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Comment by jvanderbot | Hacker News Reader

OK, so the "Storing data in the network ... " title made me remember something.

If you transmit a message to Mars, say a rover command sequence, and the outgoing buffer is deleted on the sending side (the original code is preserved, but the transmission-encoded sequence doesn't stick around), then that data, for 20-90 minutes, exists nowhere _except_ space. It's just random-looking electrical fluctuations that are propagating through whatever is out there until it hits a conducting piece of metal millions of miles away and energizes a cap bank enough to be measured by a digital circuit and reconstructed into data.

So, if you calculate the data rate (9600 baud, even), and set up a loopback/echo transmitter on Mars, you could store ~4 MB "in space". If you're using lasers, it's >100x as much.

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During NASA's Deep Space Optical Comms demo (https://www.nasa.gov/mission/deep-space-optical-communicatio...), they transmitted video at 267 Mbps from 16 million kilometers away. That's 1.78 GiB stored in space while in transit (assuming 53.3 seconds light-speed delay).

The furthest they did was 8.3 Mbps at 400 million km which is around ~1.38 GiB in transit.

That’s so cool! Never knew that

Definitely one of the harder drives feasible!

Tom 7 did something reminiscent of this if you hadn't seen already: https://youtu.be/JcJSW7Rprio.

Love Tom7! The peculiarities of my brain's weirdness obligates me to sing his praises every time he is mentioned.

It's just a fancy form of delay-line memory [1].

[1] https://en.wikipedia.org/wiki/Delay-line_memory

In a universe with mass–energy equivalence, show me a storage medium that isn’t effectively a delay line :)

What about entangled qubits?

you beat me to it - or https://en.wikipedia.org/wiki/Delay-line_memory in general, space is probably closer to an electrical delay line in practice.

You could totally do that with the mirror on the moon. (Retroreflector + optical data transmission).

The moon is approximately (it varies) 1.3 light seconds away, i.e. a 2.6 second round trip, and optical links can have very high data rates. You could fit quite a lot of data on there! (Edit: although maybe the data rate won't be so high at these distances)

Some amateur radio folks do something along similar lines: https://en.wikipedia.org/wiki/Earth%E2%80%93Moon%E2%80%93Ear...

There is an archive of a lot of television transmission in space.

archive.space

You just need to be traveling faster than the radio waves, catch up and enjoy :)

People of Earth. I AM LRRR, RULER OF THE PLANET OMICRON PERSEI 8! We will raise your planet's temperature by one million degrees a day, for five days, unless we see McNeal at 9pm tomorrow - 8 central!

Pretty sure just one day would do it for us. Maybe it's Omicronian metric degrees and they're really precise?

Assuming some pass through non-empty media, isn't it technically possible?

With gravitational lensing, this is actually viable! Just send a signal at a gravity sink, and travel at sublight speeds to position yourself in a place where it will be redirected to eventually along a longer path, and you can intercept your own signal! You just have to be really, really lucky.

There's a short story by Qntm called "Valuable Humans in Transit" that I like quite a bit which hinges on this subject: https://qntm.org/transi

One of my favorite pieces of short fiction.

You can use fiber optics as an optical delay line too! About 60KB/km at 100Gbps.

https://en.wikipedia.org/wiki/Delay-line_memory

Indeed: https://qntm.org/transi

My friend Joe Allen did this with the air in a room!

https://youtu.be/a5hOmPdxw0U

The distance from Earth to Mars is about 3 to 22 light minutes, not 20 to 90. That doesn't change anything about your point, except the capacity is lower.

https://xclacksoverhead.org/home/about

"Going Postal" was brilliant. GNU Terry Pratchett.

allegedly, this was used long ago. a teacher told us similar stories from his early career in the 80s

made my mind tickle for quite a while

So if we can somehow preserve the signal and make it go round and round, can we get long term storage out of nothing?

Not a scientist, but I assume the signal would degrade or mutate over time due to space radiation and other radio waves.

It should be same logic we use for repeaters, so it'll be fine.

The logic we typically use for repeaters (EDFA, erbium-doped fiber amplifiers) for long-distance lines amplifies but does not clean noise (so across the oceans, you are very much bound by SNR). And you need one of them every 80 km or so in typical fiber.

Electromagnetic waves have perfect/lossless superposition, so radiation can’t really degrade a signal that way.

The big limiting factors are free space path loss and noise.

That's only true in classical electrodynamics, as it happens. If you're in a very strong B-field like you might find near a compact object you'll get nonlinear QED effects.

You can get a low order correction with Euler-Heisenberg: https://en.wikipedia.org/wiki/Euler%E2%80%93Heisenberg_Lagra...

"Nothing" is a funny name for an interplanetary communication network.

You're still storing your data in the same EM field, just in a slightly different non-inertial reference frame.

This is possible but you'd have to deploy it right by a black hole: https://en.wikipedia.org/wiki/Photon_sphere

i wonder how sensitive your equipment would need to be to read it from the back scatter off the interstellar medium.

https://www.youtube.com/watch?v=JcJSW7Rprio

pingfs has similar inspiration, where storage capacity scales with latency.

https://code.kryo.se/pingfs/

Discussed in 2015:

https://news.ycombinator.com/item?id=9844725

Lacks the capability of random access, which limits the practicality of it. Cool idea still

Before I consumed calories over days to figure out syntax. Now, a language model exhausts those calories away in seconds. Eventually we will advance too far into the future that the tail end of humanity will forget how to make pants.

"a man is not dead while his name is still spoken"

GNU John Dearheart

> If you transmit a message to Mars, say a rover command sequence

Don't you worry!

AI rover robots are soon going to dominate Mars.

"Commenter shows off how smart they are with cool fun fact"

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