Yes, eventually assuming all "c coins" were spent.  As long as outputs prior to the fork remain unspent they could continue to be spent on either (or both) networks.

Well 31 OCT if you count encryption usenet.

http://article.gmane.org/gmane.comp.encryption.general/12588/

I believe (not 100% positive) this is the first announcement of Bitcoin using the word "Bitcoin".  Satoshi may have posted earlier possibly under another psuedonym and not using the word Bitcoin (speaking in general terms about p2p cash) but that would be pretty hard to track down.   Note the date, the whitepaper was published roughly a year two months before the first client and genesis block.  Interestingly Satoshi must have decided on the name by August 2008 because that is when bitcoin.org was registered.

Satoshi Nakamoto Sat, 01 Nov 2008 16:16:33 -0700

http://www.mail-archive.com/cryptography@metzdowd.com/msg09959.html



Some more dates from the early history
https://en.bitcoin.it/wiki/History

Fun fact the first recorded exchange rate was 1309 BTC per USD.  That would be worth ~$1.5 million today.  Lots of people talk about the million dollar pizza but this first trader only got a buck.

It is a little more than a little. 

Bitcoin right now has monetary inflation of >11% annually.  Of course that will decline over time.  It is the future expectation which has caused demand to exceed supply and the price to rise.

How many blocks passed between when you sent the tx and it was included in a block.  Remember mining is an average of 10 minutes per block.  It may have been possible that just 1 or 2 (and your tx didn't get into that miner's work before it was found) blocks were found in that time period.

A block hash isn't a hash of a private key.   It is the resulting random hash the miner will find that "solves" a block (solve being a block hash which is smaller than the target required by current difficulty).

Still if one was worried about a paradox you could instead say this:


BTW this is the hash for the message in the post above.  After block 300,000 I could reveal the message and one could hash the message to independently verify it was known prior to the event using a publicly available SHA-256 hash tool like:
http://www.xorbin.com/tools/sha256-hash-calculator

Then the cartel created an alt-coin.  It is important to understand that in this scenario 50% has no special meaning.  It can be done with 1% or 99% of network hashrate and/or 1% or 99% of the nodes.  As long as each network has at least one node which is also mining (creating blocks) then both networks will continue to coexisting with some level of usage.

The A, B, C grouping of "coins" above is not the complete story.   Remember Bitcoin doesn't work on the concept of "coins" or balances it works on the concept on unspent outputs.    If someone on network "A" mines a new block this creates an output which exists on network A only, lets call this output A001.  Now lets also assume that miner has an unspent output which existed prior to the split, lets call that output C001.  Now this miner pays someone using both those outputs.

Transaction
Inputs:
A001
C001

Outputs
A002 - receiver
A003 - change

Since the tx is only valid on the "A" network (any tx with one or more "A" input will be seen as invalid on the "B" network), the outputs are also only valid on the "A" network.  The thing to note is that coins have been erased from the "C" category.  Even though a C input was used (lets say it was 10 BTC) the output is no only usable on the A network.  So it isn't just the newly created coins it is any future outputs which use any input which is only valid on one network.  Obviously the same effect applies on the "B" network as well.  

So if the fork occured right now, most txs would propogate on both networks however like a fork in the road the two networks will rapidly diverge.  This will happen organically but it can also be "forced".  If one wanted to ensure their tx only propagated on one network you could ensure (likely use a client that makes sure) that all created txs use at least one "A" (or "B") input thus the tx can't propagate on more than one network.  Since the change of any such tx is network specific you can ensure all future tx are restricted to a single network as well.

Also as casascius pointed out 50% of the nodes (or miners) doesn't matter.  This scenario (creating an alt-coin which uses Bitcoin's legacy history) can happen with any % of the network.  1%, 50%, 99% of nodes and/or miners there is no special significance to 50%.  Essentially you just have a new altcoin which lacks a unique genesis block and thus shares Bitcoin's history up to the point of the fork.  It will have to survive on its own merits.  If even some users remain on the original Bitcoin network it will continue to coexist.   Most (all?) altcoins today have thrown away Bitcoin's history using just the source code + modifications + new genesis block.  This creates a new incompatible blockchain from block zero, you can consider it a fork at the genesis block.  However this doesn't have to happen you can fork the history at any point in time.  The scenario you describe in the OP has always been possible.  It doesn't need any specific % of miners or any specific % of nodes.  You, yourself, alone could do it right now with a network of one.  Modify the Bitcoin source code (probably need to hardcode initial difficulty back to a lower level) and start a single mining node.  You now have an new altcoin which shares Bitcoin's history prior to the fork.
  

Yes someone could lookup in the blockchain the blockhash for a block that is the future relative to where the traveler is going.  It can be any block but making it a round significant block might be cooler.

Simply come back and tell people what it is.

For example:


Now you just need to wait for block 300,000 to confirm my story. BTW I may or may not be serious in the proclamation above.

There isn't $30T in cash in off shore accounts.  there are $30T in ASSETS in offshore accounts.  Big difference.

Globally the entire M2 is roughly $25T, there is only ~$5T of M0 (currency).   However total global wealth (stocks, bonds, precious metals, property, patents, land, etc) is ~$240T.

have you stopped beating your wife yet?

Then ask MtGox why they are ripping you off charging 20x what is necessary.  Then look at how much they are actually paying.   MtGox ripping customers off is nothing new it also has nothing to do with Bitcoin.

Ask Pirate about that.  Unlawful selling of securities is a felony not just a civil complaint however the SEC was filling to go after him for asset forfeiture civilly as well.  In addition to being charged with running a ponzi scheme he was charged with offering unlicensed securities.  Then again if RS is unknown it doesn't really matter.   Can't charge someone if you can't find them.

Yeah it probably has nothing to do with the 600% run in the last 30 days.  Over the long run Bitcoin has apreciated against the dollar by ~0.5% per day or 15% per month.  The last 30 days was 40x that.

Or not but even if so the answer your provided is incomplete.  The same private key could be used for LiteCoin without issue.  Someone might want to do exactly that to simplify backups.  Have the exact same private keys in multiple wallets on different chains.  Another option would be to generate a paper wallet for both Bitcoin and LiteCoin using the same private key.   If you lost either one you could still recover funds by using the other one.

Well not exactly.

You could use the same private key and public key for Litecoin (or any coin which uses ECDSA public keys and the same curve, which AFAIK is every clone coin to date).  However LiteCoin uses a different ADDRESS structure so you would need to compute the proper address for those keypairs.


Remember address =/= public key.  

There are three distinct elements:
Private key = random (or deterministic) 256 bit number.
Private key + ECDSA "magic" + particular ECC curve = public key.
Hashed public key with checksum, version information, and encoded into base 58 = public address.

After the fact make sure it is a country with no extradition to Australia.  Of course if victims organized quickly they could ask the courts to retain his passport to ensure he can't leave.  Having $12M in nearly untraceable currency which is easily transportable and usable just about anywhere in the world would probably be seen by most courts as a flight risk.  Then again I don't wear a black robe so who knows.

Simple version: No.

More complex version: Coins don't move.  So there is no scenario where coins "leave" one wallet and vanish, get deleted, or end up corrupted before "arriving" at another wallet.  We use words like "send coins" which make it seem like "coins" are moving but they aren't.  A tx simply transfers "ownership" of the asset.  Simplified a transaction is essentially saying "I the owner of these particular coins (provable by looking at prior txs and verifying my digital signature is correct) transfer ownership of them to the receivers listed below".  The transaction exists publicly in the blockchain and that combined with the recevier's private key is all that is needed to "spend/send" them (by the same process).  So either the tx is included in the blockchain and the receiver "owns" them permanently or it never does and the sender still owns them.

The only possibility of coins being lost would be an error where it was sent to a wrong address, even then someone will get the coins although it might be the wrong "someone".  It is possible to send coins to an address which exists but for which nobody has the private key by a typo.  However Bitcoin includes a checksum so most typos will simply be invalid tx and never sent.  The odds of making a typo which by bad luck produces another address which also happens to be valid is about ~1 in 4 billion.

I think your right.  Bitcoin has plummeted in value, interest, media attention, and adoption since the first ASIC was released. 

If the private key is truly lost then the coins are permanently lost baring some future cryptographic break in the primitives used for Bitcoin.

The number in supply will decline but likely not for decades as until all are mined the rate of new minting is very likely to be higher than the rate lost.

No.  Possibly by some minority but Bitcoin works on consensus and there is no real possibility of the protocol being ammended to confiscate coins.  The network can not determine if a coin is "lost" only that it hasn't been transfered (yet).

No Bitcoin is highly divisible and if necessary (I doubt it but it is possible) that divisibility can be extended as needed.  The entire network could operate with a single Bitcoin.  Money is merely an accounting system.  The nominal number of base units is utterly irrelevant. 21 million is simply an arbitrary number.  It would have no change on the network if it was 21 trillion, or 21.

I don't know.  Some more details would be helpful.  How large in size were both transactions?  How many inputs?  Are all the inputs confirmed?  Do the outputs violate any spam rules?

As stated if for privacy reasons you don't want to share the tx ids that is fine but you are trying to propose a conclusion based on very limited data and likely will reach the wrong conclusion.