Comments on: Robot Submarine Takes a Dive to the Deepest Spot in the Ocean

By: Joh

Joh — Sat, 06 Jun 2009 08:14:27 +0000

they first have to locate the plane (impossible) wouldnt be useless to send a 1 meter (or whats the size) robot down there to check 100km area, meter by meter, that would require months (interrupted by strong atlantic conditions

By: Charlie Wentz

Charlie Wentz — Thu, 04 Jun 2009 20:33:40 +0000

Is there any hope that robots can recover the black box from this latest airplane crash in the Atlantic?

Charlie

By: Bob Parker

Bob Parker — Wed, 03 Jun 2009 23:16:51 +0000

Jim – there’s no way to go ‘wireless’ from that depth. In general, you can’t transmit radio waves through water. Navy submaries can receive ELF (Extreme Low Frequency) signals at very shallow depths, but the bandwidth is quite low, so transmissions are limited to short simple messages – even more restricted than Twitter posts!
One could go ‘wireless’ by using sound pulses, but again the potential bandwidth is quite low.
The Navy is experimenting with laser-based communication for subs, but that is limited by the depth of water that UV light pulses can penetrate – a few hundred feet under the best cicumstances.
Bottom line: the only way to transmit significant amounts of data from more than a few hundred feet deep is with electrical signals through a wire or light pulses through a fiber optics cable.

By: Jim

Jim — Wed, 03 Jun 2009 21:37:43 +0000

Why not use wireless technology to send info to surface?

By: Eliza Strickland

Eliza Strickland — Wed, 03 Jun 2009 16:43:52 +0000

Nick — now I’m confused, too. The first news reports said that Nereus had taken the deepest dive in history, beating out the previous two expeditions, but I think they should have said that Nereus is the deepest diving vehicle currently in operation.

Nereus reached 10,902 meters down. But the Trieste reportedly reached 10,916 meters, and the Japanese Kaiko reportedly reached 10,911 meters. My apologies for the error in the headline. I’ll correct it now.

As to your second question — their innovations were doing away with the heavy copper power cable (it used batteries instead), and using a new kind of ultra-light fiber optic cable.

By: Anaconda

Anaconda — Wed, 03 Jun 2009 11:15:45 +0000

It is spectacular that Science and technological advancement have allowed this achievement. Although, not at this depth, oil companies are sending submersibles to ever greater depths all the time and doing impressive feats of engineering (constructing pumping stations and what not) to produce oil from ultra-deep water.

Question: The Mariana Trench is considered to be a subduction zone by conventional geology, but is there any actual scientific evidence for this conclusion?

What I mean by “scientific evidence” is deposits or scraped off sediment at the bottom of the trench or other physical identifiers Science can study and then infer from that subduction is actually happpening in this area.

As much as geology maintains that subduction is a fact, there is a lack of actual physical evidence that indeed subduction takes place.

Deep submersibles could go a long way to providing evidence one way or the other.

By: Justin

Justin — Wed, 03 Jun 2009 06:06:38 +0000

For your first question,

I don’t think the other two robots went to the deepest part of the trench like this one did?

By: Nick

Nick — Wed, 03 Jun 2009 03:37:57 +0000

Wait… if two other craft have already been to the bottom of the Challenger Deep, how is this the deepest dive ever?

And I’m really confused about the tether – why do they say they replaced optical fibers with fiber-optic technology… is there some non-fiber-optic optical fiber technology?