You could have made very similar arguments about the early Internet.

The things that differentiated the Internet from other networks that were arising at the time, was that it was decentralised, pseudononymous and had a low barrier to entry. These are the same attributes that differentiate Bitcoin from traditional fiat currencies.

At the time, many technically adept people, most famously Bill Gates, considered the Internet to be a dead end. With hindsight, it's clear that they underestimated the power of a decentralised network that was cheap to join and easy to add new services to.

It's far from certain that Bitcoin will become as successful as the Internet; but I'm not sure I'd write it off so quickly.

Finally, tulip bulbs are somewhat different to bitcoins. One is something you put into the ground and which turns into a flower. The other is a cryptographically signed transaction history wrapped in unit of work proofs, providing a pseudononymous and decentralised way of transferring wealth across an arbitrary communications channel. The only similarity is that they were invested in by speculators.

Why?

I mean sure, it gives people a little more information about the market, albeit at the cost of increasing the number of transactions, but what exactly would it change?

It allows you to transfer wealth electronically and pseudononymously without the need for a centralised broker.

One might as well claim that the Internet has no ultimate value, as there's nothing apart from being electronic, pseudononymous and decentralised that sets it apart from traditional means of disseminating information.

No, but bitcoins can transfer wealth electronically and pseudonymously without the need for a centralised broker.

Bitcoins is to currency what the internet is to traditional media. It lowers the amount of initial capital needed to innovate with finances. Quite frankly the appreciation of bitcoins is relatively uninteresting to me; it's the sheer technical potential of a decentralised electronic currency that gets me excited.

You can. You just need to convince people that if they loaned you some bitcoins, you'll repay them after a certain time frame.

That wouldn't work. People would just swap coins between several accounts in order to reset the expiration date.

I haven't had any problems understanding what happens in each episode. In fact, I find the two new series by Steven Moffat to be considerably better than the old Russel T. Davies series.

Russel T. Davies was infamous for "Doctor Ex Machina" plots, in which the Doctor would pull technobabble solutions out of his ass at the last minute. His villains were either re-introduced monsters from old Doctor Who episodes, or extremely uninteresting evil aliens who were entirely interchangeable.

Steven Moffat actually attempts to write science fiction, in that the Doctor's solutions are based on rules set up earlier in the episode, rather than rectum-derived technobabble. The viewer gets all the information the Doctor gets, so when he reveals the solution there's a genuine feeling of "Oh, now that's quite clever". Moffat's monsters also typically have some kind of interesting gimmick and often have some relation to the real world, giving them a certain scare factor that's not present in Davies' generic aliens.

The user doesn't discard their old key pair, they just generate a new key pair for each transaction. A bitcoin user might own hundreds of different keys, each containing the proceeds from a single transaction. In aggregate, all of these accounts make up the bitcoin user's total wealth.

I'm not sure a client in the Bitcoin network counts as either. The FSA might be interested if someone started a business for exchanging bitcoins for pounds, or vice versa, but I expect it would take a while to work out whether bitcoins were something that it should be regulating.

Creating a counterfeit Bitcoin would involve breaking public key encryption. If that happens, normal financial transactions would be at just as much risk.

Bitcoin doesn't really do anything new from a cryptography perspective. It signs transactions with public keys and assumes that there isn't an easy way to find a specific SHA256 hash short of brute force.

A new public key is usually generated for each transaction, so this doesn't actually tell them anything.

I don't think you've quite understood how the system works. The situation you describe can't happen without the entire network being subverted.

This isn't quite correct either. There is a simplified payment verification method that doesn't require the full block chain. The Bitcoin network just needs enough full clients to make it infeasible to subvert the network.

What do you mean by "such a service"?

Amazon has the spammer's credit card details, knows where each email comes from, and can freeze or terminate accounts at the touch of a button (or via an algorithm). This gives it a considerable advantage over those that have to passively filter spam.

And in any case, spam filters are pretty damn good these days. I've had a public email address for going on 15 years, which used to get hundreds of spam emails every day. Now it's very rare for even one to slip past GMail's filter.

That would require AI with at least human-equivalent intelligence, which is some way off.

Or live a life currently reserved for the extremely wealthy.