Kind of difficult if A and B are Hermitian.

There are missing links because the fossil records can't be found. They disappear in a process akin to particulate adhesion to linear pastaforms (and the resulting consumption). Evolution is then obviously due to divine interference by noodly appendage, and the missing links are evidence of this.

They should have talked to whoever designed my flat.

It stops being the Argo in toto the moment the first plank is replaced and it becomes mostly the Argo. Eventually there is no Argo, except for all the parts that have been removed, assuming they still exist. Maybe consciousness works the same way, and eventually the new you will have nothing in common with the you of the past. Perhaps it would be like knowing you were once another person, but not remembering what it was like.

How are identical things, in the exact time and place, discernible as more than one thing?

So done using a language written in C, libraries written in C, and further libraries that depend on the language and libraries written in C?

Because not everyone will be on their Xbox all the time, and Microsoft might also have spare server time available for peak Xbox hours.

Usually time constraints. Alice might want to communicate securely to Bob over an extended period while separated, but they can physically meet beforehand. For example, you want a secure link with a military drone.

The weather?

That's the first thing I thought about at the mention of a "brick wall". What else is going to stop you building a super-computer that has N-times the processing power of an existing one?

Does it even qualify as scientific knowledge if it's not freely available for peer review?

I would prefer a power cable. Put the battery in my pocket.

Religiosity and intelligence.

Which is why a clearly visible shooting target, with the groin-area shot out, is more effective than an actual gun.

Completely agree. I'd add that the threat is the defense. Actually shooting the firearm is no defense at all.