Some of the "big stuff"[1] that has not happened:
- Space travel between planets and solar systems[2].
- Atomic powered rockets. And airplanes. And cars. And toasters (see next).
- Ubiquitous, essentially free power, typically atomic. Mass to energy converters are popular in the stories. Fission/fusion reactors are extremely small and safe in the stories.
- Flying cars.
- Moving walkways.
- The cold war (USA vs. USSR) is active.
- Phones had wires and operators (and rotary dials). They typically had a video feed as well. While video is available today it is not prevalent for everyday use (no thanks, I don't need to see my boss).
- Smoking. Smoking. Smoking in spaceships(!). More smoking.
- Computers are huge.
- Typewriters, telegraphs, etc.
- Phone booths.
- The concept of a cell phone is totally absent.
- Data transfer between computers (e.g. the internet).
- The computer power and size of todays computers is so much greater than the power of the (huge) computers envisioned is so far different as to be effectively a miss.
- A recurring theme is that, due to the automated production of goods, it will be the duty for people to consume products in order to keep employment from collapsing.
- Other planets in our solar system (primary Mars and Venus) are habitable and often have existing intelligent life forms.
My conclusion: speculating is fun, but the things that you think will be real in 20-50 years will still be will-o-wisps. On the other hand, a lot of the things you take for granted will be so different that it will make your grandkids laugh at you.
[1] Only considering things that don't violate known laws of physics.
[2] Well OK, interstellar travel either violates known laws of physics, or requires discovery of new laws of physics.
[1] Only considering things that don't violate known laws of physics.
[2] Well OK, interstellar travel either violates known laws of physics, or requires discovery of new laws of physics.