UPDATE: I thought I make the puzzle easier:

まとめ I am a big fan of the show since the first season and, because I am a Bitcoin developer, namely the creator of HiddenWallet, it made me very happy when I first heard TBBT is going to air a Bitcoin themed episode and I could not wait to finally watch it. In this article I will discuss and add some context to a few debatable and funny lines. I will also answer some unanswered questions, like when did they mine, what method did they use for mining and how much did they mine. Finally I will explain why this episode was left open-ended and Rajesh’s dream of buying a tiger is not over just yet.

What I Missed

いびき Unfortunately the show lacked of insider jokes and Easter eggs. Although I am not sure about the latter, maybe I am just a bad observer.

But imagine if they would have put a binary T-shirt on Sheldon, that represents a private key, which holds one Bitcoin for the fastest viewer to reclaim. How cool that would had been? In fact, even this article has $70 hidden in it. Let the race begin! (The address: 15NLS1v4JCgVZUd6Leccz8vMU7NewCdFsX and yes, the Japanese words have something to do with it.)

りょうり About the insider jokes. Ok, this one may be unfair criticism. Hodl, 2 weeks™, Goxed, To the moon!!! ┗(°0°)┛ ..○ Only Bitcoiners would have love to see such things in the episode. Fortunately we have a Brian Hoffman, who reworked the trailer and I sincerely hope he is working on the whole show at this very moment:

Does The Timeline Checks Out?

I can’t believe a single Bitcoin is worth $5000. — Howard

こおり From the price data on BitcoinWisdom, we can conclude the guys tried to recover their wallet somewhere in September of 2017.

Wait, didn’t we mine some a few years ago? — Leonard

It was seven years ago. — Sheldon

こうかん So Leonard, Rajesh and Howard were mining in 2010, possibly mid 2011. For the record, the genesis block was mined in 03/Jan/2009.

I am a theoretical physicist, so I know nothing about cryptography. — Giacomo Zucco

えんそく One of the question arises is: is it realistic that Sheldon heard about Bitcoin in 2010–2011? It is definitely plausible. Sheldon, while not perfectly, but fits the earliest Bitcoin adopter stereotype, which is: cryptographers, cyberpunks and a few developers. At the very least he must had a friend in academia to hear about it from.

The other question of course: were they able to mine it? Maybe. First take a look at some facts to evaluate their situation.

The first generation of Bitcoin miners were simple computers, mining with their CPUs. The second utilized their GPUs and the third generation switched to FPGAs.

Laszlo Hanyecz was the first person who started the GPU mining in May of 2010.

The first GPU mining software was open sourced in September of 2010.

According to Blockchain.info, at the time the hash rate was 0.01 TH/s, and this is the earliest hash rate data I can find.

The block reward was 50 bitcoins in every ten minutes at the time.

Now, before I would go into any speculation, let’s take a look at the next clue.

We definitely mined some, I remember sitting in your bedroom and writing a program, I think we ended up with a bunch of it. — Leonard

くかん My first thought was: there was absolutely zero need to write a program to mine Bitcoins. At least not pre May, 2010 and nor post September 2010. But what happened between those dates? That’s right, miners were struggling, their CPU were not mining much anymore, the few closed source GPU miners were the only ones who made some coins. In fact, around this time ArtForz held 25–50+% of the hashing power with his GPU farm. So the only way to get into Bitcoin mining is to write a software.

Therefore we can safely conclude the story only makes sense if they started mining between May, 2010 and September, 2010. Did the authors deliberately timed their story so well?

This also gives us the maximum possible duration of them mining, which is roughly one year. From May, 2010 to mid 2011.

おさめる The problem is: they were mining on Leonard’s laptop. We know around the time the guys started to mine, ArtForz was the biggest miner at around 25–50% hash rate with a dedicated GPU farm and he had <1% at August of 2011. How much one laptop’s GPU could actually mine in one year? I am not sure. I strongly suspect nothing. If someone would be able to give an educated guess on how much hashing power a laptop CPU had seven years ago, then based on the hash rate data I previously inserted we can attempt a calculation.

For now I will change to my most optimistic me and I will give a guess that they may had found one block a month, which equals 12 blocks in maximum. That is 12*50=600 BTC, which is 3 million dollar assuming $5000 Bitcoin price.

UPDATE:

dooglus’s comment to this post:

I can do better than that. I was mining for a month or two in early 2011. Look at 1PsACmccnGAYT9ee19SCFZHibQ98Z4HcNw to see the rewards sent from slush’s pool. I mined 1.37 BTC in 27 days using my laptop CPU and the standard satoshi client. I guess the guys in the show were using a GPU not a CPU, so they’d be mining maybe 100 times more. They could easily have mined 1000 BTC in a year with a GPU back then.

The First Bitcoin Purchase Ever

Stuart, I was wondering, will you be accepting Bitcoin? — Sheldon

Unfortunately the transaction did not go through, because Sheldon had a chance to become the first person who bought something with Bitcoin.

ろんぎ That being said, this chance was not that high, because we established the earliest date Sheldon could have asked Stuart was also May, 2010 and the first person who bought something with Bitcoin was Laszlo Hanyecz. Remember, he was also the first GPU miner? On May 17, 2010 he offered 10,000 BTC for two pizzas.

Honorable Mentions

Before we begin, this may have some unprecedented tax implications, we should start early, because we’re gonna be on the phone with the IRS for hours. — Sheldon

Sheldon is a visionary.

Mining some coin sounds so manly. — Rajesh

Indeed, it is.

Uh, we should sing a mining song! — Rajesh

That’s a great idea!

Don’t Give Up On The Tiger

All I did was sneak on your computer and download your Bitcoin onto a flash drive. — Sheldon

ぴっちり This guy searched through a whole landfill for his hard drive with bitcoins on it and I cannot even count the times I recovered deleted data from my old hard drives. The thing is: until you format it like two-three times, the data may be recoverable. But judging from the fact that Penny’s video and the empty Bitcoin folder were still on the drive, the wallet is most likely recoverable. If anyone they should know it, they are physicists.

Summary

The story happened seven years ago. Does it make sense? Yes.

They were mining on Leonard’s laptop. Does it make sense? No.

They wrote a software to mine bitcoins. Does it make sense? Yes.

Sheldon deleted their bitcoins and they don’t think about recovering it. Does it make sense? If there is no followup in the next episodes, then no.

Meta Update

けまりAs you might have realized I started to write these meta updates on my projects a couple of posts ago and I intend to keep it up. Since my last post was yesterday I don’t have much to report. Today we started to plan how we will find many testers for our massive scale CoinJoin deployment on the Bitcoin testnet. Brace yourself, anonymous Bitcoin is coming!

きびしい