Saw a screenshot of a Satoshi email in this thread and wanted to know more. Grok helped me find it. Pasted below:

Howdy!

I tracked down the email you're referring to—it's a 2009 exchange between Satoshi Nakamoto and early Bitcoin developer Mike Hearn, originally shared publicly in 2017 and archived on forums like Bitcointalk. (The "24 million" in Mike's question was an early draft figure before it settled on 21 million in the final code.) The screenshot you saw on r/BTC likely captured the start of Satoshi's explanation but cut off the ending, which wraps up the logic on balancing potential future value.

For context, here's the full relevant thread (lightly formatted for readability, with timestamps and headers preserved):

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**From:** Mike Hearn mike@plan99.net

**Date:** Sun, Apr 12, 2009 at 12:46 PM

**To:** satoshin@gmx.com

Hi Satoshi,

I read your paper on BitCoin with great interest. I found it a bit confusing though - I believe it may be easier to follow if you provide some examples. Specifically, it's not quite clear to me what blocks contain. If I understand correctly, there is only one (or maybe a few) global chain(s) into which all transactions are hashed. If there is only one chain recording "the story of the economy" so to speak, how does this scale? In an imaginary planet-wide deployment there would be millions of even billions of transactions per hour being hashed into the chain. I realize that each PoW can wrap many transactions in one block, nonetheless, that's a large amount of data to hash. If there are many chains, how are transactions assigned to each chain such that it is still difficult to overpower the network? Eg, if there are 10 global chains, the amount of cpu power you need to beat the system is only 10% of what it was previously.

I also wonder if the assumption of 1 core = 1 vote is sound. If the majority of nodes are on standard computers, it seems likely that an attacker could use FPGA or custom ASICs to get significantly better performance. What are your thoughts on using custom hardware to beat the chain?

I found the section on incentives hard to follow. In particular, I'm not clear on what triggers the transition from minting new coins as a reason to run a node, to charging transaction fees (isn't the point of BitCoin largely to zero transaction costs anyway?). Presumably there's some human in charge of the system - eg, you decided somehow that 24 million coins was a good number to have, and would distribute some kind of rules file saying "coins minted after this timestamp must have an N+1 zero bits prefix", which honest nodes enforce. How did you decide on the inflation schedule for v1? Where did 24 million coins come from?

What denominations are these coins? You mention a way to combine and split value but I'm not clear on how this works. For instance are bitcoins always denominated by an integer or can you have fractional bitcoins?

So many questions :) But it's rare that I encounter truly revolutionary ideas. The last time I was this excited about a new monetary scheme was when I discovered Ripple. If you have any thoughts on Ripple, I'd also love to hear them.

thanks

-mike

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**From:** Satoshi Nakamoto satoshin@gmx.com

**Date:** Sun, Apr 12, 2009 at 10:44 PM

**To:** Mike Hearn mike@plan99.net

Hi Mike,

I'm glad to answer any questions you have. If I get time, I ought to write a FAQ to supplement the paper.

There is only one global chain. The existing Visa credit card network processes about 15 million Internet purchases per day worldwide. Bitcoin can already scale much larger than that with existing hardware for a fraction of the cost. It never really hits a scale ceiling. If you're interested, I can go over the ways it would cope with extreme size.

By Moore's Law, we can expect hardware speed to be 10 times faster in 5 years and 100 times faster in 10. Even if Bitcoin grows at crazy adoption rates, I think computer speeds will stay ahead of the number of transactions.

I don't anticipate that fees will be needed anytime soon, but if it becomes too burdensome to run a node, it is possible to run a node that only processes transactions that include a transaction fee. The owner of the node would decide the minimum fee they'll accept. Right now, such a node would get nothing, because nobody includes a fee, but if enough nodes did that, then users would get faster acceptance if they include a fee, or slower if they don't. The fee the market would settle on should be minimal. If a node requires a higher fee, that node would be passing up all transactions with lower fees. It could do more volume and probably make more money by processing as many paying transactions as it can.

The transition is not controlled by some human in charge of the system though, just individuals reacting on their own to market forces.

Eventually, most nodes may be run by specialists with multiple GPU cards. For now, it's nice that anyone with a PC can play without worrying about what video card they have, and hopefully it'll stay that way for a while. More computers are shipping with fairly decent GPUs these days, so maybe later we'll transition to that.

A key aspect of Bitcoin is that the security of the network grows as the size of the network and the amount of value that needs to be protected grows. The down side is that it's vulnerable at the beginning when it's small, although the value that could be stolen should always be smaller than the amount of effort required to steal it. If someone has other motives to prove a point, they'll just be proving a point I already concede.

My choice for the number of coins and distribution schedule was an educated guess. It was a difficult choice, because once the network is going it's locked in and we're stuck with it. I wanted to pick something that would make prices similar to existing currencies, but without knowing the future, that's very hard. I ended up picking something in the middle. If Bitcoin remains a small niche, it'll be worth less per unit than existing currencies. If you imagine it being used for some fraction of world commerce, then there's only going to be 21 million coins for the whole world, so it would be worth much more per unit.

Values are 64-bit integers with 8 decimal places, so 1 coin is represented internally as 100000000. There's plenty of granularity if typical prices become small. For example, if 0.001 is worth 1 Euro, then it might be easier to change where the decimal point is displayed, so if you had 1 Bitcoin it's now displayed as 1000, and 0.001 is displayed as 1.

Ripple is interesting in that it's the only other system that does something with trust besides concentrate it into a central server.

Satoshi

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That's the complete message—no more after that in this thread. If this isn't the exact screenshot you saw (or if you have a link to the Reddit post), feel free to share more details, and I'll dig deeper!