The astronauts in the movie are able to travel billions of light years in a few seconds because of a wormhole. A wormhole is when two singularities form in two points of space and they connect forming a hole which allows travel between the connection. Unfortunately the typical shape of the wormhole is a simple cylinder with space bent around it which allows it to collapse in on itself. If the wormhole would be shaped like a sphere it would be able to stay open.
The teleporter in Star Trek is a necessity for the crew and the famous Captain Kirk to get back and forth from the planets. Since the ships that are used for travel are built in space with out and gravity acting on them the ship would not be build to handle gravity. Nor would it be able to leave the atmosphere. The warp drive is a necessity for the Star Trek universe since the expanse of space is so huge. The time it would take for any ship to go between any star would take so a large amount of time that all of the crew would have died.
The atomic bomb that was used on Hiroshima and Nagasaki was an extremely destructive force that has caused many debates since about the use of it. Some of the moral quandaries are why the bomb was even used since it is so destructive and kills so many indiscriminately. People call for the use of the bomb as a necessary evil. I believe that it is necessary because of the fear of the weapon is a deterrent to those who try and disagree with the one with the weapon.
Global warming is a climate phenomenon that is gradually changing the climate. It is causing warmer summers and colder winters. In the movie "The Day After Tomorrow" the film tries to show the affects of Global Warming. A polar ice cap that broke away from the Antarctica ice shelf. It raised the water so much it warmed up the water causing another ice age. This happened in an extremely short time of several weeks. In real life the water would slowly raise after years of warming causing changes in climate. The water would raise from the addition of freshwater from glaciers would cause a slight increase in ocean temperature which would expand the ocean causing flooding of all costal cities. Every year that people put carbon dioxide into the atmosphere it blocks more heat raising temperatures causing more ice to melt.