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Comment by wewxjfq | Hacker News Reader

Also, I didn't do the math, but I wonder if the claim that more people have been to the moon than the Hadal Zone is still true. Ironically, the same person that made the USS Johnston statement obsolete would also be responsible for that, because he made so many descents with different people.

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I haven't done a lot of research, but https://en.wikipedia.org/wiki/Hadal_zone seems to suggest it really has only been a handful of people; Jaques Picard and John Walsh, James Cameron, and a few Chinese and Japanese explorers; even unmanned craft struggle to go down that far it seems.

Which... is kinda weird to me, like with space missions, I'd expect them to launch probes or permanent unmanned observation things down there. Surely they can transfer data through water efficiently enough?

I can imagine they don't want to use nuclear power (like a RTG) on those though, which limits lifetime. A cable going to the surface will be difficult as well, because of its own weight and currents.

> Surely they can transfer data through water efficiently enough?

Actually, no. Water absorbs most of the electromagnetic spectrum pretty well, severely limiting the communication range. So you're limited to low frequencies or acoustic communication. Both have a low bandwidth, so forget live video footage.

https://en.wikipedia.org/wiki/Communication_with_submarines

Should be within the realm of the possible to use a kevlar-reinforced umbilical with fiber optics in it going to a buoy on the surface, though. Starlink to the rescue!

I am not sure you would need that much bandwidth from down there, though - I really can't see that much happening that quickly at the bottom of the Challenger Deep.

What if you could "stereolitho-encode" a bunch of data in an image, then just send the image and let the receiving sub decode the image for the data, as opposed to a bunch of linear sonic-"packets"?

For example, what if the image was a pic of various graphs and stats of the status of the machine, but at the same time other critical information is encoded in the image of a Status-Page/Dashboard style KPI image?

It is likely I’ve missed something because your idea seems clever and mine is dumb, but what about just bundling all the data up together and then letting some compression algorithm take a swing at it. (Which is I’m sure what they do already)

> then just send the image

How do you propose sending it?

I am saying that you can likely encapsulate a boat-load more pay-load in a small image, than if youre attempting to send blobs, timesequence, or other info - especially if your image is intercepted and itsa pic of your enemy's leader/flag/whatever and they have no idea what to do with the image...

Better yet, is if the image is of a flase map of current in-situ..

Why is it more likely that an image can store more information than just encoding the information directly in some format like binary? You have the added overhead of the actual image itself, now you have to transmit compress(bits(image) + bits(message)) when you could just do compress(bits(message)).

Iamgine the embeddeded encodes?

So an stegano can give you image ..> code ..Def=code.. image.. infor, it may require more itereations... look into it.

> I am saying that you can likely encapsulate a boat-load more pay-load in a small image, than if youre attempting to send blobs, timesequence

What? Why do you believe this?

From an information theory perspective, you’re talking nonsense.

You do not know steganography.

Try a wiki

Steganography does not increase the information density of a communication medium. It only uses that medium in a different way.

You need to revisit information theory and the physical and data-link layers of networking.

Originally the topic was undersea exploration. There’s no need for steganography, the issue is signal strength, not obscuring communications. There isn’t an enemy to intercept these messages.

I didnt realize that - I was just trying to convey, that mayhaps ; If a secrete message would be sent via Sonar, an image encoding might be efficient, such that the blok of info one wishes to convey, might be a really long stream, as opposed to encoded into an image which would result in shorter sonic comms...

According to the wikipedia page of the DSV Limiting Factor[1], "Over 21 people have visited Challenger Deep, the deepest area on Earth, in the DSV". This is just aboard the Limiting Factor, and doesn't include the descent of the Trieste (2 people), Deepsea Challenger (1 person), and Fendouzhe (3 people), totaling at least 27 who have been to the Challenger deep.

It looks like now, at least 3 more people have been to the Challenger Deep than have been to the moon (24 orbited it, only 12 landed on it).

[1]: https://en.wikipedia.org/wiki/DSV_Limiting_Factor

27 so far according to this list:

https://en.wikipedia.org/wiki/List_of_people_who_descended_t...

It would likely have been true a few years ago, but now 27 people have been to the Challenger Deep: https://en.wikipedia.org/wiki/List_of_people_who_descended_t...

That's more than the 12 who have walked on the moon.

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