Apologies.  I miscalculated, the figure should be 60 000 transactions per second, not 60 million (so about 4 transactions per human per week).

More meaningfully, the maximum block size would rise to a final value of 20 GB each.

Thank you.  You awakened me to a calculation error I made earlier.

I believe the proposal involves an initial jump in block size followed by temporary exponential growth with fixed parameters.  If the blocksize were increased to say 20 MB and then grown at 50% per year we'd be up 2 GB blocks in 11-12 years.  At 40% (double every 2 years) it would take 13-14 years.

Ah, I see.  No problem.

By the way, Gavin did mention the idea of having the growth end in 20 years here in A Scalability Roadmap.  The question of a desirable ultimate transaction limit was raised here too.

Well, at 365 USD/BTC, we're a little bit closer to 1000 than 100.

I highly doubt that we'll reach either in the next 3 weeks; Bitcoin's rarely that volatile.

I'd just like to layer my own observations atop this, being as unbiased as I can manage.  I'm running with your implicit assumption that "bitcoin", "millibitcoin", and "microbitcoin" are distinct units.

The bitcoin is by far the most common unit in the Bitcoin system.  This was introduced by satoshi with the release of the code (early 2009).  It is the only unit sufficiently widely recognised that it has been entered into a number of reputable dictionaries (e.g. OED).  The symbol "BTC" is the most popular, but BTC and "XBT" are also frequently seen.

The millibitcoin is easily the second most widely used unit today.  This follows naturally from "bitcoin" and the SI prefix "milli-" (1795) and was first discussed on the forum in early 2011.  I doubt it's in any dictionaries but there is basically a consensus on the term.  The symbol used is almost always "mBTC".  Nicknames vary: "millibit", "mill", "millie".

The satoshi is the third most common unit.  It was introduced in early 2011 by bitcointalk (then bitcoin forum) user ribuck (originally as a name for 0.000 001 BTC but this quickly changed to 0.000 000 01 BTC, currently the smallest possible unit).  It is, as you observe, practically the only name for this unit.  "SAT"/"Sat"/"sat" is relatively common as a symbol and a nickname.

The infamous 0.000 001 BTC unit is more the subject of flamewars than anything else, not least because two of the most popular names, "bit" and "microbit", are in direct logical conflict.  It's possible both will become accepted (just as 1 calorie = 1 kilocalorie) but the issue is far from decided.  I've seen many proposed names for this unit; off the top of my head (alphabetically, lower case): "bit", "centoshi", "fin", "finney", "hectoshi", "mic", "microbit", "microbitcoin", "mike", "mubit", "ubit", "xub", "zib".  Selecting one name may well end up attracting negative attention to your platform so please tread carefully.

As I say, these are just my observations (reading something on Bitcoin roughly once a day for the past 4+ years).  I'm happy to accept corrections and provide some citations on request.

If a block now is capable of 2k-4k tx's and the blocks grow in size by 50% per year then, in 20 years, a block will accommodate:
100 years would yield roughly 800P-1600P tx's (about 1 000 000 000 000 000 000 tx's).

Ah, that makes sense.  No problem.


Thank you, this clears things up for me.  All I don't understand here is the notion of broadcasting newly generated blocks through a Tor-connected SPV node but I imagine I can look this up.

Yeah, 40% of a 250 GB connection works out to about 23 MB depending on how you define month.  May I ask what would happen regarding TOR?

If 1 MB blocks give us, say, 3 transactions per second, then 20 years of "double every 2 years" growth starting from 20 MB would leave us with about 60 million transactions per second.  That's about 25 transaction per hour per human (assuming a world population of 8.5 billion in 20 years time).

This sounds a bit excessive to me but then again I've not thought seriously about how such a volume of transactions could be utilised.  https://en.bitcoin.it/wiki/Scalability doesn't speculate beyond a few hundred thousand transactions per second.  I'd certainly appreciate a link if a discussion on the utility of millions of transactions per second exists.

Edit: Oops.  I miscalculated "double every year for 20 years".  Starting from 1 MB blocks worth, say, 3 transactions per second, then 20 years of "double every 2 years" growth starting from 20 MB will yield about 60 000 transactions per second.  That's about 4 transactions per week per human (assuming a world population of 8.5 billion in 20 years time).

Looking forward to the block-size economics blog post.

Apologies.  I intentionally cropped some of the left-most data off because there was so little volume I considered the data almost valueless noise (much like the mining difficulty data of 2009).  I've left some of the early data on to show that this line is not a hard rule (of course) and, indeed, the price drops far below the line in the early days.

I think I have some bitcoinmarket.com trade data hanging around somewhere which would take us to early 2010.  I haven't got it to hand but vaguely recall there being price action between 0.003 USD/BTC and 0.0086 USD/BTC in its early months (leading up to early July 2010 which is when I stated trading).  If you're interested I'll try and dig it up.

40%/year = 96%/(2 years).  I hope that gets rounded to "double once every 2 years (105 000 blocks)".

Also, do you propose this growth be open-ended or terminate at some block-size commensurate with the transaction volume of an existing, mature payment system such as Visa?  Given an open-ended proposal I'd echo Theymos' concern.

This was mainly a reference to the latter months of 2011 when a number of articles proclaimed the Bitcoin experiment dead.  I believe a repeat performance is very much on the cards.

Your attention please.

Bitcoin is about to die again.  Please return to your seats and fasten your seat-belts.  We are descending steeply today so please ensure that your bitcoins are securely stowed.

Thank you.


Chart from bitcoinaverage.com.

To be fair, I don't recall there being consensus on the reason for the major rise in value last year either.


Are you sure he was talking about Bitcoin?  Sounds like AML regulations to me.

Why did these bitcoin holders buy coins in the first place?  You are presuming a large demographic of people that considered bitcoins worth having when there was little merchant adoption but not worth having now that bitcoins are more widely accepted.

Besides, there's a far simpler explanation for the 2014 bear market: A correction to the 2013 bubble(s).

I think you're after this.

"mikes" as a nickname for microbitcoins is a fairly old suggestion.  Check out this nomenclature discussion from Feb 2011?

Whatever unit you decide to adopt, I recommend appending the price in bitcoins in paretheses, perhaps in grey text or a smaller font.  If you find this too cluttered you might consider a tool-tip.

For example:
    35 µBTC  (0.000 035 BTC)

I challenge you to ask 10 "common people" what a "bit" is.

I also claim that while "µBTC" is somewhat unfriendly, if it is useful it will be softened in a natural way.  People will write "uBTC" often because there is no "µ" on most keyboards.  People may drop pronunciations such as "microbitcoin" or "u-bee-tee-cee" in favour of abbreviations such as "mic" or "ubit".  Someone may invent a currency symbol, probably a "µ" with a bar through it, like ₥ (read: mill) which already exists and means a thousandth of a currency unit.  If the unit becomes really popular prices might be typed as "240 u" or "1500 u" where the "u" is pronounced "yew" or "mics".

If "kilograms" is often abbreviated to "kilos", "millilitres" to "mills", and "gigabytes" to "gigs", then why must we plan what people are going to do about "microbitcoins"?  Can't we simply let the decentralised system which is natural language do its job?

So no.  While I can order a takeaway for 34 mills, paying a transaction fee of 200 mics, I have no need or want to adopt extra terms such as "bits".

What precisely is the problem with foreign people collecting welfare?

Ah, I see now.  I thought you were suggesting some change to the way Bitcoin works.  Perhaps "popularisation" (also "popularization") would be a better choice of word.