Bitcoins in space

[FatherMcGruder]

Fed up with the state of the Earth, a group of people decide to build a space ship and find a new habitat among the stars. Due to weight constraints, they can't bring very much stuff. Luckily, bitcoins, weigh nothing. As their favorite earthly currency, they decide to bring it with them to their new home.

Assuming that they can find another habitable rock, get there without succumbing to the hazards of space travel, not trash said rock and annihilate themselves, and then reunite somehow with Earth, will the bitcoins they will have generated still work?

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[Cdecker]

Short answer: no!

They'd be far better off with creating their own chain. The fact is that even should they generate a block, the time to send it back to earth would be far longer than the 10 minute timeframe. Probably someone on earth would have generated a block and other would already be chewing on build on that block before anybody's ever heard of yours coming from mars (http://www.wolframalpha.com/input/?i=Distance+between+earth+and+mars)

P.S.: which doesn't mean that bitcoin is not applicable, you'd just have exchange rates between Earth Bitcoins and Mars Bitcoins

[FatherMcGruder]

So, if a group of nodes separates from the rest of the network for at least ten minutes, bitcoins created after that point could become invalid. Vulnerability?

[Cdecker]

Basically yes, it's because the network has to agree on a consistent state, and the smaller group will eventually be overtaken by the larger one and all incompatible blocks are lost (Bitcoins generated in those blocks will no longer be accepted by the network).

It's not really a vulnerability, you'd be free to keep on working on the smaller chain, resulting in a network fork, but you'd have to convince people to (a) accept your coins and (b) join your network.

As long as network splits are short I don't see a big problem, but should for example china decide to drop all bitcoin connections to the outside world we'd end up with a Bitcoin block chain for China and one for the rest of the world. I guess we'll see it sooner or later. But "Don't Panic"

[FatherMcGruder]

I suppose space pilgrims could also use a custom client that would ignore bitcoins generated after the communication delay got too long. They could continue to trade with the bitcoins they started with.

How long is too long, by the way?

[hugolp]

So, if a group of nodes separates from the rest of the network for at least ten minutes, bitcoins created after that point could become invalid. Vulnerability?

If the person that generated the bitcoins joins the network before any other has found the bitcoins, it should be fine. First to notify the network the discover is the one that gets the bitcoins.

[theymos]

How long is too long, by the way?

Even 10 seconds is a significant disadvantage, though generation should still be (very rarely) possible in the 10-20 minute range.

The explorers will eventually have to create their own blocks, since without a block chain there is no protection from double-spending.

[kiba]

1. Create a stable wormhole big enough to carry information from one side to another.
2. Wire it up.
3. Viola, an internet connection to Earth.
4. Setup bitcoin...and you're DONE!

[grondilu]

1. Create a stable wormhole big enough to carry information from one side to another.
2. Wire it up.
3. Viola, an internet connection to Earth.
4. Setup bitcoin...and you're DONE!

I'm not sure you need a worm hole.

I think a large entangled set of photons would do.   But however large the number of photons would be, you could only send a finite amount of data.  But it might be enough if you plan on coming back on Earth some times to times (every century or so).  Or if you accept visits from Earth.


http://en.wikipedia.org/wiki/Quantum_entanglement

[bencoder]

I'm not sure you need a worm hole.

I think a large entangled set of photons would do.   But however large the number of photons would be, you could only send a finite amount of data.  But it might be enough if you plan on coming back on Earth some times to times (every century or so).  Or if you accept visits from Earth.


http://en.wikipedia.org/wiki/Quantum_entanglement

Quantum entanglement does not allow FTL communication.

[grondilu]

Quantum entanglement does not allow FTL communication.

Ahh I think you're right.  My bad.

[LZ]

In other star and planetary systems it is really better to create a separate block chain.
But what about nearby objects: Moon, Mars? Can we use DTN or something like that?

[grondilu]

In other star and planetary systems it is really better to create a separate block chain.
But what about nearby objects: Moon, Mars? Can we use DTN or something like that?

Correct me if I'm wrong, but I think the longer is the delay, the greater is the likelyhood of a double spending.

[LZ]

It takes just 1.28 seconds for light to reach the Moon's surface from the Earth's surface.

384,467,001 m / 299,792,458 mps = 1.282,443,873 s

[grondilu]

It takes just 1.28 seconds for light to reach Moon's surface from the Earth's surface.

384,467,001 m / 299,792,458 mps = 1.282,443,873 s

Ok so bitcoin is Moon compliant.  What about Mars ?

[LZ]

From 3 to 22 minutes depending on the position of Mars. But we should keep in mind
that Mars is not always visible from Earth - so that requires a system of repeaters.

Approximate calculations for the minimum and the maximum distances:
55,750,000,000 m / 299,792,458 mps = 185.961,983,073 s = 3.099,366,385 min
401,000,000,000 m / 299,792,458 mps = 1,337.859,778,937 s = 22.297,662,982 min

[FatherMcGruder]

Ok so bitcoin is Moon compliant.

Good quote or best quote?

[LZ]

To summarize. It seems that it is safer to use separate block chains for each planet.
However, I do not see any problems in the use of a single chain for natural satellites.

[Anonymous]

Space is the ultimate cooling system.....

[kiba]

Space is the ultimate cooling system.....

Actually, the vaccum sucks for cooling things.