Star Trek IV: The Voyage Home (1986) - 3 questions

Question: In the scene where the crew exits the ship via the retractable doorway and gets seen by the garbage men, they had enough power to beam out but decided to walk out regardless, and risk being seen. Yet every other time they beamed in and out of the ship, so why not that particular time? Furthermore, why would the garbage men dismiss it so easily and not report it or return again later.

Answer: There's no reason given, but it might have something to do with the fact that all of them are leaving the ship at the same time. It may be necessary for someone to remain on board to beam them in and out, as opposed to manually opening and closing the hatch from the outside. Being as this is a Klingon ship, the technology does not exactly work the same as their own. As to the garbage collectors, they did not report seeing anything for fear of no one believing them, being ridiculed, and possibly losing their jobs. They may also simply not believe what they are seeing.

Question: In a few scenes in the film, the characters mention how people of the 20th century still use money. Key word: still. How is the process of currency different in the 23rd century compared to the present?

Answer: The United Federation of Planets uses the credit. Its a purely electronic form of money. Necessities and luxuries both are simple and cheap to produce with the Federation's advanced technology, and humanity has matured to the point that accumulating wealth is considered vulgar. Furthering the common good or the advancement of humanity is the real status symbol in the 23rd and 24th century. These conditions result in a society with very little need for money. Citizens are paid, but since the technology built into a place of business (or starship) or home supplies all basic needs for free, most people spend money only on exotic products that aren't commonly manufactured, like art or handmade foods.

Question: What exactly was Scotty's reason as to why giving the Company boss the formula for the one inch glass wouldn't alter the future? He gave a brief response, but I honestly can't think of any reason why it wouldn't do any future damage.

Answer: Scotty says "Why? How do you know he didn't invent the thing!" If the man was in fact the inventor, this would only cause a slight causality loop problem - he "invents" it because they gave it to him, but they only know it because he "invented" it. However, since Sulu said earlier in the movie that it was about 150 years too early for transparent aluminum, it would seem they do know this, so it wasn't a smart thing to do. Of course, the real flaw in the plot is that they need the tank to be transparent at all.