In a sci-fi book that I am still to write, can I use the word 'illusion' to denote extreme cases of mind trickery where such an 'illusion' can alter things and space around, example: people are able to travel faster, fight of monsters, feel pain from pricking etc.? What's the work around if it's not possible? I don't want to use magic.
Wikipedia defines illusion as
- distortion of one's human perception of reality
- a misrepresentation of a true sensation
- they are generally shared by most people
When you talk about altering things or space, you are changing the physical perception of the concerned things or space. After the change everyone would observe the induced change but this does not always mean it is the new reality. Reality is still illusionary. Every velocity in the universe is relative and is reality only in one frame of reference. For some other frame, it is not even an illusion (a perceived reality) but something pointless. Even the absolute speed of light is absolute only because of the different perceptions of time in different frames. And all this is not even mind trickery but actual physical phenomena.
Therefore it is safe to say that whatever extent of mind trickery you do, you may say it is an illusion produced.
It is unclear what you are asking. An illusion is something that seems real but is not real.
If your 'illusion' can temporarily alter the way something looks, make your banana seem red, or make there seem to be two bananas, then calling it an illusion makes sense.
If your 'illusion' can make the banana seem to fly twice as far as I threw it, but once the illusion wears off, you see I only threw it 10 metres, not 20 metres, then fine, calling it an illusion is accurate.
If your 'illusion' can make the banana actually fly 20 metres instead of 10 then it's not an illusion. It's real.