[jcranmer]

> What does Intellectual Property and Copyright not cover that patents do when it comes to software?

Copyright cannot and does not prevent someone from clean-room engineering a replacement for your software. Patents can do that. (Whether or not they should is a different question, but that's not what you asked).

FWIW, patents are one of the forms of intellectual property.

[GoblinSlayer]

Presumably clean room implementation takes the same amount of effort as production of specification, so it doesn't save effort of invention.

[throwawayapples]

Oh, no, that's not true at all. An invention might not even be possible, let alone having a clear and (literally, provably) correct specification of inputs and outputs. Just seeing that it exists, to say nothing of getting the correct proportion of inputs and outputs, could shave a decade off your invention cycle.

Take, for example, the nuclear bomb. Just knowing that it could be done put you ten steps ahead. What if cold fusion or a warp drive were known to be possible because you could see it (even if from a great distance with little detail)? Airplane manufacturers leapt ahead (literally) after the Wright Brothers.

A tremendous amount of effort for worthy inventions is often involved simply in proving that it can be done. Once you know it can be done, you don't have to prove it anymore, and also large companies will throw buckets of money at a clone of something that's proven to work.

A patent (sometimes) prevents that -- at least, when everything is working as it should be. (In this case, clearly not!)

[GoblinSlayer]

Possibility of data compression was known since 1977, video codecs exist since 1984.

[defrost]

Shannon, C. E. (1948).

A Mathematical Theory of Communication.

Bell System Technical Journal, 27(3), 379–423.

doi:10.1002/j.1538-7305.1948.tb01338.x

https://sci-hub.ru/10.1002/j.1538-7305.1948.tb01338.x

https://en.wikipedia.org/wiki/Shannon%27s_source_coding_theo...

https://faculty.uml.edu/jweitzen/16.548/classnotes/Theory%20...

[no_wizard]

>FWIW, patents are one of the forms of intellectual property.

To keep the discussion well focused, I didn't want to get into the nuance of "patents are IP law too" since in broader discussions, IP and patents are usually discussed separately, even though yes, they exist under the same legal umbrella (Intellectual Property).

> Copyright cannot and does not prevent someone from clean-room engineering a replacement for your software. Patents can do that. (Whether or not they should is a different question, but that's not what you asked).

That's a fair point, only patents give an entity the legal "teeth" to do this, though there is room for argument that a clean room engineering replacement would then show novelty and non obvious aspect of a patent to be invalid, and could be grounds for patent invalidation

[0]: Arguably, the fact that courts are sorting this out and not specialized experts at the USPTO is one of the main drivers for why our patent system is broken. Federal judges are not required to be technical experts to oversee a patent case. In addition, this allows the USPTO to liberally grant patents as they pass the validity concerns off to the courtroom

[thaumasiotes]

Copyright can do that, in exactly the same way that patents can. It just happens not to as currently configured.

You might observe that a clean-room replacement is in and of itself evidence that a patent covering it was obvious and therefore not validly granted, which would tend to imply that patents cannot prevent this.