If you're an into-science, critically thinking person, you still (deliberately or unconsciously) follow so or so philosophical views.

Please give a short answer (yes/no and why) to the following questions:

1. A mind = substrate or function?
2. Is a time machine physically realizable?
3. Is it relevant to speak of the ontology of matter or is matter only matters inasmuch it is describable by so or so mathematical model?
4. Universe = a model of some logical system (in terms of model theory)?