The final result is a disk with a 3D stack of data layers that can hold a petabit (Pb) of information - that's the same as 125,000 gigabytes of data.

This is a mad amount of data compared to what can fit on even the fanciest flash or hybrid hard drives (HHDs).

That same petabit of information would need a stack of HHD drives as tall as a man - if you tried to put the same amount of data onto Blu-rays, you'd need about 10,000 blank ones to do your pretty pants challenge.

To pull off their feat, engineers had to make a new material for their disk's film, called "dye-doped photoresist with aggregation-induced emission luminogens."

AIE-DDPR mixes special, light-sensitive molecules that can soak up photonic data at a tiny level, which is then written using a high-tech dual-laser.

Because AIE-DDPR is so clear, designers could put layer after layer on a disk without messing up the data. This basically made a 3D "box" for digital information, which made the normal-sized disk's capacity go up a lot.

According to ZME Science, datasets used to train clever AI can have about 5.8 billion webpages, adding up to about 56 Pb of data. So, in theory, instead of using loads of power-hungry data centres, you could fit all of ChatGPT's training stuff in one of those old CD album holders you used to house your Radiohead and Artic Monkeys collections.

Sadly, a CD holder with enough data to train your own AI thing isn't likely to come anytime soon.

Making the cutting-edge disk takes ages, and is still not energy efficient. The geeks think they can sort out both problems with more tests and inventions.

If so, some of the biggest issues in modern data management could be sorted by using a very old physical format.