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Research Vehicle Reaches the Bottom of the Ocean
timothy found BBC coverage of the voyage of the Nereus, which on May 31 dove to the bottom of the Challenger Deep in the Marianas Trench. Only two vehicles have accomplished this feat before, the last 11 years ago. "The unmanned vehicle is remotely operated by pilots aboard a surface ship via a lightweight tether. Its thin, fibre-optic tether to the research vessel Kilo Moana allows the submersible to make deep dives and be highly manoeuvrable. Nereus can also be switched into a free-swimming, autonomous vehicle. ... The Challenger Deep... is the deepest abyss on Earth at 11,000m-deep, more than 2km (1.2 miles) deeper than Mount Everest is high. At that depth, pressures reach 1,100 times those at the surface."
Aye aye, Captain!
I'm impressed with the two guys who did it *manned* in the 60s
from tfa :
In January 1960, Jacques Piccard and Don Walsh made the first and only manned voyage in a Swiss-built bathyscaphe known as the Trieste.
The vessel consisted of a 2m-diameter (6ft) steel sphere containing the crew suspended below a huge 15m-long (50ft) tank of petrol, designed to provide buoyancy.
During the nine-hour mission, the two men spent just 20 minutes on the ocean floor; enough time to measure the depth as 10,916m (35,813 ft).
Invaders must die
Do they have a good pizza/wing place down there?
No, but there's a Starbuck's.
"Tell me doctor, with all of your defenses, are there any provisions for an attack by killer bees?"
Somebody smarter than myself, please comment on why we need a cable over a distance of 11km? There's a ton of off-the-shelf radio equipment that can easily handle that distance with very high bitrates.
I can imagine two possible problems:
First, the ocean might simply be good at blocking transmissions.
Second, the varying pressures and temperatures might distort a signal to the point where it is unusable. I'm referring to dielectric effects and the fact that the dielectric constant would not be constant in this sort of operation. But would it be "constant-enough"?
Men had steel balls in the 60s.
Fixed that for you.
I'm impressed with the two guys who did it *manned* in the 60s
from tfa :
In January 1960, Jacques Piccard and Don Walsh made the first and only manned voyage in a Swiss-built bathyscaphe known as the Trieste.
The vessel consisted of a 2m-diameter (6ft) steel sphere containing the crew suspended below a huge 15m-long (50ft) tank of petrol, designed to provide buoyancy.
During the nine-hour mission, the two men spent just 20 minutes on the ocean floor; enough time to measure the depth as 10,916m (35,813 ft).
Yeah, I remember seeing a special on that when I was younger (like 10 years ago), and I still remember it, because it's such an awesome story. I really suggest that if anyone is bored you look this story up, it's really awesome.
The sad thing is that once they hit the bottom, the sand down there was so fine that it threw up a cloud of it that never cleared during the time that they were there, so they didn't get to see much except for what they saw right before they landed!
-Taylor
Worldwide Military budgets: $2100 billion. Worldwide Space Exploration budgets: $38 billion. Really, world? Really?
That'll make for one traumatic moment when the lead mermaid tries to surface and bursts open from the tremendous drop in pressure. I don't think my kids would want to see that one.
Uhh. those solid state components you're thinking of tend to have voids in them, e.g. what's under that lid on the CPU.. a bare die and a bunch o' bond wires. Squish city at 1000 Atm.
What about wires? More than enough pressure to push water through the wire using the insulation as a tube.
It is REALLY, REALLY hard to design stuff to work at 1000Atm. What do you use for bouyancy? (Trieste used gasoline.. a liquid that is about the same compressibility as water) Syntactic foam with silica microspheres is fairly popular, because the tiny hollow spheres are pretty strong.
Interestingly, it's harder to design something that won't crush than something that won't explode. That is, building a compressed gas tank to hold 20,000 psi is easier than building one that won't crush under 20,000 psi.
That's why I'd do it at night.
And it's easy for Google too; no complaints about privacy breach.
They are getting sued by SCO though, for violating their patent for sinking to the lowest depths possible.
Negative moral value of force outweighs the positive value of good intentions.
There's active work going on with underwater radio. It's really tough to do in salt water. But it's not quite impossible. There's considerable interest in making something that can push data through 100 meters of water depth. Oil industry operations would like to talk to their stuff on the ocean floor.
At longer ranges, there's at least one research project which claims that there's a transmission window in seawater between 1MHz and 10MHz. They hope to get data across 1KM. That will be useful if it works.
ELF works; the US and the USSR both have used it in the 70-85 Hz band. The trouble with ELF is that the wavelengths are so long at 80Hz that you need an antenna the size of a county.
I worked on an ROV simulation back in the 90's and we needed to keep track of how many times the ROV turned around because twists accumulate in the cable. At some point you may have to sit in place and spin for a bit to undo the twists. Terrible things happen when the tether gets too twisted.
You seem to know a bit about submarines so perhaps you could answer a question that has puzzled me. If you build a submarine like an onion with a hull inside a hull and put pressurized water / air between the two hulls to half the outside pressure would each hull then only need to be strong enough to resist half the external pressure?
I can't see the flaw but it feels wrong because it seems to imply that it would be at least theoretically possible to build a submarine out of sheets of tin-foil as long as there were enough layers and the pressure could be maintained accurately enough.
I used to have a better sig but it broke.
That idea won't work because it doesn't actually make sense. While it is definitely an interesting question; and one that I was initially puzzled by, I think you will be surprised by how clumsy the intuitive logic that brings us to that conclusion is. Consider your onion, with two layers, and you are standing between them. To make things simpler, lets assume that instead of water pressure you actually have pressure from weights, and lets also change your onion from spherically shaped shells to just two flat surfaces. For example, you could imagine that you are just standing on an imaginary, levitating sheet of plywood and there is a sheet of plywood above you. The "water pressure" from above you is say 100 lbs. This is how many weights are on the sheet of plywood above you, and it is as much as you can hold. So you say, lets "pressurize" the intermediate onion layer (you), and you position springs on both sides of you (or you could use water pressure). With this new pressurized layer, you can now withstand twice as much "water pressure" from above you, for a total of 200lbs. But that has nothing to do with how much pressure is being exerted on this imaginary sheet of plywood beneath you. As you see, you could build a million onion shells and it wouldn't change anything about how much pressure the inner most layer, or the bottom sheet of plywood, must withstand. Indeed, all submarines already use your multiple hull theory, but not in the way you imagine. They all must withstand the pressure from a layer of ocean above them AND a layer of atmosphere above the ocean--the ocean doesn't protect against the atmospheric pressure.