Although Arthur C. Clark was quite imaginative and had some scientific knowledge, I doubt he ever developed any of his ideas into working projects. It was long known by scientist that geosync sats were possible once the rocket technology was advanced enough to carry it out. Clark merely took those existing scientific understandings and incorporated them into his writings. It is one thing to imagine what might be able to exist in the future, and something totally different to actually engineer that system. Same thing can be said about Star Trek writers/creators. They were very imaginative in many cases, but they certainly cannot be called the inventors of smartphones, tablets, warp drives (which are still non-existent), etc. And as far as Star Trek goes, they often borrowed heavily from SciFi movies from the 1950s like Forbidden Planet which featured wireless communicators a decade before Star Trek even aired. And BTW, communicators were far preceded by walkie talkies that have existed well before even the 1950s. It is not a quantum leap to imagine what today's technology will bring us in the future. That is only imagination, not invention. But it can also provide inspiration to future inventors and designers.