been made by remotely operated vehicles.
Unlike in space radio doesn't work and any communications with the surface have to be done via acoustic methods, which do not have very great bandwidths or by the use of a tether, which has to be very long, Even when you get down to the bottom you cannot see very far even with very bright lights, plus the only energy you have is what you brought with you as there as no solar panel will work. The Americans did have a nuclear DSV but that could only reach about 1000m, which is not deep enough for large parts of the ocean and any way NR1 has been scrapped.
The not seeing very far goes for on the way down as well, and a lot of life is suspended in the water. So you may miss the interesting bits.
If you do find something interesting and want to bring it back to the surface, you face a whole host of problems trying to keep anything alive or even faintly recognisable. Like humans diving to hundreds of feet the captives will either have to be kept at deep pressure or slowly depressurised otherwise they will quite likely explode on the way up.
While you won't have the wide variation in temperatures that occur in space you'll have a nice constant 3 Celsius to contend with, plus currents. While you will be well protected from radiation surrounded by all that water, the water is quiet corrosive and will be eating away at all your exposed systems.
In the deepest oceans, even the most complex of current survey ships like HMS Echo, with state of the art Multibeam echo sounders, would take an enormous amount of time to cover a significant area, and the resolution would be limited by the great depth. It seems unlikely anyone is likely to fund such an extensive survey of the worlds depths even then they would not tell us very much as it would miss out the content of the water column.
It may be a job that is more suited to autonomous underwater vehicles which could be sent out to record the depths, but would people be happy about any number of nuclear powered subs making their way around the world, without on board supervisions.
The one thing I am sure of is that we have the capability to analyse the data right now, it is not so super computer in the US Defense department or GCHQ but the crowd sourced power of humanity. Never before in human history has it been possible to apply such a large number of people to a single search problem and that capability grows with every day.
The analysis of the data would, by a big margin be, the most expensive part of the operation, but not if it is being done for free by citizen scientists, either by direct analysis or via distributed processor farming via BOINC. Even the funding to collect the data, while not incredibly cheap could be gained from crowd sourcing, we all rely on the sea in some way, whether it be for weather, food, recreation or transportation.
MH370 has pointed to a large blank in our knowledge, perhaps a crowd sourced solution can point us to a new way to do big science and fill in the blanks the public wants to fill in.
A figurehead needs to come forward to kick of the project perhaps James Cameron

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