does compact disc writing increase the weight/mass of the cd?

Different CD types work differently.

Commercial ones work by creating holes, therefore taking away.

Home recordable/re-recordable work by changing parts of the die from opaque to transparent and back again. No material is removed. The same as an LCD display has the same amount of material regardless of which digits are being displayed.

Information can be stored without removing/adding. E.g having a row of dice. You can encode information by re-orientating them. Nothing is removed or taken away.

Your computer does not get heavier if you fill the hard disc with things!

So its not really a universal truth at all.

the laser creates the data recording by burning "pits" onto the disc. This is to give the 0/1 digital code where a pit is a zero. Therefore adding data actually removes a tiny piece of the disc - its mass must decrease - will have to try weighing one before and after to check!!

Compact disk is actually burned with the help of laser. It evaporates the Alluminium or organic layer. So there is a mass reduced on CD when compared to new one if info is written.

But to measure the mass reduction, you need an extremely precession micro balance for that.

I would assume it would not becouse i figure when it burns it knocks out some waight then add it as it adds the audo

but im intrested to find out what the ansrw is here to.