I think that in such situations it's necessary to take a non-standard approach, since it's highly likely that if you try to influence your child's opinion about the future profession, you will meet resistance from his side and resentment that can ruin your relationship. In this situation, I would try to support the child's idea, for example, watching documentaries about famous illusionists, searching for articles on this topic and educational videos. You can use these
Free Tricks To Get Started Guides to improve your communication with your child. There are many elements of science in "magic" if think about it logically. Maybe you should just take a different look at this hobby of your child and captivate him with physics, chemistry or psychology in addition to the tricks training?