WiFi, it turns out, is a side-effect of astrophysics. Looking for black holes, O'Sullivan needed to develop a method to clean up intergalactic radio wave distortion. He never found any black holes, but instead designed the core of wireless networks.
My point is that in this example, in the example of PET scanning, the discovery of penicillin and many other examples, the aim of the original experiment was not focused on us. They weren't looking to design a medical scanner. Instead, they were trying to find the smallest particles. The fact that the benefit to us turned out to be so much more is in many ways coincidental. At the level of research, individual projects are only tiny steps towards bigger questions: at this level, it is not necessarily possible to see the benefit to us down the line. Does that make these tiny steps any less important? Without them, the bigger questions cannot be answered, even if the steps do not appear at the time to be relevant to that question. We need the knowledge base to be able to apply it later. To deny science 'for the sake of it' would mean we wouln't have PET scanning, WiFi or so many other bits of essential knowledge.
That said, in agreement with Beth, who commented on my last post, I wouldn't want to be the one to make the decision regarding the allocation of funding. It must indeed be a delicate and difficult balance.