Firstly:
Things like cars seemed impossible a hundred years ago
Check your history
But as for your question, I think that progress in technology is inevitable and unstoppable, unless we go instinct or all knowledge is lost or something like that, before we can achieve those goals.
But certain things will take longer than others.
FTL travel is absurd and if we ever manage it, it wont be for a looooooong time.
Flying cars are much more reasonable, as is commercial space flight and a moon tourist facility and things like that.
As for interplanetary travel, unless we either sort out cryogenics, or sort out FTL travel, it's a massive impracticality and is generally pointless, because the nearest planets are dead or inhospitable and take many years to get there.
Living in other galaxies, again, FTL travel.
High tech electronics... well we're already breaching from the age of information into the age of mastery of that information when it comes to such things like robots, GPS, self driving cars, superhuman advancement suits, virtual reality, holographic technology, artificial intelligence and things like that. 20-30 years into the future, who knows what's going to happen? The rich, modernised, globalised countries of technology will change its inhabitants forever. In 10 years, look around, and see how much technology is in a box of cereal, or a newspaper (if they exist in that format anymore).
Video bus adverts, contact lenses displaying information on your health, games that prevent world hunger, hold back the waste of fossil fuels. Wireless electricity throughout your home. No cables going into the socket for anything ever again. All this could be a reality in 3 years... though probably won't be common knowledge for a while.
What I want to know is, when are we going to get a dimensional perception device, to be able to percieve the dimensions we don't even know exist yet.
Also, time travel. Technically a time travel device already exists, sending one partical back to the time when the machine was first activated... but it's useless to us right now. The same goes for teleportation technology.
Oh and just a nice little extra, laser guns already exist to superheat missiles and things like that. and there's research into tasers that apparently shoots through a beam of light, but i'm not sure of the specifics. Also there's the guns that only respond to their owner.