Because it's not really. The laptop would be an immensely powerful computer by the standards of the time, certainly. The Cray-1 came out in 1976 at 80MHz. Not sure how it would compare (doing mathematical calculations) with a modern laptop but I'd guess a few orders of magnitude slower.
Now that's a lot but let's assume our theoretical laptop from the future could be assumed to be indestructible and we could rig up I/O for it, etc. without any danger. Are there fundamental problems that we could solve using it that were simply way beyond 1975 technology?
Maybe some crypto in use at the time by the USSR. (Possibly. I don't know enough to comment intelligently.) I'm not convinced there were broader scientific problems that this singular laptop would move significantly closer to solving quickly.
The technology used to build the laptop would be more interesting than using it. Even if we lacked the tools to build the tools to construct 2014 ICs etc., the laptop would reveal a lot about architectural choices and directions, i.e. you can't really drive CPUs above 3GHz or so; you go multicore. (I assume smart semiconductor engineers could figure out that sort of thing from the physical device.)
Now that's a lot but let's assume our theoretical laptop from the future could be assumed to be indestructible and we could rig up I/O for it, etc. without any danger. Are there fundamental problems that we could solve using it that were simply way beyond 1975 technology?
Maybe some crypto in use at the time by the USSR. (Possibly. I don't know enough to comment intelligently.) I'm not convinced there were broader scientific problems that this singular laptop would move significantly closer to solving quickly.
The technology used to build the laptop would be more interesting than using it. Even if we lacked the tools to build the tools to construct 2014 ICs etc., the laptop would reveal a lot about architectural choices and directions, i.e. you can't really drive CPUs above 3GHz or so; you go multicore. (I assume smart semiconductor engineers could figure out that sort of thing from the physical device.)