THREE RIDDLES

1. What do Physics, Science Fiction, and the English Monarchy have in common?

2. The same word can precede each word below so that the two phrases mean the same thing.

_ _ _ _ OPEN = _ _ _ _ CLOSED

3. What do the these three words have in common?

MADAME
MONARCH
EMPEROR

HINT:
1. It has to do with homophones.
2. It depends on your point of view.
3. MADAME is in a different category than the other two.

Answers:

1. Joules, Jules Verne,  and the Crown Jewels 
2. HALF
3. Madame Butterfly is an opera; Monarch and Emperor are types of butterflies.