> Do comets count?

The distinction between comets and asteroids is no longer scientifically valid. By composition, comets and outer Solar System bodies are the same. Comets just happen to have orbits that get so close to the Sun they evaporate water and other ices and create a tail. There are intermediate bodies in the asteroid belt and out to about Saturn that give off just a little outgassing, but not enough to create a full tail. "Dead comets" have comet-like orbits, but no longer have any volatiles to outgas, and so are indistinguishable from asteroids otherwise.

The modern way to distinguish these small Solar System bodies is:

- Never got close to the Sun, and still has all the volatiles (water, methane, etc.)
- Sometimes gets close to the Sun, and still boils off volatiles when it does
- Has spent too much time close to the Sun, and has been baked dry.

Those are verbose descriptions, so I like to borrow from steak terminology and call them Raw, Still Juicy, and Overcooked.

In fact, actual astronomers refer to all the solid objects that orbit the Sun as "planets". The come in three sizes: major planet, dwarf planet, and minor planet. The IAU Minor Planet Center ( http://www.minorplanetcenter.n... ) tracks all those things otherwise known as "asteroids".

The exact dividing lines are:

Major Planet - Round, and massive enough to have "cleared" it's orbit of other large object (it's the dominant mass in it's orbital region)
Dwarf Planet - Round, but has not cleared it's orbit, thus Ceres and Pluto fall into this category.
Minor Planet - Too small to become round under it's own gravity.

As a note, the stuff that got "cleared" falls into three groups: impacted one of the other planets and got absorbed, kicked entirely out of the Solar System, or kicked into an eccentric orbit but not ejected. That last group is called the "Scattered Disk", and there are around 400 known objects in the category. They are separate from the Kuiper Belt, which is leftovers in the outer Solar System which have not really been moved in their orbits. There are about 1200 objects in the Kuiper Belt, inlcuing Pluto.

> but how to grow your own food?

People would move back to the country if cities become unsustainable. What method to produce food depends how far civilization collapsed. Steam powered farm tractors are pretty low tech, and abandoned cities would be an abundant supply of steel to make them out of.

> The problem is that the natural resources that we are consuming now are NOT renewable (fossil fuels, minerals, metals). Once they are gone, they are gone, and there will be no recovery.

It's not like the atoms of carbon, silicon, and iron vanish when you make a product out of them. There are already bio-engineered microbes that can take sunlight & CO2 and emit new hydrocarbons (diesel and ethanol). Reprocessing other materials just takes enough energy, and there is no shortage of that as long as the Sun shines. 10,000 times as much Solar energy arrives at the Earth as we use to run our whole civilization. We only need to use a tiny fraction of that to keep things running.

This is already possible with something called "colored coins". Instead of the tokens themselves having value, they represent ownership of other things, like a share of stock or an ounce of gold. They can still be traded online, and divided into smaller parts, but additionally the holder of the colored coin can redeem them for the underlying asset. The "colors" terminology comes from each color being a different asset class. These yellow coins are backed by gold, these green ones are backed by dollars, etc. They can be freely mixed on a single block chain, as long as you have a way to tell the colors apart from each other.

> Bitcoin has no chargeback mechanism.

You are wrong about this. There is a built-in escrow function that returns payment to the sender if the conditions of the transaction are not met. Bank card charge-backs are mostly limited to 60 days, and assumes the conditions are met if there is no objection within that time. In addition to the built-in function, people can use escrow services who hold funds until the sender is satisfied. In turn, escrow services can make arrangements with merchants about holding time and amounts.

The thing about bank cards is you are paying for the charge back feature whether you need it or not. Bitcoin makes extra services "a la carte" - you don't have to pay for the ones you don't need.

> anything traded is 'currency'..

No, something generally accepted in the market as an intermediary is a currency. Direct trade (some of my stack of lumber for a dinner) is called "barter". Barter has the difficulty called "a coincidence of wants". You need people who both want what the other person has to trade. A currency simplifies this difficulty, in that I can trade my lumber for currency, then later find someone making dinner, and trade my currency for that. I don't have to find someone who wants my lumber AND is making dinner.

For a currency to be useful as an intermediary, enough people have to accept it in trade. In theory, anything at all can become a currency, but in reality only a few items become the currency of a given community because of the network effect. Whatever is most used tends to get used even more. Which items gain early acceptance depends on their features: inherent usefulness, durability, portability, fungibility, divisibility, scarcity, and others. Fish are useful, but not very durable or portable. Cattle are also useful, and reasonably durable, and portable because they are self-mobile, and in fact cattle were used as an early currency. But they are not fungible (not all identical units), and not very divisible until you eat them, so other kinds of currency with better features replaced them. Sand meets many of the features of a currency, except scarcity - there's not much point in trading for your sand, when I can go get my own. Gold is better in that respect - it's not easy to go get your own, so if you want some, it's easier to trade for it.

Gold is useful (you can attract women with it), and has all the other features except divisibility for small amounts, and portability for large amounts, so for a long time it was the best currency.

People like myself who build using the CryEngine still need a version number, so we know when to update, and what version we are building to. So they may drop the number in the branding, but we almost certainly will have it as users of the engine.

No, CryEngine is the brand name. The version you are thinking of was version 1.0. The current version of the free SDK is 3.5.8, which you can download from http://www.crydev.net/ It's only a week old. The version they will be demoing at the Game Developer's Conference is even newer, with Linux support and physically based shaders. It will probably be labeled version 3.6 or 4.0 because those are big additions.

Note the SDK is much bigger than the game engine. The game engine is the set of DLL's that get called by your compiled game executable, and take care of rendering, networking, and other functions that are common to most games. Games additionally have content (maps, textures, animations, etc.). The software development kit also includes the "Sandbox" editor, which is how you build game levels, a bunch of specialized tools for importing and creating content, and usually a sample game level and other assets.

> Perhaps the real Satoshi has a 5 year old kid and doesn't waste too much time on his pseudonymous accounts anymore.

The original Satoshi disappeared when Gavin Andresen, now lead programmer for bitcoin, mentioned he was going to talk to the CIA about the project. Satoshi immediately stopped posting on forums and hadn't been heard from until yesterday on any of those accounts. Either he was spooked by getting three letter agency spooks involved, or he *worked* for a three letter agency and thought his cover might be blown.

Analysis of the text of the original bitcoin paper (word choice, spelling, punctuation) points to Nick Szabo as the likely main creator of Bitcoin. Szabo had been working for several years before that on an idea called "bit gold", a direct technical predecessor of bitcoin. His website ( http://szabo.best.vwh.net/ ) has papers on many of the same topics that bitcoin is involved with. Japanese names are written last name first, so "Satoshi Nakamoto" and Nick Szabo both share the initials "NS". That's not proof, but it is suggestive.

Hal Finney may have made significant contributions. He developed the "proof of work" method by which bitcoin reaches consensus on the transaction history. Finney is a well known cryptography developer (he works on the PGP software). He started mining bitcoin the day after the software went live, and was the recipient of the very first bitcoin transaction, from "Satoshi" to him. Finney and Szabo are known to have met and communicated before bitcoin was created, and him starting to mine so early and getting the first transaction makes sense if they worked together on the project.

Examining the programming style of the first versions of bitcoin (before other open-source developers got involved) may help point to who created it, but I have not seen any analysis of that.

Bloomberg LLC is. They invested in venture company Andreessen-Horowitz, who in turn put $25 million into Coinbase, a company that processes merchant payments in bitcoin and deposits local currency to their bank account. They also have 1 million online wallets and sell bitcoins to individuals. Bloomberg TV does a lot of stories about bitcoin these days.

My analogy is "Bitcoin exchanges are like having sex with an alligator. You want to withdraw as soon as you are finished, or else you might get bitten."

Well, my copy from BitcoinQt is 17.2 GB, but that's because it has indexes so it can search the actual transactions faster. Still, that's only $0.65 of hard drive space, not a big deal. What will happen eventually, when it gets too big, is a bunch of people subscribe to a dedicated server with lots of storage, and pay for it with bitcoin. They can load the software themselves, and then compare it to other copies of the block chain to make sure they are identical

> If the blockchain is pruned, what is to keep someone from creating duplicate/counterfeit BitCoins that descend directly from the prune section?

Bitcoins can only be created when you find a hash for a new block. You would only prune transactions which have spent all their outputs. Therefore they have no balances left, and counterfeit balances descended from the pruned transactions would be zero. The block chain prevents double spending because you have a full record of where every balance currently is. Pruning doesn't change that, it only drops the transactions that are zeroed out by later transactions and thus no longer matter. You can check the pruned total against the latest block number, from which the current total of issued coins can be calculated. If they differ, your data is invalid.

Bitcoin "addresses" are unique. They are derived from several rounds of hashing functions on the private key of of a public-key encryption pair. Addresses hold some bitcoin balance amount, which is recorded to 8 decimal places. Bitcoin transactions move some amount of balance from one or more input addresses to one or more output addresses. The private key is required to digitally sign a transaction, so whoever knows that key, can spend the coins they control. Bitcoin "wallets" are files that contain as many keys as needed. Since they are 256 bit keys, one file can hold as many as you need.

Transactions are broadcast across a peer-to-peer network. They are collected by "miners" into "blocks" who attempt to find a low-valued hash for the block by varying the random number, where the data being hashed is [hash of previous block + hash of current block's transactions + random number]. How low the hash value needs to be is adjusted so the whole network finds one every ten minutes on average. Whoever finds the hash value first broadcasts the new block to the network, and everyone running the software updates their copy of the "Block Chain", the set of all blocks containing all past transactions.

Thus everyone has a complete history of all transactions, and every bitcoin amount can be tracked across all the transactions it has been involved with. Each block has a special "coin generation" transaction, which creates 25 new coins, and sends them to the miner's own address. Those 25 coins are worth $14,000 at today's rates, which drives the whole mining operation. Miners compete to find the next block, and claim the 25 new coins.

Since blocks are hard to create, and each block contains the previous block's hash value as data, they form a chained history which is effectively impossible to edit. Any change to any data invalidates the hash recorded in the next block, and every one after it. That is the innovation contained in bitcoin: digital data you can't edit. It is highly useful for recording financial transactions, but it can also be used for any other kind of data you don't want to change.

So not only does everyone have a copy of all past transactions, nobody can change them, because that would take all the computation power consumed since the point you want to change, and all the computation power is busy writing new blocks to earn the rewards of new coins.