Difficulty

About the work

One drawing per day, made automatically at 00:30 UTC from two measurements.

The shape: an aurora forecast. The US Space Weather Prediction Center (NOAA) publishes a forecast of the northern lights every few minutes. For every point on a one-degree grid of the Earth, it gives the probability, in percent, that aurora is visible. The drawing uses the band from 40° to 86° north, laid flat: longitude runs across, latitude runs down. Where the probability is higher, the lines are lifted higher.

The colour and the lines: a block. About every ten minutes, computers around the world compete to add a batch of transactions to a shared public ledger. The batch is called a block. To add it, a computer must find a 256-bit number, the hash, that starts with a required run of zeros. The only way to find one is to guess, trillions of times. How many zeros are required is set by the network’s difficulty.

Each drawing uses the first block after 00:00 UTC:

• Hash: the colours of the background and the angle of the lines. The leading zeros are skipped; they are the same in every block.
• Transactions, the number of payments in the block: the number of lines, from 100 to 260.
• Nonce, the number changed with each guess: how high the lines are lifted.
• Height, the block’s position in the ledger: the sheet number.

Neither measurement can be repeated.

Back to the works