Question: I was just reading an e-book and saw this sentence which really confused me:

[![enter image description here](https://i.stack.imgur.com/CuYCV.png)](https://i.stack.imgur.com/CuYCV.png)

"Played twice as fast as written" - This isn't what cut time actually means right, or are there situations where cut time means exactly that?

I thought cut time is basically just 2/2 time signature, but the speed would still depend on the bpm and the note durations...

Answer: 
It would be more accurate to say that cut time "will sound twice as fast as the same notes played in 4/4 at the same tempo". That's essentially what they're trying to get across.

But even that wouldn't really be accurate. Cut time is a duple meter, 4/4 is a quadruple meter. The difference is subtle, but it's still a difference.
The e-book was trying to contrast two different meters, 2/2 to 4/4, kind of assuming that the reader might not notice or understand the difference at all. They were trying to provide a simplified first explanation of an unfamiliar meter symbol.

They meant "Crossing the C has the effect that the conductor's hand will start moving in cycles of two beats rather than four beats and you players will have to play twice faster to keep up." 

Except that there's no conductor around which makes the entire difference more abstract to formulate and less constrained to execute.