Moneer81 said:
Most university research is funded by the government or the NSF (which is part of the government as well) ... unless you're talking about something top secret like nuclear weapons or matters of national security, which is still funded by the government but probably not carried out at public universities where students might have access to. My understanding is that private research in physics (research done by private companies or private universities) does exist but not nearly as big as government funded research.
Actually a fair amount of research at universities is funded by corporations, and in some cases, particularly biomedical, the initial research maybe government funded, but then the university may sell rights to private companies, or private biotech companies actually fund research in exchange for exclusive rights.
These days R&D is not what it used to be - private companies and the government have both cut back. R&D expenses cut into profits at companies, and the government has to worry about big spending deficits.
Professors at university are expected to bring in outside money, whether government or corporate, which was the case when I was at university. My professor obtain projects and grants from industry and government.
At DOE, since the Reagan administration, the staff have been encouraged to go outside the government for funding, or actually market their technology to industry, particularly in the case of materials and processes.
Since some R&D takes years, one will be somewhat restricted based on time and workload. If one develops an interest in other areas, one can usually find support to pursue a different course.
Military technology is very restricted.
As for corporate R&D, companies like IBM, GE, Siemens and ABB, to name a few, have extensive R&D programs.