Ciro Santilli @cirosantilli 40

the unperturbed ground state hyperfine transition frequency of the caesium-133 atom $Δ v_{C s}$ is 9 192 631 770 Hz
the speed of light in vacuum c is 299 792 458 m/s
the Planck constant h is 6.626 070 15 × $1 0^{- 34}$ J s
the elementary charge e is 1.602 176 634 × $1 0^{- 19}$ C
the Boltzmann constant k is 1.380 649 × $1 0^{- 23}$ J/K
the Avogadro constant NA is 6.022 140 76 × $1 0^{23}$ mol
the luminous efficacy of monochromatic radiation of frequency 540 × 1012 Hz, Kcd, is 683 lm/W,

The breakdown is:

actually use some physical constant:
- the unperturbed ground state hyperfine transition frequency of the caesium-133 atom $Δ v_{C s}$ is 9 192 631 770 Hz
  Defines the second in terms of caesium-133 experiments. The beauty of this definition is that we only have to count an integer number of discrete events, which is what allows us to make things precise.
- the speed of light in vacuum c is 299 792 458 m/s
  Defines the meter in terms of speed of light experiments. We already had the second from the previous definition.
- the Planck constant h is 6.626 070 15 × $1 0^{- 34}$ J s
  Defines the kilogram in terms of the Planck constant.
- the elementary charge e is 1.602 176 634 × $1 0^{- 19}$ C
  Defines the Coulomb in terms of the electron charge.
arbitrary definitions based on the above just to match historical values as well as possible:
- the Boltzmann constant k is 1.380 649 × $1 0^{- 23}$ J/K
  Arbitrarily defines temperature from previously defined energy (J) to match historical values.
- the Avogadro constant NA is 6.022 140 76 × $1 0^{23}$ mol
  Arbitrarily defines the mol to match historical values. In particular, the kilogram is not an exact multiple of the weight of an atom of hydrogen.
- the luminous efficacy of monochromatic radiation of frequency 540 × 1012 Hz, Kcd, is 683 lm/W
  Arbitrarily defines the Candela in terms of previous values to match historical records. The most useless unit comes last as you'd expect.

 Read the full article

Cool data embedded in the Bitcoin blockchain / Eternity Wall Updated 2025-07-16

 View more

eternitywall.it

This website used to allow embedding text messages with OP_RETURN, here's an archive from 2015: web.archive.org/web/20150718052659/http://eternitywall.it/

As of January 2024, it seems to read-only mode, where it simply indexes matching transactions that were made via other means: web.archive.org/web/20230929075331/https://eternitywall.it/

A Reddit announcement from July 2015: www.reddit.com/r/Bitcoin/comments/3dxy9f/eternity_wall_messages_lasting_forever/

There were 3191 hits for the search term:

git grep '\bEW '

in our data starting with tx a3b3af21514bd79a4cbcac9916a8514636a72d813539192214542fd85247082e (2015-06-24):

EW Eternity wall is live

up to the last entry on tx 28820bc14cf2cfda58ecbc9ac6df3f41a1cb90f4246543f01ba42a5e9dac3cf8 (2023-06-15)

EW May our friendship endure, signed by hg, kty, wjj, and xyz.

no doubt initials of 4 Chinesepeople. A blood brother oath comes to mind, akin to the Oath of the Peach Garden. Will these four be the ones to take down the evil dictator Xi Jinping?

The very first message gives away the name of what we assume is a web-based upload system, "EW" being its advertisement signature added to every message.

Running bitcoin-cli:

bitcoin-core.cli getrawtransaction a3b3af21514bd79a4cbcac9916a8514636a72d813539192214542fd85247082e true

shows that the messages are encoded with OP_RETURN:

  "vout": [
    {
      "value": 0.00000000,
      "n": 0,
      "scriptPubKey": {
        "asm": "OP_RETURN 455720457465726e6974792077616c6c206973206c697665

 Read the full article

Cool data embedded in the Bitcoin blockchain / OnChainMonkey Updated 2025-07-16

 View more

onchainmonkey.com/

From their site:

OCM Genesis is our flagship generative art collection that's set many historic precedents since its launch in 2021. Genesis is the first NFT collection where all 10,000 images and metadata (similar to DNA describing the NFT) were generated using code entirely on-chain in a single transaction on Ethereum. With the launch of Bitcoin Ordinals, Genesis is the first ever collection of 10,000 images to be inscribed on Bitcoin in 2023.

Some of their likely transactions were noted in our list of large transactions: github.com/cirosantilli/bitcoin-inscription-indexer/blob/master/data/payload_size_out e.g.:

004c3f1efa0095b229dd05ea247c94a5af742daf682fb082a6e62f4aeeb973f2 66033
ffc73ef454d512f98a451960e05a0a036406ed1078a1bd7082fd4036cf0af067 66021

but we haven't had the patience to index them properly yet. Boring art anyways.

 Read the full article

Cosmopedia Updated 2025-07-16

 View more

Cosmopedia is a dataset of synthetic textbooks, blogposts, stories, posts and WikiHow articles generated by Mixtral-8x7B-Instruct-v0.1.The dataset contains over 30 million files and 25 billion tokens, making it the largest open synthetic dataset to date.

 Read the full article

Course of the University of Cambridge Updated 2025-07-16

 Read the full article

Craig Steven Wright is the Billy Mitchell of Bitcoin Updated 2025-07-16

 View more

Billy Mitchell comes strongly to mind!

They even look similarly fraudulent.

 Read the full article

Cryptocurrency swapper Updated 2025-07-16

 View more

A "Cryptocurrency swapper" is a service that swaps one type of cryptocurrency for another.

It is basically the same as buying and selling from exchanges for fiat, except that you only get fiat.

Swappers are in general able to receive send coins from any address, including self custody addresses.

Centralized swappers were a good way to workaround the endless Monero bans from exchanges circa 2024, e.g. x.com/cirosantilli/status/1771900725649371240 as they effectively serve as proxies for exchanges that are still legal in other countries.

They will eventually have to ban Monero of course, and then the only way left will be decentralized exchanges.

This leads to a scenario where the only effective way to ban Monero is to also ban all other cryptocurrencies. The question is if countries will go that far or not.

 Read the full article

 There are unlisted articles, also show them or only show them.