Bitcoin Forum

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?

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 :D

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?

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" :D

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?

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.

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.

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

Quantum entanglement does not allow FTL communication.

Ahh I think you're right.  My bad.

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 (http://en.wikipedia.org/wiki/Delay-tolerant_networking) 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.

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

https://web.archive.org/web/20150616182408/https://upload.wikimedia.org/wikipedia/commons/6/60/Speed_of_light_from_Earth_to_Moon.gif

Ok so bitcoin is Moon compliant.  What about Mars ?

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

Good quote or best quote?

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.

Space is the ultimate cooling system.....

Actually, the vaccum sucks for cooling things.

Plenty of solar power though.

I would say it the other way: "Moon is bitcoin-compliant"

Indeed.

What would happen if a major disaster, natural or otherwise, severs the Terra Internet into two separate nets for a few days?

Firstly, most people think a total severance is practically impossible. There would have to be no radio communication link, nor wire or optical fiber link, nor sneakernet or avian carrier link. It's hard to imagine a disaster that would disable every last link.

If the network does get severed for a few days, then later rejoined, one of the block chains will be accepted by the majority and the other block chain will be rejected. The transactions on the rejected block chain are temporarily lost, but will normally be re-broadcast and eventually incorporated into the accepted block chain.

Any coins generated on the rejected block chain during the separation will be lost forever, even if they have been spent to someone else in the meantime.

How long did Egyptians loose interweb access for?

I saw on TV that at one point, the only way they could tweet was to call a phone number and leave a message on an answering machine, the messages were then automaticly posted on Tweeter as audio clips.

Lots of people lost their internet access, as various methods of access went down and up. But landlines kept working, didn't they? At a pinch, major Bitcoin merchants could dialup to an overseas ISP in a crisis if they needed to.

But there's a big difference between losing internet access (even if a whole country loses it), and retaining access within a country but being partitioned from the rest of the world.

bitcoin maybe the least desirable option in another planetary system, here is why:

To create bitcoin or block chain, you need two things: hardware and software.

#1. Assume you didn't bring everything with you, to create hardware (CPU in particular), you'll need to have Silicon, Boron, Phosphorous, Aluminium, Copper, Gold.... not mentioning those multi-billion dollar fabs.
http://www.tomshardware.com/picturestory/514-intel-cpu-processor-core-i7.html
"A microprocessor is the most complex manufactured product on earth. In fact, it takes hundreds of steps and only the most important ones have been visualized in this picture story"

#2. To write and maintain the bitcoin software, you'll need to have a group of programmers and make them happy (providing food,shelter,drugs, sex,games,whatever), which can be more difficult than #1.

gold, silver, or seashells will be much better choice.

The pioneering space colonists probably wouldn't have a need for currency at the start. Compensation for work done would come in the form of survival, at least for the first few generations.

There's going to be scenarios where connecting to the Internet will be difficult if not impossible. If in fact Bitcoin must be connected to the Bitcoin network to function properly I was thinking as a solution that there could be multiple Bitcoin networks running. The main Bitcoin network that we use, and a Bitcoin network running in an intranet for submarines where Internet is not always available but currency is always needed. Then to link the two networks together the same people who are trading cash for Bitcoins could also trade Bitcoins for Bitcoins on both ends of the Network. I.E., something like this [Main Bitcoin Network (Bitcoin Trader<-)]---[(->Bitcoin Trader) Submarine Bitcoin Network]

I think it would be really interesting if someone setup a Bitcoin experimentation networks to test ideas like the lost in space idea in this topic. That way we can truly see what would happen if a total netsplit were to occur and people were still performing Bitcoin transactions.

The test network is a split network from the main bitcoin one .  :D


I think a bitcoin stock market might be fun where each separate company has a different block chain and to issue shares it sells some of its sharecoins.

space = insulator. ever wonder why thermos are called vacuum flasks?

I'm not an engineer or anything, but I'm pretty sure it easy to cool an electronic device in space.  Sure, you don't have any environnmental fluid to carry heat away, but you have plenty of space that you can fill with zero-weight (considering zero gravity) metallic pans.  Maybe just behing solar panels.   Those metallic surfaces can radiate energy out.

But, that's all you can do in space. Conduction and convection are out. And just as a surface can radiate heat, it can also absorb radiation, from the Sun for example. I think that cooling equipment in space presents some interesting engineering challenges.

Oops, I'm afraid you're right.  That was silly of me but I forgot that.

I guess cooling electronic devices is indeed tricky in space.

I wonder how the ISS does it. Maybe it has radiators shadowed by the solar panels. I bet it can also make use of a fair amount of convection, since it orbits in the upper atmosphere.

You got me curious about this, so I looked it up.  The answer is apparently ammonia-filled infrared radiators:

http://spaceflightsystems.grc.nasa.gov/SpaceOps/ISS/Cooling/ (http://spaceflightsystems.grc.nasa.gov/SpaceOps/ISS/Cooling/)
http://science.nasa.gov/science-news/science-at-nasa/2001/ast21mar_1/ (http://science.nasa.gov/science-news/science-at-nasa/2001/ast21mar_1/)

Do they got actual internet on the ISS or do they use only specialized communication means (plus regular radio) ?

A money market on the planet Zlorg wouldn't be able to "communicate" quickly enough with Earth either for that matter.

What with quantum finance erupting as a new business model. It would be pointless to try and communicate a sale of USD between Earth and some planet 50 lightyears away.